Parkinson's Disease

MADRID — Patients with type 2 diabetes treated with sodium-glucose cotransporter 2 inhibitors (SGLT2is) show significant reductions in the risk of developing neurodegenerative disorders including Alzheimer’s disease, vascular dementia, and Parkinson’s disease, compared with those treated with other antidiabetic drugs, results from a large population-based cohort show.

“This was the largest nationwide population-based longitudinal cohort study to investigate the association between the use of SGLT2 inhibitors and the incidence of all-cause dementia and Parkinson’s disease,” said first author Hae Kyung Kim, MD, of the Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea, in presenting the findings at the annual meeting of the European Association for the Study of Diabetes.

Type 2 diabetes is known to increase the risk for neurodegenerative diseases such as dementia or Alzheimer’s disease, said Dr. Kim. Key factors attributed to the risk include shared pathophysiological mechanisms such as central nervous system insulin resistance and reduced cerebral glucose metabolism.

While research is lacking on the role of antidiabetic drugs in the treatment of neurodegenerative diseases, the researcher noted that “SGLT2 inhibitors, which have shown significant cardiorenal benefits and enhanced energy metabolism through ketogenesis, offer promise.”

To further investigate, Dr. Kim and her colleagues conducted the retrospective study, evaluating data on more than 1.3 million enrollees in Korea’s National Health Insurance Service Database who were aged 40 years or older, diagnosed with type 2 diabetes, and had initiated antidiabetic drugs between September 2014 and December 2019.

In the propensity score analysis, 358,862 patients were matched 1:1, in groups of 179,431 participants each, based on whether they were treated with SGLT2is or other oral antidiabetic drugs. Patients with a history of neurodegenerative disease, cancer, or use of glucagon-like peptide 1 receptor agonists were excluded.

The patients had a mean age of 57.8 years, 57.9% were men, and 6837 had incident dementia or Parkinson’s disease events reported.

With a mean follow-up of 2.88 years, after adjustment for key variables, those treated with SGLT2is had a 19% reduced risk of developing Alzheimer’s disease (adjusted hazard ratio [aHR], 0.81), a 31% reduced risk for vascular dementia (aHR, 0.69), and a 20% reduced risk for Parkinson’s disease (aHR, 0.80) compared with the non-SGLT2i group.

Furthermore, those receiving SGLT2i treatment had a 21% reduced risk for all-cause dementia (aHR, 0.79) and a 22% reduced risk for all-cause dementia and Parkinson’s disease compared with the oral antidiabetic drug group (aHR, 0.78) with a 6-month drug use lag period.

The association was observed regardless of SGLT2i exposure duration. Subgroup analyses indicated that the reductions in neurodegenerative disorders among those receiving SGLT2is were not associated with factors including age, sex, body mass index, blood pressure, glucose, lipid profiles, kidney function, health behaviors, comorbidities, diabetic complications, or other medication use.

Dr. Kim speculated that mechanisms underlying the reduced dementia risk could include SGLT2i effects of mitigating the common severe risk factors of type 2 diabetes and neurodegenerative diseases, including hypertension, heart failure, and chronic kidney disease, and improving hyperperfusion in the heart and cerebral vascular insufficiency.

Commenting on the study to this news organization, Erik H. Serné, MD, of the VU University Medical Centre, Amsterdam, the Netherlands, who comoderated the session, noted that “people with type 2 diabetes have a 50%-100% increased risk of developing dementia, particularly Alzheimer’s disease and vascular dementia.”

“The increasing prevalence of both conditions poses significant public health challenges, highlighting the need for effective prevention strategies and interventions.”

Currently, treatments for dementia are limited, with most primarily addressing symptoms and not the underlying cause of the neurodegenerative disease, he said.

He noted that, in addition to the effects mentioned by Dr. Kim, SGLT2is are also speculated to provide potential neuroprotective effects through improved glycemic control and insulin sensitivity, reduced inflammation and oxidative stress, enhanced mitochondrial function and energy metabolism, and reduced beta-amyloid and tau pathology.

“These mechanisms collectively may reduce the risk of cognitive decline, particularly in diabetic patients, and warrant further investigation in clinical trials to solidify the neuroprotective role of SGLT2 inhibitors,” said Dr. Serné.

In addition to their benefits in type 2 diabetes, SGLT2is “now offer hope in the prevention of dementia, a disease that has very limited therapeutic options thus far. The current data [presented by Dr. Kim] seem to corroborate this,” he added.

Dr. Kim and Dr. Serné had no disclosures to report.

A version of this article first appeared on Medscape.com.

MADRID — Patients with type 2 diabetes treated with sodium-glucose cotransporter 2 inhibitors (SGLT2is) show significant reductions in the risk of developing neurodegenerative disorders including Alzheimer’s disease, vascular dementia, and Parkinson’s disease, compared with those treated with other antidiabetic drugs, results from a large population-based cohort show.

“This was the largest nationwide population-based longitudinal cohort study to investigate the association between the use of SGLT2 inhibitors and the incidence of all-cause dementia and Parkinson’s disease,” said first author Hae Kyung Kim, MD, of the Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea, in presenting the findings at the annual meeting of the European Association for the Study of Diabetes.

Type 2 diabetes is known to increase the risk for neurodegenerative diseases such as dementia or Alzheimer’s disease, said Dr. Kim. Key factors attributed to the risk include shared pathophysiological mechanisms such as central nervous system insulin resistance and reduced cerebral glucose metabolism.

While research is lacking on the role of antidiabetic drugs in the treatment of neurodegenerative diseases, the researcher noted that “SGLT2 inhibitors, which have shown significant cardiorenal benefits and enhanced energy metabolism through ketogenesis, offer promise.”

To further investigate, Dr. Kim and her colleagues conducted the retrospective study, evaluating data on more than 1.3 million enrollees in Korea’s National Health Insurance Service Database who were aged 40 years or older, diagnosed with type 2 diabetes, and had initiated antidiabetic drugs between September 2014 and December 2019.

In the propensity score analysis, 358,862 patients were matched 1:1, in groups of 179,431 participants each, based on whether they were treated with SGLT2is or other oral antidiabetic drugs. Patients with a history of neurodegenerative disease, cancer, or use of glucagon-like peptide 1 receptor agonists were excluded.

The patients had a mean age of 57.8 years, 57.9% were men, and 6837 had incident dementia or Parkinson’s disease events reported.

With a mean follow-up of 2.88 years, after adjustment for key variables, those treated with SGLT2is had a 19% reduced risk of developing Alzheimer’s disease (adjusted hazard ratio [aHR], 0.81), a 31% reduced risk for vascular dementia (aHR, 0.69), and a 20% reduced risk for Parkinson’s disease (aHR, 0.80) compared with the non-SGLT2i group.

Furthermore, those receiving SGLT2i treatment had a 21% reduced risk for all-cause dementia (aHR, 0.79) and a 22% reduced risk for all-cause dementia and Parkinson’s disease compared with the oral antidiabetic drug group (aHR, 0.78) with a 6-month drug use lag period.

The association was observed regardless of SGLT2i exposure duration. Subgroup analyses indicated that the reductions in neurodegenerative disorders among those receiving SGLT2is were not associated with factors including age, sex, body mass index, blood pressure, glucose, lipid profiles, kidney function, health behaviors, comorbidities, diabetic complications, or other medication use.

Dr. Kim speculated that mechanisms underlying the reduced dementia risk could include SGLT2i effects of mitigating the common severe risk factors of type 2 diabetes and neurodegenerative diseases, including hypertension, heart failure, and chronic kidney disease, and improving hyperperfusion in the heart and cerebral vascular insufficiency.

Commenting on the study to this news organization, Erik H. Serné, MD, of the VU University Medical Centre, Amsterdam, the Netherlands, who comoderated the session, noted that “people with type 2 diabetes have a 50%-100% increased risk of developing dementia, particularly Alzheimer’s disease and vascular dementia.”

“The increasing prevalence of both conditions poses significant public health challenges, highlighting the need for effective prevention strategies and interventions.”

Currently, treatments for dementia are limited, with most primarily addressing symptoms and not the underlying cause of the neurodegenerative disease, he said.

He noted that, in addition to the effects mentioned by Dr. Kim, SGLT2is are also speculated to provide potential neuroprotective effects through improved glycemic control and insulin sensitivity, reduced inflammation and oxidative stress, enhanced mitochondrial function and energy metabolism, and reduced beta-amyloid and tau pathology.

“These mechanisms collectively may reduce the risk of cognitive decline, particularly in diabetic patients, and warrant further investigation in clinical trials to solidify the neuroprotective role of SGLT2 inhibitors,” said Dr. Serné.

In addition to their benefits in type 2 diabetes, SGLT2is “now offer hope in the prevention of dementia, a disease that has very limited therapeutic options thus far. The current data [presented by Dr. Kim] seem to corroborate this,” he added.

Dr. Kim and Dr. Serné had no disclosures to report.

A version of this article first appeared on Medscape.com.

MADRID — Patients with type 2 diabetes treated with sodium-glucose cotransporter 2 inhibitors (SGLT2is) show significant reductions in the risk of developing neurodegenerative disorders including Alzheimer’s disease, vascular dementia, and Parkinson’s disease, compared with those treated with other antidiabetic drugs, results from a large population-based cohort show.

“This was the largest nationwide population-based longitudinal cohort study to investigate the association between the use of SGLT2 inhibitors and the incidence of all-cause dementia and Parkinson’s disease,” said first author Hae Kyung Kim, MD, of the Department of Internal Medicine, Yonsei University College of Medicine, Seoul, South Korea, in presenting the findings at the annual meeting of the European Association for the Study of Diabetes.

Type 2 diabetes is known to increase the risk for neurodegenerative diseases such as dementia or Alzheimer’s disease, said Dr. Kim. Key factors attributed to the risk include shared pathophysiological mechanisms such as central nervous system insulin resistance and reduced cerebral glucose metabolism.

While research is lacking on the role of antidiabetic drugs in the treatment of neurodegenerative diseases, the researcher noted that “SGLT2 inhibitors, which have shown significant cardiorenal benefits and enhanced energy metabolism through ketogenesis, offer promise.”

To further investigate, Dr. Kim and her colleagues conducted the retrospective study, evaluating data on more than 1.3 million enrollees in Korea’s National Health Insurance Service Database who were aged 40 years or older, diagnosed with type 2 diabetes, and had initiated antidiabetic drugs between September 2014 and December 2019.

In the propensity score analysis, 358,862 patients were matched 1:1, in groups of 179,431 participants each, based on whether they were treated with SGLT2is or other oral antidiabetic drugs. Patients with a history of neurodegenerative disease, cancer, or use of glucagon-like peptide 1 receptor agonists were excluded.

The patients had a mean age of 57.8 years, 57.9% were men, and 6837 had incident dementia or Parkinson’s disease events reported.

With a mean follow-up of 2.88 years, after adjustment for key variables, those treated with SGLT2is had a 19% reduced risk of developing Alzheimer’s disease (adjusted hazard ratio [aHR], 0.81), a 31% reduced risk for vascular dementia (aHR, 0.69), and a 20% reduced risk for Parkinson’s disease (aHR, 0.80) compared with the non-SGLT2i group.

Furthermore, those receiving SGLT2i treatment had a 21% reduced risk for all-cause dementia (aHR, 0.79) and a 22% reduced risk for all-cause dementia and Parkinson’s disease compared with the oral antidiabetic drug group (aHR, 0.78) with a 6-month drug use lag period.

The association was observed regardless of SGLT2i exposure duration. Subgroup analyses indicated that the reductions in neurodegenerative disorders among those receiving SGLT2is were not associated with factors including age, sex, body mass index, blood pressure, glucose, lipid profiles, kidney function, health behaviors, comorbidities, diabetic complications, or other medication use.

Dr. Kim speculated that mechanisms underlying the reduced dementia risk could include SGLT2i effects of mitigating the common severe risk factors of type 2 diabetes and neurodegenerative diseases, including hypertension, heart failure, and chronic kidney disease, and improving hyperperfusion in the heart and cerebral vascular insufficiency.

Commenting on the study to this news organization, Erik H. Serné, MD, of the VU University Medical Centre, Amsterdam, the Netherlands, who comoderated the session, noted that “people with type 2 diabetes have a 50%-100% increased risk of developing dementia, particularly Alzheimer’s disease and vascular dementia.”

“The increasing prevalence of both conditions poses significant public health challenges, highlighting the need for effective prevention strategies and interventions.”

Currently, treatments for dementia are limited, with most primarily addressing symptoms and not the underlying cause of the neurodegenerative disease, he said.

He noted that, in addition to the effects mentioned by Dr. Kim, SGLT2is are also speculated to provide potential neuroprotective effects through improved glycemic control and insulin sensitivity, reduced inflammation and oxidative stress, enhanced mitochondrial function and energy metabolism, and reduced beta-amyloid and tau pathology.

“These mechanisms collectively may reduce the risk of cognitive decline, particularly in diabetic patients, and warrant further investigation in clinical trials to solidify the neuroprotective role of SGLT2 inhibitors,” said Dr. Serné.

In addition to their benefits in type 2 diabetes, SGLT2is “now offer hope in the prevention of dementia, a disease that has very limited therapeutic options thus far. The current data [presented by Dr. Kim] seem to corroborate this,” he added.

Dr. Kim and Dr. Serné had no disclosures to report.

A version of this article first appeared on Medscape.com.

TOPLINE:

A history of migraine is not associated with an elevated risk for Parkinson’s disease (PD) in women, regardless of headache frequency or migraine subtype, a new study suggests.

METHODOLOGY:

• Researchers analyzed data on 39,312 women health professionals aged ≥ 45 years and having no history of PD who enrolled in the Women’s Health Study between 1992 and 1995 and were followed until 2021.
• At baseline, 7321 women (18.6%) had migraine.
• The mean follow-up duration was 22 years.
• The primary outcome was a self-reported, physician-confirmed diagnosis of PD.

TAKEAWAY:

• During the study period, 685 women self-reported a diagnosis of PD.
• Of these, 18.7% of reported cases were in women with any migraine and 81.3% in women without migraine.
• No significant association was found between PD risk and a history of migraine, migraine subtypes (with or without aura), or migraine frequency.
• Migraine was not associated with a higher risk for PD than that of nonmigraine headaches.

IN PRACTICE:

“These results are reassuring for women who have migraine, which itself causes many burdens, that they don’t have to worry about an increased risk of Parkinson’s disease in the future,” study author Tobias Kurth, Charité - Universitätsmedizin Berlin, Germany, said in a press release.

SOURCE:

The study was led by Ricarda S. Schulz, MSc, Charité - Universitätsmedizin Berlin. It was published online in Neurology.

LIMITATIONS:

The study’s findings may not be generalizable to other populations, such as men and non-White individuals. The self-reported data on migraine and PD may be subject to inaccuracies. PD is often not diagnosed until symptoms have reached an advanced stage, potentially leading to cases being underreported. Changes in the status and frequency of migraine over the study period were not accounted for, which may have affected the results.

DISCLOSURES:

The authors did not disclose any specific funding for this work. The Women’s Health Study was supported by the National Cancer Institute and National Heart, Lung, and Blood Institute. Two authors reported having financial ties outside this work. Full disclosures are available in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.

TOPLINE:

A history of migraine is not associated with an elevated risk for Parkinson’s disease (PD) in women, regardless of headache frequency or migraine subtype, a new study suggests.

METHODOLOGY:

• Researchers analyzed data on 39,312 women health professionals aged ≥ 45 years and having no history of PD who enrolled in the Women’s Health Study between 1992 and 1995 and were followed until 2021.
• At baseline, 7321 women (18.6%) had migraine.
• The mean follow-up duration was 22 years.
• The primary outcome was a self-reported, physician-confirmed diagnosis of PD.

TAKEAWAY:

• During the study period, 685 women self-reported a diagnosis of PD.
• Of these, 18.7% of reported cases were in women with any migraine and 81.3% in women without migraine.
• No significant association was found between PD risk and a history of migraine, migraine subtypes (with or without aura), or migraine frequency.
• Migraine was not associated with a higher risk for PD than that of nonmigraine headaches.

IN PRACTICE:

“These results are reassuring for women who have migraine, which itself causes many burdens, that they don’t have to worry about an increased risk of Parkinson’s disease in the future,” study author Tobias Kurth, Charité - Universitätsmedizin Berlin, Germany, said in a press release.

SOURCE:

The study was led by Ricarda S. Schulz, MSc, Charité - Universitätsmedizin Berlin. It was published online in Neurology.

LIMITATIONS:

The study’s findings may not be generalizable to other populations, such as men and non-White individuals. The self-reported data on migraine and PD may be subject to inaccuracies. PD is often not diagnosed until symptoms have reached an advanced stage, potentially leading to cases being underreported. Changes in the status and frequency of migraine over the study period were not accounted for, which may have affected the results.

DISCLOSURES:

The authors did not disclose any specific funding for this work. The Women’s Health Study was supported by the National Cancer Institute and National Heart, Lung, and Blood Institute. Two authors reported having financial ties outside this work. Full disclosures are available in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.

TOPLINE:

A history of migraine is not associated with an elevated risk for Parkinson’s disease (PD) in women, regardless of headache frequency or migraine subtype, a new study suggests.

METHODOLOGY:

• Researchers analyzed data on 39,312 women health professionals aged ≥ 45 years and having no history of PD who enrolled in the Women’s Health Study between 1992 and 1995 and were followed until 2021.
• At baseline, 7321 women (18.6%) had migraine.
• The mean follow-up duration was 22 years.
• The primary outcome was a self-reported, physician-confirmed diagnosis of PD.

TAKEAWAY:

• During the study period, 685 women self-reported a diagnosis of PD.
• Of these, 18.7% of reported cases were in women with any migraine and 81.3% in women without migraine.
• No significant association was found between PD risk and a history of migraine, migraine subtypes (with or without aura), or migraine frequency.
• Migraine was not associated with a higher risk for PD than that of nonmigraine headaches.

IN PRACTICE:

“These results are reassuring for women who have migraine, which itself causes many burdens, that they don’t have to worry about an increased risk of Parkinson’s disease in the future,” study author Tobias Kurth, Charité - Universitätsmedizin Berlin, Germany, said in a press release.

SOURCE:

The study was led by Ricarda S. Schulz, MSc, Charité - Universitätsmedizin Berlin. It was published online in Neurology.

LIMITATIONS:

The study’s findings may not be generalizable to other populations, such as men and non-White individuals. The self-reported data on migraine and PD may be subject to inaccuracies. PD is often not diagnosed until symptoms have reached an advanced stage, potentially leading to cases being underreported. Changes in the status and frequency of migraine over the study period were not accounted for, which may have affected the results.

DISCLOSURES:

The authors did not disclose any specific funding for this work. The Women’s Health Study was supported by the National Cancer Institute and National Heart, Lung, and Blood Institute. Two authors reported having financial ties outside this work. Full disclosures are available in the original article.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication. A version of this article first appeared on Medscape.com.

Fecal microbiota transplantation (FMT) for Parkinson’s disease is safe but does not offer clinically meaningful improvement in symptoms, results of a new, randomized placebo-controlled trial show.

However, investigators discovered some interesting insights from the study, which they believe may help in designing future “improved, and hopefully successful, trials” with the intervention.

“Further studies — for example, through modified fecal microbiota transplantation approaches or bowel cleansing — are warranted,” they concluded. 

The study was published online in JAMA Neurology. 
 

Gut Dysfunction: An Early Symptom

Investigators led by Filip Scheperjans, MD, Helsinki University Hospital, Finland, explained that gut dysfunction is a prevalent, early symptom in Parkinson’s disease and is associated with more rapid disease progression. 

Interventions targeting gut microbiota, such as FMT, have shown promising symptomatic, and potentially neuroprotective, effects in animal models of Parkinson’s disease. 

Although several randomized clinical trials suggest efficacy of probiotics for Parkinson’s disease-related constipation, only limited clinical information on FMT is available.

In the current trial, 48 patients with Parkinson’s disease aged 35-75 years with mild to moderate symptoms and dysbiosis of fecal microbiota were randomized in a 2:1 ratio to receive FMT or placebo infused into the cecum via colonoscopy.  

All patients had whole-bowel lavage starting the day before the colonoscopy. Fecal microbiota transplantation was administered as a single-dose and without antibiotic pretreatment. 

Active treatment was a freeze-stored preparation of 30 g of feces from one of two donors who were healthy individuals without dysbiosis. The preparation was mixed with 150 mL of sterile physiologic saline and 20 mL of 85% glycerol for cryoprotection to improve viability of microbes. Placebo was the carrier solution alone, consisting of 180 mL of sterile physiologic saline and 20 mL of 85% glycerol.

The primary endpoint, a change in Parkinson’s disease symptoms as assessed on the Unified Parkinson’s Disease Rating Scale (UPDRS) at 6 months, did not differ between the two study groups.

Gastrointestinal adverse events were more frequent in the FMT group, occurring in 16 patients (53%) versus one patient (7%) in the placebo group. But no major safety concerns were observed.

Secondary outcomes and post hoc analyses showed a greater increase in dopaminergic medication, which may indicate faster disease progression, but also improvement in certain motor and nonmotor outcomes in the placebo group. 

Microbiota changes were more pronounced after FMT, but dysbiosis status was reversed more frequently in the placebo group. 

The researchers noted that the apparent futility in this trial is in contrast to several previous small clinical studies of fecal transplant that have suggested the potential for improvement of Parkinson’s disease symptoms. 

In addition, encouraging results from the probiotics field suggest that an impact on motor and nonmotor Parkinson’s disease symptoms through gut microbiota manipulation is possible. 

The researchers raised the possibility that the placebo procedure was not an inert comparator, given the relatively strong and sustained gut microbiota alteration and dysbiosis conversion observed in the placebo group, and suggested that the colonic cleansing procedure may also have had some beneficial effect. 

“It seems possible that, after cleansing of a dysbiotic gut microbiota, recolonization leads to a more physiologic gut microbiota composition with symptom improvement in the placebo group. This warrants further exploration of modified fecal microbiota transplantation approaches and bowel cleansing in Parkinson’s disease,” they concluded. 
 

Distinct Gut Microbiome 

In an accompanying editorial, Timothy R. Sampson, PhD, assistant professor, Department of Cell Biology, Emory University School of Medicine, Atlanta, pointed out that dozens of independent studies have now demonstrated a distinct gut microbiome composition associated with Parkinson’s disease, and experimental data suggest that this has the capacity to incite inflammatory responses; degrade intestinal mucosa; and dysregulate a number of neuroactive and amyloidogenic molecules, which could contribute to the disease. 

He noted that three other small placebo-controlled studies of fecal transplantation in Parkinson’s disease showed slightly more robust responses in the active treatment group, including improvements in UPDRS scores and gastrointestinal symptoms.

However, these studies tested different FMT procedures, including lyophilized oral capsules given at different dosing frequencies and either nasojejunal or colonic transfusion following a standard bowel preparation.

In addition, there is no consensus on pretransplant procedures, such as antibiotics or bowel clearance, and the choice of donor microbiome is probably essential, because there may be certain microbes required to shift the entire community, Dr. Sampson wrote. 

Understanding how microbial contributions directly relate to Parkinson’s disease would identify individuals more likely to respond to peripheral interventions, and further exploration is needed to shed light on particular microbes that warrant targeting for either enrichment or depletion, he added. 

“Despite a lack of primary end point efficacy in this latest study, in-depth comparison across these studies may reveal opportunities to refine fecal microbiota transplantation approaches. Together, these studies will continue to refine the hypothesis of a microbial contribution to Parkinson’s disease and reveal new therapeutic avenues,” Dr. Sampson concluded.
 

‘Planting Grass in a Yard Full of Weeds’

Commenting on the research, James Beck, PhD, chief scientific officer of the Parkinson’s Foundation, New York, said that whether FMT are helpful remains to be determined. 

“The key question that needs to be solved is how to best perform these transplants. One issue is that you cannot plant grass when the yard is full of weeds. However, if you take too hard an approach killing the weeds — that is, with powerful antibiotics — you jeopardize the new grass, or in this case, the bacteria in the transplant. Solving that issue will be important as we consider whether this is effective or not.”

Dr. Beck added that there is still much to be learned from research into the gut microbiota. “I am hopeful with additional effort we will have answers soon.”
 

A version of this article appeared on Medscape.com.

Fecal microbiota transplantation (FMT) for Parkinson’s disease is safe but does not offer clinically meaningful improvement in symptoms, results of a new, randomized placebo-controlled trial show.

However, investigators discovered some interesting insights from the study, which they believe may help in designing future “improved, and hopefully successful, trials” with the intervention.

“Further studies — for example, through modified fecal microbiota transplantation approaches or bowel cleansing — are warranted,” they concluded. 

The study was published online in JAMA Neurology. 
 

Gut Dysfunction: An Early Symptom

Investigators led by Filip Scheperjans, MD, Helsinki University Hospital, Finland, explained that gut dysfunction is a prevalent, early symptom in Parkinson’s disease and is associated with more rapid disease progression. 

Interventions targeting gut microbiota, such as FMT, have shown promising symptomatic, and potentially neuroprotective, effects in animal models of Parkinson’s disease. 

Although several randomized clinical trials suggest efficacy of probiotics for Parkinson’s disease-related constipation, only limited clinical information on FMT is available.

In the current trial, 48 patients with Parkinson’s disease aged 35-75 years with mild to moderate symptoms and dysbiosis of fecal microbiota were randomized in a 2:1 ratio to receive FMT or placebo infused into the cecum via colonoscopy.  

All patients had whole-bowel lavage starting the day before the colonoscopy. Fecal microbiota transplantation was administered as a single-dose and without antibiotic pretreatment. 

Active treatment was a freeze-stored preparation of 30 g of feces from one of two donors who were healthy individuals without dysbiosis. The preparation was mixed with 150 mL of sterile physiologic saline and 20 mL of 85% glycerol for cryoprotection to improve viability of microbes. Placebo was the carrier solution alone, consisting of 180 mL of sterile physiologic saline and 20 mL of 85% glycerol.

The primary endpoint, a change in Parkinson’s disease symptoms as assessed on the Unified Parkinson’s Disease Rating Scale (UPDRS) at 6 months, did not differ between the two study groups.

Gastrointestinal adverse events were more frequent in the FMT group, occurring in 16 patients (53%) versus one patient (7%) in the placebo group. But no major safety concerns were observed.

Secondary outcomes and post hoc analyses showed a greater increase in dopaminergic medication, which may indicate faster disease progression, but also improvement in certain motor and nonmotor outcomes in the placebo group. 

Microbiota changes were more pronounced after FMT, but dysbiosis status was reversed more frequently in the placebo group. 

The researchers noted that the apparent futility in this trial is in contrast to several previous small clinical studies of fecal transplant that have suggested the potential for improvement of Parkinson’s disease symptoms. 

In addition, encouraging results from the probiotics field suggest that an impact on motor and nonmotor Parkinson’s disease symptoms through gut microbiota manipulation is possible. 

The researchers raised the possibility that the placebo procedure was not an inert comparator, given the relatively strong and sustained gut microbiota alteration and dysbiosis conversion observed in the placebo group, and suggested that the colonic cleansing procedure may also have had some beneficial effect. 

“It seems possible that, after cleansing of a dysbiotic gut microbiota, recolonization leads to a more physiologic gut microbiota composition with symptom improvement in the placebo group. This warrants further exploration of modified fecal microbiota transplantation approaches and bowel cleansing in Parkinson’s disease,” they concluded. 
 

Distinct Gut Microbiome 

In an accompanying editorial, Timothy R. Sampson, PhD, assistant professor, Department of Cell Biology, Emory University School of Medicine, Atlanta, pointed out that dozens of independent studies have now demonstrated a distinct gut microbiome composition associated with Parkinson’s disease, and experimental data suggest that this has the capacity to incite inflammatory responses; degrade intestinal mucosa; and dysregulate a number of neuroactive and amyloidogenic molecules, which could contribute to the disease. 

He noted that three other small placebo-controlled studies of fecal transplantation in Parkinson’s disease showed slightly more robust responses in the active treatment group, including improvements in UPDRS scores and gastrointestinal symptoms.

However, these studies tested different FMT procedures, including lyophilized oral capsules given at different dosing frequencies and either nasojejunal or colonic transfusion following a standard bowel preparation.

In addition, there is no consensus on pretransplant procedures, such as antibiotics or bowel clearance, and the choice of donor microbiome is probably essential, because there may be certain microbes required to shift the entire community, Dr. Sampson wrote. 

Understanding how microbial contributions directly relate to Parkinson’s disease would identify individuals more likely to respond to peripheral interventions, and further exploration is needed to shed light on particular microbes that warrant targeting for either enrichment or depletion, he added. 

“Despite a lack of primary end point efficacy in this latest study, in-depth comparison across these studies may reveal opportunities to refine fecal microbiota transplantation approaches. Together, these studies will continue to refine the hypothesis of a microbial contribution to Parkinson’s disease and reveal new therapeutic avenues,” Dr. Sampson concluded.
 

‘Planting Grass in a Yard Full of Weeds’

Commenting on the research, James Beck, PhD, chief scientific officer of the Parkinson’s Foundation, New York, said that whether FMT are helpful remains to be determined. 

“The key question that needs to be solved is how to best perform these transplants. One issue is that you cannot plant grass when the yard is full of weeds. However, if you take too hard an approach killing the weeds — that is, with powerful antibiotics — you jeopardize the new grass, or in this case, the bacteria in the transplant. Solving that issue will be important as we consider whether this is effective or not.”

Dr. Beck added that there is still much to be learned from research into the gut microbiota. “I am hopeful with additional effort we will have answers soon.”
 

A version of this article appeared on Medscape.com.

Fecal microbiota transplantation (FMT) for Parkinson’s disease is safe but does not offer clinically meaningful improvement in symptoms, results of a new, randomized placebo-controlled trial show.

However, investigators discovered some interesting insights from the study, which they believe may help in designing future “improved, and hopefully successful, trials” with the intervention.

“Further studies — for example, through modified fecal microbiota transplantation approaches or bowel cleansing — are warranted,” they concluded. 

The study was published online in JAMA Neurology. 
 

Gut Dysfunction: An Early Symptom

Investigators led by Filip Scheperjans, MD, Helsinki University Hospital, Finland, explained that gut dysfunction is a prevalent, early symptom in Parkinson’s disease and is associated with more rapid disease progression. 

Interventions targeting gut microbiota, such as FMT, have shown promising symptomatic, and potentially neuroprotective, effects in animal models of Parkinson’s disease. 

Although several randomized clinical trials suggest efficacy of probiotics for Parkinson’s disease-related constipation, only limited clinical information on FMT is available.

In the current trial, 48 patients with Parkinson’s disease aged 35-75 years with mild to moderate symptoms and dysbiosis of fecal microbiota were randomized in a 2:1 ratio to receive FMT or placebo infused into the cecum via colonoscopy.  

All patients had whole-bowel lavage starting the day before the colonoscopy. Fecal microbiota transplantation was administered as a single-dose and without antibiotic pretreatment. 

Active treatment was a freeze-stored preparation of 30 g of feces from one of two donors who were healthy individuals without dysbiosis. The preparation was mixed with 150 mL of sterile physiologic saline and 20 mL of 85% glycerol for cryoprotection to improve viability of microbes. Placebo was the carrier solution alone, consisting of 180 mL of sterile physiologic saline and 20 mL of 85% glycerol.

The primary endpoint, a change in Parkinson’s disease symptoms as assessed on the Unified Parkinson’s Disease Rating Scale (UPDRS) at 6 months, did not differ between the two study groups.

Gastrointestinal adverse events were more frequent in the FMT group, occurring in 16 patients (53%) versus one patient (7%) in the placebo group. But no major safety concerns were observed.

Secondary outcomes and post hoc analyses showed a greater increase in dopaminergic medication, which may indicate faster disease progression, but also improvement in certain motor and nonmotor outcomes in the placebo group. 

Microbiota changes were more pronounced after FMT, but dysbiosis status was reversed more frequently in the placebo group. 

The researchers noted that the apparent futility in this trial is in contrast to several previous small clinical studies of fecal transplant that have suggested the potential for improvement of Parkinson’s disease symptoms. 

In addition, encouraging results from the probiotics field suggest that an impact on motor and nonmotor Parkinson’s disease symptoms through gut microbiota manipulation is possible. 

The researchers raised the possibility that the placebo procedure was not an inert comparator, given the relatively strong and sustained gut microbiota alteration and dysbiosis conversion observed in the placebo group, and suggested that the colonic cleansing procedure may also have had some beneficial effect. 

“It seems possible that, after cleansing of a dysbiotic gut microbiota, recolonization leads to a more physiologic gut microbiota composition with symptom improvement in the placebo group. This warrants further exploration of modified fecal microbiota transplantation approaches and bowel cleansing in Parkinson’s disease,” they concluded. 
 

Distinct Gut Microbiome 

In an accompanying editorial, Timothy R. Sampson, PhD, assistant professor, Department of Cell Biology, Emory University School of Medicine, Atlanta, pointed out that dozens of independent studies have now demonstrated a distinct gut microbiome composition associated with Parkinson’s disease, and experimental data suggest that this has the capacity to incite inflammatory responses; degrade intestinal mucosa; and dysregulate a number of neuroactive and amyloidogenic molecules, which could contribute to the disease. 

He noted that three other small placebo-controlled studies of fecal transplantation in Parkinson’s disease showed slightly more robust responses in the active treatment group, including improvements in UPDRS scores and gastrointestinal symptoms.

However, these studies tested different FMT procedures, including lyophilized oral capsules given at different dosing frequencies and either nasojejunal or colonic transfusion following a standard bowel preparation.

In addition, there is no consensus on pretransplant procedures, such as antibiotics or bowel clearance, and the choice of donor microbiome is probably essential, because there may be certain microbes required to shift the entire community, Dr. Sampson wrote. 

Understanding how microbial contributions directly relate to Parkinson’s disease would identify individuals more likely to respond to peripheral interventions, and further exploration is needed to shed light on particular microbes that warrant targeting for either enrichment or depletion, he added. 

“Despite a lack of primary end point efficacy in this latest study, in-depth comparison across these studies may reveal opportunities to refine fecal microbiota transplantation approaches. Together, these studies will continue to refine the hypothesis of a microbial contribution to Parkinson’s disease and reveal new therapeutic avenues,” Dr. Sampson concluded.
 

‘Planting Grass in a Yard Full of Weeds’

Commenting on the research, James Beck, PhD, chief scientific officer of the Parkinson’s Foundation, New York, said that whether FMT are helpful remains to be determined. 

“The key question that needs to be solved is how to best perform these transplants. One issue is that you cannot plant grass when the yard is full of weeds. However, if you take too hard an approach killing the weeds — that is, with powerful antibiotics — you jeopardize the new grass, or in this case, the bacteria in the transplant. Solving that issue will be important as we consider whether this is effective or not.”

Dr. Beck added that there is still much to be learned from research into the gut microbiota. “I am hopeful with additional effort we will have answers soon.”
 

A version of this article appeared on Medscape.com.

HELSINKI, FINLAND — A new gene for early-onset Parkinson’s disease has been identified, a discovery that experts believe will have important clinical implications in the not-too-distant future.

A variant in PMSF1, a proteasome regulator, was identified in 15 families from 13 countries around the world, with 22 affected individuals.

“These families were ethnically diverse, and in all of them, the variant in PMSF1 correlated with the neurologic phenotype. We know this is very clear cut — the genotype/phenotype correlation — with the patients carrying the missense mutation having ‘mild’ symptoms, while those with the progressive loss-of-function variant had the most severe phenotype,” she noted. 

“Our findings unequivocally link defective PSMF1 to early-onset PD and neurodegeneration and suggest mitochondrial dysfunction as a mechanistic contributor,” study investigator Francesca Magrinelli, MD, PhD, of University College London (UCL) Queen Square Institute of Neurology, UCL, London, told delegates at the 2024 Congress of the European Academy of Neurology.
 

Managing Patient Expectations

Those “mildly” affected had an early-onset Parkinson’s disease starting between the second and fifth decade of life with pyramidal tract signs, dysphasia, psychiatric comorbidity, and early levodopa-induced dyskinesia. 

In those with the intermediate type, Parkinson’s disease symptoms start in childhood and include, among other things, global hypokinesia, developmental delay, cerebellar signs, and in some, associated epilepsy.

In most cases, there was evidence on brain MRI of a hypoplasia of the corpus callosum, Dr. Magrinelli said. In the most severely affected individuals, there was perinatal lethality with neurologic manifestations.

While it may seem that the genetics of Parkinson’s disease is an academic exercise for the most part, it won’t be too much longer before it yields practical information that will inform how patients are treated, said Parkinson’s disease expert Christine Klein, MD, of the Institute of Neurogenetics and Department of Neurology, University of Lübeck, Helsinki, Finland. 

The genetics of Parkinson’s disease are complicated, even within a single family. So, it’s very important to assess the pathogenicity of different variants, Dr. Klein noted. 

“I am sure that you have all had a Parkinson’s disease [gene] panel back, and it says, ‘variant of uncertain significance.’ This is the worst thing that can happen. The lab does not know what it means. You don’t know what it means, and you don’t know what to tell the patient. So how do you get around this?”

Dr. Klein said that before conducting any genetic testing, clinicians should inform the patient that they may have a genetic variant of uncertain significance. It doesn’t solve the problem, but it does help physicians manage patient expectations. 
 

Clinical Relevance on the Way?

While it may seem that all of the identified variants that predict Parkinson’s disease which, in addition to PSMF1, include the well-established LRRK2 and GBA1, may look the same, this is not true when patient history is taken into account, said Dr. Klein.

For example, age-of-onset of Parkinson’s disease can differ between identified variants, and this has led to “a paradigm change” whereby a purely genetic finding is called a disease. 

This first occurred in Huntington’s disease, when researchers gave individuals at high genetic risk of developing the illness, but who currently had no clinical symptoms, the label of “Stage Zero disease.”

This is important to note “because if we get to the stage of having drugs that can slow down, or even prevent, progression to Parkinson’s disease, then it will be key to have patients we know are going to develop it to participate in clinical trials for such agents,” said Dr. Klein. 

She cited the example of a family that she recently encountered that had genetic test results that showed variants of unknown significance, so Dr. Klein had the family’s samples sent to a specialized lab in Dundee, Scotland, for further analysis.

“The biochemists found that this variant was indeed pathogenic, and kinase-activating, so this is very helpful and very important because there are now clinical trials in Parkinson’s disease with kinase inhibitors,” she noted. 

“If you think there is something else [over and above the finding of uncertain significance] in your Parkinson’s disease panel, and you are not happy with the genetic report, send it somewhere else,” Dr. Klein advised. 

“We will see a lot more patients with genetic Parkinson’s disease in the future,” she predicted, while citing two recent preliminary clinical trials that have shown some promise in terms of neuroprotection in patients with early Parkinson’s disease.

“It remains to be seen whether there will be light at the end of the tunnel,” she said, but it may soon be possible to find treatments that delay, or even prevent, Parkinson’s disease onset. 

Dr. Magrinelli reported receiving speaker’s honoraria from MJFF Edmond J. Safra Clinical Research Fellowship in Movement Disorders (Class of 2023), MJFF Edmond J. Safra Movement Disorders Research Career Development Award 2023 (Grant ID MJFF-023893), American Parkinson Disease Association (Research Grant 2024), and the David Blank Charitable Foundation. Dr. Klein reported being a medical advisor to Retromer Therapeutics, Takeda, and Centogene and speakers’ honoraria from Desitin and Bial.

A version of this article first appeared on Medscape.com.

HELSINKI, FINLAND — A new gene for early-onset Parkinson’s disease has been identified, a discovery that experts believe will have important clinical implications in the not-too-distant future.

A variant in PMSF1, a proteasome regulator, was identified in 15 families from 13 countries around the world, with 22 affected individuals.

“These families were ethnically diverse, and in all of them, the variant in PMSF1 correlated with the neurologic phenotype. We know this is very clear cut — the genotype/phenotype correlation — with the patients carrying the missense mutation having ‘mild’ symptoms, while those with the progressive loss-of-function variant had the most severe phenotype,” she noted. 

“Our findings unequivocally link defective PSMF1 to early-onset PD and neurodegeneration and suggest mitochondrial dysfunction as a mechanistic contributor,” study investigator Francesca Magrinelli, MD, PhD, of University College London (UCL) Queen Square Institute of Neurology, UCL, London, told delegates at the 2024 Congress of the European Academy of Neurology.
 

Managing Patient Expectations

Those “mildly” affected had an early-onset Parkinson’s disease starting between the second and fifth decade of life with pyramidal tract signs, dysphasia, psychiatric comorbidity, and early levodopa-induced dyskinesia. 

In those with the intermediate type, Parkinson’s disease symptoms start in childhood and include, among other things, global hypokinesia, developmental delay, cerebellar signs, and in some, associated epilepsy.

In most cases, there was evidence on brain MRI of a hypoplasia of the corpus callosum, Dr. Magrinelli said. In the most severely affected individuals, there was perinatal lethality with neurologic manifestations.

While it may seem that the genetics of Parkinson’s disease is an academic exercise for the most part, it won’t be too much longer before it yields practical information that will inform how patients are treated, said Parkinson’s disease expert Christine Klein, MD, of the Institute of Neurogenetics and Department of Neurology, University of Lübeck, Helsinki, Finland. 

The genetics of Parkinson’s disease are complicated, even within a single family. So, it’s very important to assess the pathogenicity of different variants, Dr. Klein noted. 

“I am sure that you have all had a Parkinson’s disease [gene] panel back, and it says, ‘variant of uncertain significance.’ This is the worst thing that can happen. The lab does not know what it means. You don’t know what it means, and you don’t know what to tell the patient. So how do you get around this?”

Dr. Klein said that before conducting any genetic testing, clinicians should inform the patient that they may have a genetic variant of uncertain significance. It doesn’t solve the problem, but it does help physicians manage patient expectations. 
 

Clinical Relevance on the Way?

While it may seem that all of the identified variants that predict Parkinson’s disease which, in addition to PSMF1, include the well-established LRRK2 and GBA1, may look the same, this is not true when patient history is taken into account, said Dr. Klein.

For example, age-of-onset of Parkinson’s disease can differ between identified variants, and this has led to “a paradigm change” whereby a purely genetic finding is called a disease. 

This first occurred in Huntington’s disease, when researchers gave individuals at high genetic risk of developing the illness, but who currently had no clinical symptoms, the label of “Stage Zero disease.”

This is important to note “because if we get to the stage of having drugs that can slow down, or even prevent, progression to Parkinson’s disease, then it will be key to have patients we know are going to develop it to participate in clinical trials for such agents,” said Dr. Klein. 

She cited the example of a family that she recently encountered that had genetic test results that showed variants of unknown significance, so Dr. Klein had the family’s samples sent to a specialized lab in Dundee, Scotland, for further analysis.

“The biochemists found that this variant was indeed pathogenic, and kinase-activating, so this is very helpful and very important because there are now clinical trials in Parkinson’s disease with kinase inhibitors,” she noted. 

“If you think there is something else [over and above the finding of uncertain significance] in your Parkinson’s disease panel, and you are not happy with the genetic report, send it somewhere else,” Dr. Klein advised. 

“We will see a lot more patients with genetic Parkinson’s disease in the future,” she predicted, while citing two recent preliminary clinical trials that have shown some promise in terms of neuroprotection in patients with early Parkinson’s disease.

“It remains to be seen whether there will be light at the end of the tunnel,” she said, but it may soon be possible to find treatments that delay, or even prevent, Parkinson’s disease onset. 

Dr. Magrinelli reported receiving speaker’s honoraria from MJFF Edmond J. Safra Clinical Research Fellowship in Movement Disorders (Class of 2023), MJFF Edmond J. Safra Movement Disorders Research Career Development Award 2023 (Grant ID MJFF-023893), American Parkinson Disease Association (Research Grant 2024), and the David Blank Charitable Foundation. Dr. Klein reported being a medical advisor to Retromer Therapeutics, Takeda, and Centogene and speakers’ honoraria from Desitin and Bial.

A version of this article first appeared on Medscape.com.

HELSINKI, FINLAND — A new gene for early-onset Parkinson’s disease has been identified, a discovery that experts believe will have important clinical implications in the not-too-distant future.

A variant in PMSF1, a proteasome regulator, was identified in 15 families from 13 countries around the world, with 22 affected individuals.

“These families were ethnically diverse, and in all of them, the variant in PMSF1 correlated with the neurologic phenotype. We know this is very clear cut — the genotype/phenotype correlation — with the patients carrying the missense mutation having ‘mild’ symptoms, while those with the progressive loss-of-function variant had the most severe phenotype,” she noted. 

“Our findings unequivocally link defective PSMF1 to early-onset PD and neurodegeneration and suggest mitochondrial dysfunction as a mechanistic contributor,” study investigator Francesca Magrinelli, MD, PhD, of University College London (UCL) Queen Square Institute of Neurology, UCL, London, told delegates at the 2024 Congress of the European Academy of Neurology.
 

Managing Patient Expectations

Those “mildly” affected had an early-onset Parkinson’s disease starting between the second and fifth decade of life with pyramidal tract signs, dysphasia, psychiatric comorbidity, and early levodopa-induced dyskinesia. 

In those with the intermediate type, Parkinson’s disease symptoms start in childhood and include, among other things, global hypokinesia, developmental delay, cerebellar signs, and in some, associated epilepsy.

In most cases, there was evidence on brain MRI of a hypoplasia of the corpus callosum, Dr. Magrinelli said. In the most severely affected individuals, there was perinatal lethality with neurologic manifestations.

While it may seem that the genetics of Parkinson’s disease is an academic exercise for the most part, it won’t be too much longer before it yields practical information that will inform how patients are treated, said Parkinson’s disease expert Christine Klein, MD, of the Institute of Neurogenetics and Department of Neurology, University of Lübeck, Helsinki, Finland. 

The genetics of Parkinson’s disease are complicated, even within a single family. So, it’s very important to assess the pathogenicity of different variants, Dr. Klein noted. 

“I am sure that you have all had a Parkinson’s disease [gene] panel back, and it says, ‘variant of uncertain significance.’ This is the worst thing that can happen. The lab does not know what it means. You don’t know what it means, and you don’t know what to tell the patient. So how do you get around this?”

Dr. Klein said that before conducting any genetic testing, clinicians should inform the patient that they may have a genetic variant of uncertain significance. It doesn’t solve the problem, but it does help physicians manage patient expectations. 
 

Clinical Relevance on the Way?

While it may seem that all of the identified variants that predict Parkinson’s disease which, in addition to PSMF1, include the well-established LRRK2 and GBA1, may look the same, this is not true when patient history is taken into account, said Dr. Klein.

For example, age-of-onset of Parkinson’s disease can differ between identified variants, and this has led to “a paradigm change” whereby a purely genetic finding is called a disease. 

This first occurred in Huntington’s disease, when researchers gave individuals at high genetic risk of developing the illness, but who currently had no clinical symptoms, the label of “Stage Zero disease.”

This is important to note “because if we get to the stage of having drugs that can slow down, or even prevent, progression to Parkinson’s disease, then it will be key to have patients we know are going to develop it to participate in clinical trials for such agents,” said Dr. Klein. 

She cited the example of a family that she recently encountered that had genetic test results that showed variants of unknown significance, so Dr. Klein had the family’s samples sent to a specialized lab in Dundee, Scotland, for further analysis.

“The biochemists found that this variant was indeed pathogenic, and kinase-activating, so this is very helpful and very important because there are now clinical trials in Parkinson’s disease with kinase inhibitors,” she noted. 

“If you think there is something else [over and above the finding of uncertain significance] in your Parkinson’s disease panel, and you are not happy with the genetic report, send it somewhere else,” Dr. Klein advised. 

“We will see a lot more patients with genetic Parkinson’s disease in the future,” she predicted, while citing two recent preliminary clinical trials that have shown some promise in terms of neuroprotection in patients with early Parkinson’s disease.

“It remains to be seen whether there will be light at the end of the tunnel,” she said, but it may soon be possible to find treatments that delay, or even prevent, Parkinson’s disease onset. 

Dr. Magrinelli reported receiving speaker’s honoraria from MJFF Edmond J. Safra Clinical Research Fellowship in Movement Disorders (Class of 2023), MJFF Edmond J. Safra Movement Disorders Research Career Development Award 2023 (Grant ID MJFF-023893), American Parkinson Disease Association (Research Grant 2024), and the David Blank Charitable Foundation. Dr. Klein reported being a medical advisor to Retromer Therapeutics, Takeda, and Centogene and speakers’ honoraria from Desitin and Bial.

A version of this article first appeared on Medscape.com.

Parkinson’s disease (PD) and dementia with Lewy bodies are currently defined by clinical features, which can be heterogeneous and do not capture the presymptomatic phase of neurodegeneration.

Recent advances have enabled the detection of misfolded and aggregated alpha-synuclein protein (synucleinopathy) — a key pathologic feature of these diseases — allowing for earlier and more accurate diagnosis. This has led two international research groups to propose a major shift from a clinical to a biological definition of the disease.

Both groups emphasized the detection of alpha-synuclein through recently developed seed amplification assays as a key diagnostic and staging tool, although they differ in their approaches and criteria.
 

NSD-ISS

A team led by Tanya Simuni, MD, with Northwestern University, Chicago, proposed a biological definition that combines PD and dementia with Lewy bodies under the term neuronal alpha-synuclein disease (NSD).

NSD is defined by the presence during life of pathologic neuronal alpha-synuclein (S, the first biological anchor) in cerebrospinal fluid (CSF), regardless of the presence of any specific clinical syndrome. Individuals with pathologic neuronal alpha-synuclein aggregates are at a high risk for dopaminergic neuronal dysfunction (D, the second key biological anchor).

Dr. Simuni and colleagues also proposed the NSD integrated staging system (NSD-ISS) rooted in the S and D biological anchors coupled with the degree of functional impairment caused by clinical signs or symptoms.

Stages 0-1 occur without signs or symptoms and are defined by the presence of pathogenic variants in the SNCA gene (stage 0), S alone (stage 1A), or S and D (stage 1B).

The presence of clinical manifestations marks the transition to stage 2 and beyond, with stage 2 characterized by subtle signs or symptoms but without functional impairment. Stages 2B-6 require both S and D and stage-specific increases in functional impairment.

“An advantage of the NSD-ISS will be to reduce heterogeneity in clinical trials by requiring biological consistency within the study cohort rather than identifying study participants on the basis of clinical criteria for Parkinson’s disease and dementia with Lewy bodies,” Dr. Simuni and colleagues pointed out in a position paper describing the NSD-ISS published online earlier this year in The Lancet Neurology.

The NSD-ISS will “evolve to include the incorporation of data-driven definitions of stage-specific functional anchors and additional biomarkers as they emerge and are validated.”

For now, the NSD-ISS is intended for research use only and not in the clinic.
 

The SynNeurGe Research Diagnostic Criteria

Separately, a team led by Anthony Lang, MD, with the Krembil Brain Institute at Toronto Western Hospital, Toronto, Ontario, Canada, proposed the SynNeurGe biological classification of PD.

Described in a companion paper published online in The Lancet Neurology, their “S-N-G” classification emphasizes the important interactions between three biological factors that contribute to disease: The presence or absence of pathologic alpha-synuclein (S) in tissues or CSF, an evidence of underlying neurodegeneration (N) defined by neuroimaging procedures, and the documentation of pathogenic gene variants (G) that cause or strongly predispose to PD.

These three components link to a clinical component, defined either by a single high-specificity clinical feature or by multiple lower-specificity clinical features.

As with the NSD-ISS, the SynNeurGe model is intended for research purposes only and is not ready for immediate application in the clinic.

Both groups acknowledged the need for studies to test and validate the proposed classification systems.
 

Caveats, Cautionary Notes

Adopting a biological definition of PD would represent a shift as the field has prompted considerable discussion and healthy debate.

Commenting for this news organization, James Beck, PhD, chief scientific officer at the Parkinson’s Foundation, said the principle behind the proposed classifications is where “the field needs to go.”

“Right now, people with Parkinson’s take too long to get a confirmed diagnosis of their disease, and despite best efforts, clinicians can get it wrong, not diagnosing people or maybe misdiagnosing people,” Dr. Beck said. “Moving to a biological basis, where we have better certainty, is going to be really important.”

Beck noted that the NSD-ISS “goes all in on alpha-synuclein,” which does play a big role in PD, but added, “I don’t know if I want to declare a winner after the first heat. There are other biomarkers that are coming to fruition but still need validation, and alpha-synuclein may be just one of many to help determine whether someone has Parkinson’s disease or not.”

Un Kang, MD, director of translational research at the Fresco Institute for Parkinson’s & Movement Disorders at NYU Langone Health, New York City, told this news organization that alpha-synuclein has “very high diagnostic accuracy” but cautioned that the adoption of a biological definition for PD would not usurp a clinical diagnosis.

“We need both,” Dr. Kang said. “But knowing the underlying pathology is important for earlier diagnosis and testing of potential therapies to treat the molecular pathology. If a patient doesn’t have abnormal synuclein, you may be treating the wrong disease.”

The coauthors of recent JAMA Neurology perspective said the biological definitions are “exciting, but there is “wisdom” in tapping the brakes when attempting to establish a biological definition and classification system for PD.

“Although these two proposals represent significant steps forward, a sprint toward the finish line may not be wise,” wrote Njideka U. Okubadejo, MD, with University of Lagos, Nigeria; Joseph Jankovic, MD, with Baylor College of Medicine, Houston; and Michael S. Okun, MD, with University of Florida Health, Gainesville, Florida.

“A process that embraces inclusivity and weaves in evolving technological advancements will be important. Who benefits if implementation of a biologically based staging system for PD is hurried?” they continued.

The proposals rely heavily on alpha-synuclein assays, they noted, which currently require subjective interpretation and lack extensive validation. They also worry that the need for expensive and, in some regions, unattainable biological fluids (CSF) or imaging studies (dopamine transporter scan) may limit global access to both PD trials and future therapeutics.

They also worry about retiring the name Parkinson’s disease.

“Beyond the historical importance of the term Parkinson disease, any classification that proposes abandoning the two words in either clinical or research descriptions could have unintended global repercussions,” Dr. Okubadejo, Dr. Jankovic, and Dr. Okun cautioned.

Dr. Beck told this news organization he’s spoken to clinicians at meetings about this and “no one really likes the idea” of retiring the term Parkinson’s disease.

Frederick Ketchum, MD, and Nathaniel Chin, MD, with University of Wisconsin–Madison, worry about the “lived” experience of the asymptomatic patient after receiving a biological diagnosis.

“Biological diagnosis might enable effective prognostication and treatment in the future but will substantially change the experience of illness for patients now as new frameworks are slowly adopted and knowledge is gained,” they said in a correspondence in The Lancet Neurology.

“Understanding and addressing this lived experience remains a core task for health professionals and must be made central as we begin an era in which neurological diseases are redefined on a biological basis,” Dr. Ketchum and Dr. Chin advised.

A complete list of agencies that supported this work and author disclosures are available with the original articles. Dr. Beck and Dr. Kang had no relevant disclosures.

A version of this article first appeared on Medscape.com.

Parkinson’s disease (PD) and dementia with Lewy bodies are currently defined by clinical features, which can be heterogeneous and do not capture the presymptomatic phase of neurodegeneration.

Recent advances have enabled the detection of misfolded and aggregated alpha-synuclein protein (synucleinopathy) — a key pathologic feature of these diseases — allowing for earlier and more accurate diagnosis. This has led two international research groups to propose a major shift from a clinical to a biological definition of the disease.

Both groups emphasized the detection of alpha-synuclein through recently developed seed amplification assays as a key diagnostic and staging tool, although they differ in their approaches and criteria.
 

NSD-ISS

A team led by Tanya Simuni, MD, with Northwestern University, Chicago, proposed a biological definition that combines PD and dementia with Lewy bodies under the term neuronal alpha-synuclein disease (NSD).

NSD is defined by the presence during life of pathologic neuronal alpha-synuclein (S, the first biological anchor) in cerebrospinal fluid (CSF), regardless of the presence of any specific clinical syndrome. Individuals with pathologic neuronal alpha-synuclein aggregates are at a high risk for dopaminergic neuronal dysfunction (D, the second key biological anchor).

Dr. Simuni and colleagues also proposed the NSD integrated staging system (NSD-ISS) rooted in the S and D biological anchors coupled with the degree of functional impairment caused by clinical signs or symptoms.

Stages 0-1 occur without signs or symptoms and are defined by the presence of pathogenic variants in the SNCA gene (stage 0), S alone (stage 1A), or S and D (stage 1B).

The presence of clinical manifestations marks the transition to stage 2 and beyond, with stage 2 characterized by subtle signs or symptoms but without functional impairment. Stages 2B-6 require both S and D and stage-specific increases in functional impairment.

“An advantage of the NSD-ISS will be to reduce heterogeneity in clinical trials by requiring biological consistency within the study cohort rather than identifying study participants on the basis of clinical criteria for Parkinson’s disease and dementia with Lewy bodies,” Dr. Simuni and colleagues pointed out in a position paper describing the NSD-ISS published online earlier this year in The Lancet Neurology.

The NSD-ISS will “evolve to include the incorporation of data-driven definitions of stage-specific functional anchors and additional biomarkers as they emerge and are validated.”

For now, the NSD-ISS is intended for research use only and not in the clinic.
 

The SynNeurGe Research Diagnostic Criteria

Separately, a team led by Anthony Lang, MD, with the Krembil Brain Institute at Toronto Western Hospital, Toronto, Ontario, Canada, proposed the SynNeurGe biological classification of PD.

Described in a companion paper published online in The Lancet Neurology, their “S-N-G” classification emphasizes the important interactions between three biological factors that contribute to disease: The presence or absence of pathologic alpha-synuclein (S) in tissues or CSF, an evidence of underlying neurodegeneration (N) defined by neuroimaging procedures, and the documentation of pathogenic gene variants (G) that cause or strongly predispose to PD.

These three components link to a clinical component, defined either by a single high-specificity clinical feature or by multiple lower-specificity clinical features.

As with the NSD-ISS, the SynNeurGe model is intended for research purposes only and is not ready for immediate application in the clinic.

Both groups acknowledged the need for studies to test and validate the proposed classification systems.
 

Caveats, Cautionary Notes

Adopting a biological definition of PD would represent a shift as the field has prompted considerable discussion and healthy debate.

Commenting for this news organization, James Beck, PhD, chief scientific officer at the Parkinson’s Foundation, said the principle behind the proposed classifications is where “the field needs to go.”

“Right now, people with Parkinson’s take too long to get a confirmed diagnosis of their disease, and despite best efforts, clinicians can get it wrong, not diagnosing people or maybe misdiagnosing people,” Dr. Beck said. “Moving to a biological basis, where we have better certainty, is going to be really important.”

Beck noted that the NSD-ISS “goes all in on alpha-synuclein,” which does play a big role in PD, but added, “I don’t know if I want to declare a winner after the first heat. There are other biomarkers that are coming to fruition but still need validation, and alpha-synuclein may be just one of many to help determine whether someone has Parkinson’s disease or not.”

Un Kang, MD, director of translational research at the Fresco Institute for Parkinson’s & Movement Disorders at NYU Langone Health, New York City, told this news organization that alpha-synuclein has “very high diagnostic accuracy” but cautioned that the adoption of a biological definition for PD would not usurp a clinical diagnosis.

“We need both,” Dr. Kang said. “But knowing the underlying pathology is important for earlier diagnosis and testing of potential therapies to treat the molecular pathology. If a patient doesn’t have abnormal synuclein, you may be treating the wrong disease.”

The coauthors of recent JAMA Neurology perspective said the biological definitions are “exciting, but there is “wisdom” in tapping the brakes when attempting to establish a biological definition and classification system for PD.

“Although these two proposals represent significant steps forward, a sprint toward the finish line may not be wise,” wrote Njideka U. Okubadejo, MD, with University of Lagos, Nigeria; Joseph Jankovic, MD, with Baylor College of Medicine, Houston; and Michael S. Okun, MD, with University of Florida Health, Gainesville, Florida.

“A process that embraces inclusivity and weaves in evolving technological advancements will be important. Who benefits if implementation of a biologically based staging system for PD is hurried?” they continued.

The proposals rely heavily on alpha-synuclein assays, they noted, which currently require subjective interpretation and lack extensive validation. They also worry that the need for expensive and, in some regions, unattainable biological fluids (CSF) or imaging studies (dopamine transporter scan) may limit global access to both PD trials and future therapeutics.

They also worry about retiring the name Parkinson’s disease.

“Beyond the historical importance of the term Parkinson disease, any classification that proposes abandoning the two words in either clinical or research descriptions could have unintended global repercussions,” Dr. Okubadejo, Dr. Jankovic, and Dr. Okun cautioned.

Dr. Beck told this news organization he’s spoken to clinicians at meetings about this and “no one really likes the idea” of retiring the term Parkinson’s disease.

Frederick Ketchum, MD, and Nathaniel Chin, MD, with University of Wisconsin–Madison, worry about the “lived” experience of the asymptomatic patient after receiving a biological diagnosis.

“Biological diagnosis might enable effective prognostication and treatment in the future but will substantially change the experience of illness for patients now as new frameworks are slowly adopted and knowledge is gained,” they said in a correspondence in The Lancet Neurology.

“Understanding and addressing this lived experience remains a core task for health professionals and must be made central as we begin an era in which neurological diseases are redefined on a biological basis,” Dr. Ketchum and Dr. Chin advised.

A complete list of agencies that supported this work and author disclosures are available with the original articles. Dr. Beck and Dr. Kang had no relevant disclosures.

A version of this article first appeared on Medscape.com.

Parkinson’s disease (PD) and dementia with Lewy bodies are currently defined by clinical features, which can be heterogeneous and do not capture the presymptomatic phase of neurodegeneration.

Recent advances have enabled the detection of misfolded and aggregated alpha-synuclein protein (synucleinopathy) — a key pathologic feature of these diseases — allowing for earlier and more accurate diagnosis. This has led two international research groups to propose a major shift from a clinical to a biological definition of the disease.

Both groups emphasized the detection of alpha-synuclein through recently developed seed amplification assays as a key diagnostic and staging tool, although they differ in their approaches and criteria.
 

NSD-ISS

A team led by Tanya Simuni, MD, with Northwestern University, Chicago, proposed a biological definition that combines PD and dementia with Lewy bodies under the term neuronal alpha-synuclein disease (NSD).

NSD is defined by the presence during life of pathologic neuronal alpha-synuclein (S, the first biological anchor) in cerebrospinal fluid (CSF), regardless of the presence of any specific clinical syndrome. Individuals with pathologic neuronal alpha-synuclein aggregates are at a high risk for dopaminergic neuronal dysfunction (D, the second key biological anchor).

Dr. Simuni and colleagues also proposed the NSD integrated staging system (NSD-ISS) rooted in the S and D biological anchors coupled with the degree of functional impairment caused by clinical signs or symptoms.

Stages 0-1 occur without signs or symptoms and are defined by the presence of pathogenic variants in the SNCA gene (stage 0), S alone (stage 1A), or S and D (stage 1B).

The presence of clinical manifestations marks the transition to stage 2 and beyond, with stage 2 characterized by subtle signs or symptoms but without functional impairment. Stages 2B-6 require both S and D and stage-specific increases in functional impairment.

“An advantage of the NSD-ISS will be to reduce heterogeneity in clinical trials by requiring biological consistency within the study cohort rather than identifying study participants on the basis of clinical criteria for Parkinson’s disease and dementia with Lewy bodies,” Dr. Simuni and colleagues pointed out in a position paper describing the NSD-ISS published online earlier this year in The Lancet Neurology.

The NSD-ISS will “evolve to include the incorporation of data-driven definitions of stage-specific functional anchors and additional biomarkers as they emerge and are validated.”

For now, the NSD-ISS is intended for research use only and not in the clinic.
 

The SynNeurGe Research Diagnostic Criteria

Separately, a team led by Anthony Lang, MD, with the Krembil Brain Institute at Toronto Western Hospital, Toronto, Ontario, Canada, proposed the SynNeurGe biological classification of PD.

Described in a companion paper published online in The Lancet Neurology, their “S-N-G” classification emphasizes the important interactions between three biological factors that contribute to disease: The presence or absence of pathologic alpha-synuclein (S) in tissues or CSF, an evidence of underlying neurodegeneration (N) defined by neuroimaging procedures, and the documentation of pathogenic gene variants (G) that cause or strongly predispose to PD.

These three components link to a clinical component, defined either by a single high-specificity clinical feature or by multiple lower-specificity clinical features.

As with the NSD-ISS, the SynNeurGe model is intended for research purposes only and is not ready for immediate application in the clinic.

Both groups acknowledged the need for studies to test and validate the proposed classification systems.
 

Caveats, Cautionary Notes

Adopting a biological definition of PD would represent a shift as the field has prompted considerable discussion and healthy debate.

Commenting for this news organization, James Beck, PhD, chief scientific officer at the Parkinson’s Foundation, said the principle behind the proposed classifications is where “the field needs to go.”

“Right now, people with Parkinson’s take too long to get a confirmed diagnosis of their disease, and despite best efforts, clinicians can get it wrong, not diagnosing people or maybe misdiagnosing people,” Dr. Beck said. “Moving to a biological basis, where we have better certainty, is going to be really important.”

Beck noted that the NSD-ISS “goes all in on alpha-synuclein,” which does play a big role in PD, but added, “I don’t know if I want to declare a winner after the first heat. There are other biomarkers that are coming to fruition but still need validation, and alpha-synuclein may be just one of many to help determine whether someone has Parkinson’s disease or not.”

Un Kang, MD, director of translational research at the Fresco Institute for Parkinson’s & Movement Disorders at NYU Langone Health, New York City, told this news organization that alpha-synuclein has “very high diagnostic accuracy” but cautioned that the adoption of a biological definition for PD would not usurp a clinical diagnosis.

“We need both,” Dr. Kang said. “But knowing the underlying pathology is important for earlier diagnosis and testing of potential therapies to treat the molecular pathology. If a patient doesn’t have abnormal synuclein, you may be treating the wrong disease.”

The coauthors of recent JAMA Neurology perspective said the biological definitions are “exciting, but there is “wisdom” in tapping the brakes when attempting to establish a biological definition and classification system for PD.

“Although these two proposals represent significant steps forward, a sprint toward the finish line may not be wise,” wrote Njideka U. Okubadejo, MD, with University of Lagos, Nigeria; Joseph Jankovic, MD, with Baylor College of Medicine, Houston; and Michael S. Okun, MD, with University of Florida Health, Gainesville, Florida.

“A process that embraces inclusivity and weaves in evolving technological advancements will be important. Who benefits if implementation of a biologically based staging system for PD is hurried?” they continued.

The proposals rely heavily on alpha-synuclein assays, they noted, which currently require subjective interpretation and lack extensive validation. They also worry that the need for expensive and, in some regions, unattainable biological fluids (CSF) or imaging studies (dopamine transporter scan) may limit global access to both PD trials and future therapeutics.

They also worry about retiring the name Parkinson’s disease.

“Beyond the historical importance of the term Parkinson disease, any classification that proposes abandoning the two words in either clinical or research descriptions could have unintended global repercussions,” Dr. Okubadejo, Dr. Jankovic, and Dr. Okun cautioned.

Dr. Beck told this news organization he’s spoken to clinicians at meetings about this and “no one really likes the idea” of retiring the term Parkinson’s disease.

Frederick Ketchum, MD, and Nathaniel Chin, MD, with University of Wisconsin–Madison, worry about the “lived” experience of the asymptomatic patient after receiving a biological diagnosis.

“Biological diagnosis might enable effective prognostication and treatment in the future but will substantially change the experience of illness for patients now as new frameworks are slowly adopted and knowledge is gained,” they said in a correspondence in The Lancet Neurology.

“Understanding and addressing this lived experience remains a core task for health professionals and must be made central as we begin an era in which neurological diseases are redefined on a biological basis,” Dr. Ketchum and Dr. Chin advised.

A complete list of agencies that supported this work and author disclosures are available with the original articles. Dr. Beck and Dr. Kang had no relevant disclosures.

A version of this article first appeared on Medscape.com.

Recently, the British Journal of General Practice published a paper that claimed that anxiety may be a prodromal feature of Parkinson’s disease). That news was widely picked up and spread.

The researchers certainly have some interesting data, but this sort of article, once enough general and social media websites get a hold of it, is bound to cause panic in the streets. And phone calls to my office.

An anxious-by-nature friend even emailed me the link with a laconic “Well, I’m screwed” in the subject line.

Is there a correlation between Parkinson’s disease and anxiety? Probably. Any of us practicing neurology have seen it. Some of it is likely from the anxiety of the situation, but the biochemical changes brought by the disease are also likely a big part.

But does that mean everyone with anxiety has Parkinson’s disease? Of course not. Anxiety is common, probably more common in our current era than ever before (this is why I tell patients not to watch the news and to avoid social media — they’re bad for your sanity and blood pressure).

Stories like this, once they start getting forwarded on Facebook (or another social media outlet), only raise anxiety, which results in more forwarding, and the snowball begins rolling downhill before crashing into my office (obviously this is a figure of speech, as it’s July in Phoenix).

The research is interesting. The point is valid. But the leaps the public makes are ... problematic. It’s only a matter of time before someone comes in demanding a DaT scan because they’re anxious. At $4K a test, that’s not happening.

The intersection between medical research and mass media, while not new, becomes increasingly problematic in the social media era, where things that are preliminary in the medical literature make the jump to certainty in the public arena.

Which raises anxiety all around.

Dr. Block has a solo neurology practice in Scottsdale, Arizona.

Recently, the British Journal of General Practice published a paper that claimed that anxiety may be a prodromal feature of Parkinson’s disease). That news was widely picked up and spread.

The researchers certainly have some interesting data, but this sort of article, once enough general and social media websites get a hold of it, is bound to cause panic in the streets. And phone calls to my office.

An anxious-by-nature friend even emailed me the link with a laconic “Well, I’m screwed” in the subject line.

Is there a correlation between Parkinson’s disease and anxiety? Probably. Any of us practicing neurology have seen it. Some of it is likely from the anxiety of the situation, but the biochemical changes brought by the disease are also likely a big part.

But does that mean everyone with anxiety has Parkinson’s disease? Of course not. Anxiety is common, probably more common in our current era than ever before (this is why I tell patients not to watch the news and to avoid social media — they’re bad for your sanity and blood pressure).

Stories like this, once they start getting forwarded on Facebook (or another social media outlet), only raise anxiety, which results in more forwarding, and the snowball begins rolling downhill before crashing into my office (obviously this is a figure of speech, as it’s July in Phoenix).

The research is interesting. The point is valid. But the leaps the public makes are ... problematic. It’s only a matter of time before someone comes in demanding a DaT scan because they’re anxious. At $4K a test, that’s not happening.

The intersection between medical research and mass media, while not new, becomes increasingly problematic in the social media era, where things that are preliminary in the medical literature make the jump to certainty in the public arena.

Which raises anxiety all around.

Dr. Block has a solo neurology practice in Scottsdale, Arizona.

Recently, the British Journal of General Practice published a paper that claimed that anxiety may be a prodromal feature of Parkinson’s disease). That news was widely picked up and spread.

The researchers certainly have some interesting data, but this sort of article, once enough general and social media websites get a hold of it, is bound to cause panic in the streets. And phone calls to my office.

An anxious-by-nature friend even emailed me the link with a laconic “Well, I’m screwed” in the subject line.

Is there a correlation between Parkinson’s disease and anxiety? Probably. Any of us practicing neurology have seen it. Some of it is likely from the anxiety of the situation, but the biochemical changes brought by the disease are also likely a big part.

But does that mean everyone with anxiety has Parkinson’s disease? Of course not. Anxiety is common, probably more common in our current era than ever before (this is why I tell patients not to watch the news and to avoid social media — they’re bad for your sanity and blood pressure).

Stories like this, once they start getting forwarded on Facebook (or another social media outlet), only raise anxiety, which results in more forwarding, and the snowball begins rolling downhill before crashing into my office (obviously this is a figure of speech, as it’s July in Phoenix).

The research is interesting. The point is valid. But the leaps the public makes are ... problematic. It’s only a matter of time before someone comes in demanding a DaT scan because they’re anxious. At $4K a test, that’s not happening.

The intersection between medical research and mass media, while not new, becomes increasingly problematic in the social media era, where things that are preliminary in the medical literature make the jump to certainty in the public arena.

Which raises anxiety all around.

Dr. Block has a solo neurology practice in Scottsdale, Arizona.

Individuals with anxiety have at least a twofold higher risk of developing Parkinson’s disease than those without anxiety, new research suggested.

Investigators drew on 10-year data from primary care registry to compare almost 110,000 patients who developed anxiety after the age of 50 years with close to 900,000 matched controls without anxiety.

After adjusting for a variety of sociodemographic, lifestyle, psychiatric, and neurological factors, they found that the risk of developing Parkinson’s disease was double in those with anxiety, compared with controls.

“Anxiety is known to be a feature of the early stages of Parkinson’s disease, but prior to our study, the prospective risk of Parkinson’s in those over the age of 50 with new-onset anxiety was unknown,” colead author Juan Bazo Alvarez, a senior research fellow in the Division of Epidemiology and Health at University College London, London, England, said in a news release.

The study was published online in the British Journal of General Practice.

The presence of anxiety is increased in prodromal Parkinson’s disease, but the prospective risk for Parkinson’s disease in those aged 50 years or older with new-onset anxiety was largely unknown.

Investigators analyzed data from a large UK primary care dataset that includes all people aged between 50 and 99 years who were registered with a participating practice from Jan. 1, 2008, to Dec. 31, 2018.

They identified 109,435 people (35% men) with more than one anxiety record in the database but no previous record of anxiety for 1 year or more and 878,256 people (37% men) with no history of anxiety (control group).

Features of Parkinson’s disease such as sleep problems, depression, tremor, and impaired balance were then tracked from the point of the anxiety diagnosis until 1 year before the Parkinson’s disease diagnosis.

Among those with anxiety, 331 developed Parkinson’s disease during the follow-up period, with a median time to diagnosis of 4.9 years after the first recorded episode of anxiety.

The incidence of Parkinson’s disease was 1.2 per 1000 person-years (95% CI, 0.92-1.13) in those with anxiety versus 0.49 (95% CI, 0.47-0.52) in those without anxiety.

After adjustment for age, sex, social deprivation, lifestyle factors, severe mental illness, head trauma, and dementia, the risk for Parkinson’s disease was double in those with anxiety, compared with the non-anxiety group (hazard ratio, 2.1; 95% CI, 1.9-2.4).

Individuals without anxiety also developed Parkinson’s disease later than those with anxiety.

The researchers identified specific symptoms that were associated with later development of Parkinson’s disease in those with anxiety, including depression, sleep disturbance, fatigue, and cognitive impairment, among other symptoms.

“The results suggest that there is a strong association between anxiety and diagnosis of Parkinson’s disease in patients aged over 50 years who present with a new diagnosis of anxiety,” the authors wrote. “This provides evidence for anxiety as a prodromal presentation of Parkinson’s disease.”

Future research “should explore anxiety in relation to other prodromal symptoms and how this symptom complex is associated with the incidence of Parkinson’s disease,” the researchers wrote. Doing so “may lead to earlier diagnosis and better management of Parkinson’s disease.”

This study was funded by the European Union. Specific authors received funding from the National Institute for Health and Care Research and the Alzheimer’s Society Clinical Training Fellowship program. The authors declared no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Individuals with anxiety have at least a twofold higher risk of developing Parkinson’s disease than those without anxiety, new research suggested.

Investigators drew on 10-year data from primary care registry to compare almost 110,000 patients who developed anxiety after the age of 50 years with close to 900,000 matched controls without anxiety.

After adjusting for a variety of sociodemographic, lifestyle, psychiatric, and neurological factors, they found that the risk of developing Parkinson’s disease was double in those with anxiety, compared with controls.

“Anxiety is known to be a feature of the early stages of Parkinson’s disease, but prior to our study, the prospective risk of Parkinson’s in those over the age of 50 with new-onset anxiety was unknown,” colead author Juan Bazo Alvarez, a senior research fellow in the Division of Epidemiology and Health at University College London, London, England, said in a news release.

The study was published online in the British Journal of General Practice.

The presence of anxiety is increased in prodromal Parkinson’s disease, but the prospective risk for Parkinson’s disease in those aged 50 years or older with new-onset anxiety was largely unknown.

Investigators analyzed data from a large UK primary care dataset that includes all people aged between 50 and 99 years who were registered with a participating practice from Jan. 1, 2008, to Dec. 31, 2018.

They identified 109,435 people (35% men) with more than one anxiety record in the database but no previous record of anxiety for 1 year or more and 878,256 people (37% men) with no history of anxiety (control group).

Features of Parkinson’s disease such as sleep problems, depression, tremor, and impaired balance were then tracked from the point of the anxiety diagnosis until 1 year before the Parkinson’s disease diagnosis.

Among those with anxiety, 331 developed Parkinson’s disease during the follow-up period, with a median time to diagnosis of 4.9 years after the first recorded episode of anxiety.

The incidence of Parkinson’s disease was 1.2 per 1000 person-years (95% CI, 0.92-1.13) in those with anxiety versus 0.49 (95% CI, 0.47-0.52) in those without anxiety.

After adjustment for age, sex, social deprivation, lifestyle factors, severe mental illness, head trauma, and dementia, the risk for Parkinson’s disease was double in those with anxiety, compared with the non-anxiety group (hazard ratio, 2.1; 95% CI, 1.9-2.4).

Individuals without anxiety also developed Parkinson’s disease later than those with anxiety.

The researchers identified specific symptoms that were associated with later development of Parkinson’s disease in those with anxiety, including depression, sleep disturbance, fatigue, and cognitive impairment, among other symptoms.

“The results suggest that there is a strong association between anxiety and diagnosis of Parkinson’s disease in patients aged over 50 years who present with a new diagnosis of anxiety,” the authors wrote. “This provides evidence for anxiety as a prodromal presentation of Parkinson’s disease.”

Future research “should explore anxiety in relation to other prodromal symptoms and how this symptom complex is associated with the incidence of Parkinson’s disease,” the researchers wrote. Doing so “may lead to earlier diagnosis and better management of Parkinson’s disease.”

This study was funded by the European Union. Specific authors received funding from the National Institute for Health and Care Research and the Alzheimer’s Society Clinical Training Fellowship program. The authors declared no relevant financial relationships.

A version of this article first appeared on Medscape.com.

Individuals with anxiety have at least a twofold higher risk of developing Parkinson’s disease than those without anxiety, new research suggested.

Investigators drew on 10-year data from primary care registry to compare almost 110,000 patients who developed anxiety after the age of 50 years with close to 900,000 matched controls without anxiety.

After adjusting for a variety of sociodemographic, lifestyle, psychiatric, and neurological factors, they found that the risk of developing Parkinson’s disease was double in those with anxiety, compared with controls.

“Anxiety is known to be a feature of the early stages of Parkinson’s disease, but prior to our study, the prospective risk of Parkinson’s in those over the age of 50 with new-onset anxiety was unknown,” colead author Juan Bazo Alvarez, a senior research fellow in the Division of Epidemiology and Health at University College London, London, England, said in a news release.

The study was published online in the British Journal of General Practice.

The presence of anxiety is increased in prodromal Parkinson’s disease, but the prospective risk for Parkinson’s disease in those aged 50 years or older with new-onset anxiety was largely unknown.

Investigators analyzed data from a large UK primary care dataset that includes all people aged between 50 and 99 years who were registered with a participating practice from Jan. 1, 2008, to Dec. 31, 2018.

They identified 109,435 people (35% men) with more than one anxiety record in the database but no previous record of anxiety for 1 year or more and 878,256 people (37% men) with no history of anxiety (control group).

Features of Parkinson’s disease such as sleep problems, depression, tremor, and impaired balance were then tracked from the point of the anxiety diagnosis until 1 year before the Parkinson’s disease diagnosis.

Among those with anxiety, 331 developed Parkinson’s disease during the follow-up period, with a median time to diagnosis of 4.9 years after the first recorded episode of anxiety.

The incidence of Parkinson’s disease was 1.2 per 1000 person-years (95% CI, 0.92-1.13) in those with anxiety versus 0.49 (95% CI, 0.47-0.52) in those without anxiety.

After adjustment for age, sex, social deprivation, lifestyle factors, severe mental illness, head trauma, and dementia, the risk for Parkinson’s disease was double in those with anxiety, compared with the non-anxiety group (hazard ratio, 2.1; 95% CI, 1.9-2.4).

Individuals without anxiety also developed Parkinson’s disease later than those with anxiety.

The researchers identified specific symptoms that were associated with later development of Parkinson’s disease in those with anxiety, including depression, sleep disturbance, fatigue, and cognitive impairment, among other symptoms.

“The results suggest that there is a strong association between anxiety and diagnosis of Parkinson’s disease in patients aged over 50 years who present with a new diagnosis of anxiety,” the authors wrote. “This provides evidence for anxiety as a prodromal presentation of Parkinson’s disease.”

Future research “should explore anxiety in relation to other prodromal symptoms and how this symptom complex is associated with the incidence of Parkinson’s disease,” the researchers wrote. Doing so “may lead to earlier diagnosis and better management of Parkinson’s disease.”

This study was funded by the European Union. Specific authors received funding from the National Institute for Health and Care Research and the Alzheimer’s Society Clinical Training Fellowship program. The authors declared no relevant financial relationships.

A version of this article first appeared on Medscape.com.

When doctors and patients consider the appendix, it’s often with urgency. In cases of appendicitis, the clock could be ticking down to a life-threatening burst. Thus, despite recent research suggesting antibiotics could be an alternative therapy, appendectomy remains standard for uncomplicated appendicitis.

But what if removing the appendix could raise the risk for gastrointestinal (GI) diseases like irritable bowel syndrome and colorectal cancer? That’s what some emerging science suggests. And though the research is early and mixed, it’s enough to give some health professionals pause.

“If there’s no reason to remove the appendix, then it’s better to have one,” said Heather Smith, PhD, a comparative anatomist at Midwestern University, Glendale, Arizona. Preemptive removal is not supported by the evidence, she said.

To be fair, we’ve come a long way since 1928, when American physician Miles Breuer, MD, suggested that people with infected appendixes should be left to perish, so as to remove their inferior DNA from the gene pool (he called such people “uncivilized” and “candidates for extinction”). Charles Darwin, while less radical, believed the appendix was at best useless — a mere vestige of our ancestors switching diets from leaves to fruits.

What we know now is that the appendix isn’t just a troublesome piece of worthless flesh. Instead, it may act as a safe house for friendly gut bacteria and a training camp for the immune system. It also appears to play a role in several medical conditions, from ulcerative colitis and colorectal cancer to Parkinson’s disease and lupus. The roughly 300,000 Americans who undergo appendectomy each year should be made aware of this, some experts say. But the frustrating truth is, scientists are still trying to figure out in which cases having an appendix is protective and in which we may be better off without it.
 

A ‘Worm’ as Intestinal Protection

The appendix is a blind pouch (meaning its ending is closed off) that extends from the large intestine. Not all mammals have one; it’s been found in several species of primates and rodents, as well as in rabbits, wombats, and Florida manatees, among others (dogs and cats don’t have it). While a human appendix “looks like a little worm,” Dr. Smith said, these anatomical structures come in various sizes and shapes. Some are thick, as in a beaver, while others are long and spiraling, like a rabbit’s.

Comparative anatomy studies reveal that the appendix has evolved independently at least 29 times throughout mammalian evolution. This suggests that “it has some kind of an adaptive function,” Dr. Smith said. When French scientists analyzed data from 258 species of mammals, they discovered that those that possess an appendix live longer than those without one. A possible explanation, the researchers wrote, may lie with the appendix’s role in preventing diarrhea.

Their 2023 study supported this hypothesis. Based on veterinary records of 45 different species of primates housed in a French zoo, the scientists established that primates with appendixes are far less likely to suffer severe diarrhea than those that don’t possess this organ. The appendix, it appears, might be our tiny weapon against bowel troubles.

For immunologist William Parker, PhD, a visiting scholar at the University of North Carolina at Chapel Hill, these data are “about as good as we could hope for” in support of the idea that the appendix might protect mammals from GI problems. An experiment on humans would be unethical, Dr. Parker said. But observational studies offer clues.

One study showed that compared with people with an intact appendix, young adults with a history of appendectomy have more than double the risk of developing a serious infection with non-typhoidal Salmonella of the kind that would require hospitalization.
 

A ‘Safe House’ for Bacteria

Such studies add weight to a theory that Dr. Parker and his colleagues developed back in 2007: That the appendix acts as a “safe house” for beneficial gut bacteria.

Think of the colon as a wide pipe, Dr. Parker said, that may become contaminated with a pathogen such as Salmonella. Diarrhea follows, and the pipe gets repeatedly flushed, wiping everything clean, including your friendly gut microbiome. Luckily, “you’ve got this little offshoot of that pipe,” where the flow can’t really get in “because it’s so constricted,” Dr. Parker said. The friendly gut microbes can survive inside the appendix and repopulate the colon once diarrhea is over. Dr. Parker and his colleagues found that the human appendix contains a thick layer of beneficial bacteria. “They were right where we predicted they would be,” he said.

This safe house hypothesis could explain why the gut microbiome may be different in people who no longer have an appendix. In one small study, people who’d had an appendectomy had a less diverse microbiome, with a lower abundance of beneficial strains such as Butyricicoccus and Barnesiella, than did those with intact appendixes.

The appendix likely has a second function, too, Dr. Smith said: It may serve as a training camp for the immune system. “When there is an invading pathogen in the gut, it helps the GI system to mount the immune response,” she said. The human appendix is rich in special cells known as M cells. These act as scouts, detecting and capturing invasive bacteria and viruses and presenting them to the body’s defense team, such as the T lymphocytes.

If the appendix shelters beneficial bacteria and boosts immune response, that may explain its links to various diseases. According to an epidemiological study from Taiwan,patients who underwent an appendectomy have a 46% higher risk of developing irritable bowel syndrome (IBS) — a disease associated with a low abundance of Butyricicoccus bacteria. This is why, the study authors wrote, doctors should pay careful attention to people who’ve had their appendixes removed, monitoring them for potential symptoms of IBS.

The same database helped uncover other connections between appendectomy and disease. For one, there was type 2 diabetes: Within 3 years of the surgery, patients under 30 had double the risk of developing this disorder. Then there was lupus: While those who underwent appendectomy generally had higher risk for this autoimmune disease, women were particularly affected.
 

The Contentious Connections

The most heated scientific discussion surrounds the links between the appendix and conditions such as Parkinson’s disease, ulcerative colitis, and colorectal cancer. A small 2019 study showed, for example, that appendectomy may improve symptoms of certain forms of ulcerative colitis that don’t respond to standard medical treatments. A third of patients improved after their appendix was removed, and 17% fully recovered.

Why? According to Dr. Parker, appendectomy may work for ulcerative colitis because it’s “a way of suppressing the immune system, especially in the lower intestinal areas.” A 2023 meta-analysis found that people who’d had their appendix removed before being diagnosed with ulcerative colitis were less likely to need their colon removed later on.

Such a procedure may have a serious side effect, however: Colorectal cancer. French scientists discovered that removing the appendix may reduce the numbers of certain immune cells called CD3+ and CD8+ T cells, causing a weakened immune surveillance. As a result, tumor cells might escape detection.

Yet the links between appendix removal and cancer are far from clear. A recent meta-analysis found that while people with appendectomies generally had a higher risk for colorectal cancer, for Europeans, these effects were insignificant. In fact, removal of the appendix actually protected European women from this particular form of cancer. For Parker, such mixed results may stem from the fact that treatments and populations vary widely. The issue “may depend on complex social and medical factors,” Dr. Parker said.

Things also appear complicated with Parkinson’s disease — another condition linked to the appendix. A large epidemiological study showed that appendectomy is associated with a lower risk for Parkinson’s disease and a delayed age of Parkinson’s onset. It also found that a normal appendix contains α-synuclein, a protein that may accumulate in the brain and contribute to the development of Parkinson’s. “Although α-synuclein is toxic when in the brain, it appears to be quite normal when present in the appendix,” said Luis Vitetta, PhD, MD, a clinical epidemiologist at the University of Sydney, Camperdown, Australia. Yet, not all studies find that removing the appendix lowers the risk for Parkinson’s. In fact, some show the opposite results.
 

How Should Doctors View the Appendix?

Even with these mysteries and contradictions, Dr. Vitetta said, a healthy appendix in a healthy body appears to be protective. This is why, he said, when someone is diagnosed with appendicitis, careful assessment is essential before surgery is performed.

“Perhaps an antibiotic can actually help fix it,” he said. A 2020 study published in The New England Journal of Medicine showed that antibiotics may indeed be a good alternative to surgery for the treatment of appendicitis. “We don’t want necessarily to remove an appendix that could be beneficial,” Dr. Smith said.

The many links between the appendix and various diseases mean that doctors should be more vigilant when treating patients who’ve had this organ removed, Dr. Parker said. “When a patient loses an appendix, depending on their environment, there may be effects on infection and cancer. So they might need more regular checkups,” he said. This could include monitoring for IBS and colorectal cancer.

What’s more, Dr. Parker believes that research on the appendix puts even more emphasis on the need to protect the gut microbiome — such as taking probiotics with antibiotics. And while we are still a long way from understanding how exactly this worm-like structure affects various diseases, one thing appears quite certain: The appendix is not useless. “If Darwin had the information that we have, he would not have drawn these conclusions,” Dr. Parker said.
 

A version of this article first appeared on Medscape.com.

When doctors and patients consider the appendix, it’s often with urgency. In cases of appendicitis, the clock could be ticking down to a life-threatening burst. Thus, despite recent research suggesting antibiotics could be an alternative therapy, appendectomy remains standard for uncomplicated appendicitis.

But what if removing the appendix could raise the risk for gastrointestinal (GI) diseases like irritable bowel syndrome and colorectal cancer? That’s what some emerging science suggests. And though the research is early and mixed, it’s enough to give some health professionals pause.

“If there’s no reason to remove the appendix, then it’s better to have one,” said Heather Smith, PhD, a comparative anatomist at Midwestern University, Glendale, Arizona. Preemptive removal is not supported by the evidence, she said.

To be fair, we’ve come a long way since 1928, when American physician Miles Breuer, MD, suggested that people with infected appendixes should be left to perish, so as to remove their inferior DNA from the gene pool (he called such people “uncivilized” and “candidates for extinction”). Charles Darwin, while less radical, believed the appendix was at best useless — a mere vestige of our ancestors switching diets from leaves to fruits.

What we know now is that the appendix isn’t just a troublesome piece of worthless flesh. Instead, it may act as a safe house for friendly gut bacteria and a training camp for the immune system. It also appears to play a role in several medical conditions, from ulcerative colitis and colorectal cancer to Parkinson’s disease and lupus. The roughly 300,000 Americans who undergo appendectomy each year should be made aware of this, some experts say. But the frustrating truth is, scientists are still trying to figure out in which cases having an appendix is protective and in which we may be better off without it.
 

A ‘Worm’ as Intestinal Protection

The appendix is a blind pouch (meaning its ending is closed off) that extends from the large intestine. Not all mammals have one; it’s been found in several species of primates and rodents, as well as in rabbits, wombats, and Florida manatees, among others (dogs and cats don’t have it). While a human appendix “looks like a little worm,” Dr. Smith said, these anatomical structures come in various sizes and shapes. Some are thick, as in a beaver, while others are long and spiraling, like a rabbit’s.

Comparative anatomy studies reveal that the appendix has evolved independently at least 29 times throughout mammalian evolution. This suggests that “it has some kind of an adaptive function,” Dr. Smith said. When French scientists analyzed data from 258 species of mammals, they discovered that those that possess an appendix live longer than those without one. A possible explanation, the researchers wrote, may lie with the appendix’s role in preventing diarrhea.

Their 2023 study supported this hypothesis. Based on veterinary records of 45 different species of primates housed in a French zoo, the scientists established that primates with appendixes are far less likely to suffer severe diarrhea than those that don’t possess this organ. The appendix, it appears, might be our tiny weapon against bowel troubles.

For immunologist William Parker, PhD, a visiting scholar at the University of North Carolina at Chapel Hill, these data are “about as good as we could hope for” in support of the idea that the appendix might protect mammals from GI problems. An experiment on humans would be unethical, Dr. Parker said. But observational studies offer clues.

One study showed that compared with people with an intact appendix, young adults with a history of appendectomy have more than double the risk of developing a serious infection with non-typhoidal Salmonella of the kind that would require hospitalization.
 

A ‘Safe House’ for Bacteria

Such studies add weight to a theory that Dr. Parker and his colleagues developed back in 2007: That the appendix acts as a “safe house” for beneficial gut bacteria.

Think of the colon as a wide pipe, Dr. Parker said, that may become contaminated with a pathogen such as Salmonella. Diarrhea follows, and the pipe gets repeatedly flushed, wiping everything clean, including your friendly gut microbiome. Luckily, “you’ve got this little offshoot of that pipe,” where the flow can’t really get in “because it’s so constricted,” Dr. Parker said. The friendly gut microbes can survive inside the appendix and repopulate the colon once diarrhea is over. Dr. Parker and his colleagues found that the human appendix contains a thick layer of beneficial bacteria. “They were right where we predicted they would be,” he said.

This safe house hypothesis could explain why the gut microbiome may be different in people who no longer have an appendix. In one small study, people who’d had an appendectomy had a less diverse microbiome, with a lower abundance of beneficial strains such as Butyricicoccus and Barnesiella, than did those with intact appendixes.

The appendix likely has a second function, too, Dr. Smith said: It may serve as a training camp for the immune system. “When there is an invading pathogen in the gut, it helps the GI system to mount the immune response,” she said. The human appendix is rich in special cells known as M cells. These act as scouts, detecting and capturing invasive bacteria and viruses and presenting them to the body’s defense team, such as the T lymphocytes.

If the appendix shelters beneficial bacteria and boosts immune response, that may explain its links to various diseases. According to an epidemiological study from Taiwan,patients who underwent an appendectomy have a 46% higher risk of developing irritable bowel syndrome (IBS) — a disease associated with a low abundance of Butyricicoccus bacteria. This is why, the study authors wrote, doctors should pay careful attention to people who’ve had their appendixes removed, monitoring them for potential symptoms of IBS.

The same database helped uncover other connections between appendectomy and disease. For one, there was type 2 diabetes: Within 3 years of the surgery, patients under 30 had double the risk of developing this disorder. Then there was lupus: While those who underwent appendectomy generally had higher risk for this autoimmune disease, women were particularly affected.
 

The Contentious Connections

The most heated scientific discussion surrounds the links between the appendix and conditions such as Parkinson’s disease, ulcerative colitis, and colorectal cancer. A small 2019 study showed, for example, that appendectomy may improve symptoms of certain forms of ulcerative colitis that don’t respond to standard medical treatments. A third of patients improved after their appendix was removed, and 17% fully recovered.

Why? According to Dr. Parker, appendectomy may work for ulcerative colitis because it’s “a way of suppressing the immune system, especially in the lower intestinal areas.” A 2023 meta-analysis found that people who’d had their appendix removed before being diagnosed with ulcerative colitis were less likely to need their colon removed later on.

Such a procedure may have a serious side effect, however: Colorectal cancer. French scientists discovered that removing the appendix may reduce the numbers of certain immune cells called CD3+ and CD8+ T cells, causing a weakened immune surveillance. As a result, tumor cells might escape detection.

Yet the links between appendix removal and cancer are far from clear. A recent meta-analysis found that while people with appendectomies generally had a higher risk for colorectal cancer, for Europeans, these effects were insignificant. In fact, removal of the appendix actually protected European women from this particular form of cancer. For Parker, such mixed results may stem from the fact that treatments and populations vary widely. The issue “may depend on complex social and medical factors,” Dr. Parker said.

Things also appear complicated with Parkinson’s disease — another condition linked to the appendix. A large epidemiological study showed that appendectomy is associated with a lower risk for Parkinson’s disease and a delayed age of Parkinson’s onset. It also found that a normal appendix contains α-synuclein, a protein that may accumulate in the brain and contribute to the development of Parkinson’s. “Although α-synuclein is toxic when in the brain, it appears to be quite normal when present in the appendix,” said Luis Vitetta, PhD, MD, a clinical epidemiologist at the University of Sydney, Camperdown, Australia. Yet, not all studies find that removing the appendix lowers the risk for Parkinson’s. In fact, some show the opposite results.
 

How Should Doctors View the Appendix?

Even with these mysteries and contradictions, Dr. Vitetta said, a healthy appendix in a healthy body appears to be protective. This is why, he said, when someone is diagnosed with appendicitis, careful assessment is essential before surgery is performed.

“Perhaps an antibiotic can actually help fix it,” he said. A 2020 study published in The New England Journal of Medicine showed that antibiotics may indeed be a good alternative to surgery for the treatment of appendicitis. “We don’t want necessarily to remove an appendix that could be beneficial,” Dr. Smith said.

The many links between the appendix and various diseases mean that doctors should be more vigilant when treating patients who’ve had this organ removed, Dr. Parker said. “When a patient loses an appendix, depending on their environment, there may be effects on infection and cancer. So they might need more regular checkups,” he said. This could include monitoring for IBS and colorectal cancer.

What’s more, Dr. Parker believes that research on the appendix puts even more emphasis on the need to protect the gut microbiome — such as taking probiotics with antibiotics. And while we are still a long way from understanding how exactly this worm-like structure affects various diseases, one thing appears quite certain: The appendix is not useless. “If Darwin had the information that we have, he would not have drawn these conclusions,” Dr. Parker said.
 

A version of this article first appeared on Medscape.com.

When doctors and patients consider the appendix, it’s often with urgency. In cases of appendicitis, the clock could be ticking down to a life-threatening burst. Thus, despite recent research suggesting antibiotics could be an alternative therapy, appendectomy remains standard for uncomplicated appendicitis.

But what if removing the appendix could raise the risk for gastrointestinal (GI) diseases like irritable bowel syndrome and colorectal cancer? That’s what some emerging science suggests. And though the research is early and mixed, it’s enough to give some health professionals pause.

“If there’s no reason to remove the appendix, then it’s better to have one,” said Heather Smith, PhD, a comparative anatomist at Midwestern University, Glendale, Arizona. Preemptive removal is not supported by the evidence, she said.

To be fair, we’ve come a long way since 1928, when American physician Miles Breuer, MD, suggested that people with infected appendixes should be left to perish, so as to remove their inferior DNA from the gene pool (he called such people “uncivilized” and “candidates for extinction”). Charles Darwin, while less radical, believed the appendix was at best useless — a mere vestige of our ancestors switching diets from leaves to fruits.

What we know now is that the appendix isn’t just a troublesome piece of worthless flesh. Instead, it may act as a safe house for friendly gut bacteria and a training camp for the immune system. It also appears to play a role in several medical conditions, from ulcerative colitis and colorectal cancer to Parkinson’s disease and lupus. The roughly 300,000 Americans who undergo appendectomy each year should be made aware of this, some experts say. But the frustrating truth is, scientists are still trying to figure out in which cases having an appendix is protective and in which we may be better off without it.
 

A ‘Worm’ as Intestinal Protection

The appendix is a blind pouch (meaning its ending is closed off) that extends from the large intestine. Not all mammals have one; it’s been found in several species of primates and rodents, as well as in rabbits, wombats, and Florida manatees, among others (dogs and cats don’t have it). While a human appendix “looks like a little worm,” Dr. Smith said, these anatomical structures come in various sizes and shapes. Some are thick, as in a beaver, while others are long and spiraling, like a rabbit’s.

Comparative anatomy studies reveal that the appendix has evolved independently at least 29 times throughout mammalian evolution. This suggests that “it has some kind of an adaptive function,” Dr. Smith said. When French scientists analyzed data from 258 species of mammals, they discovered that those that possess an appendix live longer than those without one. A possible explanation, the researchers wrote, may lie with the appendix’s role in preventing diarrhea.

Their 2023 study supported this hypothesis. Based on veterinary records of 45 different species of primates housed in a French zoo, the scientists established that primates with appendixes are far less likely to suffer severe diarrhea than those that don’t possess this organ. The appendix, it appears, might be our tiny weapon against bowel troubles.

For immunologist William Parker, PhD, a visiting scholar at the University of North Carolina at Chapel Hill, these data are “about as good as we could hope for” in support of the idea that the appendix might protect mammals from GI problems. An experiment on humans would be unethical, Dr. Parker said. But observational studies offer clues.

One study showed that compared with people with an intact appendix, young adults with a history of appendectomy have more than double the risk of developing a serious infection with non-typhoidal Salmonella of the kind that would require hospitalization.
 

A ‘Safe House’ for Bacteria

Such studies add weight to a theory that Dr. Parker and his colleagues developed back in 2007: That the appendix acts as a “safe house” for beneficial gut bacteria.

Think of the colon as a wide pipe, Dr. Parker said, that may become contaminated with a pathogen such as Salmonella. Diarrhea follows, and the pipe gets repeatedly flushed, wiping everything clean, including your friendly gut microbiome. Luckily, “you’ve got this little offshoot of that pipe,” where the flow can’t really get in “because it’s so constricted,” Dr. Parker said. The friendly gut microbes can survive inside the appendix and repopulate the colon once diarrhea is over. Dr. Parker and his colleagues found that the human appendix contains a thick layer of beneficial bacteria. “They were right where we predicted they would be,” he said.

This safe house hypothesis could explain why the gut microbiome may be different in people who no longer have an appendix. In one small study, people who’d had an appendectomy had a less diverse microbiome, with a lower abundance of beneficial strains such as Butyricicoccus and Barnesiella, than did those with intact appendixes.

The appendix likely has a second function, too, Dr. Smith said: It may serve as a training camp for the immune system. “When there is an invading pathogen in the gut, it helps the GI system to mount the immune response,” she said. The human appendix is rich in special cells known as M cells. These act as scouts, detecting and capturing invasive bacteria and viruses and presenting them to the body’s defense team, such as the T lymphocytes.

If the appendix shelters beneficial bacteria and boosts immune response, that may explain its links to various diseases. According to an epidemiological study from Taiwan,patients who underwent an appendectomy have a 46% higher risk of developing irritable bowel syndrome (IBS) — a disease associated with a low abundance of Butyricicoccus bacteria. This is why, the study authors wrote, doctors should pay careful attention to people who’ve had their appendixes removed, monitoring them for potential symptoms of IBS.

The same database helped uncover other connections between appendectomy and disease. For one, there was type 2 diabetes: Within 3 years of the surgery, patients under 30 had double the risk of developing this disorder. Then there was lupus: While those who underwent appendectomy generally had higher risk for this autoimmune disease, women were particularly affected.
 

The Contentious Connections

The most heated scientific discussion surrounds the links between the appendix and conditions such as Parkinson’s disease, ulcerative colitis, and colorectal cancer. A small 2019 study showed, for example, that appendectomy may improve symptoms of certain forms of ulcerative colitis that don’t respond to standard medical treatments. A third of patients improved after their appendix was removed, and 17% fully recovered.

Why? According to Dr. Parker, appendectomy may work for ulcerative colitis because it’s “a way of suppressing the immune system, especially in the lower intestinal areas.” A 2023 meta-analysis found that people who’d had their appendix removed before being diagnosed with ulcerative colitis were less likely to need their colon removed later on.

Such a procedure may have a serious side effect, however: Colorectal cancer. French scientists discovered that removing the appendix may reduce the numbers of certain immune cells called CD3+ and CD8+ T cells, causing a weakened immune surveillance. As a result, tumor cells might escape detection.

Yet the links between appendix removal and cancer are far from clear. A recent meta-analysis found that while people with appendectomies generally had a higher risk for colorectal cancer, for Europeans, these effects were insignificant. In fact, removal of the appendix actually protected European women from this particular form of cancer. For Parker, such mixed results may stem from the fact that treatments and populations vary widely. The issue “may depend on complex social and medical factors,” Dr. Parker said.

Things also appear complicated with Parkinson’s disease — another condition linked to the appendix. A large epidemiological study showed that appendectomy is associated with a lower risk for Parkinson’s disease and a delayed age of Parkinson’s onset. It also found that a normal appendix contains α-synuclein, a protein that may accumulate in the brain and contribute to the development of Parkinson’s. “Although α-synuclein is toxic when in the brain, it appears to be quite normal when present in the appendix,” said Luis Vitetta, PhD, MD, a clinical epidemiologist at the University of Sydney, Camperdown, Australia. Yet, not all studies find that removing the appendix lowers the risk for Parkinson’s. In fact, some show the opposite results.
 

How Should Doctors View the Appendix?

Even with these mysteries and contradictions, Dr. Vitetta said, a healthy appendix in a healthy body appears to be protective. This is why, he said, when someone is diagnosed with appendicitis, careful assessment is essential before surgery is performed.

“Perhaps an antibiotic can actually help fix it,” he said. A 2020 study published in The New England Journal of Medicine showed that antibiotics may indeed be a good alternative to surgery for the treatment of appendicitis. “We don’t want necessarily to remove an appendix that could be beneficial,” Dr. Smith said.

The many links between the appendix and various diseases mean that doctors should be more vigilant when treating patients who’ve had this organ removed, Dr. Parker said. “When a patient loses an appendix, depending on their environment, there may be effects on infection and cancer. So they might need more regular checkups,” he said. This could include monitoring for IBS and colorectal cancer.

What’s more, Dr. Parker believes that research on the appendix puts even more emphasis on the need to protect the gut microbiome — such as taking probiotics with antibiotics. And while we are still a long way from understanding how exactly this worm-like structure affects various diseases, one thing appears quite certain: The appendix is not useless. “If Darwin had the information that we have, he would not have drawn these conclusions,” Dr. Parker said.
 

A version of this article first appeared on Medscape.com.

As the availability of potential biomarkers for Parkinson’s disease drives the debate around diagnosing prodromal Parkinson’s disease (pPD) from theory to practice, said authors of a recent study, clinicians should weigh each patient’s preferences, circumstances, and goals against the potential benefits and harms of disclosure. The study and an accompanying editorial appeared online in Neurology.

Because markers such as SNCA, LRRK2, and GBA mutations impact small subgroups of patients at risk of developing monogenic forms of Parkinson’s disease, wrote Richard N. Rees, MBChB, MD, from the Department of Clinical and Movement Neurosciences at University College London Queen Square Institute of Neurology, and colleagues, researchers are working to identify people at risk of idiopathic Parkinson’s disease using models based on known risk and protective factors. The recent development of highly accurate cerebrospinal fluid (and potentially serum) alpha-synuclein seed amplification assays, which may show Parkinson’s disease’s signature before overt symptoms appear, will reinforce these efforts, authors added.
 

‘Tap the Brakes’

However, sources interviewed by Neurology Reviews counseled caution with potential prodromal Parkinson’s disease biomarkers. “As the science advances in Parkinson’s disease and related disorders,” said Michael S. Okun, MD, “our ability to predict who will and will not be diagnosed will improve. We should, however, tap the brakes and consider the consequences of making a diagnosis in someone at risk — especially someone without symptoms.” Dr. Okun is National Medical Advisor to the Parkinson’s Foundation and director of the Norman Fixel Institute for Neurological Diseases at University of Florida Health in Gainesville, Florida. He was not involved with the study.

Neurologists should ask themselves why they are testing for Parkinson’s disease biomarkers, said Dr. Okun, and what counseling and shared decision-making they provided beforehand. “This already complex scenario becomes even more complicated when we consider that many people with GBA gene mutations and some with LRRK2 mutations may never actually manifest Parkinson’s disease.”

A Holistic Approach to Shared Decision-Making

To avoid needlessly scaring patients, Dr. Hoy suggested broaching the topic of Parkinson’s disease biomarkers during advance care planning. “In the same conversation that you might talk about establishing surrogate decision-makers or potential do-not-resuscitate/intubate orders, you can talk about the potential of predictive testing, which is becoming more prevalent across domains of clinical practice.”

Understanding each patient’s values, preferences, and priorities requires a holistic approach, he said. “In the context of prodromal Parkinson’s disease, the benefits of enrolling in a new clinical trial or implementing lifestyle changes might vary depending on the person. Do you think this person would be likely to enroll in a clinical trial or implement those lifestyle changes?” Additionally, he recommended considering how a patient might react to a false diagnosis.

Whereas a diagnosis of mild cognitive impairment might not lead to Alzheimer’s disease or dementia, wrote Dr. Rees and colleagues, growing evidence including a review published in Neurology in 2022 supports the accuracy of alpha-synuclein seed amplification assays in detecting both established and prodromal Parkinson’s disease. For people thusly diagnosed, Dr. Rees and colleagues wrote, the psychosocial burden of inevitable progression could create feelings of helplessness, possibly undermining benefits of early knowledge.

Beyond patients’ reactions, said Dr. Hoy, a diagnosis of prodromal Parkinson’s disease could result in social stigma, changes to interpersonal relationships, or discrimination. “Understanding the implications and uncertainties of potential disclosure, relative to what a person would want to know or might be able to do about it, will be the key for deciding when is the right time,” he said.
 

Supporting Primary Care

As the shared decision-making burden likely will fall to primary care providers, Dr. Hoy added, neurologists should prioritize increasing these providers’ capacity to advise and refer patients appropriately. Although it is too soon to develop clinical guidelines, he said, neurologists could help educate such providers about pPD and the growing availability of promising biomarkers.

“Parkinson’s is thought of as a movement disorder first and foremost,” said Dr. Hoy. However, various non-motor symptoms including sleep problems, depression, anxiety, apathy, constipation, and gastrointestinal issues often appear before movement-related symptoms during the prodromal phase.

As potentially the first line of defense against prodromal Parkinson’s disease, primary care providers also should know the distinction between early and timely diagnosis, added Dr. Hoy. Introduced by Dr. Rees and colleagues in a 2018 review published in F1000Research, timely diagnosis balances patient preferences, the availability and efficacy of DMT, and health systems’ ability to support and manage individuals at every stage of disease.

The current study was funded by a Parkinson’s UK grant (which paid Dr. Rees’s salary). The editorial was supported by a National Institute of Mental Health Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative award, a grant from the National Institute on Aging, and a Wellcome Discovery Award. Dr. Hoy reported no relevant disclosures.

As the availability of potential biomarkers for Parkinson’s disease drives the debate around diagnosing prodromal Parkinson’s disease (pPD) from theory to practice, said authors of a recent study, clinicians should weigh each patient’s preferences, circumstances, and goals against the potential benefits and harms of disclosure. The study and an accompanying editorial appeared online in Neurology.

Because markers such as SNCA, LRRK2, and GBA mutations impact small subgroups of patients at risk of developing monogenic forms of Parkinson’s disease, wrote Richard N. Rees, MBChB, MD, from the Department of Clinical and Movement Neurosciences at University College London Queen Square Institute of Neurology, and colleagues, researchers are working to identify people at risk of idiopathic Parkinson’s disease using models based on known risk and protective factors. The recent development of highly accurate cerebrospinal fluid (and potentially serum) alpha-synuclein seed amplification assays, which may show Parkinson’s disease’s signature before overt symptoms appear, will reinforce these efforts, authors added.
 

‘Tap the Brakes’

However, sources interviewed by Neurology Reviews counseled caution with potential prodromal Parkinson’s disease biomarkers. “As the science advances in Parkinson’s disease and related disorders,” said Michael S. Okun, MD, “our ability to predict who will and will not be diagnosed will improve. We should, however, tap the brakes and consider the consequences of making a diagnosis in someone at risk — especially someone without symptoms.” Dr. Okun is National Medical Advisor to the Parkinson’s Foundation and director of the Norman Fixel Institute for Neurological Diseases at University of Florida Health in Gainesville, Florida. He was not involved with the study.

Neurologists should ask themselves why they are testing for Parkinson’s disease biomarkers, said Dr. Okun, and what counseling and shared decision-making they provided beforehand. “This already complex scenario becomes even more complicated when we consider that many people with GBA gene mutations and some with LRRK2 mutations may never actually manifest Parkinson’s disease.”

A Holistic Approach to Shared Decision-Making

To avoid needlessly scaring patients, Dr. Hoy suggested broaching the topic of Parkinson’s disease biomarkers during advance care planning. “In the same conversation that you might talk about establishing surrogate decision-makers or potential do-not-resuscitate/intubate orders, you can talk about the potential of predictive testing, which is becoming more prevalent across domains of clinical practice.”

Understanding each patient’s values, preferences, and priorities requires a holistic approach, he said. “In the context of prodromal Parkinson’s disease, the benefits of enrolling in a new clinical trial or implementing lifestyle changes might vary depending on the person. Do you think this person would be likely to enroll in a clinical trial or implement those lifestyle changes?” Additionally, he recommended considering how a patient might react to a false diagnosis.

Whereas a diagnosis of mild cognitive impairment might not lead to Alzheimer’s disease or dementia, wrote Dr. Rees and colleagues, growing evidence including a review published in Neurology in 2022 supports the accuracy of alpha-synuclein seed amplification assays in detecting both established and prodromal Parkinson’s disease. For people thusly diagnosed, Dr. Rees and colleagues wrote, the psychosocial burden of inevitable progression could create feelings of helplessness, possibly undermining benefits of early knowledge.

Beyond patients’ reactions, said Dr. Hoy, a diagnosis of prodromal Parkinson’s disease could result in social stigma, changes to interpersonal relationships, or discrimination. “Understanding the implications and uncertainties of potential disclosure, relative to what a person would want to know or might be able to do about it, will be the key for deciding when is the right time,” he said.
 

Supporting Primary Care

As the shared decision-making burden likely will fall to primary care providers, Dr. Hoy added, neurologists should prioritize increasing these providers’ capacity to advise and refer patients appropriately. Although it is too soon to develop clinical guidelines, he said, neurologists could help educate such providers about pPD and the growing availability of promising biomarkers.

“Parkinson’s is thought of as a movement disorder first and foremost,” said Dr. Hoy. However, various non-motor symptoms including sleep problems, depression, anxiety, apathy, constipation, and gastrointestinal issues often appear before movement-related symptoms during the prodromal phase.

As potentially the first line of defense against prodromal Parkinson’s disease, primary care providers also should know the distinction between early and timely diagnosis, added Dr. Hoy. Introduced by Dr. Rees and colleagues in a 2018 review published in F1000Research, timely diagnosis balances patient preferences, the availability and efficacy of DMT, and health systems’ ability to support and manage individuals at every stage of disease.

The current study was funded by a Parkinson’s UK grant (which paid Dr. Rees’s salary). The editorial was supported by a National Institute of Mental Health Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative award, a grant from the National Institute on Aging, and a Wellcome Discovery Award. Dr. Hoy reported no relevant disclosures.

As the availability of potential biomarkers for Parkinson’s disease drives the debate around diagnosing prodromal Parkinson’s disease (pPD) from theory to practice, said authors of a recent study, clinicians should weigh each patient’s preferences, circumstances, and goals against the potential benefits and harms of disclosure. The study and an accompanying editorial appeared online in Neurology.

Because markers such as SNCA, LRRK2, and GBA mutations impact small subgroups of patients at risk of developing monogenic forms of Parkinson’s disease, wrote Richard N. Rees, MBChB, MD, from the Department of Clinical and Movement Neurosciences at University College London Queen Square Institute of Neurology, and colleagues, researchers are working to identify people at risk of idiopathic Parkinson’s disease using models based on known risk and protective factors. The recent development of highly accurate cerebrospinal fluid (and potentially serum) alpha-synuclein seed amplification assays, which may show Parkinson’s disease’s signature before overt symptoms appear, will reinforce these efforts, authors added.
 

‘Tap the Brakes’

However, sources interviewed by Neurology Reviews counseled caution with potential prodromal Parkinson’s disease biomarkers. “As the science advances in Parkinson’s disease and related disorders,” said Michael S. Okun, MD, “our ability to predict who will and will not be diagnosed will improve. We should, however, tap the brakes and consider the consequences of making a diagnosis in someone at risk — especially someone without symptoms.” Dr. Okun is National Medical Advisor to the Parkinson’s Foundation and director of the Norman Fixel Institute for Neurological Diseases at University of Florida Health in Gainesville, Florida. He was not involved with the study.

Neurologists should ask themselves why they are testing for Parkinson’s disease biomarkers, said Dr. Okun, and what counseling and shared decision-making they provided beforehand. “This already complex scenario becomes even more complicated when we consider that many people with GBA gene mutations and some with LRRK2 mutations may never actually manifest Parkinson’s disease.”

A Holistic Approach to Shared Decision-Making

To avoid needlessly scaring patients, Dr. Hoy suggested broaching the topic of Parkinson’s disease biomarkers during advance care planning. “In the same conversation that you might talk about establishing surrogate decision-makers or potential do-not-resuscitate/intubate orders, you can talk about the potential of predictive testing, which is becoming more prevalent across domains of clinical practice.”

Understanding each patient’s values, preferences, and priorities requires a holistic approach, he said. “In the context of prodromal Parkinson’s disease, the benefits of enrolling in a new clinical trial or implementing lifestyle changes might vary depending on the person. Do you think this person would be likely to enroll in a clinical trial or implement those lifestyle changes?” Additionally, he recommended considering how a patient might react to a false diagnosis.

Whereas a diagnosis of mild cognitive impairment might not lead to Alzheimer’s disease or dementia, wrote Dr. Rees and colleagues, growing evidence including a review published in Neurology in 2022 supports the accuracy of alpha-synuclein seed amplification assays in detecting both established and prodromal Parkinson’s disease. For people thusly diagnosed, Dr. Rees and colleagues wrote, the psychosocial burden of inevitable progression could create feelings of helplessness, possibly undermining benefits of early knowledge.

Beyond patients’ reactions, said Dr. Hoy, a diagnosis of prodromal Parkinson’s disease could result in social stigma, changes to interpersonal relationships, or discrimination. “Understanding the implications and uncertainties of potential disclosure, relative to what a person would want to know or might be able to do about it, will be the key for deciding when is the right time,” he said.
 

Supporting Primary Care

As the shared decision-making burden likely will fall to primary care providers, Dr. Hoy added, neurologists should prioritize increasing these providers’ capacity to advise and refer patients appropriately. Although it is too soon to develop clinical guidelines, he said, neurologists could help educate such providers about pPD and the growing availability of promising biomarkers.

“Parkinson’s is thought of as a movement disorder first and foremost,” said Dr. Hoy. However, various non-motor symptoms including sleep problems, depression, anxiety, apathy, constipation, and gastrointestinal issues often appear before movement-related symptoms during the prodromal phase.

As potentially the first line of defense against prodromal Parkinson’s disease, primary care providers also should know the distinction between early and timely diagnosis, added Dr. Hoy. Introduced by Dr. Rees and colleagues in a 2018 review published in F1000Research, timely diagnosis balances patient preferences, the availability and efficacy of DMT, and health systems’ ability to support and manage individuals at every stage of disease.

The current study was funded by a Parkinson’s UK grant (which paid Dr. Rees’s salary). The editorial was supported by a National Institute of Mental Health Brain Research Through Advancing Innovative Neurotechnologies (BRAIN) Initiative award, a grant from the National Institute on Aging, and a Wellcome Discovery Award. Dr. Hoy reported no relevant disclosures.

DENVER – Real-world, US claims-based data show major gaps in the care and management of three major neurologic disorders: Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS).

Investigators led by Nikki Win, PhD, medical manager/team lead, OMNI Scientific Strategy and Collaborations, US Medical Affairs, Genentech/Roche, found that patients with Parkinson’s disease were referred to a specialist most often, followed by those with MS and those with AD. 

The findings were presented at the 2024 annual meeting of the American Academy of Neurology (AAN).
 

National Neurologist Shortage

The national neurologist shortage, coupled with the growing incidence of Alzheimer’s disease, Parkinson’s disease, MS, and other conditions has led the AAN and other organizations to call for expanding the role of primary care physicians in the diagnosis and management of neurologic disorders, the leading global cause of disability.

“These neurological conditions are increasing in prevalence and there’s a limited number of neurologists, so we wanted to understand what this looks like in the US,” Dr. Win said.

“There is a need to understand the patient journey from primary care to neurology care, from presentation of a suspected neurological disorder to diagnosis, referral to a specialist, and the time elapsed before the specialist visit for Alzheimer’s disease, MS, and Parkinson’s disease in the US,” Dr. Win added. 

Timely and accurate diagnoses of neurologic disorders can optimize treatment outcomes. Because many of these diseases are first detected during a visit with a primary care physician, it is important to understand the timeline from the initial visit to a specialist referral, the investigators noted. 
 

Analyzing Trends in Specialist Referrals

Using claims data from the Optum Normative Health Information database, researchers identified 48,525 adults with Alzheimer’s disease, 26,431 with Parkinson’s disease, and 8169 with MS who received a diagnosis from a primary care physician between 2016 and 2021.

They examined the proportion, timing, and demographic factors associated with referrals from primary care clinicians or other healthcare providers to specialists including neurologists, neurosurgeons, psychiatrists, and geriatric medicine specialists.

Results showed that patients with Parkinson’s disease were referred to a specialist most often (53%), followed by those with MS (42%) and those with Alzheimer’s disease (27%).

Individuals with Alzheimer’s disease waited the longest for a specialist referral, with a median of 10 months between the time of referral and the first specialist visit compared with 5.7 months for patients with Parkinson’s disease and 2.6 months for MS patients.

“Some patients with common conditions like Alzheimer’s disease, MS, and Parkinson’s disease don’t see a neurologist, and when they do, it can take as long as 10 months,” said Dr. Win.

Using zip code heatmaps, researchers found that the proportion of referrals for all neurologic disorders was higher in the Midwest and Northeast, whereas patients in the South and West were less likely to receive a referral. 

Referrals for Alzheimer’s disease were low nationwide, except for some areas of Michigan and New England. California had the lowest referral rate for MS, followed by regions in the South and Northeast. Patients with Parkinson’s disease living in the Midwest and Northeast were more likely than those in the West to receive a specialist referral. 

Previous studies have reported regional shortages of neurologists, said Dr. Win. “Our data seem to correlate that in terms of the areas with lower referral patterns, but as to whether that is causative or correlative, we don’t know.” 

Odds of referral were also influenced by demographic characteristics such as sex, age, race, and ethnicity, investigators found. 

For example, there were fewer referrals with increasing age across all three neurologic disorders, and men were more likely than women to be referred for Alzheimer’s disease and Parkinson’s disease. Compared with White patients, Parkinson’s disease referrals were less likely among African American, Asian, and Hispanic patients and Alzheimer’s disease referrals were less common among Asian and Hispanic patients.

Insurance status also affected referrals. People with MS and Parkinson’s disease who had commercial insurance were referred more often than were those with Medicare Advantage, said Dr. Win.

She also noted, “Additional research is needed to understand how being referred or not being referred to a neurologist actually impacts patient treatment, care and outcomes.”
 

Neurology Challenges

Commenting on the research, Thomas Vidic, MD, a community neurologist in Elkhart, Indiana, and clinical professor of neurology at Indiana University School of Medicine at South Bend, said that he was surprised by the variation in wait times for patients.

This, he said, could reflect a study limitation or a higher comfort level among primary care doctors in treating dementia.

With respect to MS, Dr. Vidic said that he believes primary care physicians may not be uncertain about prescribing the approved medications for the disease because there are so many of them.

In addition, patients with Alzheimer’s disease are older and perhaps less accepting of being referred to a specialist that may be hours away.

The bottom line for Dr. Vidic, though, is the lack of specialists. “It comes back to the fact we’re not doing a good job of having community neurologists available to take care of these problems,” he said.

The issue of community neurologist shortages was underlined by the study’s findings about geographic gaps in specialist referrals across the country, he said.

Neurologists make up about 2% of the medical workforce and this has remained static for some time, Dr. Vidic noted. Meanwhile, people are living longer and developing more neurologic diseases.

Dr. Vidic also pointed to the lack of neurology training programs. “There has not been a significant change in the number of programs in the last 10-15 years,” he said.

Study funding was not disclosed. Dr. Win reports receiving personal compensation for serving as an employee of Genentech and has stock in Genentech. Dr. Vidic reports no relevant financial disclosures.

A version of this article appeared on Medscape.com.

DENVER – Real-world, US claims-based data show major gaps in the care and management of three major neurologic disorders: Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS).

Investigators led by Nikki Win, PhD, medical manager/team lead, OMNI Scientific Strategy and Collaborations, US Medical Affairs, Genentech/Roche, found that patients with Parkinson’s disease were referred to a specialist most often, followed by those with MS and those with AD. 

The findings were presented at the 2024 annual meeting of the American Academy of Neurology (AAN).
 

National Neurologist Shortage

The national neurologist shortage, coupled with the growing incidence of Alzheimer’s disease, Parkinson’s disease, MS, and other conditions has led the AAN and other organizations to call for expanding the role of primary care physicians in the diagnosis and management of neurologic disorders, the leading global cause of disability.

“These neurological conditions are increasing in prevalence and there’s a limited number of neurologists, so we wanted to understand what this looks like in the US,” Dr. Win said.

“There is a need to understand the patient journey from primary care to neurology care, from presentation of a suspected neurological disorder to diagnosis, referral to a specialist, and the time elapsed before the specialist visit for Alzheimer’s disease, MS, and Parkinson’s disease in the US,” Dr. Win added. 

Timely and accurate diagnoses of neurologic disorders can optimize treatment outcomes. Because many of these diseases are first detected during a visit with a primary care physician, it is important to understand the timeline from the initial visit to a specialist referral, the investigators noted. 
 

Analyzing Trends in Specialist Referrals

Using claims data from the Optum Normative Health Information database, researchers identified 48,525 adults with Alzheimer’s disease, 26,431 with Parkinson’s disease, and 8169 with MS who received a diagnosis from a primary care physician between 2016 and 2021.

They examined the proportion, timing, and demographic factors associated with referrals from primary care clinicians or other healthcare providers to specialists including neurologists, neurosurgeons, psychiatrists, and geriatric medicine specialists.

Results showed that patients with Parkinson’s disease were referred to a specialist most often (53%), followed by those with MS (42%) and those with Alzheimer’s disease (27%).

Individuals with Alzheimer’s disease waited the longest for a specialist referral, with a median of 10 months between the time of referral and the first specialist visit compared with 5.7 months for patients with Parkinson’s disease and 2.6 months for MS patients.

“Some patients with common conditions like Alzheimer’s disease, MS, and Parkinson’s disease don’t see a neurologist, and when they do, it can take as long as 10 months,” said Dr. Win.

Using zip code heatmaps, researchers found that the proportion of referrals for all neurologic disorders was higher in the Midwest and Northeast, whereas patients in the South and West were less likely to receive a referral. 

Referrals for Alzheimer’s disease were low nationwide, except for some areas of Michigan and New England. California had the lowest referral rate for MS, followed by regions in the South and Northeast. Patients with Parkinson’s disease living in the Midwest and Northeast were more likely than those in the West to receive a specialist referral. 

Previous studies have reported regional shortages of neurologists, said Dr. Win. “Our data seem to correlate that in terms of the areas with lower referral patterns, but as to whether that is causative or correlative, we don’t know.” 

Odds of referral were also influenced by demographic characteristics such as sex, age, race, and ethnicity, investigators found. 

For example, there were fewer referrals with increasing age across all three neurologic disorders, and men were more likely than women to be referred for Alzheimer’s disease and Parkinson’s disease. Compared with White patients, Parkinson’s disease referrals were less likely among African American, Asian, and Hispanic patients and Alzheimer’s disease referrals were less common among Asian and Hispanic patients.

Insurance status also affected referrals. People with MS and Parkinson’s disease who had commercial insurance were referred more often than were those with Medicare Advantage, said Dr. Win.

She also noted, “Additional research is needed to understand how being referred or not being referred to a neurologist actually impacts patient treatment, care and outcomes.”
 

Neurology Challenges

Commenting on the research, Thomas Vidic, MD, a community neurologist in Elkhart, Indiana, and clinical professor of neurology at Indiana University School of Medicine at South Bend, said that he was surprised by the variation in wait times for patients.

This, he said, could reflect a study limitation or a higher comfort level among primary care doctors in treating dementia.

With respect to MS, Dr. Vidic said that he believes primary care physicians may not be uncertain about prescribing the approved medications for the disease because there are so many of them.

In addition, patients with Alzheimer’s disease are older and perhaps less accepting of being referred to a specialist that may be hours away.

The bottom line for Dr. Vidic, though, is the lack of specialists. “It comes back to the fact we’re not doing a good job of having community neurologists available to take care of these problems,” he said.

The issue of community neurologist shortages was underlined by the study’s findings about geographic gaps in specialist referrals across the country, he said.

Neurologists make up about 2% of the medical workforce and this has remained static for some time, Dr. Vidic noted. Meanwhile, people are living longer and developing more neurologic diseases.

Dr. Vidic also pointed to the lack of neurology training programs. “There has not been a significant change in the number of programs in the last 10-15 years,” he said.

Study funding was not disclosed. Dr. Win reports receiving personal compensation for serving as an employee of Genentech and has stock in Genentech. Dr. Vidic reports no relevant financial disclosures.

A version of this article appeared on Medscape.com.

DENVER – Real-world, US claims-based data show major gaps in the care and management of three major neurologic disorders: Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis (MS).

Investigators led by Nikki Win, PhD, medical manager/team lead, OMNI Scientific Strategy and Collaborations, US Medical Affairs, Genentech/Roche, found that patients with Parkinson’s disease were referred to a specialist most often, followed by those with MS and those with AD. 

The findings were presented at the 2024 annual meeting of the American Academy of Neurology (AAN).
 

National Neurologist Shortage

The national neurologist shortage, coupled with the growing incidence of Alzheimer’s disease, Parkinson’s disease, MS, and other conditions has led the AAN and other organizations to call for expanding the role of primary care physicians in the diagnosis and management of neurologic disorders, the leading global cause of disability.

“These neurological conditions are increasing in prevalence and there’s a limited number of neurologists, so we wanted to understand what this looks like in the US,” Dr. Win said.

“There is a need to understand the patient journey from primary care to neurology care, from presentation of a suspected neurological disorder to diagnosis, referral to a specialist, and the time elapsed before the specialist visit for Alzheimer’s disease, MS, and Parkinson’s disease in the US,” Dr. Win added. 

Timely and accurate diagnoses of neurologic disorders can optimize treatment outcomes. Because many of these diseases are first detected during a visit with a primary care physician, it is important to understand the timeline from the initial visit to a specialist referral, the investigators noted. 
 

Analyzing Trends in Specialist Referrals

Using claims data from the Optum Normative Health Information database, researchers identified 48,525 adults with Alzheimer’s disease, 26,431 with Parkinson’s disease, and 8169 with MS who received a diagnosis from a primary care physician between 2016 and 2021.

They examined the proportion, timing, and demographic factors associated with referrals from primary care clinicians or other healthcare providers to specialists including neurologists, neurosurgeons, psychiatrists, and geriatric medicine specialists.

Results showed that patients with Parkinson’s disease were referred to a specialist most often (53%), followed by those with MS (42%) and those with Alzheimer’s disease (27%).

Individuals with Alzheimer’s disease waited the longest for a specialist referral, with a median of 10 months between the time of referral and the first specialist visit compared with 5.7 months for patients with Parkinson’s disease and 2.6 months for MS patients.

“Some patients with common conditions like Alzheimer’s disease, MS, and Parkinson’s disease don’t see a neurologist, and when they do, it can take as long as 10 months,” said Dr. Win.

Using zip code heatmaps, researchers found that the proportion of referrals for all neurologic disorders was higher in the Midwest and Northeast, whereas patients in the South and West were less likely to receive a referral. 

Referrals for Alzheimer’s disease were low nationwide, except for some areas of Michigan and New England. California had the lowest referral rate for MS, followed by regions in the South and Northeast. Patients with Parkinson’s disease living in the Midwest and Northeast were more likely than those in the West to receive a specialist referral. 

Previous studies have reported regional shortages of neurologists, said Dr. Win. “Our data seem to correlate that in terms of the areas with lower referral patterns, but as to whether that is causative or correlative, we don’t know.” 

Odds of referral were also influenced by demographic characteristics such as sex, age, race, and ethnicity, investigators found. 

For example, there were fewer referrals with increasing age across all three neurologic disorders, and men were more likely than women to be referred for Alzheimer’s disease and Parkinson’s disease. Compared with White patients, Parkinson’s disease referrals were less likely among African American, Asian, and Hispanic patients and Alzheimer’s disease referrals were less common among Asian and Hispanic patients.

Insurance status also affected referrals. People with MS and Parkinson’s disease who had commercial insurance were referred more often than were those with Medicare Advantage, said Dr. Win.

She also noted, “Additional research is needed to understand how being referred or not being referred to a neurologist actually impacts patient treatment, care and outcomes.”
 

Neurology Challenges

Commenting on the research, Thomas Vidic, MD, a community neurologist in Elkhart, Indiana, and clinical professor of neurology at Indiana University School of Medicine at South Bend, said that he was surprised by the variation in wait times for patients.

This, he said, could reflect a study limitation or a higher comfort level among primary care doctors in treating dementia.

With respect to MS, Dr. Vidic said that he believes primary care physicians may not be uncertain about prescribing the approved medications for the disease because there are so many of them.

In addition, patients with Alzheimer’s disease are older and perhaps less accepting of being referred to a specialist that may be hours away.

The bottom line for Dr. Vidic, though, is the lack of specialists. “It comes back to the fact we’re not doing a good job of having community neurologists available to take care of these problems,” he said.

The issue of community neurologist shortages was underlined by the study’s findings about geographic gaps in specialist referrals across the country, he said.

Neurologists make up about 2% of the medical workforce and this has remained static for some time, Dr. Vidic noted. Meanwhile, people are living longer and developing more neurologic diseases.

Dr. Vidic also pointed to the lack of neurology training programs. “There has not been a significant change in the number of programs in the last 10-15 years,” he said.

Study funding was not disclosed. Dr. Win reports receiving personal compensation for serving as an employee of Genentech and has stock in Genentech. Dr. Vidic reports no relevant financial disclosures.

A version of this article appeared on Medscape.com.