New and Noteworthy Information—January 2014

The Bacille Calmette-Guérin (BCG) vaccine may benefit patients with clinically isolated syndrome (CIS), according to research published online ahead of print December 4, 2013, in Neurology. A total of 82 participants with CIS were randomized to BCG or placebo and monitored monthly with brain MRI for six months. All patients subsequently received IM interferon β-1a for 12 months. In an open-label extension phase, patients received disease-modifying therapies (DMTs) recommended by their neurologists. During the initial six months, the number of cumulative lesions was significantly lower among vaccinated subjects. The number of total T1-hypointense lesions was lower in the BCG group at months 6, 12, and 18. After 60 months, the probability of clinically definite multiple sclerosis was lower in the BCG plus DMT arm, and more vaccinated people remained DMT-free.

Exercise programs may significantly improve the ability of people with dementia to perform activities of daily living, according to a study published online ahead of print December 4, 2013, in the Cochrane Library. Exercise also may improve cognition in these patients, but may not affect depression. Investigators reviewed randomized controlled trials in which older people diagnosed with dementia were allocated to exercise programs or to control groups, which received standard care or social contact. Sixteen trials with 937 participants met the inclusion criteria. The trials were highly heterogeneous in terms of subtype and severity of participants’ dementia, and type, duration, and frequency of exercise. The researchers found that informal caregivers’ burden may be reduced when the family member with dementia participates in an exercise program.

Thrombin activity may enable neurologists to detect multiple sclerosis (MS) before clinical signs of the disease are present, according to research published online ahead of print November 29, 2013, in Annals of Neurology. Using a novel molecular probe, investigators characterized the activity pattern of thrombin, the central protease of the coagulation cascade, in experimental autoimmune encephalomyelitis. Thrombin activity preceded the onset of neurologic signs; increased at disease peak; and correlated with fibrin deposition, microglial activation, demyelination, axonal damage, and clinical severity. Mice with a genetic deficit in prothrombin confirmed the specificity of the thrombin probe. Scientists may be able to use thrombin activity to develop sensitive probes for the preclinical detection and monitoring of neuroinflammation and MS progression, according to the investigators.

An athlete with concussion symptoms should not be allowed to return to play on the same day, according to the latest consensus statement on sports-related concussion, which was summarized in the December 2013 issue of Neurosurgery. The Concussion in Sport Group (CISG 4) based its recommendations on the advice of an expert panel that was sponsored by five international sports governing bodies. Between 80% and 90% of concussions resolve within seven to 10 days, but recovery may take longer in children and adolescents, according to the consensus statement. The updated statement emphasizes the distinction between concussion and mild traumatic brain injury. The CISG 4 suggests that patients with concussion have normal findings on brain neuroimaging studies (eg, CT scan), but those with traumatic brain injury have abnormal imaging findings.

Vitamin D may prevent multiple sclerosis (MS) by blocking T helper (T_H) cells from migrating into the CNS, according to research published online ahead of print December 9, 2013, in Proceedings of the National Academy of Sciences. Investigators administered 1,25-dihydroxyvitamin D3 [1,25(OH)₂D₃], the bioactive form of vitamin D, to animals with experimental autoimmune encephalomyelitis, a mouse model of MS. Myelin-reactive T_H cells were generated in the presence of 1,25(OH)₂D₃, secreted proinflammatory cytokines, and did not preferentially differentiate into suppressor T cells. The cells left the lymph node, entered the peripheral circulation, and migrated to the immunization sites. T_H cells from 1,25(OH)₂D₃-treated mice were unable to enter the CNS parenchyma, however. Instead, the cells were maintained in the periphery. The mice developed experimental autoimmune encephalomyelitis when treatment ceased.

Among people with type 2 diabetes, dementia incidence may be highest among Native Americans and African Americans and lowest among Asians, according to a study published online ahead of print November 22, 2013, in Diabetes Care. Scientists identified 22,171 patients age 60 or older with diabetes and without preexisting dementia in the Kaiser Permanente Northern California Diabetes Registry. The investigators abstracted prevalent medical history and dementia incidence from medical records and calculated age-adjusted incidence densities. Dementia was diagnosed in 17.1% of patients. Age-adjusted dementia incidence densities were 34/1,000 person-years among Native Americans, 27/1,000 person-years among African Americans, and 19/1,000 person-years among Asians. Hazard ratios (relative to Asians) were 1.64 for Native Americans, 1.44 for African Americans, 1.30 for non-Hispanic whites, and 1.19 for Latinos.

Veterans with blast injuries have changes in brain tissue that may be apparent on imaging years later, according to data presented at the 99th Annual Meeting of the Radiological Society of North America. Researchers compared diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) values in 10 veterans of Operations Iraqi Freedom and Enduring Freedom who had been diagnosed with mild traumatic brain injury with those of 10 healthy controls. The average time elapsed between the blast-induced injury and DTI scan among the patients was 51.3 months. FA values were significantly different between the two groups, and the researchers found significant correlations between FA values and attention, delayed memory, and psychomotor test scores. The results suggest that blast injury may have a long-term impact on the brain.

Among college athletes, head impact exposure may be related to white matter diffusion measures and cognition during the course of one playing season, even in the absence of diagnosed concussion, according to data published online ahead of print December 11, 2013, in Neurology. Researchers prospectively studied 79 noncontact sport athletes and 80 nonconcussed varsity football and ice hockey players who wore helmets that recorded the acceleration-time history of the head following impact. Mean diffusivity (MD) in the corpus callosum was significantly different between groups. Measures of head impact exposure correlated with white matter diffusivity measures in the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory.

Among veterans, traumatic brain injury (TBI) during the most recent deployment is the strongest predictor of postdeployment symptoms of post-traumatic stress disorder (PTSD), even when accounting for predeployment symptoms, prior TBI, and combat intensity, according to research published online ahead of print December 11, 2013, in JAMA Psychiatry. A total of 1,648 active-duty Marine and Navy servicemen underwent clinical interviews and completed self-assessments approximately one month before a seven-month deployment and three to six months after deployment. At the predeployment assessment, 56.8% of participants reported prior TBI. At postdeployment assessment, 19.8% reported sustaining TBI between predeployment and postdeployment assessments. Probability of PTSD was highest for participants with severe predeployment symptoms, high combat intensity, and deployment-related TBI. TBI doubled the PTSD rates for participants with less severe predeployment PTSD symptoms.

Fidgetin inhibition could promote tissue regeneration and repair the broken cell connections that occur in spinal cord injury and other conditions, according to research presented at the 2013 Annual Meeting of the American Society for Cell Biology. Fidgetin prunes unstable microtubule scaffolding in cells, as well as unneeded connections in the neuronal network as the latter grows. Researchers used a novel nanoparticle technology to block fidgetin in the injured nerves of adult rats. The nanoparticles were infused with small interfering RNA that bound the messenger RNA (mRNA) transcribed from the fidgetin gene. The mRNA for fidgetin was not translated, and the cell did not produce fidgetin. Blocking fidgetin restarted tissue growth in the animals. The technique could benefit patients with myocardial infarction or chronic cutaneous wounds.

Deep brain stimulation may improve driving ability for people with Parkinson’s disease, according to a study published online ahead of print December 18, 2013, in Neurology. Investigators studied 23 people who had deep brain stimulators, 21 people with Parkinson’s disease without stimulators, and 21 healthy individuals. Participants were tested with a driving simulator. Individuals with stimulators completed the test once with the stimulator on, once with it off, and once with the stimulator off after receiving levodopa. People with Parkinson’s disease without stimulators performed worse than controls in almost every category. People with stimulators did not perform significantly worse than the controls. Participants with stimulators had an average of 3.8 slight driving errors on the test, compared with 7.5 for the controls and 11.4 for people with Parkinson’s disease without stimulators.

Gadolinium-based contrast medium (Gd-CM) may be associated with abnormalities on brain MRI, according to research published online ahead of print December 17, 2013, in Radiology. Researchers compared unenhanced T1-weighted MR images of 19 patients who had undergone six or more contrast-enhanced brain scans with images of 16 people who had received six or fewer unenhanced scans. The hyperintensity of the dentate nucleus and globus pallidus correlated with the number of Gd-CM administrations. Hyperintensity in the dentate nucleus and globus pallidus on unenhanced MRI may be a consequence of the number of previous Gd-CM administrations, according to the researchers. Because gadolinium has a high signal intensity in the body, the data suggest that the toxic gadolinium component remains in the body in patients with normal renal function.

—Erik Greb

The Bacille Calmette-Guérin (BCG) vaccine may benefit patients with clinically isolated syndrome (CIS), according to research published online ahead of print December 4, 2013, in Neurology. A total of 82 participants with CIS were randomized to BCG or placebo and monitored monthly with brain MRI for six months. All patients subsequently received IM interferon β-1a for 12 months. In an open-label extension phase, patients received disease-modifying therapies (DMTs) recommended by their neurologists. During the initial six months, the number of cumulative lesions was significantly lower among vaccinated subjects. The number of total T1-hypointense lesions was lower in the BCG group at months 6, 12, and 18. After 60 months, the probability of clinically definite multiple sclerosis was lower in the BCG plus DMT arm, and more vaccinated people remained DMT-free.

Exercise programs may significantly improve the ability of people with dementia to perform activities of daily living, according to a study published online ahead of print December 4, 2013, in the Cochrane Library. Exercise also may improve cognition in these patients, but may not affect depression. Investigators reviewed randomized controlled trials in which older people diagnosed with dementia were allocated to exercise programs or to control groups, which received standard care or social contact. Sixteen trials with 937 participants met the inclusion criteria. The trials were highly heterogeneous in terms of subtype and severity of participants’ dementia, and type, duration, and frequency of exercise. The researchers found that informal caregivers’ burden may be reduced when the family member with dementia participates in an exercise program.

Thrombin activity may enable neurologists to detect multiple sclerosis (MS) before clinical signs of the disease are present, according to research published online ahead of print November 29, 2013, in Annals of Neurology. Using a novel molecular probe, investigators characterized the activity pattern of thrombin, the central protease of the coagulation cascade, in experimental autoimmune encephalomyelitis. Thrombin activity preceded the onset of neurologic signs; increased at disease peak; and correlated with fibrin deposition, microglial activation, demyelination, axonal damage, and clinical severity. Mice with a genetic deficit in prothrombin confirmed the specificity of the thrombin probe. Scientists may be able to use thrombin activity to develop sensitive probes for the preclinical detection and monitoring of neuroinflammation and MS progression, according to the investigators.

An athlete with concussion symptoms should not be allowed to return to play on the same day, according to the latest consensus statement on sports-related concussion, which was summarized in the December 2013 issue of Neurosurgery. The Concussion in Sport Group (CISG 4) based its recommendations on the advice of an expert panel that was sponsored by five international sports governing bodies. Between 80% and 90% of concussions resolve within seven to 10 days, but recovery may take longer in children and adolescents, according to the consensus statement. The updated statement emphasizes the distinction between concussion and mild traumatic brain injury. The CISG 4 suggests that patients with concussion have normal findings on brain neuroimaging studies (eg, CT scan), but those with traumatic brain injury have abnormal imaging findings.

Vitamin D may prevent multiple sclerosis (MS) by blocking T helper (T_H) cells from migrating into the CNS, according to research published online ahead of print December 9, 2013, in Proceedings of the National Academy of Sciences. Investigators administered 1,25-dihydroxyvitamin D3 [1,25(OH)₂D₃], the bioactive form of vitamin D, to animals with experimental autoimmune encephalomyelitis, a mouse model of MS. Myelin-reactive T_H cells were generated in the presence of 1,25(OH)₂D₃, secreted proinflammatory cytokines, and did not preferentially differentiate into suppressor T cells. The cells left the lymph node, entered the peripheral circulation, and migrated to the immunization sites. T_H cells from 1,25(OH)₂D₃-treated mice were unable to enter the CNS parenchyma, however. Instead, the cells were maintained in the periphery. The mice developed experimental autoimmune encephalomyelitis when treatment ceased.

Among people with type 2 diabetes, dementia incidence may be highest among Native Americans and African Americans and lowest among Asians, according to a study published online ahead of print November 22, 2013, in Diabetes Care. Scientists identified 22,171 patients age 60 or older with diabetes and without preexisting dementia in the Kaiser Permanente Northern California Diabetes Registry. The investigators abstracted prevalent medical history and dementia incidence from medical records and calculated age-adjusted incidence densities. Dementia was diagnosed in 17.1% of patients. Age-adjusted dementia incidence densities were 34/1,000 person-years among Native Americans, 27/1,000 person-years among African Americans, and 19/1,000 person-years among Asians. Hazard ratios (relative to Asians) were 1.64 for Native Americans, 1.44 for African Americans, 1.30 for non-Hispanic whites, and 1.19 for Latinos.

Veterans with blast injuries have changes in brain tissue that may be apparent on imaging years later, according to data presented at the 99th Annual Meeting of the Radiological Society of North America. Researchers compared diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) values in 10 veterans of Operations Iraqi Freedom and Enduring Freedom who had been diagnosed with mild traumatic brain injury with those of 10 healthy controls. The average time elapsed between the blast-induced injury and DTI scan among the patients was 51.3 months. FA values were significantly different between the two groups, and the researchers found significant correlations between FA values and attention, delayed memory, and psychomotor test scores. The results suggest that blast injury may have a long-term impact on the brain.

Among college athletes, head impact exposure may be related to white matter diffusion measures and cognition during the course of one playing season, even in the absence of diagnosed concussion, according to data published online ahead of print December 11, 2013, in Neurology. Researchers prospectively studied 79 noncontact sport athletes and 80 nonconcussed varsity football and ice hockey players who wore helmets that recorded the acceleration-time history of the head following impact. Mean diffusivity (MD) in the corpus callosum was significantly different between groups. Measures of head impact exposure correlated with white matter diffusivity measures in the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory.

Among veterans, traumatic brain injury (TBI) during the most recent deployment is the strongest predictor of postdeployment symptoms of post-traumatic stress disorder (PTSD), even when accounting for predeployment symptoms, prior TBI, and combat intensity, according to research published online ahead of print December 11, 2013, in JAMA Psychiatry. A total of 1,648 active-duty Marine and Navy servicemen underwent clinical interviews and completed self-assessments approximately one month before a seven-month deployment and three to six months after deployment. At the predeployment assessment, 56.8% of participants reported prior TBI. At postdeployment assessment, 19.8% reported sustaining TBI between predeployment and postdeployment assessments. Probability of PTSD was highest for participants with severe predeployment symptoms, high combat intensity, and deployment-related TBI. TBI doubled the PTSD rates for participants with less severe predeployment PTSD symptoms.

Fidgetin inhibition could promote tissue regeneration and repair the broken cell connections that occur in spinal cord injury and other conditions, according to research presented at the 2013 Annual Meeting of the American Society for Cell Biology. Fidgetin prunes unstable microtubule scaffolding in cells, as well as unneeded connections in the neuronal network as the latter grows. Researchers used a novel nanoparticle technology to block fidgetin in the injured nerves of adult rats. The nanoparticles were infused with small interfering RNA that bound the messenger RNA (mRNA) transcribed from the fidgetin gene. The mRNA for fidgetin was not translated, and the cell did not produce fidgetin. Blocking fidgetin restarted tissue growth in the animals. The technique could benefit patients with myocardial infarction or chronic cutaneous wounds.

Deep brain stimulation may improve driving ability for people with Parkinson’s disease, according to a study published online ahead of print December 18, 2013, in Neurology. Investigators studied 23 people who had deep brain stimulators, 21 people with Parkinson’s disease without stimulators, and 21 healthy individuals. Participants were tested with a driving simulator. Individuals with stimulators completed the test once with the stimulator on, once with it off, and once with the stimulator off after receiving levodopa. People with Parkinson’s disease without stimulators performed worse than controls in almost every category. People with stimulators did not perform significantly worse than the controls. Participants with stimulators had an average of 3.8 slight driving errors on the test, compared with 7.5 for the controls and 11.4 for people with Parkinson’s disease without stimulators.

Gadolinium-based contrast medium (Gd-CM) may be associated with abnormalities on brain MRI, according to research published online ahead of print December 17, 2013, in Radiology. Researchers compared unenhanced T1-weighted MR images of 19 patients who had undergone six or more contrast-enhanced brain scans with images of 16 people who had received six or fewer unenhanced scans. The hyperintensity of the dentate nucleus and globus pallidus correlated with the number of Gd-CM administrations. Hyperintensity in the dentate nucleus and globus pallidus on unenhanced MRI may be a consequence of the number of previous Gd-CM administrations, according to the researchers. Because gadolinium has a high signal intensity in the body, the data suggest that the toxic gadolinium component remains in the body in patients with normal renal function.

—Erik Greb

The Bacille Calmette-Guérin (BCG) vaccine may benefit patients with clinically isolated syndrome (CIS), according to research published online ahead of print December 4, 2013, in Neurology. A total of 82 participants with CIS were randomized to BCG or placebo and monitored monthly with brain MRI for six months. All patients subsequently received IM interferon β-1a for 12 months. In an open-label extension phase, patients received disease-modifying therapies (DMTs) recommended by their neurologists. During the initial six months, the number of cumulative lesions was significantly lower among vaccinated subjects. The number of total T1-hypointense lesions was lower in the BCG group at months 6, 12, and 18. After 60 months, the probability of clinically definite multiple sclerosis was lower in the BCG plus DMT arm, and more vaccinated people remained DMT-free.

Exercise programs may significantly improve the ability of people with dementia to perform activities of daily living, according to a study published online ahead of print December 4, 2013, in the Cochrane Library. Exercise also may improve cognition in these patients, but may not affect depression. Investigators reviewed randomized controlled trials in which older people diagnosed with dementia were allocated to exercise programs or to control groups, which received standard care or social contact. Sixteen trials with 937 participants met the inclusion criteria. The trials were highly heterogeneous in terms of subtype and severity of participants’ dementia, and type, duration, and frequency of exercise. The researchers found that informal caregivers’ burden may be reduced when the family member with dementia participates in an exercise program.

Thrombin activity may enable neurologists to detect multiple sclerosis (MS) before clinical signs of the disease are present, according to research published online ahead of print November 29, 2013, in Annals of Neurology. Using a novel molecular probe, investigators characterized the activity pattern of thrombin, the central protease of the coagulation cascade, in experimental autoimmune encephalomyelitis. Thrombin activity preceded the onset of neurologic signs; increased at disease peak; and correlated with fibrin deposition, microglial activation, demyelination, axonal damage, and clinical severity. Mice with a genetic deficit in prothrombin confirmed the specificity of the thrombin probe. Scientists may be able to use thrombin activity to develop sensitive probes for the preclinical detection and monitoring of neuroinflammation and MS progression, according to the investigators.

An athlete with concussion symptoms should not be allowed to return to play on the same day, according to the latest consensus statement on sports-related concussion, which was summarized in the December 2013 issue of Neurosurgery. The Concussion in Sport Group (CISG 4) based its recommendations on the advice of an expert panel that was sponsored by five international sports governing bodies. Between 80% and 90% of concussions resolve within seven to 10 days, but recovery may take longer in children and adolescents, according to the consensus statement. The updated statement emphasizes the distinction between concussion and mild traumatic brain injury. The CISG 4 suggests that patients with concussion have normal findings on brain neuroimaging studies (eg, CT scan), but those with traumatic brain injury have abnormal imaging findings.

Vitamin D may prevent multiple sclerosis (MS) by blocking T helper (T_H) cells from migrating into the CNS, according to research published online ahead of print December 9, 2013, in Proceedings of the National Academy of Sciences. Investigators administered 1,25-dihydroxyvitamin D3 [1,25(OH)₂D₃], the bioactive form of vitamin D, to animals with experimental autoimmune encephalomyelitis, a mouse model of MS. Myelin-reactive T_H cells were generated in the presence of 1,25(OH)₂D₃, secreted proinflammatory cytokines, and did not preferentially differentiate into suppressor T cells. The cells left the lymph node, entered the peripheral circulation, and migrated to the immunization sites. T_H cells from 1,25(OH)₂D₃-treated mice were unable to enter the CNS parenchyma, however. Instead, the cells were maintained in the periphery. The mice developed experimental autoimmune encephalomyelitis when treatment ceased.

Among people with type 2 diabetes, dementia incidence may be highest among Native Americans and African Americans and lowest among Asians, according to a study published online ahead of print November 22, 2013, in Diabetes Care. Scientists identified 22,171 patients age 60 or older with diabetes and without preexisting dementia in the Kaiser Permanente Northern California Diabetes Registry. The investigators abstracted prevalent medical history and dementia incidence from medical records and calculated age-adjusted incidence densities. Dementia was diagnosed in 17.1% of patients. Age-adjusted dementia incidence densities were 34/1,000 person-years among Native Americans, 27/1,000 person-years among African Americans, and 19/1,000 person-years among Asians. Hazard ratios (relative to Asians) were 1.64 for Native Americans, 1.44 for African Americans, 1.30 for non-Hispanic whites, and 1.19 for Latinos.

Veterans with blast injuries have changes in brain tissue that may be apparent on imaging years later, according to data presented at the 99th Annual Meeting of the Radiological Society of North America. Researchers compared diffusion tensor imaging (DTI)-derived fractional anisotropy (FA) values in 10 veterans of Operations Iraqi Freedom and Enduring Freedom who had been diagnosed with mild traumatic brain injury with those of 10 healthy controls. The average time elapsed between the blast-induced injury and DTI scan among the patients was 51.3 months. FA values were significantly different between the two groups, and the researchers found significant correlations between FA values and attention, delayed memory, and psychomotor test scores. The results suggest that blast injury may have a long-term impact on the brain.

Among college athletes, head impact exposure may be related to white matter diffusion measures and cognition during the course of one playing season, even in the absence of diagnosed concussion, according to data published online ahead of print December 11, 2013, in Neurology. Researchers prospectively studied 79 noncontact sport athletes and 80 nonconcussed varsity football and ice hockey players who wore helmets that recorded the acceleration-time history of the head following impact. Mean diffusivity (MD) in the corpus callosum was significantly different between groups. Measures of head impact exposure correlated with white matter diffusivity measures in the corpus callosum, amygdala, cerebellar white matter, hippocampus, and thalamus. The magnitude of change in corpus callosum MD postseason was associated with poorer performance on a measure of verbal learning and memory.

Among veterans, traumatic brain injury (TBI) during the most recent deployment is the strongest predictor of postdeployment symptoms of post-traumatic stress disorder (PTSD), even when accounting for predeployment symptoms, prior TBI, and combat intensity, according to research published online ahead of print December 11, 2013, in JAMA Psychiatry. A total of 1,648 active-duty Marine and Navy servicemen underwent clinical interviews and completed self-assessments approximately one month before a seven-month deployment and three to six months after deployment. At the predeployment assessment, 56.8% of participants reported prior TBI. At postdeployment assessment, 19.8% reported sustaining TBI between predeployment and postdeployment assessments. Probability of PTSD was highest for participants with severe predeployment symptoms, high combat intensity, and deployment-related TBI. TBI doubled the PTSD rates for participants with less severe predeployment PTSD symptoms.

Fidgetin inhibition could promote tissue regeneration and repair the broken cell connections that occur in spinal cord injury and other conditions, according to research presented at the 2013 Annual Meeting of the American Society for Cell Biology. Fidgetin prunes unstable microtubule scaffolding in cells, as well as unneeded connections in the neuronal network as the latter grows. Researchers used a novel nanoparticle technology to block fidgetin in the injured nerves of adult rats. The nanoparticles were infused with small interfering RNA that bound the messenger RNA (mRNA) transcribed from the fidgetin gene. The mRNA for fidgetin was not translated, and the cell did not produce fidgetin. Blocking fidgetin restarted tissue growth in the animals. The technique could benefit patients with myocardial infarction or chronic cutaneous wounds.

Deep brain stimulation may improve driving ability for people with Parkinson’s disease, according to a study published online ahead of print December 18, 2013, in Neurology. Investigators studied 23 people who had deep brain stimulators, 21 people with Parkinson’s disease without stimulators, and 21 healthy individuals. Participants were tested with a driving simulator. Individuals with stimulators completed the test once with the stimulator on, once with it off, and once with the stimulator off after receiving levodopa. People with Parkinson’s disease without stimulators performed worse than controls in almost every category. People with stimulators did not perform significantly worse than the controls. Participants with stimulators had an average of 3.8 slight driving errors on the test, compared with 7.5 for the controls and 11.4 for people with Parkinson’s disease without stimulators.

Gadolinium-based contrast medium (Gd-CM) may be associated with abnormalities on brain MRI, according to research published online ahead of print December 17, 2013, in Radiology. Researchers compared unenhanced T1-weighted MR images of 19 patients who had undergone six or more contrast-enhanced brain scans with images of 16 people who had received six or fewer unenhanced scans. The hyperintensity of the dentate nucleus and globus pallidus correlated with the number of Gd-CM administrations. Hyperintensity in the dentate nucleus and globus pallidus on unenhanced MRI may be a consequence of the number of previous Gd-CM administrations, according to the researchers. Because gadolinium has a high signal intensity in the body, the data suggest that the toxic gadolinium component remains in the body in patients with normal renal function.

—Erik Greb