STOCKHOLM—People who lose their sense of smell and have a deficit in dopamine transporter (DAT) imaging likely will develop clinical signs of Parkinson’s disease, according to a study presented at the 18th International Congress of Parkinson’s Disease and Movement Disorders.
Danna Jennings, MD, Clinical Research Director at the Institute for Neurodegenerative Disorders in New Haven, and colleagues initiated the Parkinson Associated Risk Syndrome (PARS) study to identify a large-scale cohort of individuals at risk for Parkinson’s disease using olfactory testing and DAT imaging.
Subjects in the study completed clinical evaluations at baseline and at two and four years. The evaluations were performed by investigators blinded to clinical data. No individuals with a reduced ability to smell and DAT deficit were diagnosed with Parkinson’s disease at baseline. However, 28% of the patients had phenoconverted or developed motor signs sufficient for diagnosis of Parkinson’s disease by the second year, and 46% had phenoconverted by the fourth year.
“Evaluating this enriched population, the investigators of the PARS trial demonstrated that 46% of individuals with loss of sense of smell combined with a deficit on the DAT scan develop the clinical features of Parkinson’s disease within four years,” said Anthony Lang, MD, Director of the Movement Disorders Clinic at Toronto Western Hospital. “It is likely that ongoing follow-up will show further phenoconversion to Parkinson’s disease of many of the remaining individuals fulfilling these criteria.”
The knowledge that comes from this study will have important implications for the recruitment of individuals for future neuroprotective trials, he added. These trials may have a greater chance of success than previous efforts that exclusively involved patients whose disease had already evolved to the stage of manifesting the clinical features of Parkinson’s disease.
Initiative Seeks Biomarkers of Disease Progression
Researchers participating in the Parkinson Progression Marker Initiative (PPMI) have found motor and nonmotor deficits and a reduction in CSF and imaging biomarkers in patients with Parkinson’s disease. The PPMI aims to identify one or more biomarkers of Parkinson’s disease progression, which would aid the research and development of new and improved treatments for the disease.
The PPMI study assessed clinical imaging and CSF biomarkers of Parkinson’s disease in recently diagnosed patients, healthy volunteers, and people without evidence of dopaminergic deficit. Baseline data from PPMI in these untreated cohorts demonstrated motor and nonmotor deficits and a reduction in CSF and imaging biomarkers in patients with Parkinson’s disease, compared with healthy volunteers.
A comprehensive longitudinal follow-up of the PPMI cohort is under way to characterize biomarker progression. Enrollment of prodromal patients with Parkinson’s disease has begun, and these individuals will be compared with the existing PPMI subjects who are undergoing longitudinal follow-up. All study data are integrated into the PPMI study database and are available at www.ppmi-info.org.
“There is a great need for studies to identify those at risk and then conduct clinical trials to examine the efficacy of treatments at presymptomatic stages,” said Philip Thompson, PhD, Professor of Neurology at the University of Adelaide and Royal Adelaide Hospital. “A number of biomarkers have been identified that may make possible a study of presymptomatic neurodegenerations, such as Parkinson’s disease. To be effective and widely applicable, such studies require considerable precision in identifying reliable predictors and biomarkers of the disease to recruit a cohort of homogeneous patients in the presymptomatic stages. “The results of this [long-term follow-up] study have the potential to change the way clinical trials in Parkinson’s disease are undertaken in the future and the way in which patients with prodromal premotor Parkinson’s disease are managed,” Professor Thompson concluded.
Acupuncture May Improve Patients’ Symptoms
Acupuncture and bee venom acupuncture may be promising alternative therapies for patients with Parkinson’s disease. Seung-Yeon Cho and colleagues at Kyung Hee University Hospital in Seoul, evaluated 43 adults with Parkinson’s disease who had been on a stable dose of antiparkinsonism medication for at least one month. Patients were randomly assigned to acupuncture, bee venom acupuncture, or no treatment. The groups underwent stimulation of 10 acupuncture points using acupuncture or bee venom acupuncture twice per week for eight weeks. The control group received no treatment during this period.
Participants who received bee venom acupuncture showed significant improvement in Unified Parkinson’s Disease Rating Scale (UPDRS) scores, the Berg Balance Scale, and time taken to walk 30 meters. Compared with the control group, patients receiving bee venom acupuncture demonstrated significantly greater improvement in UPDRS scores. In the acupuncture group, the UPDRS and Beck Depression Inventory scores showed significant improvement. The control group showed no significant changes in any outcome measure after the first eight weeks.