New Diagnostic Criteria Narrows the Definition of Parkinson's Disease

Even though Idiopathic Parkinson's disease is, after Alzheimer's disease, the second-most common neurodegenerative disorder, approximately 5% to 10% of Parkinson's patients are misdiagnosed-and up to 20% of patients diagnosed with Parkinson's later turn out to have different disorders. Seeing a need to update the diagnostic criteria for Parkinson's that have been used in clinical trials for over 20 years, the Movement Disorders Society recently published Clinical Diagnostic Criteria for Parkinson's disease-a new set of guidelines that reflect the medical community's more recent understanding of the condition. For example, in addition to requiring a diagnosis of parkinsonism-that is, bradykinesia (slowness of movement) in conjunction with rigidity, rest tremor, or both-the guidelines include supportive criteria and a red flag list to determine whether or not Parkinson's disease is the cause of the patient's parkinsonism. Together, these guidelines allow for diagnosis of clinically established Parkinson's disease and clinically probable Parkinson's disease-and will help reduce diagnostic errors in clinical trials. Stopping Parkinson's Before it Starts The Movement Disorders Society Research Criteria also defines "prodromal Idiopathic Parkinson's disease," or preclinical Parkinson's-a stage during which patients experience brain tissue pathological changes and may even experience motor or non-motor symptoms, but don't quite meet the diagnostic criteria for Parkinson's disease. More accurate diagnosis of prodromal Parkinson's will allow clinical trials to better assess the effectiveness of newly developed neuroprotective drugs designed to stop or slow the progression of the disease. This new criteria should stimulate new research into earlier stages of Parkinson's, with the ultimate goal of designing clinical trials that can test intervention for disease prevention in individuals at risk of the disease. Tomislav Babic MD, PhD, is Vice President Neuroscience Franchise, Worldwide Clinical Trials www.Worldwide.com. He can be reached at tomislav.babic@worldwide.com.