Levodopa-associated dyskinesia risk among Parkinson disease patients in Olmsted County, Minnesota, 1976-1990.Arch Neurol. 2006 Feb; 63(2):205-9.AN
The threat of levodopa-induced dyskinesias often influences early treatment decisions in those with Parkinson disease.
To determine the long-term risks of levodopa-associated dyskinesias of any severity, dyskinesias sufficient to require medication adjustment, and dyskinesias failing medication adjustments.
The medical records linkage system of the Rochester Epidemiology Project was used to identify all incident Parkinson disease patients treated with levodopa (1976-1990). All records were independently reviewed by 2 neurologists who recorded demographic and drug data, dates when dyskinesias were initially identified, and dates when dyskinesias were sufficient to require medication changes; dyskinesias not controlled by drug adjustments were also tabulated.
We identified 126 incident Parkinson disease patients treated with levodopa for at least 2 months. By Kaplan-Meier analysis, the estimated rate of dyskinesias was 30% by 5 treatment years and 59% by 10 years. However, the rate of dyskinesias requiring medication adjustment was estimated to be only 17% by 5 years and 43% by 10 years. At 10 treatment years, the rate of dyskinesias that could not be controlled with medication adjustments was estimated at only 12%. An increased risk was associated with younger age and higher initial levodopa dose, but not with sex.
Levodopa-associated dyskinesias can be expected to develop in nearly 60% of patients in our community after 10 years, but these will be severe enough to require medication adjustments in only 43% of patients. At 10 treatment years, nearly 90% of these patients can expect to be spared dyskinesias that could not be controlled by drug adjustments. This population-based study suggests dyskinesia risk may not be a major concern for most Parkinson disease patients.