Motor fluctuations in Parkinson's disease.

OBJECTIVES: To assess patterns, prevalence, and risk factors of motor fluctuations in an unselected population of Parkinson's disease patients attending Movement Disorders Clinic of a tertiary hospital. MATERIAL AND METHODS: Eighty patients with Parkinson's disease were interviewed and data about their clinical characteristics, motor fluctuations, i.e. dyskinesia, dystonia, motor blocks and details of drug therapy, were collected. RESULTS: Forty patients had at least one type of motor fluctuation. Twenty three patients had motor blocks, 20 had dyskinesia and 11 had dystonia. Interval between onset of symptom and start of levodopa therapy and duration of levodopa therapy correlated with presence of motor fluctuations in general and to dyskinesia in particular. Patients with dyskinesia had younger age of onset of disease. Motor blocks showed a positive relationship to duration of disease. CONCLUSIONS: Fifty percent of unselected patients of Parkinson's disease had motor fluctuations after a mean duration of 5 years of illness. Early initiation and longer duration of levodopa therapy were identified as risk factors for motor fluctuations. Younger patients had more risk of developing dyskinesias. Motor blocks were more common in patients with a longer duration of illness.