Clinical problems in non-fluctuating patients with Parkinson's disease: a community-based study.

OBJECTIVE: To investigate the frequency of nonfluctuators in a community-based prevalence study of Parkinson's disease (PD) and to describe disability, non-motor problems, and health-related quality of life in patients with PD with and without motor fluctuations, and compare the findings to those of two control groups. METHODS: The study involved 245 patients with PD who were participating in a prevalence study and two control groups (100 healthy elderly individuals and 100 patients with diabetes mellitus [DM]). Data were obtained through neurologic examination and a semistructured interview, and by the use of several questionnaires. RESULTS: In this group of unselected patients with PD, 78% did not experience motor fluctuations. Mean duration of treatment with levodopa was 6.3 years. Patients with motor fluctuations had a lower age at onset of disease, longer duration of disease, and a higher daily levodopa dose than patients without fluctuations. Among the non-fluctuating patients, we found more dementia and a higher age at prevalence day. Disability (assessed by the Unified Parkinson's Disease Rating Scale subscales for activities of daily living and motor function and the Hoehn and Yahr stage) was similar in fluctuators and nonfluctuators. Depression, sleep disturbances, and fatigue were equally frequent in both patient groups. The occurrence of these difficulties was clearly more frequent among non-fluctuating patients with PD than among the control subjects. CONCLUSION: Most patients in the general population who have PD do not experience dose-dependent motor fluctuations. Severity of motor disability and neuropsychiatric manifestations are as important in non-fluctuators as in fluctuators. Patients without motor fluctuations have more depression, sleep disturbances, fatigue, and a poorer health-related quality of life than patients with DM and healthy elderly individuals. This also underlines the importance of developing better management and treatment strategies for this group of patients with PD.