Fatigue in patients with Parkinson's disease

OBJECTIVE: To compare the prevalence of fatigue in patients with Parkinson' s disease (PD) with that in healthy elderly people and to explore the sugge stion that fatigue is an independent symptom of PD. DESIGN: Questionnaire survey. SETTING: Community-based population. PATIENTS AND CONTROL SUBJECTS: 233 patients derived from a prevalence study in the county of Rogaland, Norway and 100 healthy elderly people with the same age and sex distribution as the patients with PD. MAIN OUTCOME MEASURE: A score for fatigue was obtained by combining the res ults from the rating scale for low energy in the Nottingham Health Profile (NHP) with the results obtained from a 7-point scale devised to evaluate fa tigue. RESULTS: 44.2% of the patients with PD and 18% of the healthy elderly contr ol subjects reported fatigue. Fatigue was associated with depression, demen tia, disease severity, disease duration, levodopa dose, and the use of slee ping pills. In a multivariate analysis, only depressive symptoms reached st atistical significance. The prevalence of fatigue in patients with PD who w ere not depressed, demented, or had a sleeping disturbance was similar to t hat found in the total PD population. CONCLUSION: Fatigue is a common symptom in PD. Although fatigue correlated with depressive symptoms, patients with PD who did not have depression, dem entia, or sleep disturbances also reported a high prevalence of this sympto m. This supports the hypothesis that fatigue is an independent symptom of P D overlapping with, but not causally related to, the concurrence of depress ive symptoms.