Autonomic dysfunction in Parkinson's disease: A prospective cohort study.

BACKGROUND: Dysautonomia is a frequent and disabling complication of PD, with an estimated prevalence of 30-40% and a significant impact on the quality of life. OBJECTIVES: To evaluate the rate of progression of dysautonomia and, in particular, orthostatic hypotension, in a cohort of unselected PD patients, and assess the extent to which the progression of dysautonomia affects activities of daily living, health-related quality of life, and health care utilization in PD. METHODS: We recruited 131 consecutive patients into a 12-month, prospective, observational cohort study. Clinical measures included the International Parkinson and Movement Disorder Society/UPDRS, the Scale for Outcomes in Parkinson Disease-Autonomic, the Orthostatic Hypotension Symptoms Assessment, and orthostatic blood pressure measurements. Health care utilization was quantified as the number of hospitalizations, emergency room visits, and outpatient clinic evaluations. RESULTS: The overall severity of autonomic symptoms, as measured by the the Orthostatic Hypotension Symptoms Assessment total score, worsened by 20% over 12 months (P < 0.001), with an overall increase in orthostatic hypotension prevalence from 31.1% to 46.7% (P < 0.001). Worsening of autonomic symptoms was independently associated with deterioration in daily living activities (P = 0.021) and health-related quality of life (P = 0.025) adjusting for disease duration, cognitive impairment, and motor severity. Regardless of symptomatic status, orthostatic hypotension was associated with greater deterioration in daily living activities, health care utilization, and falls (P ≤ 0.009) compared to patients without orthostatic hypotension. CONCLUSIONS: The severity of autonomic symptoms progressed by 20% over 1 year and was independently associated with impairments in daily living activities and health-related quality of life. Symptomatic and asymptomatic orthostatic hypotension were both associated with increased prevalence of falls and health care utilization. © 2017 International Parkinson and Movement Disorder Society.