Autonomic dysfunction in early Parkinson's disease: results from the United Kingdom Tracking Parkinson's study

Background: Autonomic dysfunction is common in the later stages of Parkinson’s disease (PD), but less is known about its presence and severity in early disease. Objective: To analyze features of autonomic dysfunction in recent onset PD cases, and their relationship to motor severity, medication use, other nonmotor symptoms (NMS), and quality-of-life scores. Methods: Detailed patient-reported symptoms of autonomic dysfunction were assessed in a multicenter cohort study in PD cases that had been diagnosed within the preceding 3.5 years. Results: There were 1746 patients (1132 males, 65.2%), mean age 67.6 years (SD 9.3), mean disease duration 1.3 years (SD 0.9), mean Movement Disorder Society Unified Parkinson’s Disease Rating Scale motor score 22.5 (SD 12.1). Orthostatic symptoms were reported by 39.6%, male erectile dysfunction by 56.1%, and female anorgasmia by 57.4%. Sialorrhea was an issue in 51.4% of patients, constipation in 43.6%, and dysphagia in 20.1%. Autonomic features increased with higher modified Hoehn and Yahr stages (P < 0.001). The severity of autonomic dysfunction was associated with the postural instability gait difficulty motor phenotype [bcoefficient 1.7, 95% confidence interval (CI) 0.7, 2.6, P < 0.001], depression (b-coefficient 4.1, CI 3.0, 5.2, P < 0.001), and excess daytime sleepiness (b-coefficient 3.1, CI 1.9, 4.2, P < 0.001). Dopamine agonists were the only drug class associated with greater autonomic dysfunction (P = 0.019). The severity of autonomic dysfunction strongly correlated with the presence of other NMS (q = 0.717, P < 0.001), and with poorer qualityof-life scores (q = 0.483, P < 0.001). Conclusions: Autonomic dysfunction is common in early PD. Autonomic dysfunction correlates with the presence of other NMS, and with worse quality of life.