Acute Effects of Automated Peripheral Stimulation on Autonomic and Functional Capacity in Parkinson's Disease

BACKGROUND: Parkinson's disease (PD) is characterized by both motor and nonmotor impairments, including cardiovascular autonomic dysfunction. Automated mechanical peripheral somatosensory stimulation (AMPS) has shown potential to improve motor performance and cardiovascular autonomic regulation in patients with PD. However, evidence from randomized controlled trials regarding its immediate effect remains limited. OBJECTIVES: The aim of the study was to evaluate the acute effects of AMPS on heart autonomic control and functional capacity in patients with PD. METHODS: Eighteen participants diagnosed with idiopathic PD (Hoehn and Yahr scale 1-3) underwent two AMPS sessions: (1) active and (2) sham, with the first session randomized by a blinded team member. A 2-week washout period separated the sessions. Physiological parameters, Timed Up and Go, Tinetti test, 10-m walk test, and linear heart rate variability (HRV) indexes were assessed. RESULTS: A significant improvement was found in the balance item of the Tinetti test (P = 0.03, r = 0.86) and in gait velocity (P = 0.05; r = 0.61) after active AMPS. HRV index at rest showed that low-frequency (LF) and LF/high-frequency (HF) indices after active AMPS were significantly higher than those after sham AMPS (P = 0.049; d = 0.49; P = 0.049; d = 2.14, respectively). Additionally, HRV indexes in orthostatic and supine deltas revealed that the delta value of the LF/HF index after active AMPS was significantly lower than that after sham AMPS. CONCLUSIONS: A single session of AMPS acutely improved functional capacity and influenced cardiac autonomic control at rest and in response to an orthostatic challenge in patients with PD.