Exploring Cardiovascular Autonomic Function before and after Chronic Deep Brain Stimulation in Parkinson's Disease

Background Blood pressure control in Parkinson's disease (PD) under subthalamic deep brain stimulation (STN‐DBS) is influenced by several intertwined aspects, including autonomic failure and levodopa treatment. Objective To evaluate the effect of chronic STN‐DBS, levodopa, and their combination on cardiovascular autonomic functions in PD. Methods We performed cardiovascular reflex tests (CRTs) before and 6‐months after STN‐DBS surgery in 20 PD patients (pre‐DBS vs. post‐DBS). CRTs were executed without and with medication (med‐OFF vs. med‐ON). Results CRT results and occurrence of neurogenic orthostatic hypotension (OH) did not differ between pre‐ and post‐DBS studies in med‐OFF condition. After levodopa intake, the BP decrease during HUTT was significantly greater compared to med‐OFF, both at pre‐DBS and post‐DBS evaluation. Levodopa‐induced OH was documented in 25% and 5% of patients in pre‐DBS/med‐ON and post‐DBS/med‐ON study. Conclusion Chronic stimulation did not influence cardiovascular responses, while levodopa exerts a relevant hypotensive effect. The proportion of patients presenting levodopa‐induced OH decreases after STN‐DBS surgery.