Remifentanil stabilizes hemodynamics with modulating subthalamic beta oscillation during deep brain stimulation

General anesthesia is a promising method for advanced Parkinson's disease patients unable to tolerate awake deep brain stimulation (DBS) surgery. However, anesthetic agents must be kept at relatively low levels to preserve the quality of intraoperative microelectrode recordings, which can lead to unstable hemodynamic conditions. Remifentanil, with its sedative and analgesic properties, could offer a solution. This study retrospectively analyzed microelectrode recordings of the subthamic nucleus (STN) and hemodynamic responses in patients with Parkinson's disease who received deep brain stimulation surgery under controlled volatile anesthesia with/without remifentanil infusion. From October 2017 to June 2019, 24 patients with Parkinson's disease who received bilateral subthalamic deep brain stimulation surgery in Hualien Tzu Chi Hospital with (n = 12) or without remifentanil infusion (n = 12) were enrolled in this study. We conducted a comprehensive spike analysis, examining frequency, inter-spike interval properties, modified burst index, modified pause index, and modified pause ratio. Additionally, we performed spike frequency spectrum analysis to investigate oscillatory activity in high-frequency, multi-unit, and single-unit neuronal activity. Our findings revealed no differences in STN firing characteristics, while a significant decrease in high beta power was observed in multi-unit activity in the remifentanil group. Notably, nine patients in the non-remifentanil group required additional nicardipine, whereas none in the remifentanil group did. Conclusively, for patients with advanced Parkinson's disease sensitive to external stimulation at low minimum alveolar concentration, remifentanil co-administration is an option to avoid unstable hemodynamic conditions during subthalamic deep brain stimulation surgery.