Programming parameter analysis of subthalamic deep brain stimulation for the treatment of Parkinson′s disease

Objective To analyze the changes in stimulation parameters post subthalamic nucleus(STN) deep brain stimulation (DBS) for the treatment of Parkinson′s disease. Methods Ninety-five cases of patients with Parkinson′s disease treated with STN-DBS at Department of Neurosurgery, Zhongnan Hospital of Wuhan University from November 2011 to June 2017 were analyzed retrospectively. The stimulation parameters of 95 patients were as follows: the monopolar stimulation was main (98.3%, 175/178), The stimulus contacts were mainly in the upper STN (90.9%, 171/188), and most of them were single contact stimulation (94.4%, 168/178). Patients were evaluated in 3 months, 6 months, 1 year and 2 years. The primary outcome was assessed included the post-operation parameters, the unified Parkinson′s disease rating scale Ⅲ(UPDRS-Ⅲ), the improvement rate[(preoperative score-postoperative score) / preoperative score × 100%], the stimulus energy(voltage2×frequency×pulsewidth/impedance×1 s), the stimulation-related adverse events. Results The electrodes of 95 patients were implanted into preset targets based on intraoperative microelectrode recording and postoperative MRI images.The score of UPDRS-Ⅲ was (12.7 ±6.7)points, which was better than that before operation(P<0.05), and the improvement rate was (70.7±12.1)%. During the follow-up period, the improvement rate of UPDRS-Ⅲ decreased gradually (F=2.421, P=0.048). The voltage increased gradually (F=24.633, P<0.001), the pulse width increased slightly (F=3.118, P=0.015), but the frequency did not change significantly (F=1.332, P=0.257). The energy increased gradually (P<0.05), the contacts in zona incerta (ZI) increased gradually (P<0.05), the bipolar stimulation increased slightly (P<0.05), and the double contacts gradually increased gradually (P<0.05). During the follow-up period, a total of 35 patients developed stimulation-related adverse events, including 14 patients with troublesome dyskinesia, 4 patients with gait disorder or disequilibrium, 1 patients with anxiety and depression, 2 patients with dysphagia or drinking cough, 8 patients with hallucinations, 1 patient with hypophrenia, 2 patients with increased excitability, 1 patient with eye opening difficulty. Conclusions With the passage of time in the treatment of Parkinson′s disease with STN-DBS, the stimulation voltage and energy increased gradually, and the stimulation mode of double contacts increased gradually, but it was still dominated by unipolar stimulation, and the upper part of STN is the best stimulus site. Key words: Parkinson disease; Subthalamic nucleus; Deep brain stimulation; Post-operation programming