Supplementary Material for: Surgical Complications in Subthalamic Nucleus Deep Brain Stimulation for Parkinson’s Disease: experience in 800 patients

Introduction. We present our surgical complications resulting in neurological deficit or additional surgery during 25 years of DBS of the subthalamic nucleus (STN) for Parkinson’s Disease (PD).
Methods. We conducted a retrospective chart review of all PD patients that received STN DBS in our DBS center between 1998 and 2023. Outcomes were complications resulting in neurological deficit or additional surgery. Potential risk factors (number of microelectrode recording tracks, age, anesthesia method, hypertension, and sex,) for symptomatic intracerebral hemorrhage (ICH) were analyzed. Furthermore, lead fixation techniques were compared.
Results. Eight hundred PD patients (507 men, 293 women) received unilateral (n=11) or bilateral (n=789) implantation of STN electrodes. Neurological deficit due to ICH, edema, delirium or infarction was seen in 8.4% of the patients (7.4% transient, 1.0% permanent). Twenty-two patients (2.8%) had a symptomatic ICH following STN DBS, for which we did not find any risk factors, and five had permanent sequelae due to ICH (0.6%). Of all patients, 18.4% required additional surgery; the proportion was reduced from 27% in the first 300 cases to 13% in the last 500 cases (p<0.001). The infection rate was 3.5%, which decreased from 5.3% in the first 300 cases to 2.2% in the last 500 cases. The use of a lead anchoring device led to significantly less lead migrations than miniplate fixation.
Conclusion. STN DBS leads to permanent neurological deficit in a small number of patients (1.0%), but a substantial proportion needs some additional surgical procedure after the first DBS system implantation. The risk of revision surgery was reduced over time, but remained significant. These findings need to be discussed with the patient in the preoperative informed consent process in addition to the expected health benefit.