gms | German Medical Science

Objective: Deep brain stimulation (DBS) is an effective treatment option for diverse neurological diseases. Despite its widespread use, the surgical techniques differ widely among functional neurosurgeons. Traditional methods such as intraoperative microelectrode recording (MER) and macrostimulation (MS) during awake surgery are questioned. The aim of this study is to elucidate the impact of these techniques by evaluating lead trajectory adjustment rates and comparing intraoperative clinical results between anatomically planned (PSP) and definite stimulation points (DSP), along with followup outcome.

Methods: We performed a retrospective analysis of prospectively collected datasets of 101 Parkinson’s disease (PD) patients that underwent bilateral implantation in the subthalamic nucleus. In all patients, awake DBS surgery with MER and MS was performed and intraoperative weighted motor outcomes between the stimulation sites were compared. Additionally, lead trajectory adjustments and outcome according to Unified PD Rating Scale-III (UPDRS-III), levodopa equivalent daily dose (LEDD) and DBS related adverse events (AE) at six months were analyzed.

Results: In 47 patients (47%) intraoperative lead adjustment was performed. Of 202 implanted leads, 59 (29%) were adjusted due to MS and six (3%) due to MER. The mean response to MS referenced to L-Dopa tests per side improved significantly when comparing PSP and DSP (37.07 ± 2.18% vs. 41.38 ± 2.15%; p < 0.001) with even better results when exclusively adjusted electrodes being analyzed (18.08 ± 3.78 % vs. 31.47 ± 2.78 %; p < 0.001). This resulted in a number needed to treat of 8.1 per electrode. At 6 months, follow-up UPDRS-III (pre DBS ON/OFF 23.3 ± 1.1 vs. post DBS ON/ON 15.6 ± 0.8; p < 0.001) and LEDD (pre DBS 1262.3 ± 60.9 mg/d vs. post DBS 487.7 ± 39.2 mg/d; p < 0.001) improved significantly. From 101 patients, 15 (15%) had stimulation or surgery related adverse events including three intracranial hemorrhages (3%). Mean DBS procedure time was slightly prolonged with each stimulation site, but no correlation between AE and duration of surgery or number of stimulation sites was found.

Conclusion: Our results suggest that the use of MER and MS has an important impact on the intraoperative decision of final lead placement. It prevents poor DBS outcome in a subgroup of patients and affects the overall response to stimulation in the whole cohort. Follow-up UPDRS-III results, LEDD reductions and DBS related AE correspond to previously published data.