Introduction: Targeting in DBS surgery is performed by microelectrode recordings (MER) or intraoperative magnetic resonance imaging (iMRI). A reported benefit to iMRI technique is decreased risk of intracranial hemorrhage (ICH), however, these comparisons are typically done with historical data. We hypothesize that the ICH rate in MER-guided DBS surgery would improve over time due to improved safety of MER. ICH rates following MER-guided DBS surgery range from 7-8% in the 1990s to 3.1-3.3% in the early 2000s and 0-2.8% more recently. We report on ICH following DBS surgery for movement disorders at our institution, comparing targeting techniques and microelectrodes as our institution changed electrodes in 2013.

Methods: We performed a retrospective chart review of patients undergoing DBS surgery for Parkinson’s disease and essential tremor at our institution between January 2005 and November 2017. All but one patient had imaging (either CT or MRI) within 24 hours after surgery. Hemorrhages were classified as intraventricular, intraparenchymal, or subarachnoid.

Results: We reviewed 208 DBS leads (MER: 161, iMRI: 47) implanted in 124 patients within the study period. Three electrode implantations resulted in asymptomatic intracranial hemorrhages (two subarachnoid and one intraventricular); no symptomatic hemorrhage was observed. Of the three, only the patient with intraventricular hemorrhage had a history of hypertension. Overall hemorrhage rate was 1.44% per lead. On average, 2.11 microelectrode passes were made in MER-guided procedures since 2013. Hemorrhage rate with MER was comparable to that for iMRI (1.86% vs. 0%, p-value = 0.35). Hemorrhage rates were similar between targets (GPI: 3.23%, STN: 1.48%; p-value = 0.51) and between year groups (2005-2012: 2.5%, 2013-2017: 1.19%; p-value = 0.53).

Conclusions: In our cohort, ICH rate following DBS surgery was 1.44%, which compares favorably to historical data and is consistent with our hypothesis of improved MER safety over time. This rate was comparable to that for iMRI-guided DBS.

Patient Care: This research demonstrates that MER-guided DBS surgery is a safe and improving method for treating patients with movement disorders.

Learning Objectives: By the conclusion of this session, participants should be able to: 1) Discuss the benefits of microelectrode recording and intraoperative MRI guided DBS surgery in movement disorders. 2) Discuss improvements in microelectrode recording and their relation to morbidity in MER-guided DBS.

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