Journal Article

Motor evoked potentials versus Macrostimulation in predicting the postoperative motor threshold in STN Deep brain stimulation

Greene, Ryan, Morris, Susan, Potvin, Christine, McCormick, Ian, Hong, Murray, Quick-Weller, Johanna, Weise, Lutz Martin, Restrepo, Carlos, Hill, Ron, Flynn, Peggy

2022

Overview

Accuracy is crucial in Deep Brain Stimulation (DBS). Electrophysiological and image-based techniques are used to avoid suboptimal positioning. Macrostimulation is the gold standard to delineate the therapeutic window intraoperatively. Despite this, electrode revision rates due to malpositioning are as high as 17%. The goal was to compare motor evoked potentials (MEPs) with the gold standard of Macrostimulation. We assessed accuracy and precision as well as the correlation in predicting motor side effects at the initial mapping 4 weeks postoperatively. In this prospective study intraoperative MEPs from 94 contacts in 16 patients undergoing STN DBS under local anesthesia were correlated to the postoperative threshold for stimulation-induced motor side effects and compared to intraoperative Macrostimulation. Analysis of accuracy, precision and correlation (Pearson) was performed. MEPs of the upper extremity had a mean percentage error of 25% (SD 38.8%) and correlated significantly with the motor threshold at postoperative mapping (R=0.235). Macrostimulation was less accurate and precise with a mean percentage error of − 68% (SD 78.8%) but had a higher correlation (R=0.388). MEPs rarely (3%) overestimated the threshold by maximally 1 mA. In contrast, Macrostimulation overestimated the threshold by over 1 mA in 69% leading to a false sense of security. MEPs are feasible in an awake setting during Deep Brain Stimulation in the STN for PD patients. MEPs of the upper extremity are more accurate and precise predicting the motor threshold and avoid a false sense of security in comparison to the gold standard of Macrostimulation. •Motor evoked potentials are feasible in awake Deep Brain Stimulation.•They are more accurate and precise than Macrostimulation.•Macrostimulation underestimates motor thresholds and gives a false sense of security.•Dysarthria and facial pulling are the most common limiting motor symptoms in STN DBS.

• Publisher: Elsevier B.V,Elsevier Limited
• Subject: Anesthesia / Deep brain stimulation / Dysarthria / Electrodes / Ethics / Intraoperative neurophysiology / Local anesthesia / Localization / Macrostimulation / Mapping / Medical imaging / Motor evoked potentials / Movement disorders / Neurology / Neurosurgery / Parkinson's disease / Patients / Side effects / Solitary tract nucleus / Surgery