OBJECTIVE To evaluate cylindrical depth electrodes in the interhemispheric fissure as an alternative to subdural strip electrodes for direct cortical stimulation (DCS) leg motor evoked potential (MEP) monitoring. METHODS A cylindrical depth electrode was positioned in the interhemispheric fissure of 37 patients who underwent supratentorial brain surgery. Leg sensory and motor cortices were localized by highest tibial nerve somatosensory evoked potential amplitude and lowest DCS leg MEP threshold; the lowest-threshold electrode was then used for DCS leg MEP monitoring. RESULTS Intraoperative leg MEPs were obtained from all the patients in the series. The mean intensity applied for leg MEP monitoring with the cylindrical depth electrode was 15.2 ± 4.0 mA. No complications secondary to neurophysiological monitoring were detected. CONCLUSIONS Lower extremity MEPs were consistently recorded using a multi-contact cylindrical depth electrode in the interhemispheric fissure by DCS. SIGNIFICANCE Cylindrical depth electrodes may be a safe and effective alternative for DCS in the interhemispheric fissure, where subdural strips are difficult to place.

中文翻译：

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在半球间裂中用圆柱形深度电极直接刺激皮层以监测腿部运动诱发电位

目的 评估半球间裂中的圆柱形深度电极作为硬膜下条状电极的替代品，用于直接皮层刺激 (DCS) 腿部运动诱发电位 (MEP) 监测。方法 在接受幕上脑外科手术的 37 名患者的半球间裂中放置一个圆柱形深度电极。腿部感觉和运动皮质由最高的胫神经体感诱发电位幅度和最低的 DCS 腿部 MEP 阈值定位；然后将最低阈值电极用于 DCS 腿部 MEP 监测。结果 术中腿部 MEP 均来自该系列中的所有患者。使用圆柱形深度电极监测腿部 MEP 的平均强度为 15.2 ± 4.0 mA。没有检测到继发于神经生理监测的并发症。结论 DCS 在半球间裂中使用多触点圆柱形深度电极一致地记录下肢 MEP。意义 在难以放置硬膜下带的半球间裂中，圆柱形深度电极可能是 DCS 的一种安全有效的替代方法。