Jeong Ha-Neul, Ahn Sang-Il, Na Minkyun, Yoo Jihwan, Kim Woohyun, Jung In-Ho, Kang Soobin, Kim Seung Min, Shin Ha Young, Chang Jong Hee, Kim Eui Hyun
Department of Neurology, Yonsei University College of Medicine, Seoul, Korea.
Department of Neurology, Myongji Hospital, Goyang, Korea.
J Korean Neurosurg Soc. 2021 Mar;64(2):282-288. doi: 10.3340/jkns.2020.0179. Epub 2020 Dec 23.
Electrooculography (EOG) records eyeball movements as changes in the potential difference between the negatively charged retina and the positively charged cornea. We aimed to investigate whether reliable EOG waveforms can be evoked by electrical stimulation of the oculomotor and abducens nerves during skull base surgery.
We retrospectively reviewed the records of 18 patients who had undergone a skull base tumor surgery using EOG (11 craniotomies and seven endonasal endoscopic surgeries). Stimulation was performed at 5 Hz with a stimulus duration of 200 μs and an intensity of 0.1-5 mA using a concentric bipolar probe. Recording electrodes were placed on the upper (active) and lower (reference) eyelids, and on the outer corners of both eyes; the active electrode was placed on the contralateral side.
Reproducibly triggered EOG waveforms were observed in all cases. Electrical stimulation of cranial nerves (CNs) III and VI elicited positive waveforms and negative waveforms, respectively, in the horizontal recording. The median latencies were 3.1 and 0.5 ms for craniotomies and endonasal endoscopic surgeries, respectively (p=0.007). Additionally, the median amplitudes were 33.7 and 46.4 μV for craniotomies and endonasal endoscopic surgeries, respectively (p=0.40).
This study showed reliably triggered EOG waveforms with stimulation of CNs III and VI during skull base surgery. The latency was different according to the point of stimulation and thus predictable. As EOG is noninvasive and relatively easy to perform, it can be used to identify the ocular motor nerves during surgeries as an alternative of electromyography.
眼电图（EOG）通过记录带负电荷的视网膜与带正电荷的角膜之间的电位差变化来反映眼球运动。我们旨在研究在颅底手术中，通过电刺激动眼神经和外展神经能否诱发可靠的EOG波形。
我们回顾性分析了18例行颅底肿瘤手术并使用EOG的患者记录（11例开颅手术和7例鼻内镜手术）。使用同心双极探针，以5Hz的频率进行刺激，刺激持续时间为200μs，强度为0.1 - 5mA。记录电极置于上睑（活性电极）和下睑（参考电极）以及双眼外眦；活性电极置于对侧。
所有病例均观察到可重复触发的EOG波形。在水平记录中，电刺激Ⅲ和Ⅵ脑神经分别引出正向波形和负向波形。开颅手术和鼻内镜手术的中位潜伏期分别为3.1ms和0.5ms（p = 0.007）。此外，开颅手术和鼻内镜手术的中位波幅分别为33.7μV和46.4μV（p = 0.40）。
本研究表明在颅底手术中刺激Ⅲ和Ⅵ脑神经可可靠地触发EOG波形。潜伏期因刺激部位而异，因此具有可预测性。由于EOG是非侵入性的且操作相对简单，它可作为术中识别眼运动神经的一种替代肌电图的方法。
