Department of Neurosurgery, Yamaguchi University School of Medicine, Ube, Japan.
Clin Neurophysiol. 2012 Jun;123(6):1248-54. doi: 10.1016/j.clinph.2011.09.025. Epub 2011 Nov 21.
Motor-evoked potentials (MEPs) are commonly recorded from upper-extremity muscles, whereas lower-extremity MEP (LE-MEP) monitoring has not been adequately established. The goal of the study was to develop a MEP monitoring method using direct cortical stimulation (DCS) for predicting motor deficits of lower extremities.
Intra-operative LE-MEP monitoring was performed in 22 patients. After craniotomy, a subdural electrode was placed on the cortex so that the optimal contact was positioned 2 cm lateral from the midline on the motor cortex. The electrodes for stimulation consisted of a cathode at Fpz and an anode at the optimal contact site on the motor cortex. After stimulation was performed with short trains of five stimuli, LE-MEPs were recorded from the lower-limb muscles.
LE-MEPs were consistently recorded in all patients. Disappearance or amplitude reduction of MEP waveforms was observed in five patients, but the MEP waveforms had recovered and remained at the control level by dural closure, and no permanent motor deficit was observed in any patient.
We accomplished LE-MEP recording during supratentorial surgery using monopolar DCS with a subdural electrode placed on the convex side of the motor cortex.
A useful method of intra-operative LE-MEP recording was described.
运动诱发电位（MEPs）通常记录于上肢肌肉，而下肢的 MEPs（LE-MEPs）监测尚未得到充分建立。本研究的目的是开发一种使用皮层直接刺激（DCS）的 MEPs 监测方法，以预测下肢运动缺陷。
对 22 例患者进行术中 LE-MEP 监测。开颅术后，在硬脑膜下放置一个硬膜下电极，使最佳接触点位于运动皮质中线外侧 2cm 处。刺激用的电极由 Fpz 上的阴极和运动皮质最佳接触点上的阳极组成。在进行五次短串刺激后，从下肢肌肉记录 LE-MEPs。
所有患者均能持续记录到 LE-MEPs。在 5 例患者中观察到 MEP 波形消失或振幅降低，但在关闭硬脑膜时 MEP 波形已恢复并保持在对照水平，任何患者均未出现永久性运动缺陷。
我们使用置于运动皮质凸面的硬膜下电极的单极 DCS 成功记录了幕上手术期间的 LE-MEPs。
描述了一种术中 LE-MEPs 记录的有用方法。
