Simon Mirela V, Lee Daniel K, Choi Bryan D, Talati Pratik A, Yang Jimmy C, Koch Matthew J, Jones Pamela S, Curry William T
Department of Neurology, Massachusetts General Hospital, Boston, Massachusetts.
Department of Neurosurgery, Stanford University, Stanford, California.
Oper Neurosurg. 2021 Jan 13;20(2):219-225. doi: 10.1093/ons/opaa330.
Subcortical mapping of the corticospinal tract has been extensively used during craniotomies under general anesthesia to achieve maximal resection while avoiding postoperative motor deficits. To our knowledge, similar methods to map the thalamocortical tract (TCT) have not yet been developed.
To describe a neurophysiologic technique for TCT identification in 2 patients who underwent resection of frontoparietal lesions.
The central sulcus (CS) was identified using the somatosensory evoked potentials (SSEP) phase reversal technique. Furthermore, monitoring of the cortical postcentral N20 and precentral P22 potentials was performed during resection. Subcortical electrical stimulation in the resection cavity was done using the multipulse train (case #1) and Penfield (case #2) techniques.
Subcortical stimulation within the postcentral gyrus (case #1) and in depth of the CS (case #2), resulted in a sudden drop in amplitudes in N20 (case #1) and P22 (case #2), respectively. In both patients, the potentials promptly recovered once the stimulation was stopped. These results led to redirection of the surgical plane with avoidance of damage of thalamocortical input to the primary somatosensory (case #1) and motor regions (case #2). At the end of the resection, there were no significant changes in the median SSEP. Both patients had no new long-term postoperative sensory or motor deficit.
This method allows identification of TCT in craniotomies under general anesthesia. Such input is essential not only for preservation of sensory function but also for feedback modulation of motor activity.
在全身麻醉下的开颅手术中，皮质脊髓束的皮质下定位已被广泛应用，以实现最大程度的切除，同时避免术后运动功能缺损。据我们所知，尚未开发出类似的用于定位丘脑皮质束（TCT）的方法。
描述一种用于2例接受额顶叶病变切除术患者的TCT识别神经生理学技术。
使用体感诱发电位（SSEP）相位反转技术识别中央沟（CS）。此外，在切除过程中对中央后回的N20和中央前回的P22电位进行监测。使用多脉冲序列（病例1）和彭菲尔德（Penfield）技术（病例2）在切除腔内进行皮质下电刺激。
中央后回内（病例1）和CS深部（病例2）的皮质下刺激分别导致N20（病例1）和P22（病例2）的波幅突然下降。在两名患者中，一旦停止刺激，电位立即恢复。这些结果导致手术平面的重新调整，避免了对初级体感区（病例1）和运动区（病例2）的丘脑皮质输入的损伤。切除结束时，正中SSEP无明显变化。两名患者术后均无新的长期感觉或运动功能缺损。
该方法可在全身麻醉下的开颅手术中识别TCT。这种输入不仅对于保留感觉功能至关重要，而且对于运动活动的反馈调节也至关重要。
