Department of Neurology, Massachusetts General Hospital and Harvard Medical School, 55 Fruit Street, Boston, MA 02114, USA.
Department of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA; Department of Neurological Surgery, Columbia University, New York, NY, USA.
J Clin Neurosci. 2014 Jun;21(6):1011-7. doi: 10.1016/j.jocn.2013.12.015. Epub 2014 Jan 29.
Neurophysiologic mapping of the primary motor cortex (PMC) is commonly used in supratentorial surgery. Electrical cortical stimulation is guided by anatomic landmarks towards the precentral gyrus, with recording of the triggered primary motor responses (TPMR) in the contralateral hemibody. Thus, factors such as distortion of the pericentral anatomy, small surgical fields, brain shifts and miscalibrated neuronavigational systems may lengthen the process and result in unnecessary stimulations, increasing the probability of triggering seizures. We hypothesized that central sulcus localization via the median somatosensory evoked potentials phase reversal technique (MSSEP PRT) accurately guides the surgeon, resulting in prompt identification of the PMC with minimal electrical stimulation. Multivariate Cox regression was used to study the impact of MSSEP PRT on time spent performing electrical cortical stimulation to TPMR. The analysis was adjusted for presence of increased cortical excitability, high motor thresholds, lesions close to PMC and fMRI data, in 100 consecutive standardized motor mapping procedures for brain tumor resection and epilepsy surgery. Phase reversal and change morphology of the recorded somatosensory evoked potentials quadrupled (hazard ratio [HR] 4.13, p<0.0001) and doubled (HR 2.14, p=0.02) the rate of obtaining TPMR, respectively. A 1mA increase in motor threshold decreased the rate by 9% (HR 0.91, p=0.0002). Afterdischarges triggered before TPMR and lesions in close proximity to PMC decreased the rate of TPMR by 76% (HR 0.23, p<0.0001) and 48% (HR 0.52, p=0.04), respectively. Informative PRT decreases stimulation time. Afterdischarges triggered before TPMR, high motor thresholds and lesions close to the PMC increase it.
大脑初级运动皮层（PMC）的神经生理学定位在幕上手术中被广泛应用。通过解剖学标志引导皮质电刺激，朝向中央前回，记录对侧肢体的触发原发性运动反应（TPMR）。因此，诸如中央区解剖结构变形、手术野小、脑移位和神经元导航系统校准不当等因素可能会延长这一过程，并导致不必要的刺激，增加引发癫痫的可能性。我们假设，通过正中感觉诱发电位相位反转技术（MSSEP PRT）定位中央沟，可以准确指导外科医生，实现快速识别 PMC，并最大限度减少电刺激。使用多变量 Cox 回归分析研究 MSSEP PRT 对完成 TPMR 皮质电刺激所花费时间的影响。该分析调整了皮质兴奋性增加、高运动阈值、靠近 PMC 的病变和 fMRI 数据的影响，对 100 例连续标准化运动映射程序进行了研究，这些程序用于脑肿瘤切除和癫痫手术。记录的体感诱发电位的相位反转和形态变化分别使 TPMR 获得率提高了 4 倍（危险比[HR]4.13，p<0.0001）和 2 倍（HR 2.14，p=0.02）。运动阈值增加 1mA，使 TPMR 获得率降低 9%（HR 0.91，p=0.0002）。在 TPMR 之前触发的迟发性放电和靠近 PMC 的病变使 TPMR 获得率分别降低了 76%（HR 0.23，p<0.0001）和 48%（HR 0.52，p=0.04）。信息性 PRT 可减少刺激时间。在 TPMR 之前触发的迟发性放电、高运动阈值和靠近 PMC 的病变会增加刺激时间。
