Rossini P M, Gigli G L, Marciani M G, Zarola F, Caramia M
Electroencephalogr Clin Neurophysiol. 1987 Mar;68(2):88-100. doi: 10.1016/0168-5597(87)90036-0.
The topography of scalp SEPs to mixed and sensory median nerve (MN) and to musculocutaneous nerve stimulation was examined in 20 healthy subjects through multichannel (12-36) recording in a 50 msec post-stimulus epoch. MN-SEPs in both frontal leads were characterized by an N18, P20, N24, P28 complex showing maximal amplitude at contralateral parasagittal sites. This was sometimes partly obscured by a wide wave N30 having a fixed latency, but a steep amplitude gradient moving toward the scalp vertex. A P40 component followed, having longer peak latencies, moving the recording sites from contralateral medial parietal toward the vertex and frontal ipsilateral positions. MN-SEPs in contralateral parietal leads contained a widespread N20 with a maximum source posterior to the Cz-ear line. The following P25 enveloped two subcomponents - early and late P25 - having different distributions. The late P25 showed a maximum - coincident with that of wave N20 - which was localized more posteriorly than that of the early P25. An inconstant wave N33 with progressively longer peak latencies from sagittal toward lateral positions was then recorded. MN-SEPs in contralateral central positions showed a well-localized P22 wave in which both the parietal early P25 and the frontal P20 were vanishing. Common or separate generators for frontal, central and parietal SEPs were discriminated by evaluating the influence of stimulus rate and intensity, as well as of general anesthesia and transient CBF deficits, investigated in 7 patients undergoing carotid endarterectomy. Unifocal anodal threshold shocks were separately delivered to each of the scalp electrodes and motor action potentials were recorded from the target muscle in order to delineate the scalp representation of the motor strip for the upper limb and, consequently, to monitor, through SEP tracings, the short-latency sensory input to the motor cortex for hand and shoulder muscles. This was characterized by a boundary zone separating the parietal N20-early P25 complex, from the fronto-central N18-P22 one. This zone had an oblique direction strongly resembling that of the central sulcus.
通过在刺激后50毫秒时段进行多通道（12 - 36通道）记录，对20名健康受试者头皮体感诱发电位（SEP）对混合神经和感觉正中神经（MN）以及对肌皮神经刺激的地形图进行了检查。两个额部导联中的MN - SEP均以N18、P20、N24、P28复合波为特征，在对侧矢状旁位点显示最大振幅。这有时会部分被一个潜伏期固定的宽波N30掩盖，但该波向头皮顶点移动时振幅梯度很陡。随后是一个P40成分，其峰值潜伏期更长，记录位点从对侧顶叶内侧向顶点和同侧额叶位置移动。对侧顶叶导联中的MN - SEP包含一个广泛分布的N20，其最大源位于Cz - 耳线后方。随后的P25包含两个子成分——早期P25和晚期P25——具有不同的分布。晚期P25显示出一个最大值——与波N20的最大值重合——其定位比早期P25更靠后。然后记录到一个从矢状位向外侧位峰值潜伏期逐渐延长的不恒定波N33。对侧中央位置的MN - SEP显示出一个定位良好的P22波，其中顶叶早期P25和额叶P20均消失。通过评估刺激频率和强度以及全身麻醉和短暂性脑血流量不足的影响，对7例接受颈动脉内膜切除术的患者进行研究，区分了额部、中央和顶叶SEP的共同或独立发生器。将单焦点阳极阈值电击分别施加到每个头皮电极，并从目标肌肉记录运动动作电位，以描绘上肢运动皮层的头皮代表区，从而通过SEP描记图监测手部和肩部肌肉向运动皮层的短潜伏期感觉输入。其特征是一个边界区域，将顶叶N20 - 早期P25复合波与额中央N18 - P22复合波分开。该区域具有一个强烈类似于中央沟方向的倾斜方向。
