Stereotactic recordings of median nerve somatosensory-evoked potentials in the human pre-supplementary motor area
Stereotactic recordings of median nerve somatosensory-evoked potentials in the human pre-supplementary motor area
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DOI：
10.1046/j.0953-816x.2000.01393.x
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发表时间：
2001-01-01
影响因子：
3.4
通讯作者：
Mauguière, F
中科院分区：
文献类型：
--
作者：
Barba, C;Frot, M;Mauguière, F
采用立体定向植入8例癫痫患者额叶的皮层内电极记录了正中神经体感诱发电位（SEP），以评估辅助运动区（SMA）前部亚区（即所谓的前SMA）产生的体感反应的波形、潜伏期和表面-深度分布。皮质内反应在两个潜伏期范围内进行分析：刺激后0-50 ms和50-150 ms。在所有患者中，我们在刺激后的前50 ms记录了两个正P14和P20电位，然后是N30负性。在刺激对侧的大脑半球，P20-N30电位表现出明显的幅度从额叶的外部到内部的方面与最小的幅度在前SMA。在刺激同侧大脑半球，P20和N30波幅从内侧额叶皮层到外侧额叶皮层逐渐降低。在50-150 ms的潜伏期范围内，植入SMA前的触点在60-70 ms的潜伏期范围内记录了负电位，在5名患者中，随后在刺激后80-110 ms出现正响应峰值。这些潜能是不能被更肤浅的接触所发现的。我们的结论是，没有早期SEP产生的前SMA在第一个50毫秒刺激后，而一些电位峰值在60-100毫秒刺激后很可能起源于这一皮质区。在我们的患者中记录的前SMA反应的潜伏期支持这一假设，即前SMA不通过直接丘脑皮质投射接收短潜伏期体感输入。更可能的是，前SMA通过功能性次级运动和躯体感觉区接受由多突触经皮质传递介导的躯体感觉输入。
Median nerve somatosensory-evoked potentials (SEPs) have been recorded using intracortical electrodes stereotactically implanted in the frontal lobe of eight epileptic patients in order to assess the waveforms, latencies and surface-to-depth distributions of somatosensory responses generated in the anterior subdivision of supplementary motor areas (SMAs), the so-called pre-SMA. Intracortical responses were analysed in two latency ranges: 0-50 ms and 50-150 ms after stimulus. In all patients, we recorded in the first 50 ms after stimulus two positive P14 and P20 potentials followed by a N30 negativity. In the hemisphere contralateral to stimulation, the P20-N30 potentials showed a clear amplitude decrease from the outer to the inner aspect of the frontal lobe with minimal amplitudes in the pre-SMA. In the hemisphere ipsilateral to stimulus, P20 and N30 amplitudes were decreasing from mesial to lateral frontal cortex. In the 50-150 ms latency range, contacts implanted in the pre-SMA recorded a negative potential in the 60-70 ms latency range which, in five patients, was followed by a positive response peaking 80-110 ms after stimulus. These potentials were not picked up by more superficial contacts. We conclude that no early SEP is generated in pre-SMA in the first 50 ms after stimulation, while some potentials peaking in the 60-100 ms after stimulus are likely to originate from this cortical area. The latency of the pre-SMA responses recorded in our patients supports the hypothesis that the pre-SMA does not receive short-latency somatosensory inputs via direct thalamocortical projections. More probably the pre-SMA receives somatosensory inputs mediated by a polysynaptic transcortical transmission through functionally secondary motor and somatosensory areas.