Timing and spatial distribution of somatosensory responses recorded in the upper bank of the Sylvian fissure (SII area) in humans
Timing and spatial distribution of somatosensory responses recorded in the upper bank of the Sylvian fissure (SII area) in humans
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DOI：
10.1093/cercor/9.8.854
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发表时间：
1999-12-01
期刊：
影响因子：
3.7
通讯作者：
Mauguière, F
中科院分区：
文献类型：
--
作者：
Frot, M;Mauguière, F
我们研究了额叶顶叶皮质对电刺激的反应，在对耐药的颞叶癫痫患者进行立体定向脑电术前评估时，皮层内电极记录了这一反应。电刺激腕部正中神经后，我们在刺激对侧的侧裂上岸持续记录到负-正双相反应，在刺激后60ms(N60)和90ms(P90)达到峰值。记录这些反应的电极触点的Talairach立体定向坐标覆盖了侧裂上岸的前后部(25；lt；x<；55 mm；-27；lt；y<；+13 mm；0；lt；z<；21 mm)，符合MAN中SII区的公认定位。这些反应的发源点位于距正中矢状面约40 mm处的侧裂上岸皮质内，部分位于岛叶皮质内。此外，这项研究表明，偶极SII源的存在辐射到头皮表面，这在磁记录中被忽略了。在SII中记录的体感诱发电位(SEP)与在初级体感皮质中产生的SEP相比，延迟了约40ms。SI和SII响应之间的这种长时间延迟没有得到完全的解释，尽管它与从MEG源模拟数据发出的激活时间一致。
We studied responses of the parieto-frontal opercular cortex to electric stimuli, as recorded by intra-cortical electrodes during stereotactic EEG presurgical assessment of patients with drug-resistant temporal lobe epilepsy. After electrical stimulation of the median nerve at the wrist, we consistently recorded a negative-positive biphasic response peaking at 60 ms (N60) and 90 ms (P90) post-stimulus in the upper bank of the sylvian fissure contralateral to stimulation. Talairach stereotactic coordinates of the electrode contacts recording these responses covered the pre- and post-rolandic part of the upper bank of the sylvian fissure (25 < x < 55 mm; -27 < y < +13 mm; 0 < z < 21 mm), corresponding to the accepted localization of SII area in man. The sources of these responses were deeply situated in the cortex of the upper bank of the sylvian fissure at similar to 40 mm from the midline sagittal plane, so that some of them could be located in the insular cortex. Moreover this study suggests the existence of dipolar SII sources radial to the scalp surface, which are overlooked in magnetic recordings. Somatosensory evoked potentials (SEPs) recorded in SII are delayed by similar to 40 ms as compared with SEPs generated in the primary somatosensory cortex. This long delay between SI and SII responses is not fully explained though it is coherent with the timing of activation issued from MEG source modeling data.