第一側頭回後部における聴覚反応

AUDITORY RESPONSE AT THE POSTERIOR PART OF THE FIRST TEMPORAL CONVOLUTION

I．はじめに

　第一側頭回後部に存在する聴覚領付近の電気刺激による聴覚反応についてはPenfieldら^3）の記載があるが，多数例での知験を正確に集積する事は各例での共通座標がないために不可能であつた。celesia^1）は側頭葉先端からの距離によつて刺激反応点を分析したがこの方法も充分とは言えない，我々は定位的深部脳波記録をてんかん患者に行なう際，深部電極による双極電気刺激反応および音刺激による誘発電位陽性点を予め定めた前交連後交連線（AC-PC線）および後交連の前端におけるAC-PC線に対すろ垂線（V-PC線）を座標軸として分析し興味ある知見を得たので報告したい。

Among the epileptic patients investigated by the stereotactic E. E. G. (Talairach) whose electrodes were introduced at or around the auditory cortex (Area 41, 42), the topography of the auditory re-sponses by the electrical bipolar stimulation and that of the auditory evoked potential by the bilateral click sound stimulation were studied in relation to the ac-pc line (Talairach).

The positive points of auditory responses and those of evoked potential were found in the posterior part of the first temporal convolution at or around the Hesch's transverse gyrus. The contralateral auditory responses to the stimulating electrodes situated more anterior and superior than the homolateral responses in lateral projection and more medial in frontal projection. The points of the sensation of "elevation" or "fall"elicited by the electrical stimulation which were thought to be related to the vestibular function were scattered more superior and posterior than the points of the auditory responses in lateral pro-jection and more medial in frontal projection. This study gave the accurate topography concerning the auditory responses, the positive auditory evoked potentials and the vestibular function related sen-sation (sensation of "elevation " or " fall ").

Further study will be required to elucidate the functional anatomy of the human auditory cortex.