硬膜上誘導の聴性誘発反応の観察

SOME OBSERVATIONS ON EXTRADURAL AUDITORY EVOKED POTENTIAL IN MAN

I．緒言

　近年，脳波学の進歩とともに大脳の機能的活動をより正確に把握する目的で皮質ないし深部脳波が多く活用されている。

　一方，1939年Davisら^1）2），の業績以来，脳波上に音響刺激により誘発反応の生ずることが知られているが，本聴性反応は大脳生理機構の解明に利用されると同時に耳科学領域においては他覚的聴検の指標とするこころみが発表されている。

In order to use the scalp auditory response for clinical audiometry, it is necessary to investigate more basic informations on the origin of the various components.

In five subjects extradural evoked responses were examined under various conditions. The amplitude of the extradural response was five to six times as large as the scalp response, the difference of which corres-ponded to 10~30 dB in auditory input.

In the present study any potentials faster than 40 msec could not be obtained so we could not concluded that they might be myogene, but the later compo-nents following 40 to 50 msec were considered to re-present secondary or non-specific evoked potentials.