内耳圧の實驗的研究—内耳圧変化の蝸牛電気反応に及ぼす影響に就て

　緒言

　内耳圧と聽力との関係に就て，内耳静水圧のOptimumよりの偏移は常に聽能の悪化を伴うというKerekes^1）の臨床実験に基づく結論は従来の内耳圧生理に於けるテーゼとされていたが，その実験的研究の成果は必ずしも之を肯定するものではない．又先に私^2）は脳脊髄液圧と共に内耳圧の変動を主として藥物学的に観察し，内耳圧に量的の変動を与えるものは脳脊髄液圧であるとの結論を述べた．即ち脳脊髄液圧の変化と共に内耳圧に著明な変化の現われるのを見たのであるが，斯る内耳圧の変動が実際聽力に影響を与えるものであるか否かに就ては，文献的考察を基礎として単なる私見を仮定するのみであつた．私は今回蝸牛電気反応を用い，内耳圧変化のこれに及ぼす影響に就て研究し，略一定の成績を得たと信んずるので此所に発表し，以て内耳圧と聽力との関係に就て一考察を与えてみたいと思う．

By changing the pressure of the perilymphatic space at the basal whorl of the cochlea. Sakamoto has in-vestigated its effects on the electric cochlear reaction and obtained the following results.

1) With those cases in which pressure is applied. (+10mmHg, +20mmHg) as well as with those of negative pressure

(-30mmHg,-40mmHg), excepting two high tones (increase of voltage-gain), a decrease in voltage-gain has been perceived in all cycles of 2-A Audicmeter.

2) It has been ascertained that the lowered voltage has returned to the original value as soon as the pressure has become normal, or in a short time afterwards, but not wholly been retovered even afrer the Presswre has been rendered no-rmal, if it has been changed repeatedly or if a strong pressure been applied for a long time.

3) Considering the fact that the electric cochlear reaction has undergone no change in the experi-ment in which the pressure of the inner ear is slightly altered from the intra cranial space, it can be assumed that though the inner ear pre-ssure undergoes changes there is a certain ran-ge within which it does not affect the hearing acuity.