Horner K C, Erre J P, Cazals Y
Inserm Unité 229, Université Bordeaux II, Hôpital Pellegrin, France.
Acta Otolaryngol Suppl. 1989;468:65-9. doi: 10.3109/00016488909139023.
We have previously shown by chronic implantation of round window electrodes, that after the experimental induction of endolymphatic hydrops by surgical blockade of the endolymphatic canal, in the guinea pig, there is a low/mid-frequency fluctuant hearing loss, followed by a very high frequency loss and after a few months the audiogram is flat. This evolution reproduces exactly that observed in Meniere's patients. The aim of this study was to investigate the evolution of one aspect of vestibular function in parallel with audiogram changes. The nystagmic responses in the dark were tested every month during the 4 months which followed hydrops induction. There was considerable variation in the number of evoked saccades for different control animals and even between different recordings for the same control animal. However, in general, the number of saccades to right and left rotation was symmetrical for control animals, whereas for hydropic animals there was a period, within the first 2 months post-operation, when there was a reduction of saccades to the left (operated side) with sometimes an increase to the right. This asymmetry which occurred in the period of fluctuant hearing losses did not however appear synchronized with audiogram fluctuations. The nystagmic responses tended to become symmetrical over the 4 months post-operation. Oral administration of glycerol to animals whose nystagmus was asymmetric brought the vestibular response towards symmetry in 50% of the cases. Although episodes of vertigo, as known in Meniere's disease, were never observed in operated guinea pigs, these data indicate that they have some functional vestibular disturbance.
我们之前通过圆窗电极的慢性植入表明，在豚鼠中，通过手术阻断内淋巴管实验性诱导内淋巴积水后，会出现低频/中频波动性听力损失，随后是极高频听力损失，几个月后听力图变为平坦。这种演变与梅尼埃病患者中观察到的情况完全一致。本研究的目的是调查前庭功能的一个方面与听力图变化并行的演变情况。在诱导积水后的4个月内，每月测试一次黑暗中的眼震反应。不同对照动物诱发扫视的数量存在相当大的差异，甚至同一对照动物的不同记录之间也有差异。然而，一般来说，对照动物左右旋转时的扫视数量是对称的，而对于积水动物，在术后的前2个月内，存在向左（手术侧）的扫视减少，有时向右增加的时期。然而，在波动性听力损失期间出现的这种不对称与听力图波动并不同步。术后4个月内，眼震反应趋于对称。对眼震不对称的动物口服甘油，50%的情况下前庭反应恢复对称。虽然在手术的豚鼠中从未观察到梅尼埃病中已知的眩晕发作，但这些数据表明它们存在一些功能性前庭障碍。
