メニエール病の発作期眼振

Abstract

The spontaneous positional nystagmus during vertiginous attacks of Ménière's disease was observed in 15 patients using the Frenzel glasses. The direction-fixed positional nystagmus toward the affected side was observed in 13 patients, and toward the non-affected side in two. In nine of the fifteen, the course of the positional nystagmus was observed. In seven patients, the positional nystagmus frequently change both the direction of the quick phase and the plane of eye-ball rotation. There were great individual variations. At about 20 hours after the onset of the vertiginous attack, there was little vertigo but a weak nystagmus was still found beating to the non-affected side in most patients. In a specific indivisual, changing of the nystagmus was similar in each attack. In the same patient, pure-tone audiometry was performed during the acute stage in addition to the observation of the positional nystagmus. The results of the pure-tone audiometry showed that the pure-tone threshold was elevated only at low-frequency ranges before the onset and it elevated at both low and high frequencies just after the vertiginous onset. Two hours following the onset, pure-tone thresholds at lower frequencies recovered. Taking all the results in the present study together, it can be speculated that during the acute vertigo in Ménière's disease, the pathology may change on an hourly basis. This would affect a part or more of the labyrinth and result in hyper- and hypo-functions of each different endorgan, which would manifest themselves in changes in spontaneous positional nystagmus. From the results of one patient, it was also speculated that the cochlear-saccular hydrops appeared before the onset, and that the disease was recovered initially in part of the cochlea, and then in the vestibular organs.