急性音響外傷に伴う反復性聴平衡障害の一例

抄録

We present here a 25-year-old flier who developed recurrent acoustico-equilibrium disorders following recovery from acute acoustic trauma of the left ear suffered during a military air force exercise. Several recent reports have described vertigo associated with acoustic trauma as probably due to endolymphatic hydrops (ELH) caused by trauma. However, detailed studies of these reports fail to reveal definite evidence of ELH, and the incidence of ELH among patients whose vertigo was related to acoustic trauma seemed to be lower than the incidence reported in the literature.
The clinical data of the patient presented here, inciuding ECochG and glycerol test are compatible with bilateral ELH, although his symptoms were in the left ear only. Since military personnel inevitably experience not only noise trauma but also various physiological and psychological stresses, factors such as genetic traits may play a role in the development of ELH. Therefore, we believe that ELH had been present before the onset of his inner ear symptoms and that the acoustic trauma might have changed the inner ear condition from nonsymptomatic to symptomatic ELH.
Two patients with histological evidence of temporal bone pathology, as well as the results of basic studies reported previously, support our concept regarding acute acoustic trauma and recurrent acoustico-equilibrium disorders.