両側前庭神経炎が疑われた特発性両側性前庭機能低下症の一例

抄録

　Generally, the prognosis of vestibular neuronitis is considered favorable due to vestibular compensation. In cases where semicircular canal function is not restored, however, a floating sensation during body motion can persist for a long period. Cases of bilateral vestibular loss are especially intractable. The onset and course of bilateral vestibular neuronitis is similar to that of sequential type idiopathic bilateral vestibular hypofunction with multiple episodes of vertigo. In this study, we experienced a case of suspected bilateral vestibular neuronitis, with onset first in the left ear and then in the right. The patient was a 55-year-old man who visited our hospital with a chief complaint of a floating sensation persisting for more than 2 months after experiencing rotational vertigo. The patient showed direction-fixed right-beating horizontal nystagmus in all head positions without cochlear symptoms. According to the caloric test, a higher rate of decline in the vestibular function of the left ear was observed. Based on these findings, the patient was diagnosed as having left vestibular neuronitis. Although vestibular function in the left ear improved after vestibular rehabilitation, vestibular hypofunction appeared in the right ear approximately 4 years later, and we thought that bilateral vestibular neuronitis had developed in our patient. Oscillopsia was observed in the early stage, but disappeared after rehabilitation at the hospital. According to posturography findings, improvement was observed. Vestibular rehabilitation is considered important in order to recover vestibular function and promote compensation of the core function of the impaired vestibule.