患側骨導閾値の上昇を伴う後半規管型BPPV症例の検討

Benign paroxysmal positional vertigo with higher frequency hearing threshold elevation

はじめに

　後半規管型benign paroxysmal positional vertigo（BPPV）は特発性で通常は聴力が正常もしくは左右差を見出せない場合が多い。しかし，一部にはメニエール病や一側性感音難聴を伴った症例に遭遇することがある。今回われわれは，めまいを主訴に来院し，後半規管型BPPVと診断した症例のなかで，すでに患側の難聴もしくは健側に比較して患側の骨導閾値の上昇を伴っていた症例を検討したので，若干の文献的考察を加えて報告する。

　Benign paroxysmal positional vertigo（BPPV）is a common vestibular disorder originating from the posterior semicircular canal（pSCC）. We retrospectively analyzed the clinical characteristics of 6 patients with BPPV who had higher frequency hearing threshold elevation in the affected side. They were all women with 55-76 years of age, accompanied with two chronic unilateral sensorineural hearing loss, two endolymphatic hydrops, one chronic otitis media, and one head injury. As canalith repositioning procedure was effective in 5 out of 6 cases, canalolithiasis in the pSCC was thought to be the cause of these vertigos. Occurrence of BPPV could be much influenced by the various inner ear disorders on the affected side showing higher hearing threshold elevation than unaffected side.