LAUSR

上半規管裂隙症候群(Superior canal dehiscence syndrome:SCDS)は1998年にMinorらに より初めて報告された。上半規管を覆う頭蓋骨が 欠損するために圧変化(咳,くしゃみ,怒責)や 強大音により誘発されるめまい,自声強調,耳閉 感,耳鳴などの臨床症状を呈する病態である。保 存的治療のみで経過観察するケースが多いが,症 状の改善がみられず,日常生活に支障がある場合 The superior semicircular canal dehiscence syndrome (SCDS), which presents with comprehensive symptoms such as hyperacusis, autophony, and pressure-induced vertigo, has been recently recognized in Japan. Three patients with SCDS, in whom severe vestibular symptoms were unable to be controlled with conservative treatments, underwent capping surgery through the middle fossa approach. The preoperatively air-bone gap (AB gap) in the audiometry, the decreased threshold of cervical vestibular evoked myogenic potentials (cVEMP) and bone dehiscence of the superior semicircular canal could be observed in all patients on CT imaging. All patients suffered from positional vertigo for about one week after the operation. However, their cochlear and vestibular symptoms associated with the SCDS were relieved within a few months after the operation. The capping procedure decreased the AB gaps and increased the thresholds of cVEMP in all patients. We suggest that capping surgery via the middle fossa approach for the SCDS is an efficient procedure without severe side effects. 原 著