돌발성난청에서 회복 예측인자로서 후반고리관 기능의 의의

Abstract

Objectives: Postulated etiologies for idiopathic sudden sensorineural hearing loss (SSNHL) include viral cochleitis, microvascular events. If SSNHL is caused by vascular compromise of common cochlear artery that supplies cochlea and post-erior semicircular canal (PC), PC also can be damaged with cochlea. We aim to evaluate the prognostic value of PC function in relation to hearing recovery of SSNHL. Methods: Seventy-six patients who were diagnosed and treated for SSNHL and who underwent video head impulse test (vHIT) and follow-ups for more than 3 months were reviewed retrospectively. We defined impairment of PC function as lower PC gain (＜0.7) or definite overt/covert saccade in vHIT. Patients were divided into 3 groups: group 1, SSNHL without dizziness; group 2, SSNHL with dizziness and impaired PC function; group 3, SSNHL with dizziness, but intact PC function. Hearing thresholds were repeatedly measured on the initial visit, 1 week, 1 month, and 3 months after treatment. Treatment outcome was analyzed by comparing hearing recovery rate using Siegel’s criteria and posttreatment audiometric changes among 3 groups. Results: Thirty-two (29.6%), 33 (30.6%), and 43 patients (39.8%) were included into the groups 1, 2, and 3, respectively. The hearing recovery rate of the group 2 (39.4%) was significantly lower than that of groups 1 (65.6%) and 3 (65.1%) (p=0.043). Pre- and posttreatment changes of the PTA threshold was significantly lower in group 2 than group 1 (p=0.009). The change of speech discrimination in each group were not different. Conclusions: Our findings suggest that the presence of PC impairment may be a poor prognostic sign for hearing recovery in patients with SSNHL.