Prognostic evaluation of electrocochleography in idiopathic sudden sensorineural hearing loss.

Abnormal action potential (AP) recovery from adaptation was manifested as increased recovery (iR) or decreased recovery (dR) relative to the normal recovery range. dR was not analyzed statistically due to the very small number of cases. iR is considered an unfavorable prognostic indicator, whereas a normal AP recovery (nR), enhanced SP/AP ratio (≥0.35), and lower AP threshold are favorable prognostic indicators for idiopathic sudden sensorineural hearing loss (iSSNHL). This study aimed to determine the prognostic efficacy of AP recovery examinations associated with other electrocochleography (ECochG) findings in iSSNHL. ECochG was performed transtympanically in 58 iSSNHL ears. AP recovery was measured by a paired-click stimulation paradigm, and hearing outcome was classified into three groups. Additionally, the relationships of other confounding prognostic factors to hearing outcomes were assessed. iR was significantly more common in the no-recovery group, while nR and an enhanced SP/AP ratio were significantly more common in the cure and improvement groups. The AP threshold was significantly lower in the cure group than in the other two groups. The other confounding prognostic factors generally showed similar trends to those reported previously.