Registering grades of sudden deafness to predict the hearing outcome via an inner-ear test battery

Abstract

Objectives: An inner ear test battery comprising audiometry and ocular vestibular-evoked myogenic potential (oVEMP), cervical VEMP (cVEMP), and caloric tests was applied to patients with sudden deafness to map their lesions and predict hearing outcome. Design: Retrospective study. Study sample: Seventy-five patients with unilateral sudden deafness underwent an inner-ear test battery. Registering the grades of sudden deafness was based on the number of abnormal test results in the inner ear test battery. Results: After treatment for three consecutive months, mean hearing gain declined significantly from Grade I (one abnormal test) to Grade IV (four abnormal tests). Significant relations existed between hearing outcome and oVEMP test results (p < 0.05), caloric test results (p < 0.05), but not cVEMP test results and pre-treatment mean hearing level. Combined caloric and oVEMP test results demonstrated a stronger predictor with a c statistic of 0.722 than either test alone, indicating that this regression model fits the whole set of observations well and is effective in predicting the hearing outcome. Conclusion: Abnormal caloric and oVEMP test results in sudden deafness patients may indicate poor prognosis for hearing improvement, whereas hearing recovery can be anticipated when both tests reveal normal responses.