Hearing outcome of recurrent sudden deafness: ipsilateral versus contralateral types

Patients with recurrent sudden deafness demonstrating normal vestibular-evoked myogenic potentials (VEMPs) in the lesion ear of the second episode may indicate a good hearing outcome.

This study retrospectively reviewed our experience of patients with recurrent sudden deafness during the past 20 years.

Sixteen (1.4 %) of 1156 patients with sudden deafness were diagnosed as having a recurrent episode, including ipsilateral type in 7 and contralateral type in 9. All patients underwent an audiovestibular test battery and blood and MRI examinations. After 2000, nine patients underwent the VEMP test.

In the ipsilateral type, the mean interval between two episodes was 2 ± 2 years, which did not differ significantly from 3 ± 3 years in the contralateral type. There were no significant differences in relation to age at onset of the second episode, inter-episode interval, gender, presence of vertigo, and abnormal caloric results. However, abnormal rate of VEMP test in the contralateral type (five of five patients) was significantly higher than that in the ipsilateral type (none of four patients). At the second episode, all four patients with normal VEMPs on the lesion ear had improved hearing, while four of five patients with absent or delayed VEMPs showed unchanged hearing. Altogether, the hearing improvement rate in both types of recurrent sudden deafness was 50%.