Sudden sensorineural hearing loss with positional vertigo: Initial findings of positional nystagmus and hearing outcomes.

Objectives: To investigate the initial findings of positional nystagmus in patients with sudden sensorineural hearing loss (SSNHL) and positional vertigo, and to compare hearing improvement among patients with different types of positional nystagmus.

Design: The characteristics of positional nystagmus upon initial examination were analysed, and the initial mean pure-tone audiometry (PTA) threshold was compared with that at three months after treatment.

Study Sample: Forty-four SSNHL patients with concomitant positional vertigo were included.

Results: Positional nystagmus was classified into five subgroups; persistent geotropic direction-changing positional nystagmus (DCPN) in head-roll test (HRT) and negative Dix-Hallpike test (DHT), persistent apogeotropic DCPN in HRT and negative DHT, positive DHT and negative HRT, persistent geotropic DCPN in HRT and positive DHT, and persistent apogeotropic DCPN in HRT and positive DHT. PTA threshold improvement was significantly greater in SSNHL patients with negative DHT than with positive DHT (p = 0.027).

Conclusions: When geotropic DCPN was elicited by HRT, the nystagmus was persistent, which suggests that alteration of specific gravity of the endolymph, rather than the lateral canal canalolithiasis, may be a cause of this characteristic positional nystagmus. Positive DTH may be a prognostic factor for worse hearing recovery among patients with SSNHL and positional vertigo.