Prognostic factors for vestibular impairment in sensorineural hearing loss

The clinical course and prognosis in sensorineural hearing loss (SNHL) may be even worse if vestibular system is also involved, especially due to near location of anatomical structures in the inner ear. The aim of the study was to determine prognostic value of some clinical, audiological and demographic factors associated with SNHL in predicting a possibility of vestibular impairment. The study was conducted on 124 consecutive patients (183 ears) diagnosed for sensorineural hearing loss during 1 year in our department. In all of them, audiological (pure-tone, speech and impedance audiometry, ABR) and ENG examinations (visual ocular-motor, positional, kinetic and caloric tests) were performed. The correlations between ENG outcome and the following variables associated with sensorineural hearing loss were investigated: audiological (degree and location of hearing loss, audiogram configuration), clinical (tinnitus, vertigo, dizziness) and demographic (age, sex) factors. Normal ENG was recorded in 26.6%, vestibular impairment of peripheral type in 38.7%, and central type in 34.7% of the patients. In a multivariate stepwise linear regression analysis, the degree of hearing loss was the main variable correlating with abnormal ENG result. Tinnitus and location of hearing loss were also found to be the two other variables which, to some minor extent, can influence the ENG outcome. Peripheral vestibular impairment was observed more frequently in patients with residual hearing/deafness. The degree of hearing loss, presence of tinnitus and location of hearing loss are factors predicting the possibility of abnormal ENG outcome in sensorineural hearing loss.