Deafness associated with vertebrobasilar insufficiency.

The incidence of auditory disturbances in vertebrobasilar insufficiency (VBI) is considered much rarer than vestibular disturbances, but no routine audiometric test results for VBI patients have been published. To determine the incidence of deafness associated with VBI and the sites predominantly involved in deafness, we studied 70 vertiginous patients with VBI using a routine audiological examination and magnetic resonance imaging (MRI). MRI detected a lacunar infarct involving the cochlear nuclei in one patient, but lacunae did not involve central auditory structures in the other patients. Twenty-five patients experienced tinnitus, deafness, or both, during vertigo episodes. Audiological examinations confirmed the development of unilateral deafness in 15 (21%) patients, involving the cochlea in 14 and cochlear nuclei in one. These findings indicate that hearing loss occurs in approximately one-fifth of VBI patients, much less frequently than vestibular disturbances, and that deafness associated with VBI mainly involves the cochlea.