AUDITORY AND VESTIBULAR SYSTEM FINDINGS IN PATIENTS WITH VERTEBROBASILAR DOLICHOECTASIA

Impairment of the auditory-vestibular system has been reported in pati ents with vertebrobasilar dolichoectasia (VBD), but little is known ab out the underlying cause of the symptoms. Auditory testing (pure tone audiometry, auditory brain stem response and stapedius reflex) and ves tibular tests (assessment of nystagmus, eye tracking tests, caloric te st and rotational test) were performed in 23 patients with auditory-ve stibular symptoms and/or cranial nerve impairment associated with VBD. Specific evidence of auditory and/or vestibular system impairment was observed in 19 cases (83%). Among patients with abnormal test finding s, 47% had evidence suggesting peripheral impairment, 16%, evidence su ggesting central dysfunction, and 37% evidence suggesting both periphe ral and central dysfunction. Although compression of the vestibulococh lear nerve plays an important role in the genesis of the auditory-vest ibular dysfunction in patients with VBD, mechanism such as brain stem- cerebellar ischemia and impaired blood supply to the vestibular labyri nth may be just as important.