Bilateral vestibular loss in vertebrobasilar dolichoectasia.

Bilateral vestibular loss (BVL) is a relatively uncommon syndrome that may produce problems of balance; unsteady gait, especially in the dark; and visual disorders and/or oscillopsia associated with walking and head movements. Sometimes patients with BVL remain asymptomatic. Ototoxic drugs are the most frequently identified cause of BVL, but there are many other possible causes. The aetiology remains unknown in a large percentage of patients. In some, vascular aetiology may be suspected. Here we report 4 cases of vertebrobasilar dolichoectasia (VBD) and symptomatic BVL. In 3 subjects, hearing was preserved, but in the 4th, there was retrolabyrinthine hearing loss. In our opinion, VBD may be the cause of BVL associated or not associated with hearing loss, the reason being that since the anterior vestibular artery is small and has no anastomoses, the horizontal semicircular canal is selectively susceptible to ischemia.