Sudden bilateral simultaneous deafness with vertigo as a sole manifestation of vertebrobasilar insufficiency.

A 68 year old woman presented with bilateral sudden simultaneous hearing loss and transient spontaneous vertigo as a sole manifestation of vertebrobasilar insufficiency. Extensive investigation to exclude other causes was unremarkable. Magnetic resonance imaging of the brain, including diffusion images, showed no abnormalities. A magnetic resonance angiogram showed severe stenosis of the middle third of the basilar artery. A pure tone audiogram showed moderate sensorineural-type hearing loss bilaterally. The localisation and mechanism of an isolated cochleovestibular dysfunction are discussed.