[A case of brain stem infarction with bilateral hearing loss]

The study case was a 66-year-old man who had bilateral neurosensory hearing impairment due to brain stem infarctions. He noticed mild hearing loss, frequent vertigo and tinnitus. About one month later, his hearing took a sudden turn for the worse, and he suffered from dysarthria, dysphagea and abasia. Neurological examination revealed pseudobulber palsy, left hemiparesis, cerebeller ataxia, disturbance of pain and temperature sensation on the right face and left side of the body. Brain stem auditory evoked potentials (BAEPs) showed a delayed small wave V with the abscence of previous waves on the right side and no significant waves on the left side. Brain magnetic resonance images (MRI) revealed infarctions in the bilateral middle cerebellar peduncles, including in the right lateral portions of pons, and the right lower pontine base. We believe that not only peripheral, but also central auditory pathways adjacent to infarctions were damaged. Magnetic resonance angiography (MRA) showed severe stenosis or occlusion of left vertebral artery and basilar artery. We concluded that hypoperfusion of the vertebrobasilar artery territories caused ischemia of the cochlear nerve and the auditory tracts in the brain stem, which resulted in bilateral hearing loss.