[A case of brain stem infarction with bilateral hearing impairment and tinnitus at the onset].

We reported a 49-year-old male with brain stem infarction who had bilateral hearing impairment and tinnitus at the onset and subsequently developed various neurological symptoms, including bilateral lateral inferior pontine syndrome, one and a half syndrome and upward gaze palsy. Although CT scan failed to reveal any abnormalities initially, MRI revealed symmetrical foci bilaterally from the lateral inferior pons to the middle cerebellar peduncle, as well as in the paramedian portion of the mid-pons. Cerebral angiography: The left vertebral artery (VA) occluded at the 4th segment. The right VA showed severe stenosis at the 4th segment. The basilar artery (BA) was found to be occluded in the lower 1/3 below the clivus. Furthermore, CAG demonstrated upper portion of the BA, bilateral superior cerebellar artery and posterior cerebral artery via the posterior communicating artery, but the bilateral anterior inferior cerebellar arteries (AICAs) were absent or occluded. Neuroradiological findings suggested ischemia in the bilateral AICA and the middle portion of the BA. Bilateral hearing impairment rarely accompanies cerebrovascular disorders. This case of bilateral hearing impairment, tinnitus at the onset, followed by bilateral lateral inferior pontine syndrome was considered to be an extremely rare pathological condition.