Ruptured intrameatal anterior inferior cerebellar artery aneurysm associated with obstructed internal auditory artery in a patient with sudden hearing loss and vertigo.

BACKGROUND: Intrameatal aneurysms arising from the meatal loop of the anterior inferior cerebellar artery (AICA) are extremely rare. CASE PRESENTATION: We report a 60-year-old man presenting with severe vertigo and sudden left hearing loss associated with subarachnoid hemorrhage caused by rupture of a saccular aneurysm arising from the meatal loop of the AICA, which was entirely buried in the meatus. Intraoperatively, we identified the occluded internal auditory artery arising from the meatal loop of the AICA, where the aneurysm originated, and performed neck clipping. CONCLUSION: These findings suggest that internal auditory artery occlusion is a potential cause of loss of auditory and vestibular functions.