Vertebral basilar insufficiency with anterior inferior cerebellar artery syndrome.

Two patients complaining of hearing loss with vertigo were examined radiologically and neurotologically. Electronystagmography and positional nystagmus testing showed central disturbances. Vertebral angiography (VAG) showed narrowings in the vertebral artery (VA) concomitant with defects in the anterior inferior cerebellar artery (AICA) diagonally opposite to the respective impaired VA branch. We demonstrate in this study that the AICA syndrome resulted from vertebral basilar insufficiency (VBI).Today, due to improvements in CT, MRI and angiography, the AICA syndrome is much better understood. Since VBI will futher complicate AICA syndromes and other secondary disturbances, we conclude that VAG should be performed with care certain cases of vertigo thought to be caused by VBI.