Abstract
The posterior fossa is not a common site for arteriovenous (AV) malformations. Only six of 92 AV malformations seen by Kempe were located below the tentorium. Of these, four were located laterally in the cerebellar hemisphere and cerebellopontine angle and two were situated in the vermis. Only one half of the patients presented with a history of hemorrhage (subarachnoid or parenchymal). Three of the patients with laterally located lesions presented with signs and symptoms suggestive of a mass lesion, ie, intermittent headaches, pain in the distribution of the trigeminal nerve, nystagmus, diminished hearing, and truncal ataxia. Two of these patients complained of tinnitus when lying on the side of the lesion. In only one of six cases was a bruit audible to the examiner.