[Posterior fossa angiomata with slow evolution: clinical aspects (author's transl)]

The AA. report 9 cases of arteriovenous angiomata in the posterior cranial fossa with chronic evolution: in 8 of these the diagnosis was made before a subarachnoid haemorrhagic episode precipitated the symptomatology. Angiomata in the posterior cranial fossa are detected less often than sopratentorial angiomata, and the possible reasons of this are considered. During the last 11 years in the Neurosurgical Institute of the University of Padua the incidence was 23%, one of the highest reported in literature. The clinical diagnostic criteria of angioma in the posterior cranial fossa with chronic evolution are also discussed. The importance of a fluctuating development of the symptomatology is emphasised with an almost constant association of signs of pyramidal and cerebellar involvement, as well as the differential diagnostic problems with multiple sclerosis. In six of the cases the malformation was so extensive to make it impossible to determine afferences and drainages, so that a surgical operation could not be carried out. This finding seemed rather peculiar, owing to the relatively poor simptomatology, mainly if compared with smaller supratentorial malformations. It appears from the literature that angiomata in the posterior cranial fossa including those found at autopsy are as common as the supratentorial ones; this would suggest that many of these lesions are not diagnosed in life.