[Atypical termination of the vertebral artery and of the inferior posterior cerebellar artery (author's transl)].

A rare varient in the termination of the vertebral artery is described associated with a low origin of an unpaired inferior posterior cerebellar artery lying between C. 1 and C. 2. This is illustrated radiographically. An attempt is made to explain this radiologically and to classify it. Possible clinical significant of this anomaly, particularly in relation to subarachnoid haemorrhage, is discussed.