[Anatomic characteristics and clinical signs of congenital anomalies in the circle of Willis].

Anatomical characteristics and clinical importance of congenital anomalies of cerebral arteries were examined based on the results obtained by dissection of the circle of Willis blood vessels of 70 native cadaveric brains. Anomalies were most frequently found in posterior communicant artery and their most frequent type was hypoplasia of the blood vessel. Multiple anomalies of the circle of Willis were found in 3 cadavers. Premortal neurological symptomatology (PNS) existed in 5 cadavers. There was no significant difference in PNS occurrence at autopsy in cases with or without anomalies. Association of aneurisms with anomalies of the circle of Willis was found in two cases, but it was not significant in comparison to the control group with no anomalies.