OBJECTIVE To identify the anatomical variations in cerebral arterial circle of Willis. STUDY DESIGN Descriptive study. PLACE AND DURATION OF STUDY Department of Anatomy, University of Health Sciences, Lahore, from February 2009 to January 2010. METHODOLOGY Human brains were removed from fifty-one consecutive cadavers at the time of autopsy from Forensic Department, King Edward Medical Uni...

A hypertensive 69-year-old man presented with an incidentally discovered non-ruptured aneurysm of the persistent primitive olfactory artery (POA). The POA originates at the terminal portion of the internal carotid artery, runs along the olfactory tract anteriorly toward the crista galli, and forms an acute angle with the distal anterior cerebral artery. The aneurysm was located at this characte...

A case is presented of a 67-year-old woman with hypertension and arteriosclerosis who died from cerebral infarction. There was an associated arteriosclerotic aneurysm of the right vertebral artery, and incidental congenital or berry aneurysms of the anterior communicating and left internal carotid or anterior cerebral artery. The latter aneurysm was situated within the left optic nerve.

Arterial bifurcations in the circle of Willis were observed three-dimensionally in 44 cases of cerebral aneurysm and 45 control cases. Variations of the circle of Willis were also studied in relation to cerebral aneurysm. The following results were obtained : 1. Aneurysm always occurred at the apex of the cerebral arterial bifurcation where axial flow in the parent artery immediately proximal t...