Large anterior communicating artery aneurysm with temporal hemianopsia. Case report.

Giant or large anterior communicating artery (ACOA) aneurysms producing bitemporal hemianopsia are extremely rare. A case is presented of an ACOA aneurysm measuring 2 X 1.4 cm with the patient having had a post-traumatic amaurosis of the left eye for many years. Then he had a subarachnoid hemorrhage and subsequently developed impaired vision in the right eye and temporal hemianopsia. The aneurysm was visible on C.T. but disappeared on post-operative scans. Visual acuity improved radically after treatment with neck ligation and opening of the sac.