[Rare abnormalities of the circle of Willis: infra-optic pathway of the anterior cerebral arteries (author's transl)].

The authors report a new case of "sub optic" course of anterior cerebral arteries with an anterior communicating artery aneurysm controlled at surgery. The patient had also a distal Moya Moya, a median artery of the corpus callosum and an aortic coarctation. He underwent a first operation for cerebral aneurysm and in a second step another for aortic malformation. The authors discuss the anomaly by the way of Lasjaunia's embryologic scheme of ophthalmic arteries formation.