Abstract

A rare case of a hypoplastic internal carotid artery (ICA) terminating in the ophthalmic artery with multiple intracranial saccular aneurysms in the contralateral ICA, anterior communicating artery fenestration and triple A2 was identified. The aetiology and pathogenesis of ICA hypoplasia are subjected to certain hypotheses. Developing several collaterals to preserve the blood supply of the ipsilateral cerebral hemisphere could result in aneurysm formation due to flow overload on the contralateral vasculature, but it could also result in hemicranial hypoplasia, cerebral atrophy and deep watershed infarcts, as in our case.