Mycotic Aneurysm of Intracavernous Internal Carotid Artery Presenting as Cavernous Sinus Syndrome

Mycotic intracranial aneurysms are infectious aneurysms accounting for 0.7%–6.5% of all intracranial aneurysms and are most commonly located in distal branches of the middle cerebral arteries, particularly at the bifurcation area. They are caused by weakening of the vessel wall secondary to infection of a segment of the artery that can be endovascular as in infective endocarditis or extravascular as in meningitis or cavernous sinus thrombophlebitis. The rare occurrence of the mycotic cavernous internal carotid artery aneurysm, its variable clinical picture and limited knowledge of its natural course is a challenge for both diagnosis and management.