intracranial aneurysm intracranial aneurysm an intracranial aneurysm, also known as a cerebral aneurysm, is a cerebrovascular disorder in which weakness in the wall of a cerebral artery or vein causes a localized dilation or ballooning of the blood vessel. intracranial aneurysmother namescerebral aneurysm, brain aneurysmaneurysm of the basilar artery and the vertebral arteriesspecialtyinterventional neuroradiology, neurosurgery, neurology symptomsnone, severe headache, visual problems, nausea and vomiting, confusionusual onset30–60 years oldcauseshypertension, infection, head traumarisk factorssmoking, old age, family history, cocaine usediagnostic methodangiography, ct scantreatmentendovascular coiling, surgical clipping, cerebral bypass surgery, pipeline embolization aneurysms in the posterior circulation (basilar artery, vertebral arteries and posterior communicating artery) have a higher risk of rupture. basilar artery aneurysms represent only 3–5% of all intracranial aneurysms but are the most common aneurysms in the posterior circulation. classification