About 2% of the adult population have an asymptomatic cerebral aneurysm.
Unruptured aneurysms can cause symptoms such as headache, visual acuity loss, cranial neuropathies (particularly thrid nerve palsy), pyramidal tract dysfunction, and facial pain; these are thought to be due to mass effect on the aneurysm.
20 to 30% of people with a cerebral aneurysm, have multiple aneurysms; Don't miss co-existing aneurysms on CTA or MRI.
The majority of intracranial aneurysms are located in the anterior circulation, most commonly in the Circle of Willis.
When localizing aneurysm on CTA and MRI, common sites include:
--- junction of the anterior communicating artery (ACOM) with the anterior cerebral artery (ACA)
--- junction of the posterior communicating artery (PCOM) with the internal carotid artery (ICA)
--- bifurcation of the middle cerebral artery (MCA)
References
Singer, et al. "Unruptured Intracranial Aneurysms." November 2007. UptoDate online 16.2.
