A 50-year-old woman presents with sudden thunderclap headache. CT shows subarachnoid haemorrhage and angiography reveals a saccular aneurysm. At which site do the majority of such aneurysms arise?
- A Posterior communicating artery
- B Anterior communicating artery ✓
- C Middle cerebral artery bifurcation
- D Basilar artery tip
Correct answer: B. Anterior communicating artery
Explanation
Approximately 30 to 35 percent of saccular berry aneurysms arise at the anterior communicating artery, making it the single commonest site, followed closely by the posterior communicating artery origin and the middle cerebral artery bifurcation. All three lie within the anterior part of the circle of Willis, where congenital deficiency of the tunica media at branch points predisposes to aneurysm formation. The basilar tip accounts for under 10 percent of cases.
Reference: Robbins and Cotran Pathologic Basis of Disease, 10th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.