A 40-year-old woman with autosomal dominant polycystic kidney disease presents with sudden thunderclap headache, neck stiffness, and photophobia. CT shows blood in the basal cisterns. The most likely source of bleeding is:

• A Dissection of the vertebral artery
• B Rupture of a Charcot-Bouchard microaneurysm in the basal ganglia
• C Rupture of a saccular (berry) aneurysm at an arterial bifurcation in the circle of Willis ✓
• D Rupture of a mycotic aneurysm of the middle cerebral artery

Explanation

Berry aneurysms occur at bifurcation points of the circle of Willis, most commonly at the anterior communicating artery junction, and rupture causes subarachnoid hemorrhage presenting as sudden severe headache. They are associated with ADPKD, Ehlers-Danlos syndrome type IV, coarctation of the aorta, and family history. Charcot-Bouchard aneurysms are small intraparenchymal aneurysms of hypertensive patients causing intracerebral, not subarachnoid, hemorrhage. Mycotic aneurysms are infected and rare, and vertebral dissection causes ischemic stroke more often than subarachnoid bleed.

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.