Question
What is the most common site of berry aneurysm in the circle of Willis?
| A. |
ACA |
| B. |
MCA |
| C. |
Basilar artery |
| D. |
Vertebral artery |
Show Answer
|
Correct Answer � A Explanation |
 |
Berry (Saccular) Aneurysms
– Thin-walled saccular outpouchings at arterial bifurcations in circle of Willis.
– Most common sites: AComA > PComA > MCA > basilar tip.
– Risk factors: Hypertension, smoking, ADPKD, Ehlers-Danlos syndrome.
– Presentation (ruptured): Sudden “thunderclap” headache, neck stiffness, photophobia (SAH signs), cranial nerve palsies (esp. CN III if PComA involved).
– Diagnosis: Non-contrast CT brain → if negative, lumbar puncture (xanthochromia); CT/MR angiography for localization.
– Management: Surgical clipping or endovascular coiling; nimodipine to prevent vasospasm post-SAH.