Rupture of a berry aneurysm of the Circle of Willis

Rupture of a berry aneurysm of the Circle of Willis would likely produce hemorrhage into the 

A. Epidural space 
B. Cerebellum 
C. Subarachnoid space 
D. Subduraispace

Answer. C. Subarachnoid space

• Subarachnoid hemorrhage is much less common than hypertensive intracerebral hemorrhage, and most often it results from rupture of a berry aneurysm.

• Berry aneurysms are saccular aneurysms that result from congenital defects in the media of arteries.

• They are not the result of atherosclerosis. Instead, berry aneurysms are called congenital, although the aneurysm itself is not present at birth.

• Berry aneurysms are most commonly found in the circle of Willis.

• The chance of rupture of berry aneurysms increases with age (rupture is rare in childhood).

• Rupture causes marked bleeding into the subarachnoid space and produces severe headaches, typically described as the worst headache ever.” Additional symptoms include vomiting, pain and stiffness of the neck (due to meningeal irritation caused by the blood), and papilloedema and death.