pathogenesis
Last reviewed 12/2022
In aneurysmal SAH, increasing size of the aneurysm is associated with corresponding thinning and weakening of the wall to the point of rupture. Release of arterial blood into the subarachnoid space then produces a sudden rise in intracerebral pressure which may limit the bleeding.
The bleeding point is sealed by clot and fibrin but later may re-bleed as repair of the vessel wall is accompanied by fibrinolysis. Intracerebral or intraventricular bleeding may occur if the aneurysm becomes adherent to the brain.