Complex sentence: If a rupture or bleeding incident occurs, the blood may penetrate either into the brain tissue (cerebral hemorrhage) or into the subarachnoid space, which is located between the sheaths (meninges) surrounding the brain (subarachnoid hemorrhage).
Split into simpler sentences: If a rupture or bleeding incident occurs, the blood may penetrate either into the brain tissue (cerebral hemorrhage) or into the subarachnoid space. This space is located between the sheaths (meninges) surrounding the brain (subarachnoid hemorrhage).