Pathophysiology

Hemorrhagic stroke occurs when there is bleeding within the brain, leading to the disruption of normal brain function. The two main types of hemorrhagic stroke are intracerebral hemorrhage (ICH) and subarachnoid hemorrhage (SAH), each with distinct pathophysiological mechanisms.

• Intracerebral Hemorrhage (ICH):
  • ICH is characterized by bleeding directly into the brain tissue. It is most commonly caused by the rupture of small blood vessels damaged by chronic hypertension.
  • The elevated blood pressure weakens the vessel walls, leading to vessel rupture and subsequent bleeding into the surrounding brain tissue.
  • The accumulation of blood within the brain parenchyma causes compression of adjacent structures, disrupts normal neuronal function, and results in neurologic deficits.
• Subarachnoid Hemorrhage (SAH):
  • SAH occurs when there is bleeding into the subarachnoid space, the area between the arachnoid and pia mater layers of the meninges.
  • The most common cause of SAH is the rupture of an intracranial aneurysm, a weakened and bulging area in the wall of a cerebral artery.
  • When an aneurysm ruptures, blood is released into the subarachnoid space, leading to an increase in intracranial pressure and subsequent neurologic symptoms.

Both types of hemorrhagic stroke can cause secondary brain injury through various mechanisms, including mass effect from the expanding hematoma, disruption of cerebral blood flow, ischemia from vasospasm, and inflammation in the surrounding brain tissue. These processes contribute to the development of cerebral edema, increased intracranial pressure, and further neurologic deterioration.

Understanding the pathophysiology of hemorrhagic stroke is crucial for guiding treatment decisions and implementing appropriate management strategies to minimize secondary brain injury and improve patient outcomes.