Hemorrhagic Stroke ll: Pathophysiology

A hemorrhagic stroke happens when a blood vessel in the brain ruptures, resulting in bleeding into the brain tissue called intracerebral hemorrhage, or ICH, or into the subarachnoid space, known as subarachnoid hemorrhage, or SAH.

As blood accumulates, it forms a hematoma, which raises intracranial pressure and compresses nearby brain tissue.

This compression damages brain cells and disrupts normal blood flow, leading to further injury.

Beyond the initial bleeding, secondary injury happens when blood components such as hemoglobin and iron leak into the surrounding tissue. These components are toxic to brain cells and trigger oxidative stress and inflammation.

In response, microglia release inflammatory cytokines and generate reactive oxygen species, worsening cell damage and compromising the blood-brain barrier.

In SAH, vasospasm or prolonged narrowing of blood vessels may happen, causing delayed cerebral ischemia.

Meanwhile, blood entering the cerebrospinal fluid can block drainage pathways, leading to hydrocephalus.

Together, these interconnected processes result in significant brain injury and long-term neurological deficits.