Strokes

Strokes are medical emergencies characterized by sudden disruption of blood supply to part of the brain, leading to brain tissue damage and neurologic deficits. They are broadly categorized into ischemic strokes, caused by blockage of an artery, and hemorrhagic strokes, caused by bleeding within the brain or surrounding spaces. Prompt diagnosis and treatment are critical to minimize disability and death.

Ischemic strokes account for the majority of cases. They arise from atherosclerotic plaque, cardioembolism (often related to atrial fibrillation), or small vessel disease. A transient ischemic attack is a brief episode of stroke-like symptoms that resolves without lasting damage; it signals elevated risk of future stroke.

Hemorrhagic strokes include intracerebral hemorrhage, due to rupture of small or large vessels often linked to hypertension, and subarachnoid hemorrhage, commonly due to an aneurysm or arteriovenous malformation. Symptoms may include sudden severe headache, vomiting, decreased consciousness, or focal deficits.

Emergency evaluation uses brain imaging to distinguish ischemic from hemorrhagic stroke: non-contrast CT is usually first, followed by MRI or CT angiography; blood tests; assessment of risk factors and possible sources of emboli, such as heart rhythm monitoring.

Ischemic stroke treatment aims to restore blood flow. Intravenous thrombolysis with alteplase is recommended within 4.5 hours of onset for eligible patients, and mechanical thrombectomy is effective for selected large vessel occlusions up to 24 hours. Supportive care, blood pressure management, and prevention of complications are essential. In hemorrhagic stroke, management focuses on stopping bleeding, reversing anticoagulation if present, controlling intracranial pressure, and, when needed, surgical evacuation or clipping.

Prevention centers on managing risk factors: controlling blood pressure, treating diabetes and high cholesterol, quitting smoking, maintaining a healthy weight, and addressing atrial fibrillation. Secondary prevention includes antithrombotic therapy, statins, rehabilitation, and lifestyle changes to reduce the risk of recurrent stroke.