Stroke

Definition:

• A stroke is a medical condition in which poor blood flow to the brain results in cell death. There are two main types: ischemic (due to lack of blood flow) and hemorrhagic (due to bleeding).

Epidemiology:

• A leading cause of disability and death worldwide.
• Risk increases with age, but strokes can occur at any age.

Pathophysiology:

1. Ischemic Stroke:
   • Accounts for about 85% of strokes.
   • Caused by interruption of blood flow due to a blood clot (thrombosis) or embolism.
   • Results in cerebral infarction.
2. Hemorrhagic Stroke:
   • Accounts for about 15% of strokes.
   • Caused by bleeding either within the brain (intracerebral) or into the subarachnoid space (subarachnoid hemorrhage).

Risk Factors:

• Hypertension, diabetes, smoking, obesity, high cholesterol, atrial fibrillation, previous stroke or transient ischemic attack (TIA), family history, age.

Clinical Features:

• Sudden onset of neurological deficit, such as weakness or numbness on one side of the body, difficulty speaking or understanding speech, vision problems, dizziness, and loss of balance.
• FAST (Face drooping, Arm weakness, Speech difficulties, Time to call emergency services) is a quick tool to recognize stroke symptoms.

Diagnosis:

• Clinical assessment using the National Institutes of Health Stroke Scale (NIHSS).
• Imaging: CT scan or MRI to differentiate between ischemic and hemorrhagic stroke.
• Additional tests: Carotid ultrasound, echocardiogram, blood tests.

Management:

• Ischemic Stroke: Thrombolysis (e.g., IV alteplase), mechanical thrombectomy.
• Hemorrhagic Stroke: Control of blood pressure, surgery or endovascular procedures to control bleeding.
• Secondary prevention: Antiplatelets (e.g., aspirin), anticoagulants (for atrial fibrillation), control of risk factors.

Rehabilitation:

• Physical, occupational, and speech therapy.
• Multidisciplinary approach to help regain as much function as possible.

Prognosis:

• Depends on stroke type, severity, rapidity of treatment, and presence of comorbid conditions.
• Early treatment improves outcomes significantly.