Overview
Definition
An episode of neurological dysfunction caused by focal brain, spinal cord, or retinal infarction due to a reduction in blood flow.
Epidemiology
Accounts for ~85% of all strokes. A leading cause of serious, long-term disability.
Etiology & Risk Factors
- Thrombotic (local occlusion due to atherosclerosis)
- Embolic (clot originating elsewhere, typically from Atrial Fibrillation or carotid artery stenosis)
- Hypoperfusion (systemic hypotension/shock)
Clinical Symptoms
- Sudden numbness or weakness of the face, arm, or leg (especially on one side)
- Sudden confusion, trouble speaking (aphasia), or understanding speech
- Sudden trouble seeing in one or both eyes (hemianopia)
- Sudden trouble walking, dizziness, loss of balance
Clinical Approach
Diagnosis
- Non-contrast Head CT (IMMEDIATELY, to rule out hemorrhagic stroke before giving tPA)
- MRI Brain (Diffusion-Weighted Imaging - DWI is the most sensitive for acute ischemia)
- ECG and Echocardiogram (to check for A-Fib or mural thrombus)
- Carotid ultrasound/CTA (to evaluate for carotid stenosis)
Management
- Thrombolytic therapy (IV tPA / Alteplase) if symptom onset is < 4.5 hours and no contraindications
- Mechanical Thrombectomy (Endovascular therapy) if large vessel occlusion (LVO) is present and within 24 hours
- Secondary prevention: Aspirin or Clopidogrel, high-intensity Statin, BP control, and Anticoagulation (if A-Fib)
Complications
- Hemorrhagic transformation (bleeding into the infarcted area)
- Cerebral edema and increased ICP
- Aspiration pneumonia
- Deep Vein Thrombosis (due to immobility)