Clinical Features of Acute Ischemic Stroke
Acute ischemic stroke presents with sudden onset of focal neurologic deficits that are referable to a specific vascular territory, with symptoms typically beginning abruptly while the patient is active rather than at rest. 1
Temporal Pattern and Onset
- Symptoms begin suddenly (though can evolve over minutes to hours), distinguishing ischemic stroke from other neurologic conditions 1
- The hallmark feature is awakening with or experiencing abrupt onset of focal neurologic deficits 2
- Unlike intracerebral hemorrhage, ischemic stroke symptoms do not typically show smooth progression over minutes to hours 3
- Symptoms are time-dependent, with up to 2 million neurons lost per minute during large vessel occlusion 1
Most Common Presenting Symptoms
- Speech disturbance is the most common presenting symptom 2
- Unilateral weakness (hemiparesis) affecting one side of the body is the second most common presentation 2
- Symptoms are referable to the affected brain region and divided into anterior versus posterior circulation patterns 1
Anterior Circulation Features
- Contralateral motor weakness or sensory loss 1
- Aphasia (if dominant hemisphere affected) 1
- Visual field defects 1
- Facial droop 4
Posterior Circulation Features
- Altered level of consciousness (may require aggressive airway management) 1
- Vertigo, ataxia, or incoordination 1
- Cranial nerve deficits 1
- Bilateral motor or sensory symptoms 1
Hemodynamic Presentation
- Majority of patients present hemodynamically stable 1
- Circulatory collapse or cardiac arrest is uncommon in isolated ischemic stroke 1
- If cardiac arrest occurs, consider concurrent acute myocardial infarction, atrial fibrillation, or congestive heart failure 1
Key Distinguishing Features from Hemorrhagic Stroke
- Headache is less common in ischemic stroke compared to intracerebral hemorrhage 3
- Vomiting is less common than in hemorrhagic stroke 3
- Blood pressure elevation is typically less severe than in intracerebral hemorrhage (which often presents with systolic BP >220 mm Hg) 3
- Impaired consciousness is less common at onset compared to hemorrhagic stroke 3
Common Stroke Mimics to Exclude
- Hypoglycemia is the most common stroke mimic and should be identified immediately with fingerstick glucose 1
- Seizure with postictal paralysis 2
- Conversion disorder 2
- Migraine with aura 2
Critical Assessment Requirements
- Neuroimaging is mandatory to distinguish ischemic stroke from hemorrhagic stroke, as clinical features alone are insufficient for reliable differentiation 3, 5
- Non-contrast CT should be completed within 25 minutes of emergency department arrival 1, 5
- Early CT may show no signs of brain ischemia in the first few hours 1
- Blood glucose must be checked immediately to exclude hypoglycemia 1
Neurological Deterioration Patterns
- Clinical deterioration occurs in 25% of patients after initial assessment 1
- One-third deteriorate due to stroke progression, one-third from brain edema, 10% from hemorrhage, and 11% from recurrent ischemia 1
- Cerebral edema typically peaks 3-4 days after injury but can occur within 24 hours with early reperfusion of large infarcts 1
Pitfalls to Avoid
- Do not rely on clinical presentation alone to differentiate ischemic from hemorrhagic stroke—imaging is essential 3, 5
- Do not assume normal early CT excludes stroke—early ischemic changes may not be visible in the first hours 1
- Do not delay imaging for patients with suspected stroke, as time-sensitive interventions are critical 5, 6
- Rapidly improving symptoms do not automatically exclude the need for treatment—clinical judgment is required to determine if the patient is truly near baseline 5