What is the differential diagnosis and treatment approach for acute ischemic stroke vs migraine with hemiplegic symptoms?

Differential Diagnosis and Treatment Approach for Acute Ischemic Stroke vs Hemiplegic Migraine

Brain imaging with non-contrast CT is mandatory to differentiate between acute ischemic stroke and hemiplegic migraine, as clinical features alone are insufficient for definitive diagnosis. 1, 2

Key Clinical Features for Differential Diagnosis

Acute Ischemic Stroke Features

• Sudden onset of focal neurological deficits
• Persistent symptoms (typically >24 hours)
• Risk factors: hypertension, diabetes, atrial fibrillation, smoking
• Usually no prior history of similar episodes with complete recovery
• May have accompanying dysarthria, aphasia, visual field defects
• Typically no headache at onset (though can occur)

Hemiplegic Migraine Features

• Headache (often severe) with accompanying hemiplegia
• Visual or sensory aura preceding motor weakness
• Prior history of similar episodes with complete recovery
• Family history may be positive (in familial hemiplegic migraine)
• Symptoms typically resolve within 24-72 hours 3
• May have accompanying dysarthria, aphasia, confusion
• Often younger patients with history of migraine

Red Flags Suggesting Secondary Headache/Stroke 1

• Thunderclap headache (subarachnoid hemorrhage)
• Progressive headache (space-occupying lesion)
• Headache onset at >50 years of age
• Headache with fever/neck stiffness (meningitis)
• Focal neurological symptoms that don't fit typical migraine pattern
• Altered consciousness or personality changes

Diagnostic Approach

1. Immediate Brain Imaging

   • Non-contrast CT scan is first-line to exclude hemorrhage 1, 2
   • MRI with diffusion-weighted imaging has higher sensitivity for early ischemia and can detect small infarcts missed by CT 1
   • Perfusion imaging may show hypoperfusion in both conditions (hemiplegic migraine can show transient hypoperfusion similar to stroke) 4

2. Vascular Imaging

   • CTA or MRA of head and neck should be performed in suspected stroke to evaluate for vessel occlusion or stenosis 1
   • Helps identify stroke mechanism and guide treatment decisions

3. Additional Testing for Stroke Evaluation

   • ECG to identify atrial fibrillation
   • Blood glucose, electrolytes, renal function tests
   • Complete blood count including platelet count
   • Coagulation studies (PT/INR, aPTT) 1

Treatment Algorithm

If Acute Ischemic Stroke Confirmed:

1. Time-Sensitive Interventions

   • If within 4.5-hour window and no contraindications, administer IV thrombolysis (tPA) 1, 2
   • Consider endovascular therapy for large vessel occlusions
   • Monitor for hemorrhagic transformation, especially after reperfusion therapy

2. Blood Pressure Management

   • Allow permissive hypertension up to 220/120 mmHg if not receiving thrombolysis
   • If receiving thrombolysis, maintain BP <180/105 mmHg 2

3. Secondary Prevention

   • Antiplatelet therapy (aspirin 160-300 mg within 48 hours) 2
   • Identify and address stroke etiology (carotid stenosis, atrial fibrillation, etc.)

If Hemiplegic Migraine Confirmed:

1. Acute Treatment

   • NSAIDs as first-line medication for pain relief
   • Avoid triptans in hemiplegic migraine due to theoretical risk of vasoconstriction 1
   • Antiemetics for nausea/vomiting
   • In severe cases, consider hospitalization and IV fluids 3

2. Preventive Treatment

   • Consider preventive therapy if attacks occur ≥2 times per month or are severely disabling
   • Options include calcium channel blockers (verapamil, flunarizine) and antiepileptic medications 3
   • Avoid triggers

Common Pitfalls and Caveats

1. Misdiagnosis Risk

   • Nearly 2% of patients evaluated for stroke have an ultimate diagnosis of migraine 5
   • Approximately 18% of stroke mimics treated with thrombolysis have a final diagnosis of migraine 5
   • Conversely, migraine is a common incorrect diagnosis initially given to stroke patients

2. Treatment Risks

   • Administering thrombolytics to a patient with hemiplegic migraine carries risk of intracerebral hemorrhage, though this risk is low 5
   • Delaying thrombolysis in true stroke can lead to permanent disability

3. Diagnostic Challenges

   • Perfusion imaging may show hypoperfusion in both conditions, making differentiation difficult 4
   • Some patients with hemiplegic migraine may initially present similarly to stroke patients requiring thrombolysis evaluation 4
   • Sporadic hemiplegic migraine may lack the family history clue 6

4. Follow-up

   • Patients diagnosed with hemiplegic migraine should have follow-up to ensure complete resolution of symptoms
   • Patients with stroke require comprehensive secondary prevention strategies

By following this structured approach to differential diagnosis and treatment, clinicians can more accurately distinguish between these conditions and provide appropriate care while minimizing risks associated with misdiagnosis.