What is the immediate management for a patient presenting with slurred speech, weakness in the left arm and right leg, and anisocoria (unequal pupils) with the left pupil being more dilated than the right?

Immediate Management of Acute Stroke with Anisocoria

This patient requires immediate activation of emergency medical services and transfer to a comprehensive stroke center with neurosurgical capabilities, as the combination of crossed motor deficits (left arm and right leg weakness) with anisocoria suggests either brainstem involvement or increased intracranial pressure with potential herniation—both life-threatening emergencies requiring urgent neuroimaging and possible neurosurgical intervention. 1

Critical Recognition and Triage

The presentation of slurred speech with weakness affecting opposite sides of the body (left arm, right leg) indicates either:

• Bilateral hemispheric involvement from multiple embolic events or progressive thrombotic stroke 1, 2
• Brainstem stroke affecting bilateral descending motor tracts, particularly in the basilar artery territory 2, 3

The dilated left pupil is a red flag that dramatically escalates urgency, as it may indicate:

• Uncal herniation with third cranial nerve compression from increased intracranial pressure 4
• Brainstem ischemia causing pupillary dysfunction, which correlates with decreased brainstem blood flow (<40 ml/100 g/min) and poor outcomes 4
• Direct brainstem involvement from posterior circulation stroke 5

Immediate Actions (Within Minutes)

Call 911 immediately and ensure high-priority dispatch to a comprehensive stroke center with:

• On-site CT/MRI imaging capabilities 5, 1
• Access to IV thrombolysis and endovascular thrombectomy 1
• Neurosurgical availability for potential herniation management 1

Establish exact time of symptom onset or last known normal time to determine thrombolysis eligibility (3-4.5 hour window for IV tPA) 1

Perform bedside glucose check immediately to rule out hypoglycemia as a stroke mimic 2

Use Cincinnati Prehospital Stroke Scale for rapid assessment: facial droop, arm drift, and abnormal speech—presence of any one finding has 72% probability of stroke 5

En Route and Emergency Department Management

Maintain airway, breathing, and circulation with particular attention to:

• Respiratory status (brainstem involvement can cause respiratory failure) 5
• Blood pressure control: Keep BP <185/110 mmHg if thrombolysis candidate; otherwise treat only if diastolic >120 mmHg or systolic >220 mmHg 1

Urgent neuroimaging within 24 hours (ideally immediately upon ED arrival):

• CT head without contrast to rule out hemorrhage and assess for mass effect/herniation 1
• MRI with diffusion-weighted imaging preferred over CT for detecting acute infarction 1
• CTA or MRA from aortic arch to vertex to identify vascular occlusion and assess for large vessel occlusion amenable to thrombectomy 1

Critical Diagnostic Pitfalls to Avoid

Do not dismiss the anisocoria as benign—pupillary dilation in acute stroke indicates either brainstem ischemia or impending herniation, both associated with poor outcomes and requiring immediate neurosurgical consultation 4

Do not delay imaging for "clinical stability"—the crossed motor deficits with pupillary changes suggest rapidly evolving pathology with highest stroke recurrence risk in first 48 hours (up to 10% within first week) 1, 3

Do not rely solely on clinical examination to localize the lesion—posterior circulation strokes may lack typical focal findings in one-third to two-thirds of cases 1

Acute Treatment Considerations

IV thrombolysis (rtPA) if patient presents within 3-4.5 hours of symptom onset and meets eligibility criteria (no hemorrhage on CT, BP controlled, no contraindications) 1

Endovascular thrombectomy consideration if large vessel occlusion identified on CTA/MRA, particularly for basilar artery occlusion given the clinical presentation 1

Neurosurgical consultation for potential:

• Decompressive craniectomy if massive hemispheric infarction with herniation 4
• External ventricular drain if hydrocephalus from posterior fossa stroke 4

Additional Urgent Workup

12-lead ECG to identify atrial fibrillation or other cardioembolic sources 1, 3

Prolonged cardiac monitoring and echocardiography to identify cardioembolic sources 1

Laboratory studies: Complete blood count, coagulation studies, metabolic panel 1

Post-Acute Planning

Antiplatelet therapy (aspirin, clopidogrel, or combination based on etiology) for secondary prevention if ischemic stroke confirmed 1

Anticoagulation if cardioembolic source identified (e.g., atrial fibrillation) 1

Comprehensive rehabilitation addressing motor, speech, and cognitive deficits once medically stable 1