What is the best course of action for a patient with a history of chest pain, now presenting with numbness on the left side of the face, left arm, and left foot, as well as numbness on the right side of the head, and an electrocardiogram (EKG) showing a nonspecific T wave abnormality, with normal vital signs?

Immediate Neurological Emergency: Urgent Stroke Evaluation Required

This patient requires immediate transfer to the emergency department by EMS for urgent stroke evaluation with brain imaging (CT or MRI) within minutes of arrival, as the constellation of unilateral facial numbness, ipsilateral arm numbness, and contralateral foot numbness with recent chest pain strongly suggests acute posterior circulation stroke, particularly lateral medullary syndrome. 1

Critical Recognition of Stroke Presentation

The pattern of left-sided facial and arm numbness combined with left foot numbness represents a neurological emergency, not a cardiac emergency, despite the preceding chest pain. The nonspecific T-wave abnormality on EKG and normal vital signs make acute coronary syndrome less likely as the primary pathology. 2

Key Distinguishing Features Present:

• Crossed sensory deficits (ipsilateral face/arm with involvement of lower extremity) are pathognomonic for brainstem stroke, specifically lateral medullary syndrome (Wallenberg syndrome) 1
• The additional "numbness to right side of head" suggests bilateral involvement or extension of the ischemic territory 1
• Facial numbness in acute coronary syndrome would be exceedingly rare and would not explain the specific distribution pattern described 3, 4

Immediate Actions Required

Within 10 Minutes:

1. Activate stroke protocol immediately - Time is brain tissue; every minute of delay increases disability 2

2. Obtain complete neurological examination focusing on:

   • Cranial nerve function (particularly corneal reflexes, facial sensation in all three trigeminal distributions, and facial motor function) 1, 5
   • Presence of Horner syndrome (ptosis, miosis, anhidrosis) on the affected side 1
   • Dysarthria, dysphagia, or hoarseness suggesting bulbar involvement 1, 5
   • Limb ataxia and gait instability 1
   • Nystagmus or vertigo 1

3. Repeat 12-lead ECG to document any evolution of the T-wave abnormality, but do not delay neurological evaluation 2

Within 30 Minutes:

1. Obtain urgent brain MRI with diffusion-weighted imaging (DWI) and thin brainstem slices - This is the gold standard for detecting acute posterior circulation stroke 1

   • If MRI unavailable or contraindicated, obtain non-contrast head CT to exclude hemorrhage, though CT may miss acute brainstem infarction 1

2. Measure cardiac troponin to definitively exclude myocardial infarction, as the chest pain history cannot be ignored 2, 3

Why This is NOT Primarily Cardiac

The temporal sequence and symptom pattern argue against acute coronary syndrome as the primary diagnosis:

• Chest pain has resolved and patient now "denies pain" 3
• ACS does not cause unilateral facial numbness or the specific crossed sensory pattern described 3, 4
• While left arm numbness can occur with ACS, it would not be accompanied by ipsilateral facial numbness and contralateral foot involvement 6
• Normal vital signs make cardiogenic shock or hemodynamic compromise unlikely 2

However, the nonspecific T-wave abnormality requires explanation: It may represent:

• Coincidental finding unrelated to current symptoms 2
• Neurogenic cardiac changes from acute stroke (common in posterior circulation events) 1
• Prior cardiac disease that is not currently active 2

Critical Differential Diagnoses to Exclude

Posterior Circulation Stroke (Most Likely):

• Lateral medullary syndrome presents with ipsilateral facial numbness, ipsilateral Horner syndrome, contralateral body numbness, ataxia, and bulbar symptoms 1
• The ipsilateral upper motor neuron facial weakness can occur with aberrant corticobulbar fiber involvement in the medulla 1

Alternative Neurological Emergencies:

• Basilar artery thrombosis - Can present with bilateral symptoms and altered consciousness (check level of alertness carefully) 1
• Multiple embolic strokes - Could explain bilateral involvement if right-sided head numbness represents separate territory 1

Less Likely But Must Consider:

• Facial onset sensory and motor neuropathy (FOSMN) - Presents with facial numbness spreading to neck and arms, but evolves over months to years, not acutely 7, 5
• Seizure with Todd's paralysis - Left arm numbness with syncope can represent focal seizures, but would not explain the specific facial and crossed pattern 6

Transport and Disposition

Transfer by EMS immediately, not by private vehicle: 2, 8

• Trained personnel can monitor for deterioration en route 2
• Brainstem strokes can rapidly progress to respiratory compromise or loss of protective airway reflexes 1
• Direct communication with receiving stroke center allows preparation of imaging and neurology team 2, 8

Destination hospital must have:

• 24-hour stroke neurology coverage 8
• Advanced neuroimaging capabilities (MRI with DWI) 1
• Interventional neurology/neurointerventional radiology if available for potential thrombectomy 8

Critical Pitfalls to Avoid

1. Do not dismiss neurological symptoms as "atypical" cardiac presentation - The pattern is too specific for stroke 2, 4
2. Do not delay transfer to obtain serial troponins in office setting - This can be done in the ED while pursuing stroke evaluation 2, 8
3. Do not assume normal vital signs exclude serious pathology - Brainstem strokes frequently present with normal blood pressure and heart rate initially 1
4. Do not rely on initial head CT alone - Posterior fossa strokes are frequently missed on CT; MRI is essential 1

Time-Sensitive Treatment Implications

If acute ischemic stroke is confirmed:

• Intravenous thrombolysis (tPA) window: 4.5 hours from symptom onset (if no contraindications) 8
• Mechanical thrombectomy window: up to 24 hours for select patients with large vessel occlusion 8
• Every 15-minute delay in treatment increases disability and mortality 8

The preceding chest pain does not contraindicate thrombolysis unless it represents active acute coronary syndrome with elevated troponin requiring anticoagulation, which would need to be weighed against stroke severity 9