What is the next step for a patient with a resolved transient curtain-like visual disturbance in one eye and normal diagnostic tests, including complete blood count (CBC), basic metabolic panel (BMP), troponin, electrocardiogram (ECG), noncontrast head computed tomography (CT), and point-of-care bedside eye ultrasound?

Immediate Stroke Risk Evaluation is Required

This patient requires immediate evaluation for stroke risk (Option A) because a curtain-like shadow in one eye represents transient monocular vision loss (TMVL), which is a retinal transient ischemic attack that demands urgent stroke workup within 24-48 hours, regardless of symptom resolution. 1

Why This is a Medical Emergency

• TMVL is a retinal TIA that carries the same stroke risk as cerebral TIA, with up to 10% risk of stroke within 90 days and half of those strokes occurring within the first 48 hours 2, 3
• The "curtain-like" or "shade descending" description is pathognomonic for retinal arterial ischemia from embolic sources 4
• Up to 31% of patients with TMVL have silent brain infarctions on MRI, and 20% have a major embolic source requiring urgent intervention 1, 5
• The highest stroke risk occurs within the first 7 days after the event 6

Critical Distinction from Transient Visual Obscurations

• This is NOT a transient visual obscuration (TVO), which lasts only seconds and suggests papilledema from raised intracranial pressure 4
• The 20-minute duration and curtain-like quality definitively indicate TMVL/amaurosis fugax, not TVO 4
• TVOs would require evaluation for intracranial pressure, but TMVL requires stroke workup 4

Required Immediate Workup

Brain and Vascular Imaging (Within 24 Hours)

• Brain MRI with diffusion-weighted imaging (DWI-MRI) is mandatory to identify silent cerebral infarctions, found in 11.8-30.8% of TMVL patients 1
• Vascular imaging from aortic arch to vertex (CTA or MRA) to identify carotid stenosis, present in up to 70% of retinal arterial occlusion patients 1, 6

Cardiac Evaluation

• Continuous cardiac monitoring and echocardiography to identify atrial fibrillation or other cardioembolic sources 1
• Approximately 20% of TMVL patients have a major embolic source requiring urgent anticoagulation 5

Additional Testing

• Complete stroke laboratory panel if not already done (lipids, hemoglobin A1c, hypercoagulable workup if indicated) 1

Why Other Options Are Incorrect

• Option B (ophthalmology in 3 days): Dangerously delayed; Canadian guidelines specify that TMVL within 48 hours requires same-day assessment at a stroke center, not routine ophthalmology follow-up 1
• Option C (PCP in 1 week): Completely inappropriate; this timeframe is only for patients presenting >2 weeks after symptom onset 1
• Option D (psychiatry): Misses a life-threatening diagnosis; the curtain-like description with 20-minute duration is classic for retinal ischemia, not functional symptoms 4

Common Pitfall

The normal point-of-care ultrasound and complete symptom resolution do not eliminate stroke risk. The bedside ultrasound likely evaluated for retinal detachment but cannot assess for embolic sources, carotid stenosis, or silent brain infarctions that drive the high stroke risk 1, 6. Even with reperfusion and normal initial testing, the patient remains at highest risk for recurrent events in the immediate 48-hour period 1, 2.

Management Algorithm

1. Immediate transfer to ED or stroke center with capacity for advanced imaging 1
2. Brain MRI with DWI and vascular imaging (CTA/MRA) within 24 hours 1
3. Cardiac monitoring and echocardiography 1, 3
4. Initiate antiplatelet therapy (aspirin 325mg loading dose) unless contraindicated 3
5. Admit or place in observation unit for rapid diagnostic protocol completion 7
6. Ophthalmology consultation during admission for funduscopic examination and retinal evaluation 1