What could cause transient loss of vision in one eye, accompanied by a headache, that resolved on its own after a few minutes?

Transient Monocular Vision Loss with Headache: Urgent Stroke Evaluation Required

This presentation represents a transient monocular vision loss (TMVL) or "ocular TIA" and requires immediate emergency department evaluation at a stroke center, as it carries significant risk for subsequent stroke and permanent vision loss. 1

Immediate Action Required

Send this patient immediately to the nearest emergency department affiliated with a certified stroke center with a note indicating "Ocular TIA." 1 The patient should be informed of the risk of stroke and acute coronary syndrome, and the emergency department should be called ahead to warn them that "a stroke patient is on the way." 1

Why This Is Urgent

• Patients with TMVL have a high risk of subsequent cerebrovascular events, including permanent stroke 1
• The episode described (grey vision lasting 2-3 minutes with ipsilateral headache) is classic for retinal arterial ischemia 1
• Even though symptoms have completely resolved, the underlying vascular pathology remains and requires immediate workup 1
• Patients seen even a few days after the episode still need urgent stroke workup, though ideally evaluation should occur within 24 hours 1

Differential Diagnosis Considerations

Most Likely: Retinal Arterial Ischemia (Ocular TIA)

• The brief duration (2-3 minutes), monocular nature, grey vision, and complete resolution are pathognomonic for transient retinal arterial occlusion 1
• Associated ipsilateral headache can occur with vascular events 1
• This represents embolic or thrombotic compromise of retinal arterial circulation 1

Alternative Considerations to Evaluate

Migraine with Visual Aura:

• Migraine can cause transient visual symptoms and headache 2, 3
• However, typical migraine aura evolves over 5-20 minutes (not 2 minutes), involves positive visual phenomena (scintillations, zigzags) rather than pure grey vision, and affects both eyes (homonymous visual field) rather than monocular vision 2
• The rapid onset and monocular nature make this less likely 2

Intermittent Angle Closure:

• Can present with blurred vision, halos, eye pain, and headache 1
• However, typically causes eye redness, corneal edema, and elevated intraocular pressure during episodes 1
• Vision loss is usually described as blurred with halos rather than grey 1
• Episodes typically last longer and may have residual findings 1

Giant Cell Arteritis:

• Must be considered urgently in any patient over 50 with TMVL 1
• Can cause TMVL followed by permanent vision loss if untreated 1
• Associated symptoms include scalp tenderness, jaw claudication, and temporal region pain 1

Critical Workup at Stroke Center

The stroke center evaluation should include:

• Carotid imaging to assess for significant stenosis, as patients with carotid stenosis have high rates of concomitant cardiac disease 1
• Cardiac evaluation including ECG and echocardiography to identify cardioembolic sources 1
• Brain and vascular imaging (MRI/MRA or CT/CTA) to evaluate for acute infarction and vascular pathology 1
• Laboratory assessment including ESR and CRP if age >50 to rule out giant cell arteritis 1
• Immediate antiplatelet therapy should be initiated without delay 1

Key Clinical Pitfalls to Avoid

• Do not delay referral to perform additional ophthalmologic testing yourself - the priority is immediate stroke center evaluation 1
• Do not reassure the patient that "everything is fine now" - complete symptom resolution does not eliminate stroke risk 1
• Do not attribute symptoms to migraine without stroke workup first - vascular causes must be excluded 1
• Do not wait for symptoms to recur - the window for secondary prevention is now 1

If Patient Presents Days Later

Even if the patient presents several days after the episode, they still require urgent stroke workup, which can be obtained by a neurologist with stroke expertise as an outpatient, and should be started on antiplatelet therapy immediately. 1