Visual Cortex Infarction
- Ischemic stroke of visual cortex
- May be unilateral or bilateral
- Caused by systemic hypotension, vertebrobasilar or cardiac embolism, hypercoagulability
- Acute loss of vision
- Homonymous hemianopia, unilateral or bilateral
- Confrontation visual field testing may disclose these defects, but formal visual field testing more sensitive
- Visual acuity preserved if hemianopia unilateral, but often severely compromised if hemianopia bilateral
- Eye examination otherwise normal
- Brain CT shows occipital lucency within 48 hours of symptom onset
- Brain MRI diffusion-weighted sequence shows unilateral or bilateral occipital signal abnormality within 2 hours of symptom onset
- Refer patient urgently to ophthalmologist, who may refer to emergency room physician, neuro-ophthalmologist, internist, depending on findings
- If imaging discloses acute stroke, patient will be placed on anti-platelet agent and evaluated for embolic source or other cause
- Vision recovery usually limited and complete within 4 weeks of symptom onset