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