A 58-year-old man is found repeatedly walking into furniture. He insists his vision is perfectly normal and becomes irritated when questioned. He has bilateral 3/60 acuity, normal pupils that react briskly to light, and normal fundi. MRI shows bilateral occipital infarcts. The diagnosis is:
- A Anton syndrome (cortical blindness with anosognosia) ✓
- B Bilateral optic neuropathy
- C Balint syndrome
- D Prosopagnosia
Correct answer: A. Anton syndrome (cortical blindness with anosognosia)
Explanation
Bilateral occipital cortical destruction causes cortical blindness with preserved pupillary light reflexes, because the pretectal afferents branch off before the lateral geniculate body. Denial of blindness despite objective visual loss defines Anton syndrome, attributed to disconnection of the visual cortex from association areas and language centres. Balint syndrome is the triad of simultanagnosia, optic ataxia and gaze apraxia from bilateral parieto-occipital lesions, and pupils are irrelevant there.
Reference: Harrison's Principles of Internal Medicine, 21st ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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