Introduction: Anton’s syndrome (AS), or cortical blindness with denial of vision loss, is a rare neurobehavioral condition typically resulting from bilateral occipital lobe injury. It remains poorly understood, with only 28 reported cases between 1965 and 2016. We present a case of a 32-year-old woman who developed Anton’s syndrome in the setting of posterior reversible encephalopathy syndrome (PRES).
Description: A 32-year-old female with a history of hypertension presented with acute bilateral vision loss, preceded by several days of bifrontal headache, nausea, and vomiting. On arrival, blood pressure (BP) was 250/170, and heart rate was 101. Assessment was notable for disorientation, rightward gaze deviation, and dilated but reactive pupils. Head CT revealed bilateral occipital hypoattenuation concerning for PRES; CT angiography was unremarkable. She received intravenous labetalol and was admitted to the intensive care unit on a nicardipine infusion. Brain MRI showed bilateral asymmetric diffusion restriction in the right occipital lobe with FLAIR hyperintensities. The differential included PRES and vasculitis. Cerebral angiography revealed vasculopathy. Extensive workup for secondary hypertension and autoimmune disease, including a brain biopsy, was unrevealing. Her mental status improved with blood pressure control; however, the vision loss persisted, which she vehemently denied, consistent with Anton’s syndrome. She was ultimately discharged with persistent symptoms and referral to neuro-ophthalmology.
Discussion: The underlying mechanism of AS likely involves bilateral damage to the visual cortices with disconnection from conscious awareness and language centers, leading to false visual narratives. Diagnosis is clinical, with a normal ocular exam, intact pupillary reflexes, and absent blink-to-threat response. This patient had extensive workup, including cerebral angiography and brain biopsy to investigate a broad differential. Her unremarkable biopsy challenges the theory that structural white matter lesions are the underlying cause of Anton’s syndrome. In the absence of a positive workup, PRES was the defining diagnosis. Although PRES can improve with aggressive BP control, this case highlights that irreversible cortical blindness and confabulation can still occur despite early treatment.
