Reversible Bilateral Vision Loss: An Unusual Presentation of Wernicke-Korsakoff Syndrome.

Neuro-ophthalmic manifestations of Wernicke encephalopathy (WE) are uncommon and vary from nystagmus, oculomotor palsies, anisocoria, and optic disc edema to vision loss. We describe a case of a 53-year-old woman presenting with subacute bilateral painless vision decline, lower-extremities weakness with impaired ambulation, headache, and abdominal pain. Neurological examination was pertinent for confabulation, bilateral decreased visual acuity with an absent blink to threat, absent afferent pupillary defect and fundus abnormalities, and significant allodynia in bilateral lower extremities. Besides elevated inflammatory marker with an erythrocyte sedimentation rate (ESR) of 130 mm/hr, her infectious, autoimmune, paraneoplastic, and neuromyelitis optica work-up was overall unremarkable. Brain MRI showed abnormal fluid-attenuated inversion recovery (FLAIR) signaling in bilateral mammillary bodies and around periaqueductal gray matter concerning WE. Due to concerns of Wernicke-Korsakoff syndrome (WKS), parenteral high-dose thiamine was initiated with significant clinical improvement. The patient was also later found to have a positive anti-myelin oligodendrocyte glycoprotein (MOG) antibody, which was deemed false positive given the atypical phenotype and symptomatic improvement with thiamine supplementation. This case encourages the consideration of vision loss as a manifestation of WKS, especially in patients who have risk factors. Testing serum levels of thiamine is strongly encouraged; however, initiating empiric treatment is advocated for high clinical suspicion due to its reversible nature and minimal risk for side effects.