Thiamine-deficient optic neuropathy associated with Wernicke's encephalopathy in patients with chronic diarrhea

The deficiency of thiamine manifesting as Wernicke's encephalopathy (WE) and concurrent optic neuropathy is rare. Herein, we report the case of a 29-year-old patient who suffered from bilateral sudden blindness and a disturbance of consciousness after 2 months of chronic diarrhea and minimal food intake. In addition, bilateral abducens nerve palsy with multidirectional nystagmus and no light perception in both eyes were noted. An ophthalmoscopic examination revealed bilateral disc edema with peripapillary flame-shaped hemorrhages. Although the results of analyzing the composition of cerebrospinal fluid showed that they are within normal limits, magnetic resonance imaging (MRI) revealed bilateral hyperintensity over the mammillary body, dorsal medial thalamus, and periaqueductal gray matter. As we suspected thiamine deficiency-induced WE, a high dose of intravenous thiamine was prescribed. After the administration of thiamine, both visual acuity and visual field rapidly improved with the simultaneous recovery of consciousness. This case indicates that, although rare, thiamine deficiency with WE may still occur in patients with chronic diarrhea in Taiwan. Thiamine deficiency should be considered in the differential diagnosis for patients who encounter sudden visual loss after prolonged periods of poor food intake and poor vitamin supplementation.