A 22-year-old woman was admitted to the emergency department with headache, dizziness, and numbness on the left side of the body. Neurologic examination revealed gaze-evoked nystagmus. Cranial magnetic resonance imaging, venous and arterial magnetic resonance angiography were normal. Generalized epileptogenic activity was observed in the electroencephalography. The erythrocyte thiamine transketolase levels were found to be 13 u/L. She received intravenous thiamine. On discharge, she had no neurologic sequelae. The diagnosis of Wernicke encephalopathy in our patient is based on increased thiamine requirement due to pregnancy, nystagmus, low transketolase level, and reversal of symptoms after thiamine replacement. .