Wernicke’s encephalopathy is a deficiency pathology caused by a profound deficiency in thiamine (vitamin B1). It most often occurs on an alcoholic ground, but it can occur in other pathological situation, sometimes it is difficult to diagnose but the evolution in the absence of treatment leads to severe cognitive sequelae. Magnetic resonance imaging is the reference examination to confirm the diagnosis, but in 40% of cases it is strictly normal. The diagnosis then remains based on the clinical signs and above all, on the significant improvement after treatment with thiamine. We report the case of a 32-year-old woman with hyperemesis gravidarum, causing symptomatic Wernicke’s encephalopathy with normal radiology