Gayet-Wernicke encephalopathy is a neuropsychiatric emergency due to thiamine (vitamin B1) deficiency, secondary to several factors, it is a disorder characterized by confusion of acute onset, nystagmus, partial ophthalmoplegia and ataxia. The diagnosis is mainly clinical. The disorder may resolve with treatment, persist, or degenerate into Korsakoff's psychosis. We report a case of Gayet-Wernicke encephalopathy in a 39 year old non-ethylic patient, pregnant at 17 weeks of age who presented with consciousness disorders with paresthesia of the 4 limbs and dyspnea. Clinical and magnetic resonance imaging (MRI) have an important place, especially in the diagnosis of non-alcoholic Wernicke's encephalopathy.