BackgroundThe dramatic evolution of incoercible vomiting in pregnancy is at the origin of a rare and serious neurological complication known as EGW; its symptomatology is polymorphic posing a diagnostic problem. MRI is the test of choice for screening. Early vitamin supplementation is essential to improve the maternal-fetal prognosis.Case presentationA 35-year-old parturient, G5P1, without particular pathological history presented incoercible vomiting at 8 weeks, which led to dehydration, undernutrition, and impairment of general condition. Neurological signs: headaches, confused scored at 14 on the Glasgow scale, amnesia, a cerebellar syndrome, sensory-motor deficit. Ophthalmological examination revealed: edema in the eye fundus, a decrease in visual acuity, nystagmus, and ophthalmoplegia. The biological analysis showed moderate hepatic cytolysis.Given the polymorphic neurological symptomatology presented by our parturient, several differential diagnoses were evoked: intracranial hypertension (headache - vomiting - decrease in visual acuity - papillary edema), brain stroke (sensory-motor deficit, ground “pregnancy”), deficit in vitamin B12 (sensory-motor deficit, confusion, memory impairment), and GWE (nystagmus-confusion-ataxia). Cerebral MRI has allowed us to establish the diagnosis of GWE.ConclusionAll pregnant with severe hyperemesis gravidarum should be supplemented with thiamine prior to glucose administration to prevent and improve the prognosis of GWE.