[When the brain starves: A life-threatening neurological complication following bariatric surgery].

In this case report, we describe a 31-year-old female patient who presented with intermittent diplopia, progressive gait instability, dizziness and forgetfulness. Clinical examination revealed decreased level of consciousness (Glasgow Coma Scale score of 14), horizontal and vertical gaze-evoked nystagmus, bilateral abducens nerve palsy, and severe truncal and gait ataxia. Laboratory analyses did not reveal any diagnostic findings. Brain magnetic resonance imaging (MRI) showed bilateral FLAIR-hyperintensities in the dorsomedial thal-amus, mammillary bodies, and around the third ventricle extending into the quadrigeminal plate of the midbrain, findings indicative of Wernicke's encephalopathy. Given the patient's history of sleeve gastrectomy performed three months earlier, and the presumed thiamine (vitamin B1) deficiency due to malabsorption, reduced nutritional intake, and lack of micro-nutrient supplementation, the diagnosis of Wernicke's encephalopathy was established and high-dose intravenous thiamine therapy was initiated.