Wernicke's Encephalopathy Secondary to Cannabis Hyperemesis Syndrome.

A woman in her 20s presented with an 8-week history of nausea and vomiting. She reported poor appetite and unintentional weight loss of more than 10 kg of her body mass. Two weeks before admission, she developed double vision followed by unsteady gait and confusion. Neurological examination revealed bilateral lateral rectus palsy with horizontal nystagmus in her eyes and ataxic gait. Brain MRI revealed T2/fluid attenuation inversion recovery (FLAIR) high signal in symmetrical thalamic hyperintensities suggestive of Wernicke's encephalopathy (WE). The patient was given intravenous thiamine and made a rapid and dramatic recovery. Through this case, we wish to highlight a rare presentation of WE in a non-alcoholic patient precipitated by thiamine deficiency secondary to Cannabis hyperemesis syndrome.