An Uncommon Presentation of Hyperthyroidism Can Culminate in Devastating Neurological Consequences: A Case Report.

Wernicke's encephalopathy remains largely an underdiagnosed condition. It has two variants: alcoholic and non-alcoholic. A 56-year-old female patient presented with two weeks of persistent nausea, vomiting, and unintentional weight loss. Initial investigations revealed hypercalcemia associated with pancreatitis of biliary origin for which she underwent cholecystectomy as well as thyroiditis resulting in postoperative initiation of methimazole. Persistent symptoms prompted esophagogastroduodenoscopy (EGD), which was unremarkable. She developed diffuse weakness and impaired memory with poor orientation. Magnetic resonance imaging of the brain showed fluid-attenuated inversion recovery (FLAIR) hyperintensity at the central pons and bilateral thalami. Her mental status continued to worsen rapidly within a few days, and she became minimally responsive, hypothermic, and hypotensive; as such, she was intubated for airway protection. Cerebrospinal fluid analysis was unremarkable. She received a thiamine replacement. Repeat MRI after a few days showed improving thalamic hyperintensities with improvement in mentation. This case serves to remind clinicians of the uncommon link between hyperthyroidism and non-alcoholic Wernicke's encephalopathy (WE).