Case Presentation: A 13- year-old male with a history of food aversions receiving outpatient feeding therapy and normal BMI presented to the ED with one month of vomiting, dysphagia, anorexia, and an unintentional ten-pound weight loss. He was afebrile with normal vital signs. On exam, he had dry mucus membranes and mild diffuse abdominal tenderness. Labs were notable for low bicarbonate, total bilirubin 2.3 mg/dL, lipase 313 U/L, uric acid 12.2 mg/dL, and high urine specific gravity. Complete blood count, thyroid stimulating hormone, lactate dehydrogenase, inflammatory markers, remainder of electrolytes, urinalysis and liver function panel were normal. He was admitted and treated with dextrose containing intravenous (IV) fluids, pantoprazole, and ondansetron. History revealed a limited diet with intake of eight specific foods for several years. Abdominal ultrasound, upper GI series, upper endoscopy, and CT head were all noncontributory. Three days into admission, lateral nystagmus was noted; and otherwise, he had improved oral intake and resolution of emesis. Five days into admission, he had bilateral lower extremity weakness and altered mental status. Physical exam was notable for upper extremity dysmetria, diffuse hyperreflexia, up beating and lateral nystagmus, and generalized weakness. MRI brain showed diffusion restriction in bilateral caudate nuclei and thalami. MRI spine and lumbar puncture studies were unremarkable. Given his history of restricted eating and MRI findings, Neurology and Genetics were consulted – medical teams were most concerned for thiamine deficiency and he was started on empiric high dose IV thiamine. Within 36 hours, he had improved mentation, confirming a diagnosis of Wernicke Encephalopathy. Thiamine level returned at 39 nmol/L (70-180 nmol/L) and multiple additional micronutrient deficiencies were found. He was treated with high dose IV thiamine for seven days followed by maintenance dosing. He was diagnosed with avoidant/restrictive food intake disorder. He had an enteral tube placed to optimize nutrition with ongoing physical and occupational therapies.
Discussion: Wernicke Encephalopathy (WE) is an acute neurologic disorder caused by thiamine deficiency characterized by nystagmus, cerebellar dysfunction, and altered mental status. WE is most often seen in adults with high alcohol intake; however, can occur in children with malnutrition, extended ICU stays, malignancies, and post bariatric surgery. Nutritional deficiencies are often difficult to identify, especially in the context of a normal BMI or recent illness. A high index of suspicion is required with a concerning dietary history.
Conclusions: This case highlights the importance of obtaining a detailed nutritional history and considering the administration of thiamine when starting dextrose-containing fluids in patients suspected of having nutritional deficiencies. Thiamine is relatively inexpensive, has a minimal side effect profile, and can prevent progression to medical emergencies such as WE.