Wernicke Encephalopathy in a Pediatric Patient with Avoidant Restrictive Food Intake Disorder: A Rare Presentation of Thiamine Deficiency.

BACKGROUND Wernicke encephalopathy is traditionally associated with chronic alcoholism, nutritional imbalance, prolonged intravenous feeding, hyperemesis, anorexia nervosa, and malabsorption syndromes. We report a case of Wernicke's encephalopathy in a 12-year-old girl with avoidant restrictive food intake disorder. CASE REPORT The patient had lost 45.4 kg of body weight due to self-imposed changes to her diet, before presenting with decreased oral intake for 2-3 weeks, intermittent nausea, crampy epigastric pain, and post-prandial emesis. Her weight on admission was 78.2 kg. She received intravenous fluids of dextrose 5% with normal saline while she initially attempted to eat, but the post-prandial emesis persisted. She developed a fear of vomiting, which led to even more severe food intake restriction. After a week, she began to report double vision and blurred peripheral vision, with physical findings of nystagmus and an ataxic gait. She was empirically started on thiamine after negative neurology workup, with improvement of her gait, blurry vision, and nystagmus. Thiamine deficiency was later confirmed. CONCLUSIONS In patients with large amounts of weight loss presenting with neurological symptoms, Wernicke's encephalopathy must be considered in the differential diagnosis. Avoidant restrictive food intake disorder is rarely reported to cause Wernicke's encephalopathy. To the best of our knowledge, this is the first pediatric case demonstrating that Wernicke encephalopathy can occur in this type of eating disorder and not just in anorexia nervosa.