Suspected Thiamine Deficiency Secondary to Chronic Gastrointestinal Illness: A Case Report.

Introduction: Thiamine deficiency, also known as beriberi, is a nutritional disorder caused by a lack of thiamine (vitamin B₁) in the diet. It can occur in 2 forms: dry beriberi, which affects the nervous system, and wet beriberi, which affects the cardiovascular system. Gastrointestinal beriberi is a subtype that affects the digestive system and can lead to multisystem involvement. In the United States (US), thiamine deficiency often arises from chronic malnutrition secondary to alcoholism, known as Wernicke-Korsakoff Syndrome.

Case presentation: A 45-year-old female with no known past medical history or alcohol use disorder came to the emergency department with an altered mental status and with a history of intractable nausea and vomiting for several months prior to presentation. During intake, the medical team discovered she had bilateral lower extremity weakness and an anion gap metabolic acidosis. Her inpatient workup ruled out meningitis, encephalitis, peritonitis, diabetic ketoacidosis, and cerebrovascular accident. A thiamine deficiency was the most probable cause of her presentation, secondary to her protracted history of vomiting and poor oral medication intake. Refeeding syndrome complicated her hospitalization. After replenishing thiamine, the patient experienced significant improvement in mental status and lower extremity weakness. The healthcare team later discharged her with home physical therapy rehabilitation and nutritional counseling.

Conclusion: Thiamine deficiency is not common in the US. However, this case highlights the importance of including this deficiency in the differential when a patient arrives with a history of malnourishment secondary to a gastrointestinal illness with signs of altered mental status and neurological symptoms.