A Rare Case of Thiamine Deficiency Leading to Dry Beriberi, Peripheral Neuropathy, and Torsades De Pointes

Thiamine (vitamin B1) is an essential nutrient and one of the eight B vitamins. As a water-soluble vitamin, thiamine is not stored; therefore, a balanced diet is required to ensure adequate intake of this essential vitamin. Thiamine deficiency is known to cause both wet and dry beriberi, but rarely in combination. Thiamine deficiency has also been known to cause QTc prolongation, but the mechanism remains unclear. In the most severe cases, this can lead to the lethal arrhythmia of torsades de pointes. This case describes a patient who became malnourished after a closed head injury and initially presented with seizure-like activity and syncopal episodes with nonspecific numbness. He was found to have prolonged QTc, leading to torsades de pointes requiring an implanted cardioverter defibrillator. With extensive workup, including genetic testing, the patient was found to have indetectable thiamine levels. With supplementation, the patient no longer had any recorded ventricular arrhythmias, and neurological function improved with only residual tingling in the hands. This case emphasizes the profound effects of thiamine deficiency and why this should be included in our differential diagnosis for patients presenting with the sequelae of the signs and symptoms discussed.