Severe Thiamine Deficiency Secondary to Hyperemesis Gravidarum Mimicking Guillain–Barré Syndrome: A Fatal Case Report

Severe thiamine deficiency during pregnancy is rare but may lead to serious neurological complications mimicking Guillain–Barré syndrome, resulting in diagnostic delay. We report the case of a 27-year-old pregnant woman at 20 weeks of gestation with type 1 diabetes who presented with persistent vomiting followed by progressive neurological impairment. Brain magnetic resonance imaging was normal, while chest imaging revealed bilateral bronchopneumonia. Cerebrospinal fluid analysis showed albuminocytologic dissociation, initially suggesting Guillain–Barré syndrome. However, prolonged hyperemesis gravidarum raised suspicion of severe thiamine deficiency with neurological involvement. Intravenous thiamine therapy and intensive care support were initiated. The patient developed respiratory failure requiring mechanical ventilation and died due to severe pulmonary infection. This case highlights the importance of early recognition and empirical treatment of thiamine deficiency in pregnant women with prolonged vomiting, particularly in low-resource settings.