Thiamine deficiency in oncology: Clinical insights from two cases of Wernicke's encephalopathy

Wernicke's encephalopathy (WE) is a neurological disorder primarily caused by thiamine deficiency, typically presenting with malnutrition, confusion or delirium, oculomotor abnormalities (such as nystagmus or ophthalmoplegia), and ataxia. Although commonly associated with alcoholism, WE is frequently observed in oncology patients but is often under-recognised, leading to inadequate diagnosis and treatment. Malnutrition and rapid weight loss in cancer patients can increase the risk of this condition. We report two patients with cancer who presented with significant malnutrition and weight loss, leading to a diagnosis of WE. Both patients were diagnosed based on clinical presentation and magnetic resonance imaging, which is crucial for detecting neurological deficits. Immediate treatment with intravenous thiamine led to a positive clinical response. Early recognition and treatment of WE in oncology patients is essential, as the neurological deficits are potentially reversible. Intravenous thiamine supplementation, and supportive care, can prevent long-term complications.