Non-alcoholic Wernicke encephalopathy in an esophageal cancer patient receiving radiotherapy: A case report

BACKGROUND Wernicke encephalopathy is a rare but potentially fatal adverse event caused by thiamine deficiency. Reports of non-alcoholic Wernicke encephalopathy due to malignancy are scarce in the literature, with those reported mainly being on haematological cancer, followed by gastrointestinal cancer. As a result, there is considerable under-recognition and delay in the diagnosis and treatment of Wernicke encephalopathy in oncology departments. To our knowledge, there has been no report of Wernicke encephalopathy in a patient with esophageal cancer while receiving radiotherapy. CASE SUMMARY A 64-year-old man presented to the oncology outpatient clinic with a history of dysphagia for 2 mo, and was diagnosed with locally advanced esophageal squamous cell carcinoma (stage IIIB). Radiotherapy was initiated to alleviate dysphagia due to malignant esophageal stenosis; however, the patient exhibited consciousness disturbances starting on day 10 of radiotherapy. Brain magnetic resonance imaging indicated the development of Wernicke encephalopathy. Subsequent treatment with thiamine led to rapid improvement in the patient's neurological symptoms. CONCLUSION Wernicke encephalopathy may develop in non-alcoholic patients undergoing radiotherapy for esophageal cancer. Early diagnosis and sufficient thiamine supplementation during radiotherapy are essential.