RESUMEN
INTRODUCTION: Nowadays, reports of beriberi are rare in developed countries. Wernicke encephalopathy may be present in about 25% of patients with beriberi. CASE REPORT: We report the case of a woman with history of depression and chronic eating disorder, who complained Wernicke encephalopathy and beriberi. Sural nerve and muscular biopsy were performed, showing severe axonal neuropathy. Thiamine supplementation was started with rapid improvement of the pulmonary and cardiac affections; improvement of peripheral neuropathy was incomplete. CONCLUSIONS: Thiamine deficiency can be misdiagnosed. Beriberi is an important cause of acute flaccid paralysis; hence, clinicians should consider this diagnosis and prompt start thiamine treatment to avoid permanent neurological sequelae.