Anticholinergic toxicity masquerading as neuroleptic malignant syndrome: a case report and review

Patients who present with acute neuropsychiatric syndromes pose difficult diagnostic and treatment challenges. A history of psychiatric illness and treatment with psychotropic medication may be valuable clues to diagnosis and management of such patients. However, this information may also tempt a clinician to focus on a premature diagnosis, excluding other important possibilities. A case of a 42-year-old male with recurrent psychotic illness who developed an abrupt deterioration in mental and physical status is presented. Despite an initial good response to physostigmine, he was diagnosed with neuroleptic malignant syndrome and did not receive subsequent treatment with cholinesterase inhibitors. The patient expired within hours of arriving in the emergency room. The postmortem benztropine level was elevated, leading to the attribution of death to anticholinergic toxicity. This case serves to illustrate the difficulties in distinguishing features of anticholinergic toxicity and neuroleptic malignant syndrome.