An atypical presentation of neuroleptic malignant syndrome: diagnostic dilemma in a critical care setting.

Neuroleptic malignant syndrome (NMS) is a life-threatening condition associated with the use of neuroleptic agents and is characterized by a clinical syndrome of mental status change, muscle rigidity, fever, and autonomic instability.1 We present a case of NMS in a patient on neuroleptic therapy who had the atypical presentation of not having muscle rigidity, in spite of an extremely elevated CK level, which was initially misdiagnosed as a case of acute liver failure secondary to acetaminophen toxicity. Atypical presentations such as these pose a challenge to the early diagnosis and treatment of NMS, and we highlight the importance of having a high index of suspicion for this condition.