Neuroleptic malignant syndrome (NMS) is a rare, potentially life-threatening disorder that results from the use of neuroleptics. NMS was first recognised as a complication of dopamine receptor antagonists characterized by extrapyramidal disturbances, hyperthermia, muscle rigidity, autonomic instability, mental status changes and elevated serum creatine kinase levels. Concepts of NMS have changed because medications other than classic neuroleptic drugs have been implicated as triggering agents. The incidence of NMS is about 0.2% with a mortality between 4-30%, which may be diminished by treatment. The neurochemical key features in all these conditions probably result from disruption of the dopamine system in the brain and the effects of neuroleptics on muscle. Recognition of NMS is the most important step in its management by discontinuation of the causative drugs and applying supportive care and therapeutic measures. Specific therapeutic measures include the application of dopamine receptor agonists, e.g. dantrolene and use of benzodiazepines. The differential diagnosis of NMS comprises an extensive list of disorders presenting with fever and with muscle rigidity. Neuroleptics may be reintroduced in the majority of patients by using an atypical neuroleptic drug such as clozapine.
