Neuroleptic malignant syndrome (NMS) is an uncommon but potentially fatal adverse effect of neuroleptic, both classic and atypical drugs.

To review the incidence, clinical characteristics, diagnosis and treatment of NMS.

We have described the case of a man of 32 years of age diagnosed with bipolar disorder treated with lithium. He precised high-dose corticosteroids after having tonsillitis. Then, he presented manic decompensation requiring neuroleptic treatment (oral risperidone). After 72 hours, he presented an episode characterized by muscular rigidity, fever, altered mental status and autonomic dysfunction. Life support measures and suspension of neuroleptic treatment were required.

A literature review of the NMS was performed using the PubMed database.

The frequency of NMS ranges from 0.02 to 2.4%. The pathophysiology is not clearly understood but the blockade of dopamine receptors seems to be the central mechanism. Some of the main risk factors described are: being a young adult, the concomitant use of lithium and metabolic causes, among others. NMS occurs most often during the first week of treatment or after increasing the dosage of the neuroleptic medication. Some issues of NMS are those related with diagnosis, treatment and reintroduction of antipsychotic treatment or not.

NMS can be difficult to diagnose due to the variability in the clinical symptoms and presentation. Because of it diagnosis is of exclusion, clinicians should always take it into consideration when a patient is treating with neuroleptic, especially when the dosage has been recently increased. NMS is a clinical emergency.

The authors have not supplied their declaration of competing interest.