A patient on antipsychotics presents with muscle rigidity and fever. What condition might they have?

Neuroleptic Malignant Syndrome (NMS) is a potential life-threatening condition often associated with the use of antipsychotic medications. It is characterized by a classic triad of symptoms: severe muscle rigidity, hyperthermia (elevated body temperature), and autonomic dysregulation (which may manifest as changes in heart rate and blood pressure).

The muscle rigidity and fever presented in the scenario are hallmark signs of NMS. Additionally, other symptoms can include altered mental status, sweating, and increased creatine kinase levels due to muscle breakdown. This condition typically arises after the initiation or dose increase of antipsychotic medication, as these drugs can disrupt dopamine transmission in the central nervous system.

In contrast, while serotonin syndrome presents with some similar symptoms, it is generally associated with an excess of serotonin and occurs primarily with serotonergic agents rather than antipsychotics. Extrapyramidal symptoms consist of movement disorders that can occur with antipsychotic use but do not include the hyperthermia and autonomic instability seen in NMS. Akathisia is a type of movement disorder characterized by inner restlessness and an uncontrollable urge to be in constant motion, but it does not involve fever or severe rigidity.

Understanding these distinctions