• Neuroleptic Malignant Syndrome (NMS) is a life-threatening complication of anti-psychotic medication therapy.
   
• While NMS is rare (0.02 to 2.44% amongst those taking neuroleptic drugs), its associated mortality (up to 12%) and morbidity (i.e. rhabdomyolysis, pneumonia, seizures, renal failure, disseminated intravascular coagulation (DIC), respiratory failure) are severe.
   
• Historically, there has been little consensus about universally accepted diagnostic criteria for NMS, until an expert panel of various physician specialists recently convened and determined the following criteria:

           - Exposure to dopamine agonist or dopamine agonist withdrawal within past 72 hours
           - Hyperthermia
           - Rigidity
           - Mental status alteration
           - Elevated creatinine phosphokinase
           - Sympathetic nervous system lability (2 or more of the following: elevated blood pressure, fluctant blood pressure, urinary incontinence, diaphoresis)
           - Tachycardia and tachypnea
           - Negative work-up for infectious, metabolic, neurologic, or toxic etiologies.

• Treatment includes immediate withdrawal of any antipsychotic medication and is, otherwise, largely supportive.

 

References

• The Neuroleptic Malignant Syndrome Information Service. International Expert Panel Consensus on Diagnostic Criteria for NMS.