Neuroleptic Malignant Syndrome - Diagnosis Neuroleptic Malignant Syndrome is an idiosyncratic reaction to antipsychotic medications classically characterized by the following tetrad: altered mental status, generalized rigidity, hyperthermia, and autonomic instability. This classic tetrad is present in 97% of NMS patients. Triggers: - Antipsychotics (higher risk with IV admin, but not dose dependent and can occur at any tine after initiation of antipsychotics) - Antiemetics - Withdrawal or dose decrease of dopaminergic medications (i.e. when treating Parkinsons) DDx for diffuse rigidity, dysautonomia, and altered mental status: • NMS, Serotonin Syndrome, Delirium tremens, Nonconvulsive status epilepticus, Malignant catatonia, Stiff-person syndrome, Anti-NMDA receptor encephalitis, Tetanus Presentation: - Altered mental status: catatonic signs and mutism are prominent - Rigidity: "lead pipe rigidity" +/- tremor → cogwheel effect (+/- dystonia, dysarthria, dysphagia, trismus, chorea, sialorrhea), Reflexes are decreased - Hyperthermia: 40% of patients have temps >40 degrees C - Autonomic instability: Tachycardia, labile or increased BP, tachypnea, diaphoresis, dysrhythmias SCVMC Internal Medicine @SCVMCMed #Neuroleptic #Malignant #Syndrome #Diagnosis #neurology
