Sections View Full Chapter Figures Tables Videos Annotate Full Chapter Figures Tables Videos Supplementary Content + Download Section PDF Listen ++ For further information, see CMDT Part 25-11: Schizophrenia Spectrum Disorders + Key Features Download Section PDF Listen +++ ++ A catatonia-like state manifested by Extrapyramidal signs Blood pressure changes Altered consciousness Hyperpyrexia Uncommon complication of antipsychotic treatment Comorbid affective disorder as well as concomitant lithium use may increase risk In most cases, occurs within 2 weeks of starting antipsychotic agent + Clinical Findings Download Section PDF Listen +++ ++ Muscle rigidity, involuntary movements, confusion, dysarthria, dysphagia Pallor, cardiovascular instability, pulmonary congestion, diaphoresis Can result in stupor, coma, death Differential diagnosis Malignant catatonia Malignant hyperthermia Neurotoxic syndromes (including AIDS) Various other conditions such as viral encephalitis, Wilson disease, central anticholinergic syndrome, and hypertonic states (eg, tetany, strychnine poisoning) + Diagnosis Download Section PDF Listen +++ ++ Elevated creatine kinase and leukocytosis with left shift in 50% of cases + Treatment Download Section PDF Listen +++ ++ Control of fever and intravenous fluid support Bromocriptine, 2.5–10.0 mg three times daily orally, and amantadine, 100–200 mg twice daily orally, can be tried Dantrolene, 50 mg intravenously as needed to maximum of 10 mg/kg/day, can alleviate rigidity Efficacy of these three agents as well as the use of calcium channel blockers and benzodiazepines remains controversial Electroconvulsive therapy has been used in resistant cases Clozapine has been used safely in patients with a history of neuroleptic malignant syndrome