Neuroleptic Malignant Syndrome: The Daily PANCE Blueprint

The answer is B. Dopamine D2 receptor blockade in the hypothalamus and basal ganglia

This is neuroleptic malignant syndrome (NMS). Antipsychotics block dopamine D2 receptors: in the hypothalamus that disrupts temperature regulation and the autonomic nervous system, and in the nigrostriatal pathway it produces “lead-pipe” rigidity. The tetrad is fever, rigidity, altered mental status, and autonomic instability, with a very high CK; it develops over days, usually soon after starting or increasing a high-potency antipsychotic, or after abruptly stopping levodopa. Treatment: stop the drug, cool, give IV fluids to protect the kidneys from myoglobin, give benzodiazepines, and add dantrolene or bromocriptine in severe cases. Serotonin syndrome comes on within hours with hyperreflexia and clonus. Malignant hyperthermia is a ryanodine receptor defect triggered by inhaled anesthetics or succinylcholine. Anticholinergic toxicity causes hot, dry skin without rigidity.