Movement Disorders USMLE Step 1 Practice Question
A 59-year-old man with schizophrenia on haloperidol develops confusion, diffuse lead-pipe rigidity, and diaphoresis 3 days after a dose increase. Vital signs show temperature 39.8°C, heart rate 118/min, blood pressure 156/92 mmHg, and respiratory rate 22/min. Serum creatine kinase is 3,200 U/L. Reflexes are normal. Which of the following best distinguishes this condition from serotonin syndrome?
Answer choices
- AOnset within minutes of ingestion is more typical of neuroleptic malignant syndrome
- BLead-pipe rigidity and dopamine blockade are more typical of neuroleptic malignant syndromeCorrect answer
- CHyperreflexia and clonus are more typical of neuroleptic malignant syndrome
- DExposure to monoamine oxidase inhibitors is more typical of neuroleptic malignant syndrome
- EMydriasis and diarrhea are more typical of neuroleptic malignant syndrome
- FElevated creatine kinase with normal reflexes is more typical of neuroleptic malignant syndrome
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