A 67-year-old man with Parkinson disease treated with levodopa/carbidopa 25/100 mg four times daily for 5 years presents with involuntary writhing movements of his extremities and trunk that worsen 2–3 hours after each dose and improve with the next medication administration. Vital signs: BP 138/82, HR 88, RR 16, Temp 37°C, SpO2 98%. Neurological examination reveals choreoathetoid movements predominantly affecting the neck and upper limbs during peak plasma drug levels. MRI brain shows no acute abnormalities. He denies recent medication changes. Which of the following best describes this complication?
- A)Chorea from excessive dopamine in the cerebellum
- B)Akathisia from serotonin depletion
- C)Dystonia from carbidopa accumulation in the basal ganglia
- D)Tremor from inadequate MAO-B inhibition
- E)Dyskinesias from long-term levodopa exposure and dopamine receptor sensitizationGABARITO
Explicação
Long-term levodopa therapy causes dyskinesias due to pulsatile dopamine stimulation and sensitization of striatal dopamine receptors. These involuntary movements are dose-dependent and occur years after treatment initiation, correlating with medication timing ... Ver explicação completa e trilha adaptativa →