Neuroanatomy USMLE Step 1 Practice Question
A 68-year-old man presents with sudden onset of violent, involuntary flinging movements of the left upper limb that are jerky and irregular. Vital signs show BP 158/92 mmHg, HR 88 bpm, RR 16, temp 37°C, SpO2 98% on room air. CT head reveals a right subthalamic nucleus infarct. Neurologic exam shows no sensory deficits or weakness. This patient's condition best represents loss of which of the following?
Answer choices
- AExcitatory input to the medial (internal) globus pallidusCorrect answer
- BDopaminergic input to the caudate
- CInhibitory input to the caudate
- DGlutamatergic input to the caudate nucleus
- EGABAergic input to the lateral globus pallidus
- FSubstantia nigra pars reticulata GABAergic output
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