Question

This patient is taking an analog of dopamine which binds to D1 receptor on the striatum, increasing its activity to send out inhibitory GABA signal to the GPi, which has GABA inhibitory projection to the VA/VL nuclei of the thalamus. This ultimately leads to a disinhibition of the thalamus by GPi causing him to have excessive body movements.

Options:
a) High frequency deep brain stimulation targeted at suppressing neuronal activity to the subthalamic nucleus
b) High frequency deep brain stimulation targeted at suppressing neuronal activity to the globus pallidus interna

Answer 1

To reduce the patient's excessive body movements, the appropriate treatment would be high frequency deep brain stimulation targeted at the globus pallidus interna (GPi), which would help to suppress the overactive indirect pathway responsible for the symptoms.

Step-by-step explanation:

The patient's symptoms of excessive body movements due to the use of a dopamine analog activating D1 receptors suggest a treatment involving deep brain stimulation (DBS). In the context of reducing excessive movement, the globus pallidus interna (GPi) is usually the target for DBS because of its role in the indirect pathway which, when overactive, can inhibit movement excessively. Considering that GPi receives inhibitory GABAergic inputs from the striatum, which would reduce its inhibitory effect on the thalamic nuclei and result in increased motor activity, it is logical to target the GPi to suppress this pathway and reduce motor activity.

Given this reasoning, option b), which is high frequency deep brain stimulation targeted at suppressing neuronal activity to the globus pallidus interna (GPi), would likely be the more appropriate treatment to reduce the patient's excessive body movements.