Fig. 2
From: Hemichorea in a patient with ipsilateral cortical infarction: a case report
The subthalamic nucleus (excitatory) is directly activated by cortical inputs, enhancing the inhibitory activity of the globus pallidus internal. This leads to increased inhibition of the thalamus, and then decreased motor response. B. When the cortex is impaired, the inhibition of thalamus decreases, and then motor response increases. The picture was drawn by Mr. Wende Zhang