Background: Hemiballism/hemichorea commonly occurs as a result of a lesion in the subthalamic region.
Case report: A 38-year-old male with Parkinson's disease developed intractable hemiballism in his left extremities due to a small lesion that was located adjacent to the right deep brain stimulation (DBS) lead, 10 months after bilateral subthalamic nucleus (STN)-DBS placement. He underwent a right globus pallidus internus (GPi)-DBS lead implantation. GPi-DBS satisfactorily addressed his hemiballism.
Discussion: This case offered a unique look at basal ganglia physiology in human hemiballism. GPi-DBS is a reasonable therapeutic option for the treatment of medication refractory hemiballism in the setting of Parkinson's disease.
Keywords: Globus pallidus internus; deep brain stimulation; hemiballism; stroke; subthalamic nucleus.