Deep brain stimulation: how does it work?

Deep brain stimulation has significantly improved the motor symptoms in patients with Parkinson's disease (PD) and other movement disorders. The mechanisms responsible for these improvements continue to be explored. Inhibition at the site of stimulation has been the prevailing explanation for the symptom improvement observed with deep brain stimulation. Research using microelectrode recording during deep brain stimulation in the MPTP monkey model of PD has helped clarify how electrical stimulation of structures within the basal ganglia-thalamocortical circuit improves motor symptoms, and suggests that activation of output and the resultant change in pattern of neuronal activity that permeates throughout the basal ganglia motor circuit is the mechanism responsible for symptom improvement.