Deep brain stimulation - definition
involves implantation of an electrode in the brain. The electrode can be programmed to emit electrical impulses, which affect brain activity. Deep brain stimulation has been found to have therapeutic benefits in some cases of treatment-resistant Parkinson's disease, depression, and several other disorders. The mechanism by which it works, however, is still not very clear.
Deep brain stimulation in Parkinson's disease: Uncovering the mechanism