How does deep brain stimulation (dbs) treat parkinson's disease?

We don't fully know: But the wires are placed into deep basal ganglia nuclei and the electrical impulses stimulate the electrochemical discharges and basically help management of fluctuations and varying symptoms. One item of interest is absence of benefit if unresponsive to L-DOPA, so, obviously, this is one potential explanation, but not all to it.