Tiny implants that produce stimulation deep inside the brain to block the tremors of Parkinson's disease. Deep brain stimulation, or DBS, uses tiny electrical jolts from a pacemaker-like generator near the collarbone to disable overactive nerve cells to stop the shaking.

The latest development involving brain pacemakers is to expand the use of these brain stimulators to tackle the most severe cases of depression, obsessive-compulsive disorder and Tourette's syndrome.