Movement disorders are neurological conditions that cause abnormal movements. Two of the most common movement disorders are Parkinson's disease and essential tremor. Deep brain stimulation (DBS) is a surgical procedure where electrodes are placed in the brain and then connected to a pacemaker-like device in the chest. When the stimulation is turned on, it can help the symptoms of both Parkinson's disease and essential tremor. Patients are candidates for DBS when their medications don't work well to control tremor.