Deep brain stimulation
Deep brain stimulation (DBS) is one of a group of treatments involving surgical implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain. DBS was approved by the Food and Drug Administration (FDA) in 1997 as a treatment for essential tremor and in April 2003 as a treatment for dystonia. The FDA approved DBS for Parkinson's disease in 2002. DBS may also alleviate symptoms in treatment-resistant clinical depression, and has been used experimentally in the treatment of other conditions. While DBS is helpful for some patients, there is potential for serious complications and side effects.
The deep brain stimulation system consists of three components: the implanted pulse generator (IPG), the lead, and the extension. The IPG is a battery powered neurostimulator encased in a titanium housing, which sends electrical pulses to the brain to interfere with neural activity at the target site. The lead is a coiled wire insulated in polyurethane with four platinum iridium electrodes and is placed in one of three areas of the brain. The lead is connected to the IPG by the extension, an insulated wire that runs from the head, down the side of the neck, behind the ear to the IPG, which is placed subcutaneously below the clavicle or in some cases, the abdomen. The IPG can be calibrated by a neurologist, nurse or trained technician to optimize symptom suppression and control side effects.
DBS leads are placed in the brain according to the type of symptoms to be addressed. For essential tremor and Parkinsonian tremors, the lead is placed in the thalamus. For dystonia and symptoms associated with Parkinson's disease (rigidity, bradykinesia/akinesia and tremor), the lead may be placed in either the globus pallidus or subthalamic nucleus.