JAMA patient page. Deep brain stimulation.

The JAMA Patient Page is a public service of JAMA. The information and recommendations appearing on this page are appropriate in most instances, but they are not a substitute for medical diagnosis. For specific information concerning your personal medical condition, JAMA suggests that you consult your physician. This page may be photocopied noncommercially by physicians and other health care professionals to share with patients. To purchase bulk reprints, call 312/464-0776. Deep brain stimulation requires precisely locating a specific target area in the brain using stereotactic (3-dimensional) imaging techniques with x-ray, computed tomography (CT), or magnetic resonance imaging (MRI). After drilling a small hole in the skull, special hardware allows accurate image-guided placement of an electrode in the targeted part of the brain. Testing during the surgery may be done to ensure that the electrode will stimulate only neurons (nerve cells) that reduce symptoms. Each neurological disease has specific target neurons. For example, for Parkinson disease, these are neurons in the subthalamic nucleus or globus pallidus (regions of the brain); for essential tremor or epilepsy, neurons in the thalamus (another region in the brain). Because the most effective intensity and frequency of electric stimulation vary among diseases and patients, electrode placement is followed by testing to choose proper stimulation settings. Although it is unclear how DBS works, the most likely explanation is that it rewires brain circuits and leads to a better balance between inhibitory and excitatory pathways in the brain.