How DBS Works
In Parkinson’s disease (PD), essential tremor, dystonia and certain other neurological disorders, abnormal signals exist in various parts of the brain. Deep brain stimulation overrides these abnormal signals to reduce your symptoms.
Your doctor inserts an electrode(s) into your deep brain structures and connects them to a pacemaker-like device in the chest, called an implantable pulse generator. When the electrodes are stimulated, they create an electrical field that disrupts and modulates the abnormal signals at the target location in your brain.
DBS has replaced most of the earlier procedures that permanently disrupted the abnormal signals by creating a lesion at the target brain site.
What Parts of the Brain Does DBS Target?
Deep brain stimulation targets three areas in the brain. Each patient who has DBS has only one of these targets stimulated, as they do different things. A patient’s disease, disability and safety determines which target to stimulate.
- Ventralis intermedius nucleus of the thalamus – This powerful anti-tremor target is primarily used for essential tremor, sometimes PD
- Subthalamic nucleus (STN) – This target helps to suppress tremor as well as reduce slowness and stiffness; a primary target for PD, sometimes dystonia
- Globus pallidus interna (GPi) – This target helps reduce slowness and stiffness as well as tremor, suppresses excessive movements (dyskinesia) and is a primary target for PD and dystonia
Parts of the DBS System
Three main components form the DBS system: the electrodes, the pulse generator and the programmer.
We place the electrodes into the brain at the specified target. We often do this while you’re awake to make sure they are in the right position. While we implant the device while you are awake, the procedure is painless. We then connect the electrodes by an extension lead under the skin to a pulse generator that sits below the collarbone.
We implant the pulse generator while you’re under general anesthesia. The pulse generator contains both the electronics of the system and the battery.
We adjust the settings of DBS with an external programmer that’s connected wirelessly to the pulse generator. We use the programmer to optimize benefit and minimize adverse effects.
Finding the best settings for your pulse generator can take about three months of outpatient visits.