Deep Brain Stimulation

Boston Children’s Hospital is now offering deep brain stimulation (DBS) for children with primary dystonia, a type of movement disorder in which faulty brain signals cause involuntary muscle contractions. These lead to abnormal, taxing movements, typically repetitive twisting or contorting of the arms, legs, neck or other body parts. Primary dystonia, unlike secondary dystonia caused by a brain injury, is thought to be genetic in origin.


Dystonia may occur only in a specific part of the body, like the eyelid or hand, or it may affect many body regions. Often, the dystonia progresses and spreads most rapidly in the first five years after its onset, then begins to stabilize. Dystonia may be present at rest, but often becomes much worse when the child is doing a specific task or motion, like writing or walking. As a result, dystonia can become highly disabling.

Primary dystonia is often painful, and the abnormal movements and postures may embarrass the child and make it difficult to perform well in school. Some children become wheelchair-bound, and if dystonia is left untreated for years, it can cause permanent damage to joints and muscles as the limb “freezes” into the dystonic position. Most children with primary dystonia have a normal life expectancy.

What is deep brain stimulation and how can it help?

DBS therapy uses a small device similar to a pacemaker, called a neurostimulator, to send mild electrical pulses to the parts of the brain that are responsible for the involuntary movements. The neurostimulator, manufactured by Medtronic, is implanted just under the skin, usually below the collarbone. It is connected to electrodes (or “leads”) implanted in the brain by a thin, flexible wire. The electrodes are precisely placed in a part of the brain called the basal ganglia, part of the brain's motor circuit.

When the neurostimulator is turned on, it can give children with primary dystonia more control over their body movements. The settings are adjustable with a handheld wireless device, so the doctor can program the stimulator to the child’s individual needs. The family also receives a programming device to monitor and adjust the device as needed. The system can be safely removed at any time.

How DBS works isn’t completely known, but it has proven effective in several neurological disorders (not just dystonia). It is thought that the brain cells of children with primary dystonia signal too much, and that extra signals “spill over” to activate the wrong muscles. The electrical stimulation “dials back” these abnormal signals. DBS has been in use for more than 20 years, and according to the device manufacturer, more than 100,000 people around the world have received DBS therapy.

Because dystonia is relatively rare compared with disorders like Parkinson disease (the most common DBS application), the Food and Drug Administration (FDA) has granted approval under a Humanitarian Device Exemption. This designation is used for treatments that are recognized to be safe but that require further study in larger groups of patients to know how best to use them.

Patient Story

How Tim Froio became a bionic man

Implanting electrodes deep in the brain sounds like something out of science fiction,  but it's helped calm down violent, involuntary jerky movements that were robbing Tim Froio of a normal life. Read his fascinating, still-evolving story here.