Deep brain stimulation (DBS) is a variation of an old surgery that may be used to treat tremors in people with conditions such as multiple sclerosis, Parkinson's disease, and essential tremor. In the 1960s, surgery was used to destroy a small area deep in the brain called the thalamus (thalamotomy) or another part of the brain called the globus pallidus (pallidotomy).

These surgeries are still done today, although less frequently because of the availability of deep brain stimulation. These surgeries carry significant risks: both thalamotomy and pallidotomy require purposeful destruction of the brain. If the surgeon is off by even a fraction of an inch, the surgery may not be effective and severe complications such as paralysis, loss of vision or loss of speech can result.

Deep brain stimulation is a way to inactivate parts of the brain without purposefully destroying the brain. Therefore, the risks are much lower. In deep brain stimulation, an electrode is placed with the tip of the electrode in the thalamus (for tremor and multiple sclerosis) or in the globus pallidus or subthalamic nucleus (for Parkinson's disease).

The electrode for deep brain stimulation is left in the brain. It is connected by a wire to a pacemaker-like device that is implanted under the skin over the chest. The pacemaker-like device generates the electrical shocks.

What Are the Advantages of Deep Brain Stimulation?

Deep brain stimulation offers many advantages. The electrical stimulation is adjustable, whereas surgical destruction is not. The electrode has four metal contacts that can be used in many different combinations. Even if one electrode contact is not in the exact location, it is likely that one of the others or some combination of the electrical contacts will be closer to the proper target. As the patient's response to surgery changes over time, the stimulation can be adjusted without requiring a repeat operation.

Another significant advantage of deep brain stimulation relates to future treatments. Destructive surgery, such as thalamotomy or pallidotomy, may reduce the patient's potential to benefit from future therapies. With deep brain stimulation, the stimulator could be turned off if other therapies were to be tried.

How Do People With MS Benefit From Deep Brain Stimulation?

The main purpose of deep brain stimulation for people with multiple sclerosis is to control the tremor related to the disease. In the case of multiple sclerosis, other problems such as loss of vision, sensation, or strength are not helped by deep brain stimulation.

Can Deep Brain Stimulation Cure MS?

No. Electrical stimulation does not cure multiple sclerosis nor does it prevent the disease from getting worse; it helps to relieve the symptom of tremor related to MS.

Is Deep Brain Stimulation Considered Experimental?

Deep brain stimulation is not experimental. The FDA has approved DBS to treat Parkinson's disease, essential tremor and dystonia. Dystonia is a type of movement disorder characterized by abnormal postures and twisting motions.

The FDA has not specifically approved deep brain stimulation of the thalamus to treat multiple sclerosis. However, this does not mean that the treatment is experimental or that it would not be covered by insurance. There are many examples of treatments that are used every day and are standard and accepted but that have not been approved by the FDA.

Who Should Consider Deep Brain Stimulation?

There are many important issues to be addressed when considering deep brain stimulation. These issues should be discussed with a movement disorders expert or a specially trained neurologist.

Before considering surgery, you should have tried medication first. Surgery should not be undertaken if medications are able to control your symptoms. However, surgery should be considered if you do not achieve satisfactory control through medications. If you are unsure if DBS is right for you, consult a movement disorders expert or a neurologist who has experience with movement disorders.

Where Should the Operation Be Performed?

The surgery should be performed in a center where there is a team of experts to care for you. This means neurologists and neurosurgeons who have experience and specialized training in doing these types of surgeries.

Another thing to consider when deciding where to go for the surgery is to find out how the target (that is the thalamus) is localized. Different centers may perform the surgeries in different ways. It is clear that the chances of benefit and the risks of complications are directly related to how close the electrode is to the correct target.