Deep Brain Stimulation - Parkinson's Treatment
Deep brain stimulation (DBS) is a relatively new surgical technique designed to control the symptoms of Parkinson’s disease - and it’s already producing very promising results.
It’s been particularly useful in reducing tremors and dyskinesias (involuntary movements) induced by the widely prescribed drug levodopa. However it is not suitable for everyone, particularly those who have not responded to drug therapy.
In the majority of cases surgery is only ever used as a last resort, when all other treatments have started to fail. Many physicians still believe that the best treatment for Parkinson’s is medication.
So what exactly is Deep Brain Stimulation?
It’s a type of surgery, normally done under local anesthetic. Using Magnetic Resonance Imaging (MRI) or Computed Tomography Imaging (CT scan) a surgeon determines the exact area of the brain to be targeted before making a hole in the skull. These brain sections include the subthalamic nucleus, thalamus and globus pallidus, which all control movement.
Thalamic stimulation is usually used exclusively to treat tremors; pallidal stimulation is for levodopa induced dyskinesias and subthalamic stimulation can have an effect on most symptoms of Parkinson’s.
Small electrodes are placed in the targeted area and a small wire attached to the electrode is passed under the skin of the head and neck before being connected to a device very similar to a pacemaker placed underneath the collarbone.
This device stimulates the specific areas of the brain which control movement and blocks or paralyses the brain signals causing the symptoms. By swiping a hand-held magnet over the device the patient can turn it on and off. Patients can also control the level of stimulation going to the brain.
Generally surgeons like a patient to be awake while undergoing this procedure so that they can ensure, from a person’s physical response, that the correct area is being targeted.
Side effects such as tingling or slurred speech are usually mild and reversible. However, as with all surgery there are risks, and these increase according to a patient’s age. Older patients are more likely to have other age-related health problems such as high blood pressure. Paralyses, stroke, bleeding in the brain, infection and fits, have all been reported although the risk of suffering any of these more serious adverse effects is relatively low (about 5%).
One of the major benefits of Deep Brain Stimulation is that its effects are reversible (as soon as you switch off the device the symptoms return) and it doesn’t destroy any part of the brain unlike pallidotomy and thalamotomy surgery which involves the burning of brain cells. This means that patients won’t be excluded from receiving any new treatments that emerge in future.
The downside of the treatment is that it is very expensive and quite specialized because of the sophisticated equipment involved. It is only currently available in specialist centers around the world.
In many countries the cost of the treatment is covered by the state and in America Medicare and most of the other health insurance plans cover the majority of expenses related to thalamic DBS.