Deep Brain Stimulation
Deep brain stimulation (DBS) is a surgical procedure in which electrodes are implanted in certain areas of your brain. These electrodes deliver electrical impulses that affect abnormal activity in the brain. The stimulation is produced by a pacemaker-like device implanted under the skin in your upper chest. The device is connected to the electrodes in your brain by a wire traveling under the skin.
Deep Brain Stimulation is a treatment option for:
- Parkinson’s disease
- Essential tremor
- Vocal tremor
- Obsessive-compulsive disorder
- Chronic pain
The treatment is reserved for people with symptoms not controlled with medication.
Deep Brain Stimulation Devices
DBS involves the placement of an electronic device. There has been tremendous progress in the device technology and options available in the last several years. A stimulator consists of three parts:
The DBS lead is an insulated wire with metal contacts at its end. The lead is inserted deep into the brain so that its tip directly stimulates the target site. Its other end, near the surface of the brain, is anchored to the inside of the skull. Some newer leads have extra metal contacts with an improved ability to direct electrical current into brain tissue. This gives your doctor more options for programming the device and may allow improved stimulation effectiveness while reducing side effects.
The connecting wire runs under the skin from the DBS lead at the scalp site, behind the ear, and down the neck into the chest where it connects to the battery pack, or implantable pulse generator (IPG).
The implantable pulse generator (IPG) resides like a pacemaker beneath the skin of the chest wall under the collar bone. The IPG is a metal disc less than 2 inches in diameter and less than one-half inch thick. It contains a small battery and a computer chip. The IPG sends electrical impulses through the connecting wire to the DBS electrode implanted in the brain. Patients have a choice between a nonrechargeable battery, that will need to be replaced with a small surgery in 3-5 years, and a rechargeable battery, that they need to remember to charge by holding a device over the skin several times a week but that can last 10-15 years without surgery.
When is Deep Brain Stimulation performed?
DBS is most effective for individuals who experience disabling tremors, wearing-off spells, and medication-induced dyskinesia.
- Tremors – Some people with Parkinson’s disease have tremors that simple do not respond to medication.
- Wearing off–After several years of taking medications, including levodopa, many people experience a shortening of benefit following each oral dose, a problem called “wearing off”.
- Dyskinesias–Many people with Parkinson’s disease develop drug-induced, involuntary twisting and writhing movements, known as “dyskinesias.”
- Side Effects–Some patient’s experience intolerable side effects of their medications.
It is important to recognize that some symptoms of Parkinson’s disease respond better to surgery than others. DBS does not help with freezing, backwards falling, dementia, apathy, anxiety, or depression.
How should I prepare for Deep Brain Stimulation?
Your surgeon will work with you to plan a procedure that gives you the best chance of achieving your goals while minimizing any pain and discomfort. There are many different technologies and options for doing the procedure in a way that fits your preferences. Surgery can be done awake or asleep. It can be done all in one day or broken up into stages several days or even weeks apart.
Placement of the DBS lead
The goal of the operation is to place, within millimeter accuracy, 1 or 2 DBS electrode leads deep inside the brain. The successful outcome depends critically upon accurate targeting. The first step of the operation is attachment of the targeting device, a metal frame, or other device, to the patient’s skull at several points. Parts of this procedure are sometimes done awake under local anesthesia. It is not painful but some patients do complain of pressure or headache afterwards. This can also be done asleep.
Next, the patient undergoes a short brain imaging scan, a CT scan. The calibrations on the targeting device are merged with the brain image to form a computerized map of the brain. This map becomes the blueprint for planning and measuring the trajectories of the electrode leads into the deep brain regions.
Next, while the patient is asleep, the surgeon next makes a small opening in the top of the skull to create a passageway for the insertion of the stimulating electrode into the brain. As an additional means to ensure the accuracy of lead, the surgeon and team may perform electrical brain mapping during surgery. This technique uses tiny electrodes that can record electrical activity from individual brain cells within deep brain regions. These “microelectrodes” are much smaller and more delicate than the electrodes that provide the deep brain stimulation. They are used to identify cells within the deep brain targets and adjacent structures and help steer the main probe towards the desired surgical target.
Depending on what was discussed and planned before surgery, the patient may then be woken up from anesthesia. The surgeon and neurologist may ask the patient to make certain movements or ask questions about he or she is feelings and what symptoms he or she is experiencing. The patient is kept comfortable with light anesthesia during this part of the procedure. When testing is complete, the patient then goes back to sleep while the surgeon finishes the procedure. The accuracy of the lead position is confirmed with another brain imaging scan.
Depending on each patient’s needs and preferences, sometimes two DBS leads are implanted in the same operation; at other times, they are staged over two operations that are weeks or months apart. Sometimes, the surgeon places the entire apparatus– DBS lead, connecting wire, and implantable pulse generator (IPG, ie. the battery)–in a single day. Other times the surgeon first performs the DBS lead insertion and delays the rest of the work to a second procedure the following week. Some individuals prefer the idea of stages procedures so they can recover between steps, while others “just want to get it over and done.”
How is Deep Brain Stimulation performed?
Before surgery, patients and families should educate themselves about the procedure and weigh the risks and benefits with your doctor. Both the surgeon and your neurologist can discuss the risks, benefits, and options in more detail. Additional information is available on this site or through the links provided. Anyone from our team can also provide printed reading material.
It can also be helpful and reassuring to meet someone who has already gone through the experience. Our team can help introduce you to a community of people who have had the Deep Brain Stimulation (DBS) procedure. You can speak with someone one-on-one in person or by phone, or join one of our regular support group information sessions.
After detailed discussions with the treating neurologist and the surgeon, the patient typically undergoes a brain imaging study (MRI) and additional neuropsychological testing. You will also have a general medical examination and additional medical tests to make sure that you are a good candidate for surgery.
What can I expect after Deep Brain Stimulation?
Patients usually tolerate the procedure very well. After the operation, patients usually find themselves tired, and perhaps slightly confused. Some complain of mild headache. These symptoms usually resolve within 24 hours. Most individuals recover quickly and can be safely discharged from the hospital just one or two days after the surgery. Most individuals should remain on their preoperative medication at discharge. Typically, patients return home with scalp staples or stitches in place, to be removed one week later in the surgeon’s office or during the battery placement procedure if it has not already occurred.
Placing the Battery
The DBS electrode lead requires a power source. Once the deep brain electrode has been inserted, the remaining surgical task is implanting the extension wire and the battery, or implantable pulse generator (IPG). This may be done at the same time as the brain implant, or may be deferred to a later date–usually, one week after the brain operation. The operation is relatively simple and is done completely asleep under anesthesia for patient comfort. The surgeon makes an incision under the collarbone, creates a small pocket under the skin, and inserts the IPG. The IPG is attached to the connecting wire, which is tunneled up the neck, behind the ear, and to the scalp site. The connecting wire attached to the DBS lead. At this point, the entire apparatus is in place under the skin which is then closed with stitches or staples. The battery can produce a visible bump on the chest, especially in people who are thin. The battery can be placed on either side of the chest, left or right, depending on patient preference. In some cases, the battery can be placed lower down in the abdomen. When people wake up after the procedure, they may experience chest or neck discomfort and require pain medication. Patients usually return 1 week later to have any stitches or staples and so that the deep brain stimulation system can be activated.
Programming the Stimulator
After the operation, individuals are discharged to home. They must now begin a period of stimulator adjustments, performed over the course of several outpatient visits. The stimulator adjustments and settings are different for every patient. Improvement may take several weeks, even months, while the stimulator settings are being improved and medications adjusted to the appropriate level. In the first months following implantation, patients may require frequent adjustments. After this period, the electrical settings usually stabilize.
You may have a device, similar to a remote control, which allows you to turn the system on and off and check the battery. You may also be able to adjust the stimulation within options programmed by your doctor.