Thalamic deep brain stimulation (DBS)
Information for patients and families
Essential tremor is a common movement disorder that usually affects the arms or hands.
Living with tremor can be frustrating, embarrassing, and even disabling at times. Daily
activities such as dressing, feeding, and writing can become difficult to perform.
Medications sometimes help, but not all patients can control their tremors adequately with
medications. Such patients sometimes turn to deep brain stimulation (DBS) as a way to
further control tremors.
This brochure has been provided to answer questions you and your family may have about
DBS. After reading the information, talk with your doctor. Together, you will decide if this
treatment may be right for you.
What is thalamic DBS?
DBS is a treatment that involves electrical stimulation of the brain. It is done in several
stages and is usually performed on one side of your body. First, surgery is performed to
place an electrode in a region of the brain called the
Who is a good candidate for
thalamus. After about one week, the patient returns to
thalamic DBS surgery?
the hospital to have a pulse generator, or “pacemaker,”
placed under the skin of the chest. The pulse generator is
 Patients with essential or
connected to the brain electrode by an extension wire
parkinsonian tremor that is not
that runs under the skin. Several weeks later, the pulse
well controlled with prescription
medications
generator is turned on and begins to activate the
electrode in the brain.

Patients who are able to travel to
BIDMC for follow-up
appointments
How does DBS work to control my tremor?
The implanted electrode interrupts the jumbled
messages in your brain that are causing your tremor.
 Patients who are 30-80 years old
Exactly how this is achieved is not clear and is still a topic of research and debate.
However, we do know that a low level of electricity delivered into the thalamus can help
decrease tremors. Once your electrode is in place, a clinician can make adjustments from
outside the body using a special programming device. The strength of the electrical
stimulation can be changed, all from outside the body. Over time, as your tremor changes,
the electrode settings may also be changed to continue to treat your tremor.
You can also adjust aspects of the DBS system yourself. For example, many patients choose
to turn their stimulation off at night to help conserve the battery. You will be given a device
that you can hold over the battery in your chest to turn your stimulator on or off. However,
only your neurologist or someone on the neurologist’s staff will be able to change the
strength of the stimulation you receive.
What is the procedure like?
Before the surgery begins, you will have an MRI while wearing a head frame – a device
that helps your surgeon locate the target for surgery. The head frame will stay on
throughout the operation. The operation is done using strong sedatives given by vein. You
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will be asleep for much of the surgery, but we will awaken you at times so we can judge
your response to brain stimulation. We may ask you to perform some simple tasks or
answer some questions. By using electrical recordings, in combination with your responses,
your surgeon locates (or “maps”) the exact area in your brain that needs treatment. A
permanent stimulating electrode is then placed in the thalamic nucleus. The electrode
stimulates the brain with low-level electricity in the operating room, and the doctor checks
to see if the stimulation is helping your tremor. If so, the electrode is left in place. On rare
occasions when the tremor fails to improve, the electrode is removed because you probably
would not benefit from undergoing DBS stimulation. The surgery takes about four to five
hours. Throughout the procedure, you will be given medication to make sure you are not
anxious or in pain. After surgery, your medication will be resumed and a CT or MRI scan
will be done. You will stay in the hospital for one or two nights. When you go home, you
will have the brain electrodes in place, but stimulation will not be turned on.
About a week later, you will return to have a pulse generator implanted under the skin just
below the collarbone. This is the device that will deliver the stimulation to your brain. You
will be under general anesthesia while the device is being implanted; the procedure takes
about one hour. (Patients having an electrode placed on both sides of the brain will have
two pulse generators.) The pulse generator will be connected to the brain electrode by an
extension wire running under the skin from the top of the head and behind the ear to the
pulse generator. You will go home on the same day, but your device will not yet be turned
on. Your first programming session – when your device will be activated – will be
scheduled for approximately three to four weeks after the pulse generator is implanted.
What follow-up care is required if I have this treatment?
You will need to be seen at least every 6 months to check how well your system is working
and to make any necessary changes.
Will I be able to feel the devices or stimulation in my body?
You may notice small bumps on either side of your head at the surgical sites. The stimulator
pacemakers can be felt under the skin. A wire that connects the pacemaker in the chest to
the scalp can also be felt under the skin but is not visible. There is a small amount of
discomfort just after these devices are placed in your body, which is controlled with mild
pain medication. After a few days, there is no discomfort from either the brain electrode or
the electrical device in the chest.
When the electrode is first activated or is being adjusted, you may feel a tingling or pulling
feeling in your legs, arms, or face. This sensation should subside within a few moments. If
not, the settings of your electrode will be changed to correct the sensation. Your electrode
continuously stimulates the targeted brain region; however once it is turned on and set
correctly, you should not feel anything.
Are there other surgical treatments for tremor? What are the advantages
of DBS over other surgical treatments?
A procedure called “thalamotomy” is another surgical option for patients who have tremor
that is not well controlled by medication. In this procedure, the tissue in the brain that is
causing the tremor is identified and destroyed using a heated electrode. It can only be done
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safely on one side of the body. Today, thalamotomy is rarely done. DBS has some
advantages when compared to this procedure. DBS does not destroy brain tissue and it is
reversible. Also, the level of stimulation in DBS can be adjusted for each patient to provide
the best tremor control. It can be done on one or both sides of the brain, though usually only
one side is performed at first followed by the other side several months later if necessary.
DBS has some disadvantages that are important to consider. The battery must be replaced
as needed. Battery life is different for every patient, and depends in part on the stimulation
settings that are in place. Another disadvantage of DBS is the need to return to the
outpatient clinic for re-programming. For some patients who live a long distance from the
medical center or have problems arranging transportation, return visits to the hospital may
pose a problem. In this case, DBS is probably not the best treatment choice. (Surgical risks
associated with DBS surgery are discussed below.)
Overall, thalamic DBS is preferred over thalamotomy because brain tissue is not destroyed,
lowering the risk of surgery-related neurological complications.
If the treatment works, will I see an improvement right away? Will the
improvement last?
Some patients notice a temporary improvement after the initial surgery, before the pulse
generator is even in place. The improvement is the result of minor damage or swelling in
nerve cells in the thalamus that occurs during the electrode-placement surgery. This can
sometimes cause a temporary reversal of symptoms lasting several days to weeks.
As noted above, you will return to the hospital to have your stimulator programmed for the
best control of your particular symptoms. Once this has been done, you will begin to notice
an improvement almost immediately. Tremor responds to stimulation very quickly – within
a few moments. If you turn the stimulation off at night before going to bed, the tremor will
return shortly after the pulse generator is turned off. In a small number of patients, the
severity of tremor may continue to progress. In these cases, the improvements seen right
after surgery may lessen over time.
Are some tremors helped more than others?
DBS is helpful in treating both parkinsonian tremor (usually a tremor that is present when
the arms and hands are resting or being still) and essential tremor (usually a tremor that
occurs while performing a task, such as bringing a cup of water to your mouth). The surgery
seems more helpful in controlling tremors affecting the arms as compared to those affecting
the legs. Patients who have the stimulation treatment on both sides may notice improved
head and voice tremor if these are present.
Are there patients who should not receive this treatment?
The treatment is generally not offered if any of the following exist:
 significant dementia or confusion
 active psychiatric problem such as depression
 another significant brain disorder
 a medical condition that makes general anesthesia unsafe
 a medical condition that requires body MRI on a regular basis
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Are there risks associated with DBS?
Any surgical procedure carries some risk, and this is also true of DBS surgery. Your overall
health will be evaluated carefully before you are recommended for this surgery to make
sure the risk of problems is low. Fortunately, neurologic side effects of DBS are very
uncommon. The most potentially serious side effect is bleeding in the part of the brain
where each electrode is inserted. Some bleeding in the brain occurs in 1-2% of procedures
in which a needle, wire, or electrode is passed through the brain. In the majority of cases,
this bleeding does not cause problems. (Your doctor will talk with you about stopping any
blood thinners or other medicine that would increase the risk of bleeding.)
DBS hardware problems are possible months to years after the system has been installed.
These include breakage of the electrode wire under the skin in the scalp or neck and skin
infection or skin breakdown in the scalp. Many of these problems can be corrected without
removal or replacement of the brain electrode.
Having an MRI can damage the device or the tissues near it. If an MRI is needed, you need
to tell the radiology staff that you have a DBS in place. In some cases, patients may have an
MRI of the head if special precautions are taken. At present, MRI of other parts of the body
is not done in anyone who has a DBS. Other tests, such as CT (“CAT”) scans, ultrasound,
or x-ray can be done safely.
Also, diathermy (e.g., shortwave diathermy, microwave diathermy or therapeutic ultrasound
diathermy) – a special kind of heat treatment used to treat certain conditions – cannot be
done in someone with a DBS. The heat energy can be transferred through the DBS system,
which can cause tissue damage and can result in injury or death. If you have surgery that
will require the surgeon to use electrocautery to control bleeding, you will need to let your
surgeon know that you have a DBS system. The DBS may need to be turned off prior to
your surgery.
Your neurologist and neurosurgeon will give you additional, detailed information about
possible complications and answer all your questions.
I think DBS may be right for me. What happens next?
If you and your doctor decide that you may be a good candidate for this surgery, we will
ask you to meet with our neurologist and neurosurgeon for an evaluation. The neurologist
will assess your tremors by observing you perform various tasks. Prior to surgery, the
neurosurgeon will also evaluate you and you will have a chance to talk about any questions
or concerns you may have about the surgery. If needed, an MRI examination of the brain
will be scheduled. For more information on deep brain stimulation visit the websites below:
http://www.medtronic.com/your-health/essential-tremor/index.htm
http://www.wemove.org/
We hope you have found this information helpful. Please discuss this information with members of your
health care team. Ask any questions you have about this or any other treatment you are receiving.
This material was prepared by clinicians from the department of neurology at Beth Israel Deaconess Medical Center. It is produced
and distributed by the Beth Israel Deaconess Learning Center. © 2009, Beth Israel Deaconess Medical Center. All rights reserved.
MC0920 10/09
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