What is deep brain stimulation (DBS)?
DBS is a treatment option for people with Parkinson's whose motor (movement) symptoms no longer respond adequately to medication. DBS is also used for other movement disorders such as dystonia and essential tremor.
DBS therapy uses a small, pacemaker-like device to send electronic signals to a precise area in the brain that controls movement (either the subthalamic nucleus (STN) or the internal globus pallidus) via very thin wires. Stimulation of these areas appears to block the brain messages that cause disabling motor symptoms and so can provide greater symptom control. Each person has a programmer and once this has been programmed by a specialist, the programmer can be adjusted to give a level of stimulation that provides the best possible symptom control. For the right candidate, this can provide greater control over body movement and so improve quality of life but DBS is not suitable and will not work for everyone.
Potential benefits, risks and side effects
DBS is not suitable for everyone, so it's important to talk with your doctor about the potential benefits and risks. You should also discuss with a DBS neurologist the potential risks relating to not treating Parkinson's, Parkinson’s medication and other types of therapies. This information will enable you to make an informed decision on whether DBS is the right treatment to most effectively manage your specific symptoms.
In the right candidate DBS can provide longer periods of relief from motor symptoms such as tremor, stiffness and slow movement. It can also reduce the frequency and duration of abnormal, involuntary movements (dyskinesia) which often occur as a side effect of Parkinson's medications. Such benefits can improve your quality of life.
You may also be able to reduce the amount of medication you take if DBS provides good symptom control. This can be particularly helpful during pregnancy.
DBS is reversible as the neurostimulator can be switched off at any time and removed if necessary, although this will require further surgery.
As with any surgery, there are risks including serious or even life-threatening complications such as coma, bleeding inside the brain, seizures, and infection. Once implanted, the system may become infected or cause skin discomfort. Mechanical or electrical problems may also occur which could require additional surgery or mean that symptoms are not well controlled.
Potential side effects
Whilst DBS therapy in Parkinson’s can improve gait and balance, some people may experience a worsening of gait and falls. DBS may also cause speech difficulties.
Some people experience a change in their thinking or personality, for example depression, mania, apathy or confusion. Such changes are more likely in people who have previously experienced problems as a result of their Parkinson’s or Parkinson’s medication although others may also be affected.
Other side effects may include:
- dizziness or light headedness
- facial and limb muscle weakness or partial paralysis
- abnormal, involuntary muscle contractions (dyskinesias)
- movement problems or reduced coordination
- jolting or shocking sensation
If unwanted symptoms or side effects occur, stimulation parameters will be adjusted over time to try to minimise side effects and maximise symptom control.
When is the right time to consider DBS?
Usually the medication used to treat Parkinson’s symptoms is very effective at first. But over time medication tends to work less well and symptoms emerge that affect quality of life.
The right time for DBS therapy is when your body no longer responds as well to medication as it used to, but before medication stops working completely. It is important to remember that if you wait too long, DBS will not be an option. DBS is not a last resort.
DBS will be most effective in treating your Parkinson’s if you:
- have responded well to the medication levodopa
- still benefit from medication, but it's becoming less effective or causing intolerable side effects
- require multiple medications, higher dosages, or more frequent doses to manage your symptoms.
Who is suitable for DBS?
Not everyone is suitable for DBS and this should always be discussed with your doctor and a DBS specialist. The following questions may be helpful in assessing whether or not you might be a candidate.
- Have you had Parkinson’s for at least 4 years?
- Do you have symptoms which are troublesome and interfere with your day to day activities?
- Do you take dopaminergic medications in a typical day (eg Levodopa, Sinemet, Stalevo, Parcopa, Co-careldopa, Co-beneldopa)?
- Do you notice an improvement in your symptoms when you take your medication?
If you answered "Yes" to some of the questions above, you may want to discuss DBS therapy as an option with your doctor. Only a neurologist or neurosurgeon can determine if DBS is right for you.
Here are some factors which your specialist will consider when determining yours suitability for DBS:
- You must be physically able to cope with the surgery
- You should not have significant cognitive difficulties or dementia
- You must understand the nature of the therapy and be able to operate the neurostimulator controller.
- You must be available for periodic follow-up visits.
What would happen if I have DBS?
The duration and surgical steps may vary depending on the type of system used but typically, surgery to implant the DBS system lasts several hours. Your hospital stay is usually a few days and includes a pre-operative assessment, the surgery itself and initial healing before you return home.
Your surgical team will include a neurologist, a DBS specialist neurosurgeon, an anaesthetist, a radiologist and other healthcare professionals.
The components of a DBS system are:
- Neurostimulator – this pacemaker-like device is the power source for the system. There are several rechargeable and non-rechargeable stimulators. Each contains a small battery and a computer chip programmed to send electrical pulses to control Parkinson's symptoms.
- Lead – an insulated wire terminating in four electrodes which transfer electrical current to your brain .
- Extension – an insulated wire placed under your scalp and outside your skull to connect to the lead and run behind the ear, down the neck, and into the chest below the collar- bone where it connects to the neurostimulator.
- Programmer – the doctor uses this external programmer to set the parameters for stimulation. Each person responds to DBS in their own way so the programmer will be used to customise the signals to your brain.
- Patient controller – in some DBS systems you can use this to turn the neurostimulator on and off. It may also be used to adjust stimulation settings within the limits set by your doctor.
Your pre-operative assessment is designed to prepare you and your surgical team for the surgery. This may include an MRI scan and a conversation with DBS experts.
Your head will be kept still using a frame while very thin leads are placed in a precise area of your brain using mapping from an MRI or CT scan. The leads deliver stimulation from the neurostimulator to your brain.
In some cases you will be awake but lightly sedated and will not feel any pain – the brain has no pain receptors and cannot feel pain. Your surgeon may stimulate areas of the brain while you move your arms or legs, tap your fingers, move your hands, or pretend to drink from a cup. This helps your surgeon find the best lead position to control symptoms such as tremor, rigidity or slowness of movement.
For some systems this surgery will be carried out while you are asleep under an anaesthetic. Your neurosurgeon will decide which type of surgery is best for you.
Implanting the neurostimulator
The same day, or shortly after, the neurostimulator will be implanted under the skin of your chest. You will be asleep for this part of the procedure. The surgeon will then connect the leads from your brain to the neurostimulator using extensions that are placed under the skin from the chest, up to your neck and head.
Post surgery and recovery
You should be ready to return home a few days after surgery and there healing will continue for several weeks. Your doctor or nurse will give you instructions about care at home and when to return to your daily activities. It’s normal to feel some discomfort or pain at the incision sites, and your care team will advise on how to manage this with medication. Your device will not be turned on until your first programming session. At that time your Parkinson’s medication may also be adjusted.
The goal of programming is to control your symptoms while minimising side effects. Programming begins after you have healed from surgery and you will need several follow-up sessions to adjust settings until the best symptom control is achieved. Settings can be adjusted as often as necessary to allow for some change in symptoms as Parkinson’s progresses.
If, despite the programming adjustments made, you do not achieve the expected level of symptom control, surgery may be required to reposition or replace the leads, replace the system, or remove the system.
Depending on your device, you may have a controller that allows you to turn the system on and off, adjust the stimulation and check the battery.
Daily Activities and Exercise
During your recovery, follow your care team’s instructions about activities that include bending your neck, raising your arms over your shoulders, or strenuous activities such as lifting heavy objects.
Be careful when participating in activities that may result in accidents or falls as these could damage parts of your DBS system. This could mean further surgery to replace damaged components. Sudden jerky movements may also cause the lead in your brain to move.
When to seek medical advice
You should contact your DBS care team if you:
- experience pain, redness, or swelling along the scalp, neck, or chest where the stimulation system is implanted
- are not getting relief from your symptoms even though the neurostimulator is turned on
- feel uncomfortable or painful sensations during stimulation (turn off the neurostimulator before calling your doctor)
- cannot turn the neurostimulator off (or on)
- experience unexpected changes in your symptoms
- experience any unusual symptoms that you think may be caused by electromagnetic interference (for example, from theft detectors or airport security scanners)
- lose your patient programmer.
- Make sure you tell any healthcare professionals that treat you that you have an implanted DBS system, and tell them where it is located.
- If you experience any unusual symptoms that you think may be related to your neurostimulator, contact your doctor.
- Attend all follow-up appointments to make sure you get the best care.
- When the neurostimulator is turned off, your symptoms will return. Some symptoms return quickly. Other symptoms may take longer to return.
Frequently asked questions (FAQs)
Would DBS therapy prevent me from using future treatments or cures that may come along?
No. DBS therapy will not reduce your future therapy options. DBS therapy is reversible and the system can be removed.
Is DBS just for tremor?
No, DBS also treats stiffness and slow or absent movement and may provide relief from some non-motor symptoms, such as sleep disturbance.
Is DBS something to put off as a last resort?
No. The window of opportunity for DBS Therapy opens when your body isn't responding to medication as well as it used to, but before your medicine stops working completely. If you wait too long, DBS Therapy will not be able to help you as much as it could have done earlier.
How long will it take for DBS to work after the implant procedure?
Each person responds to DBS differently but it generally takes several months. Usually you need to heal fully from surgery before programming can begin and you will then need several programming sessions before you achieve good symptom control.
What does the stimulation feel like?
Most people don't feel the stimulation. However, some people may feel a brief tingling sensation when the stimulation is first turned on. If the stimulation changes or becomes uncomfortable, contact your doctor immediately.
Does the brain stimulation system make any noise?
Will I be able to resume my normal daily activities?
For the first few weeks after surgery, you should avoid strenuous activity, arm movements over your shoulder, and excessive stretching of your neck. You may gradually want to try activities that were difficult before your surgery. Talk about this with your doctor first, and make sure you follow all of your doctor's instructions.
Will the neurostimulator be visible?
Depending on your body build, the neurostimulator may be noticeable as a small bulge under the skin. However, your doctor will try to place the neurostimulator where it is most comfortable and cosmetically acceptable.
Will I be able to increase or decrease the strength of stimulation?
In most cases, only your doctor can change the strength of stimulation. Depending on the type of neurostimulator you have, you may be able to choose from a range of stimulation settings that your doctor has programmed for you.
Is it safe to have medical tests with the system implanted?
Consult your doctor before you have any medical treatment or diagnostic test (for example, MRI scan, mammogram, or heart defibrillation). Some but not all DBS systems are MRI safe if certain conditions are met. Diathermy (deep heat treatment) and therapeutic ultrasound should not be permitted under any circumstances.
Can stimulation be used during pregnancy?
DBS is safe in pregnancy and may mean that Parkinson’s medications can be reduced during this time.
Is this a permanent procedure?
DBS is a reversible procedure. It is also adjustable, which means that the stimulation can be adjusted to match changes in your symptoms. The system can be deactivated or even removed through further surgery.
What happens if the neurostimulator stops working?
Your symptoms will return. If you can't determine the possible cause and correct the problem, contact your doctor.
How long will the neurostimulator battery last?
This depends on the type of system used. Your neurosurgeon will be able to advise. If the neurostimulator battery needs to be replaced, this will done through surgery, before the battery runs out. Typically the leads and extensions will stay in place and simply be reconnected to the new neurostimulator.
Some systems use rechargeable batteries, reducing the need for further surgery to replace batteries.