Deep Brain Stimulation (DBS)

The most common reason to consider DBS for Parkinson’s is to reduce medication response fluctuations – where there is variability in how well the medications work throughout the day. This covers both “wearing off” (where the benefit of medication runs out before the next dose) and “dyskinesias” (excessive movements, often described as pulling, wriggling or jerking movements). In general, DBS cannot improve Parkinson’s better than what the medications can do – the advantage of DBS is that it runs continuously 24/7 so that it can keep you close to your best throughout the day. It is a continuous therapy for fluctuating Parkinson’s. If you are thinking about DBS, it is important that you have considered the other continuous therapies that use a small pump to trickle in a constant amount of medication, just like an insulin pump.

Another good reason for DBS is tremor that is not adequately controlled with medications.

It is rare for people to have medication side effects where they cannot tolerate enough medication to control their Parkinson’s symptoms. This is also a good reason consider exploring DBS.

Remember that DBS cannot address all the symptoms of Parkinson’s. Be sure to ask about the symptoms that are most bothersome to you, and how well they might respond. Also remember that DBS cannot cure or reverse Parkinson’s. DBS does not work for conditions that mimic Parkinson’s (such as multiple system atrophy or progressive supranuclear palsy).

It is a common mistake that people think of DBS or other continuous therapies as ‘last resort’. Most people say, “I wish I had DBS sooner”, so that the Parkinson’s had less impact on their lives.

Common motor symptoms of dystonia include pulling, jerking movements, restricted movement, and pain. Deep Brain Stimulation (DBS) can help improve each of these symptoms.

The symptoms experienced, and their impact, depend on which region of the body is affected. Dystonia is usually worse when the affected area is being used. It often improves or disappears when the affected area is at rest. For example, hand dystonia typically worsens when using the hand.

DBS may be an appropriate treatment option when these symptoms have a significant impact on daily life. There are many causes of dystonia, and the effectiveness of DBS can vary depending on the underlying cause. For this reason, it is important to obtain as precise a diagnosis as possible.

The most common situation is known as ‘idiopathic isolated dystonia’. This means dystonia is the only symptom and there is no identifiable cause. This form of dystonia often responds well to DBS. The literature suggests that approximately 80% of people experience a worthwhile benefit from DBS, and while the improvement can sometimes be dramatic, this is not always the case. Some people may not experience the level of benefit that was hoped; however, our experience suggests that response rates may be slightly better than those reported in the literature.

Other conditions that often respond very well to DBS include tardive dystonia, SGCE-related myoclonus dystonia, and TOR1A-related dystonia.

Some conditions appear to respond poorly, or not at all, to DBS. These include ATP1A3-related dystonia, which may even worsen with DBS. It is therefore important that these conditions are carefully considered during the assessment and workup process.

It is important to remember that DBS is not a cure for dystonia, rather, a treatment that can help reduce symptoms.

A key question to consider is how much the symptoms affect your activities of daily life. For example, does the tremor make it difficult to carry a cup, do you need to drink through a straw, do you avoid eating or drinking in public, can you sign your name, or does the tremor interfere with your ability to work or enjoy your hobbies?

Have all treatment options for tremor been considered?

Many forms of tremor can respond to medication, although the improvement is often relatively mild. This means that when tremor is more than mild, medication may not be enough to reduce the impact it has on daily life. Some types of tremors can respond well to botulinum toxin injections, such as Botox, Dysport, or Xeomin.

There are also many devices available that aim to reduce the impact of tremor. For example, an electric spoon that stabilises food by moving the tip of the spoon in the opposite direction to the tremor - like how noise-cancelling headphones work. These types of devices may be worth considering. Check in with your Movement Disorders Neurologist or physiotherapist whether a device might be worth trying. Consider discussing with your Movement Disorders Neurologist or Physiotherapist whether a device may be suitable to try.

Although brain surgery can sound risky, DBS is generally considered a low-risk procedure, which can be surprising. A recent study compared 30-day complications across multiple types of surgery. This including over 4,500 DBS surgeries and over 2.5 million other surgeries performed in the United States between 2015 and 2021. Remarkably, it found DBS had around 70% fewer complications compared to many other surgeries.

• The risk of any complication with DBS was about the same as for hernia repair, tonsillectomy and thyroid surgery.
• DBS had about half the complication rate of appendicectomy, gallbladder surgery, tubal ligation, weight loss surgery and breast surgery.
• The complication rate of DBS was less than one-quarter that of hip replacement, caesarean section delivery, prostatectomy, and hysterectomy.

You might be thinking, “Yes, but it’s my brain!” That is an understandable concern. Brain surgery does carry a risk of complications, including bleeding in the brain that can cause a stroke, however, the risk of a stroke with DBS was less than half that of other surgeries studied (0.43% verses 0.89%).

There are three types of risks associate with DBS: surgical risks, hardware-related issues, and stimulation-induced side effects. The risks will vary from person to person, so we can only provide a general overview. Your DBS team will be able to personalise these risks to your individual circumstances and answer questions you may have.

Surgical risks include:

• The overall risk of a poor outcome following DBS surgery is typically less than 1-2%, despite all measures taken to minimise risk. Potential surgical complications include intracranial bleeding leading to stroke, myocardial infarction (heart attack), deep vein thrombosis (DVT), with possible progression to pulmonary embolism (PE), and post-operative delirium (which can present as confusion, agitation, or hallucinations).
• The brain is a soft structure, so slight movement can occur during electrode insertion, resulting in lead malposition (the electrode not being placed in the ideal position). This may reduce the benefit of the DBS and could require additional surgery to reposition the electrode. The likelihood of this is occurring is approximately 1%.
• Some people develop temporary brain swelling around the DBS leads known as peri-lead oedema. Typically, this develops a few days after surgery and can cause symptoms such as confusion, behavioural changes, weakness of the limbs or face, or severe dyskinesias. The symptoms will depend on the location of the swelling. The swelling and the accompanying symptoms disappear within a few weeks.

Hardware-related issues include:

• Device failure, such as wire breakage or unexpected battery depletion. These are rare.
• Infection: once any component of the DBS hardware becomes infected, it is difficult to resolve the infection without removing the hardware.
• Infection can be introduced locally, before wound healing is complete. It can also occur later, for example if the skin over the hardware breaks down by picking, rubbing, pressure, or following a surgery or injury near the DBS system.
• Infection can spread through the bloodstream to the DBS system. For example, from a dental abscess or another infected wound site.
• Scar tissue can develop around the wires in the neck and gradually contract over time, a process called bowstringing. This is uncommon and is less frequent with newer hardware.

Stimulation-induced side effects:

• These are usually managed by adjusting the DBS stimulation settings. However, in some cases, mild side effects, such as a softer voice, may need to be accepted in order to achieve the best DBS response.
• Most people experience mild, or no significant stimulation-related side effects.
• Side effects can vary depending on where the DBS targets.
• Possible stimulation-related side effects with the STN target are:
• Changes in speech, such as, becoming softer, altered pace either slower or faster, poor breath control, or slurring.
• Cognitive symptoms, such as difficulty finding the right words.
• Behavioural changes, such as mania-like symptoms or feeling unusually good. You may not recognise that there is a problem, but the people around you may notice the changes. They need to be informed, empowered and able to contact the DBS Team.
• Impulsive or irritable behaviour.
• Reduction in motivation to do things.
• Reduction in emotional responses.
• Impaired walking and balance, which may increase the risk of falls.
• Pulling or tightening of the fingers or face.
• Impaired coordination.
• Some stimulation related side effects associated with the GPi targets include:
• Speech becoming softer, rushed, slurred or affected by stuttering.
• Rapid, short shuffling steps where the feet do not keep up with the body.
• Cognitive and behavioural symptoms, although these are less common with GPi than with STN stimulation.
• Pulling or tightening of the fingers or face.
• Seeing sparkles in the vision.
• Some stimulation side effects for the Vim / DRTT target are:
• Slurred speech.
• Clumsy hands, poor coordination.
• Unsteady walking.
• Double vision.
• Other things to note:
• After otherwise successful DBS for Parkinson’s, some symptoms may even be worse than they were when medications were working at their best prior to DBS surgery. This includes speech, freezing of gait and balance.
• There have been reports of problems with swimming after DBS. It is not clear exactly why this happens, but the consequences can be serious.
• There are some restrictions after DBS. You should avoid contact sports and MRI scans may be difficult, or in some cases, not possible. If you have surgery, the surgeon should not use “monopolar diathermy”. Ideally, the surgeon should contact your DBS Team well ahead of time.
• When someone has DBS, it is tempting to link any medical issue to DBS. Sometimes this can result in doctors being reluctant to assess or treat conditions that are unrelated to DBS or the movement disorder. Please ask them to contact the DBS Team directly if they think there is a DBS-related problem.
• It is possible that DBS will not achieve the expected outcomes.
  • There are several reasons for this, including an incorrect diagnosis, surgical complication, inaccurate lead placement, or the selection of an inappropriate target. These problems are rare.
  • It is more common that people expect DBS to achieve more than is possible, despite multiple discussions with various DBS Team members. There have been times when people have shown a clear understanding of DBS prior to surgery, but after surgery feel disappointed because DBS did not do something it was not intended to do, such as fix a family problem. It is common for there to be a difference in expectations between what the mind understands and what the heart feels.

Minimising your risks:

• Make sure the team knows every medication, supplement and remedy that you take. Ask whether any of them could cause problems with surgery, such as blood thinners, diabetes medications, sedatives or sleeping tablets.
• Be as fit and healthy as possible. This includes regular vigorous exercise, maintaining good gut health, and having a good support network around you.
• Keep your teeth and gums healthy: Eat a healthy diet, brush teeth twice a day, floss teeth at least once a day, see your dentist regularly.
• Take care of your wounds as the team advised.
• Do not scratch or pick at the wounds, as this can introduce infection.
• Avoid movements that stretch the wounds for a couple of months, as this may cause the wound to open.
• Avoid pressure over the DBS system, for example, make sure the arms of your glasses do not press into the skin over the wire behind your ear, and avoid lying with too much weight on the DBS device in the chest.
• Let the DBS Team know if you have any unexpected problems after surgery.

*Make sure the people around you know to contact your DBS Team if they are worried about you.

We take a patient-centred whole person approach. We have developed a comprehensive work-up process to address several important questions to inform your decision whether DBS is right for you.

These include –

• What is the diagnosis?
• How well does this condition respond to DBS?
• Have I considered treatment options other than DBS?
• Do I have issues that could affect the potential benefits or risks of DBS?
• What can I do to minimise the risks and maximise the benefits?
• Do I have appropriate goals and expectations?
• Are there any special considerations for me, such as my goals, expectations or lifestyle factors?
• Are there risks that are particularly relevant to me, including my health issues, goals, lifestyle, or occupation?

The work-up will include consultations with the DBS neurologist, neurosurgeon, psychiatrist and nurse. We will complete rating scales to document symptom severity, quality of life.

Once a decision has been made, your surgeon will discuss possible dates for surgery with you.

You will probably stay in hospital for 3-10 days, depending on your condition and several other factors. While you are in hospital, you and your support people will have several responsibilities.

These include knowing -

• Your new medication schedule
• How to use your DBS remote control, including why and when to use it
• How to care for your surgical wounds
• Your follow-up appointment details
• What to expect in the coming weeks and months
• Who to contact if unexpected issues arise

After going home, it can be difficult to remember what to do when something happens, even when you have already been given the information. You can empower yourself by keeping notes in words that make sense to you. Keep these notes somewhere safe but easy to access. This can help you feel more prepared, proactive and in control.

It can take several appointments over many months to achieve the best results from DBS. It is important to be patient and to keep in mind what DBS can and cannot do for you.

Roles of DBS Team members

It is a privilege to work within a highly specialised team dedicated to achieving the best possible outcomes for you. The team members involved in your care may vary depending on your individual circumstances. The DBS at Westmead started in 2006, and since the first case we have been constantly reviewing outcomes and processes.

The Team has evolved over time, with an ongoing commitment to improvement, including staying current with the latest medical literature. We are the major centre in NSW for training Neurologists in DBS.

See below for some of key team members and what they do, along with examples of individuals within the Team. The team members involved in your care may vary depending on your individual circumstances. You may also encounter other healthcare professionals not listed here, including anaesthetists, MRI and CT radiographers, physiotherapists, occupational therapists, and speech pathologists. Delivering DBS care is a collaborative effort involving a wide multidisciplinary team.

DBS work-up coordinator – Your central point of contact (Sandra Kessler)

• Provide information and assist in answering your questions
• Coordinate and organise the DBS work-up
• Review your goals, expectations, markers of success
• Support and guide you through the DBS journey

DBS nurse (David Tsui, Donna Galea, Cassie Chen, Katrina Mastello)

• Provide education on DBS and other treatment options
• Perform appropriate clinical rating scales and videos
• Conduct cognitive screening tests
• Review your goals and expectations

Neurosurgeon (Jacqueline McMaster, Brian Owler, and Neurosurgical Practice Nurse Danielle Crighton, Katrina Mastello, and Kathleen Pegg)

At your initial consultation the team will -

• Discuss the DBS procedure, including potential benefits and risks
• Identify factors relevant to surgery, such as managing blood thinning medications, infection risks, anaesthetic risks
• Review your goals and expectations
• Discuss surgical details, including awake verses asleep surgery, targets, etc
• Obtain consent for Surgery
• Arrange hospital admission, preoperative CT scans, and operating theatre

During your hospital stay:

• Perform the DBS surgery
• Manage wound care
• Provide clearance for discharge home or to inpatient rehabilitation

After discharge:

• Arrange a follow up consultation 4-6 weeks after surgery
• Replace the DBS system when the battery runs out after several years

DBS Neurologist (Neil Mahant¹, Sai Nagaratnam, Jessica Qiu, Movement Disorders Fellow)

• Review your diagnosis
• Consider all available treatment options
• Provide education about DBS benefits, risks, goals, expectations, and process
• Consider surgical details, such as awake verses asleep surgery, targets, etc
• Liaise and collaborate with your long-term neurologist

DBS Psychiatrist (Ian Assumption, Padmini Howpage, Rebecca Moss)

• Optimise your mental health in preparation for surgery
• Identify factors that might impact the DBS journey
• Review your goals and expectations

DBS Procedural Neurologist (Neil Mahant¹): prior to surgery

• Oversee the DBS work-up
• Carefully review the MRI brain scan
• Consider surgical details, including awake verses asleep surgery, targets, etc
• Identify the DBS target in three-dimensions and the determine the safest path to it
• Align the surgical CT scan with the MRI scan to calculate the three-dimensional coordinates for electrode placement
• Confirm accurate electrode positioning by recording brain activity, perform test stimulation to assess the benefit and potential side effects and identify any issues
• Ensure the electrode is in the best possible location using intraoperative imaging, such as X-ray or CT
• Collaborate closely with your neurosurgeon

DBS Procedural Neurologist (Dr Neil Mahant¹) Post surgery will -

• Determine the final location of the DBS electrodes by aligning the post-operative CT scan with pre-operative imaging
• Generate three-dimensional models of the brain regions influenced by DBS
• Estimate the most effective DBS stimulation settings
• Handover care to inpatient neurologist and neurosurgeon

Inpatient Neurologist (Neil Mahant¹, Shekeeb Mohammed², Sai Nagaratnam, Jessica Qiu, Movement Disorders Fellow) will -

• Manage the movement disorder symptoms
• Identify and manage any complications, that may arise
• Adjust medications as required
• Commence DBS stimulation
• Provide education, answer your questions, including how and why to use the DBS remote controller
• Ensure necessary arrangements are in place prior to discharge
• Provide clearance for discharge home or transfer to inpatient rehabilitation
• Handover to yours care to the DBS neurologist

DBS Nurse Practitioner (David Tsui) may -

• Provide regular telehealth consultations throughout the early post-discharge phase (note that Medicare restrictions apply)
• Participate in combined clinics with DBS neurologist

The DBS Neurologist (Neil Mahant¹, Sai Nagaratnam, Jessica Qiu, Movement Disorders Fellow) will -

• Adjust medications and DBS settings following surgery
• Maintain regular long-term follow-up
• Liaise and collaborate with your long-term neurologist

You, the patient, are encouraged to -

• You are at the centre of the work-up
• Share what matters most to you so the Team can understand your priorities
• Bring support people to appointments
• Ensure you understand the information provided
• Ask questions if something is unclear
• Attend scheduled appointments
• Maintain communication with the DBS team
• Inform the Team of any issues or concerns that arise
• Be open and honest with the team

Notes

• ¹ Adult and paediatric patients
• ² Paediatric patients