Your Questions Answered: Deep Brain Stimulation (DBS)
On Monday, April 22, 2024, Parkinson Wellness Projects (PWP) partnered with Dr. Kieran Tuck, MBBS, to host Your Questions Answered: Deep Brain Stimulation (DBS). Dr. Tuck is a Neurologist and Movement Disorder Specialist at the Royal Jubilee Hospital, and wanted to answer some broad questions our participants had about this treatment option. Below are some highlights from his session:
What is DBS?
Deep Brain Stimulation (DBS) is a type of surgical therapy that uses electrical stimulation to treat certain medical conditions, such as Parkinson’s disease (PD). DBS involves implanting electrodes in the parts of the brain that control movement, which then send electrical signals that can help relieve tremors and other movement symptoms.
Contraindications can include being unresponsive to levodopa, cognitive impairment, or having another condition that increases the risk for surgery complications.
When to Consider DBS?
There are no strict criteria for when a doctor may (or may not) recommend this treatment option. Some reasons include:
Motor fluctuations (when a drug wears off, or because of dose failures or dyskinesias) that are not responsive to subsequent adjustments to medication.
Frequent levodopa dosing.
Tremors that are not responsive to levodopa.
An intolerance of levodopa.
Alternatives to DBS include:
Additional medication changes.
Duopa pump.
Vyalev: subcutaneous infusion.
Focused ultrasound.
Working up to DBS
An evaluation by a movement disorder specialist is needed to confirm a diagnosis. Patients considering DBS will often be asked to perform a variety of movements (such as walking or rising up from a chair) while on and off medication. Patients may also be asked to undergo some neuropsych testing. After some observation and evaluation, a team of specialists will discuss the best treatment plan for each patient. If the team agrees that you are a good candidate for DBS, you will be contacted to schedule an appointment with a surgeon.
How Does DBS Work?
DBS interrupts abnormal electrical signals in the brain that cause tremors and other movement symptoms. It achieves this in three ways:
By altering the local electrical functions of the nerves.
By altering the release of neurotransmitters.
And by reorganizing the function of brain circuits in the basal ganglia.
What is the basal ganglia?
Normal muscle movement, timing, and coordination depend on complex electrical circuits or feedback loops in the brain. The basal ganglia are responsible for activating and inhibiting these feedback loops.
With PD, parts of the basal ganglia are either under- or over-stimulated. Normal movement is replaced by tremor, rigidity and stiffness. DBS of specific ganglia reorganizes the abnormal brain circuits and helps stabilize the feedback loops, thus reducing symptoms.
DBS can target the following brain areas:
The globus pallidus interna (GPi) - better for dyskinesia and dystonia.
The subthalamic nucleus (STN) - better for tremors and reduces the need for medications.
The thalamus - effective in only treating tremors.
What Does (and Doesn’t) DBS help?
As mentioned earlier, DBS can help with uncontrollable tremors that are not responsive to medication, or occur when the drugs wear off, despite medication adjustments. DBS can also help with motor fluctuations caused by dyskinesias, dystonia, rigidity, or bradykinesia.
However, Dr. Tuck shared that DBS cannot help with other symptoms that are not improved by levodopa. This can include:
Cognition issues.
Constipation.
Sleep disruption.
Troubles with gait or balance.
What Are Some Risks?
Other than general complications of any surgery, which can include bleeding, infection, blood clots, and reactions to anesthesia, there are a few risks associated with this procedure. For example, DBS can cause worsening some symptoms, such as tingling, muscle contractions, visual changes, troubles with speech, and worsening of gait. If you develop any side effects from a stimulation adjustment, you need to return to the office for further programming.
What Happens After Surgery?
After surgery, patients often enter what Dr. Tuck calls a “honeymoon period.” Patients may notice an improvement in their symptoms, which can last days or weeks after surgery, despite their DBS system not starting yet. Patients may also be tempted to lower their medication dose(s), but should first consult their neurologist before making any changes.
About two to four weeks later, patients return to the hospital for initial programming. The implanted stimulator (or electrodes) are programmed and medication dosage is adjusted. After which, the patient is monitored to determine the best program to control their symptoms. This continues until good settings are found. Patients can also adjust their own stimulation; after they are sent home, patients can turn the electrodes on and off, select programs, and adjust the strength of the stimulator.
After three to five years, the battery that operates the DBS stimulator may need to be changed.
Dr. Tuck’s seminar was an opportunity for our participants and their care partners to connect and learn about one of the leading treatment options for Parkinson’s disease. Stay up to date with the latest information from PWP events by subscribing to our blog on our website: parkinsonwellness.ca/blog.
Dr. Keiran Tuck, MBBS, grew up in the USA and studied medicine at the University of Sydney in Australia. He completed his neurology residency and a fellowship in movement disorders at the Oregon Health and Science University in Portland, Oregon. Since then, his research on palliative care in Parkinson’s disease has been published and he was named the co-director of the Legacy Portland Parkinson's Program. Recently, Dr. Tuck moved to Victoria, BC to start a Parkinson's and Movement Disorders clinic at Royal Jubilee.