“DBS, Focused Ultrasound & Stereotactic Radiotherapy for PD” – Webinar Notes Stanford PD Community Blog

Deep Brain Stimulation Graphic — source; Magnific

In July 2026, the American Parkinson Disease Association (APDA) hosted a webinar on three treatments for Parkinson’s disease (PD): deep brain stimulation (DBS), focused ultrasound (FUS), and stereotactic radiotherapy (SRT). Three different neurosurgeons discussed the three treatments. They shared basic definitions of each procedure, pros and cons, and who might be a good candidate for each procedure. The webinar was part of the APDA’s “Dr. Gilbert Hosts” series.

A recording of the webinar is available on the APDA YouTube channel

These are the major points from the seminar:

Each treatment aims at changing activity within the same circuits in the brain, with the goal of reducing tremor and other movement symptoms. Treatments vary in their approach to getting to that circuit, and their method of modulating brain activity.
DBS involves the surgical, permanent placement of electrodes deep within the brain, to disrupt abnormal brain activity as needed. FUS and SRT use beams of ultrasound and radiation, respectively, to create small lesions in the brain tissue.
The technology and techniques of these treatments have improved over the past decades, as have the understanding of the risks and benefits. The field is still developing; physicians are researching more options among regions of the brain they may target to treat different symptoms.

You can find more resources about DBS and FUS on the Stanford Parkinson’s website

Below are my full notes.

– Jordan

“Dr. Gilbert Hosts: DBS, Focused Ultrasound & Stereotactic Radiotherapy for PD”

Speakers: Dr. Brian Dalm, neurosurgeon, Ohio State University; Dr. Andreas Lozano, neurosugeon, University of Toronto; Dr. Evan Thomas, neurosurgeon, University of Miami.

Webinar Host: American Parkinson Disease Association (APDA)

Webinar Moderator: Dr. Rebecca Gilbert

Webinar Date: July 16, 2026

Summary by: Jordan Dagan, Stanford Parkinson’s Community Outreach

Editor’s Note: Dr. Brian Dalm discussed DBS, Dr. Andreas Lozano discussed FUS, and Dr. Evan Thomas discussed SRT.

BRIEF DESCRIPTION OF EACH TREATMENT

Each treatment aims at modulating brain activity within regions involved in movement, with the goal of reducing tremor and other movement symptoms. Which region a surgeon targets, and the intensity of treatment, depends on the individual patient’s symptoms.

Deep brain stimulation (DBS) treatment involves an open surgery, where electrodes with “leads” are placed directly in the brain. These electrodes deliver an electric charge to specific regions of the brain, with the aim of disrupting abnormal electrical signals. The electrodes are powered by a battery, which is implanted near the patient’s collarbone.

Focused ultrasound (FUS) treatment does not require any incision. Magnetic resonance guides high-intensity beams of sound onto one point in the brain. The heat this generates creates a lesion in the brain, providing near-immediate symptom relief.

Stereotactic radiotherapy (SRT) was once known as stereotactic radiosurgery (SRS), a name that reflected the precision needed for an effective and safe procedure. However, FUS and SRT are not true surgeries. This treatment is similar to FUS, but uses radiation instead of ultrasound. This approach has less-immediate effects than FUS, as a tiny scar develops around the point of lesion.

WHAT SYMPTOMS DO THESE SURGERIES TREAT?

Generally, tremor is the symptom most effectively treated by each of these options.

In DBS, the STN (subthalamic nucleus) may also be targeted to control motor symptoms, or the GPi (globus pallidus internus) to control dyskinesia and improve overall motor control.

In FUS, research is ongoing to treat rigidity, bradykinesia, gait disturbances, and dyskinesias. Several FUS treatments have been FDA-approved for treating these symptoms.

SRT’s major focus is tremor, and it doesn’t treat non-tremor symptoms such as stiffness and slowness.

None of these treatments directly provide relief from non-motor symptoms of PD, and they do not treat cognitive decline. The underlying cause of PD, die-off of dopaminergic neurons, is not treated.

WHO IS A GOOD CANDIDATE FOR STEREOTACTIC RADIOTHERAPY?

SRT is not as widely-known as DBS or FUS. Dr. Thomas says the best candidates for radiotherapy, as opposed to other treatments, are those who:

Have medical comorbidities that increase risk from other treatments, such as those who can’t be taken off blood thinners, or those who have a heart risk which makes anaesthesia dangerous.
Don’t want a device implanted, or don’t want traditional surgery.
Have a skull thickness or density not favorable for FUS, making the FUS procedure ineffective or uncomfortable.
Struggle to hold still, which may make DBS or FUS more difficult.

Radiotherapy (SRT) is likely not a good option:

If tremor is not your primary symptom.
If you want immediate tremor relief, FUS would be a better choice.
If you want adjustable results, DBS would be a better choice.
If both sides of the body need treatment. SRT doesn’t have as much data on this, and a longer wait time between treatments is needed.

WHAT ARE THE RISKS ASSOCIATED WITH THESE TREATMENTS?

Physicians can generally pinpoint what specific place in the brain to target within 0.5-1 mm accuracy. This precision is achieved with careful planning and MRI brain imaging, as well as frames or masks during the procedure to keep the patient’s head steady. DBS electrode implantation is completed using robotics. X-rays are taken to verify the placement of the electrodes.

Risks of DBS:

Surgical risk cannot be completely mitigated. There is always a chance of bleeding or misplacement. Dr. Dalm estimates there is about a 1% chance of a patient experiencing brain hemorrhage, and about a 2 to 3% chance of infection post-surgery.
DBS involves a battery and electrodes permanently placed in the patient’s body. Problems with the hardware necessitating repair or replacement may occur, in about 5-15% of cases.
Adverse effects of electrical stimulation itself can occur. This is one advantage DBS has over other methods of surgical treatment: the stimulation can be modulated or turned off entirely, if side effects are troublesome.

Risks of FUS and SRT:

Some patients, about 5%, see an overgrowth of scar tissue after SRT treatment, and their surgeon may prescribe a medication to slow the growth of scar tissue.
About 10% of patients experience a moderate headache after the procedure, and this is often helped by an over-the-counter anti-inflammatory such as Tylenol.
Dr. Thomas estimates the risk of changes in sensation, such as numbness in the fingertips or lips, to be about 5%.
Some patients, about 3%, experience weakness in their hands or slurring of their words after treatment. If this is caught early, it is often reversible with a steroid treatment.
Very occasionally, scar tissue may grow out of control. Dr. Thomas estimates this may happen in 0.3-0.5% of cases: approximately 3 to 5 in every thousand patients who undergo the procedure.

WHAT SHOULD PATIENTS EXPECT FROM EACH PROCEDURE?

If you or your loved one chooses any surgical procedure for your treatment, your surgeon will first use an MRI, or series of MRIs, to plan your treatment very carefully. They’ll consult you on what symptoms are most troubling to you, so they can plan what precise area of the brain to target.

If you choose DBS, the patient’s head is shaved for the procedure. During the surgery, a set of metal tools is used to hold the head still and align the trajectory of the probes. The surgery itself is done using robotics, improving accuracy and reducing risk. Surgery can be done awake or under general anesthesia, with similar accuracy.

After the lead placement, doctors will confirm the leads are placed in the correct spot using X-rays. Lead placement accuracy is usually within 1mm accurate even between various techniques.

Post-surgery, the directional leads will allow the electrical current to be pinpointed, reducing adverse effects. These days, the stimulation is adaptive to the patient’s needs, and is applied to the brain only when an abnormal brain signal is detected. The strength of stimulation can be controlled by the patient, or turned off entirely.

If you or your loved one chooses SRT, there will be a lot of planning involved, though the procedure is very quick. The physician will create a mask to hold your head still, and a CT scan will be done with your face in the mask. Using the results of the scan, your physician will tailor the planned procedure to your anatomy.

On treatment day, the patient is positioned on a table, the mask is applied, and more imaging is taken to align the patient in the machine within 0.5mm precision. The machine and table will move around very slowly, delivering X-rays. Dr. Thomas describes the experience as “a very un-exciting roller coaster.” The procedure takes about 20 minutes.

Once the treatment is complete, no recovery time is needed. The procedure is done outpatient/outside of a hospital, so you’ll be able to go back to your normal activities almost immediately.

Over time, a tiny scar tissue will develop in the circuit of the brain responsible for tremor.

Improvement after SRT typically begins in 4 to 8 weeks, though this varies. Your doctor will have you do an MRI follow up every 3 to 6months, to monitor for any overgrowth of scar tissue.

If you or your loved one chooses FUS, the procedure will be very similar to SRT. Patients may see immediate improvement in tremors. After the FUS procedure, patients stay at the clinic for about one hour, and then they can go home.

Patients will likely see an immediate improvement in essential tremor symptoms, and these results will likely be sustained even up to five years post operation.

FUS procedure can be done on both sides of the brain. However, your surgeon should always leave an interval of 6 to 9 months between each procedure, to let the brain recover.

QUESTIONS AND ANSWERS

Question: Dr. Lozano discussed the pallidothalamic tractotomy (PTT) procedure to treat slowness and stiffness. Can this procedure also help with tremor?

Answer: Studies are currently researching this. PTT seems to be effective for tremor, yes.

Question: Does a bilateral PTT procedure lead to more relief from symptoms, compared to non-bilateral PTT?

Answer: Not many people have had this done, not enough data. Most with PTT have only had it done on one side.

Question: Other presenters on surgical treatments for PD have seemed to prefer DBS over other treatments. Why?

Answer by Dr. Lozano: Some centers don’t have all treatments available. These treatments are all very similar at treating tremor, so the difference between them comes down to patient preference. Some patients don’t want an implant, and some don’t want to be awake during the procedure.

Answer by Dr. Dalm: Side effects are very similar between these treatments. We have researched DBS most extensively; practitioners know the primary targets for treating movement symptoms, and where to put leads for different effects. Use of DBS for the treatment of symptoms other than tremor is currently developing. There may be more data coming out soon. And the precision of targeting for FUS and SRT is improving.

Question: If someone has had one procedure, does that prevent them from having another, of a different kind?

Answer: If someone wants this done, the answer isn’t an automatic ‘no,’ but their case must be handled carefully.

Patients can have FUS and then have other procedures after that. Patients generally cannot have DBS and then FUS, because the ultrasound interferes with the DBS leads. This has happened, but it’s very rare.

Patients can have DBS and then SRT, but it’s very rare. This is done if there’s a hardware failure or an infection, in which case the DBS implant has been removed or entirely deactivated.

Very rarely, some patients don’t create a lesion after SRT, in which case they may be referred to FUS.

Question: Is the presence of a cardiac pacemaker an issue with any of these treatments?

Answer: Not usually, if the pacemaker can be placed in safe MRI mode.

Question: How would a surgeon handle the case of a patient with claustrophobia?

Answer: FUS and DBS can each be done under general anaesthesia, if someone can’t lie down, can’t stay still, etc. Even when treating patients who are awake and don’t like small spaces, coaching or medication can help a lot. SRT treatment is done in a much more open space, with the device moving around the patient rather than containing them.

Question: At what point in PD trajectory are these done? Can we do this early in disease progression?

Answer by Dr. Thomas: This would be a personal decision for each family, depending on the patient’s quality of life. Some want to avoid procedures as long as possible, while some want to reduce medications they’re on, and some want to minimize the impact of symptoms on their work or day to day life, etc. Patients can be treated as early as in their 20s, or they can wait until the disease isn’t responding to medication.

Answer by Dr. Dalm: This depends on the symptom you’re trying to treat. If tremor is impacting independence, feel free to look into treatment. Surgeons can compare the impact of your symptoms on and off medication, to evaluate whether someone is a good fit for surgery. If you know the possible risks and implications, and think surgery is a good fit for you, there is no need to wait.

Answer by Dr. Lozano: PD causes opportunity costs to career and life! If quality of life can be improved, feel free to approach treatment before disability advances.

Question: Do these procedures help non-tremor symptoms, such as freezing of gait and speech difficulty?

Answer: It depends on the symptom, and what location will be targeted. GPi targeting with DBS may worsen freezing of gait. If a certain symptom gets better with levodopa, it is likely to improve with DBS as well. Generally, surgical procedures are best at treating tremor and slowness of movement. Speech may get worse with surgical therapy. If you’re sensitive to changes in your speech, stimulation from DBS can always be turned down or off.