Focused ultrasound and Parkinson’s: treatment and research in Canada

Latest update: August 25, 2026

Focused ultrasound therapy (FUS) is a technology being used to treat Parkinson’s that uses sound waves to target specific areas of the brain without making an incision in the skull. It is also sometimes called transcranial focused ultrasound, which simply means that the sound waves pass through the skull. 

There are two main types of focused ultrasound used or studied in Parkinson’s, and they both work in very different ways. High-intensity focused ultrasound is available as a treatment for certain Parkinson’s movement symptoms in a small number of carefully selected people with Parkinson’s. Low-intensity focused ultrasound is an experimental approach being studied in Parkinson’s research as a possible way to deliver medications to the brain or temporarily influence activity in brain circuits.  

High-intensity focused ultrasound 

High-intensity focused ultrasound uses concentrated ultrasound energy to heat and destroy a very small, targeted area of brain tissue involved in abnormal movement signals. This is medically referred to as lesioning or ablation. The procedure can be done on one side of the brain or in two stages to target both sides of the brain. Depending on the area of the brain being targeted, the procedure may help reduce symptoms such as tremors that are not adequately controlled by medication, or dyskinesia.  

The medical team uses magnetic resonance imaging, or MRI, throughout the procedure to help identify the treatment area and monitor changes in temperature. Unlike deep brain stimulation, focused ultrasound does not require implanted electrodes, a battery, or ongoing programming. However, the change made to the brain is permanent and cannot be adjusted after the procedure. 

High-intensity focused ultrasound uses a device licensed by Health Canada and is available in Canada. Its role in Parkinson’s remains quite limited, and it is not an appropriate option for most people living with Parkinson’s. A small number of people may qualify following an assessment by a multidisciplinary team. Access is generally through movement disorder clinics that offer advanced therapies, following a referral process similar to the one used for deep brain stimulation. 

Treatment may be performed on one side of the brain or, in some instances, on both sides through separate procedures. When both sides are treated, the procedures are staged so the medical team can assess the benefits and any side effects of the first procedure before proceeding with the second. Potential risks include changes in speech or swallowing, numbness, and difficulties with walking, coordination, or balance. 

Low-intensity focused ultrasound 

Low-intensity focused ultrasound uses lower levels of energy and does not heat or permanently ablate brain tissue. Its use in Parkinson’s is still experimental and is currently being studied in clinical trials. 

One area of research involves using low-intensity focused ultrasound to temporarily open the blood-brain barrier. The blood-brain barrier protects the brain from potentially harmful substances circulating in the blood, but it can also prevent potentially helpful treatments from reaching the areas where they are needed.  

During this type of procedure, the medical team introduces microscopic bubbles into the bloodstream. When low-intensity ultrasound is directed at the targeted area, the bubbles vibrate and temporarily allow substances to pass through the blood-brain barrier. This may allow a treatment given through the bloodstream to enter a specific area of the brain more effectively. The opening is temporary and generally closes within hours.  

A study at Sunnybrook Research Institute in Toronto is examining whether low-intensity MRI-guided focused ultrasound can help deliver glucocerebrosidase, or GCase, an enzyme where lower activity has been associated with some forms of Parkinson’s, across the blood-brain barrier¹. This early-stage study will help determine if the approach can be carried out safely and as intended. 

Researchers are also studying low-intensity focused ultrasound as a form of neuromodulation, which means temporarily influencing activity in targeted brain circuits. Current research is examining whether this approach could one day help manage symptoms such as tremor, but it is not currently an established treatment for Parkinson’s. 

Researchers at the University of British Columbia have also studied whether low-intensity focused ultrasound can temporarily influence deep areas of the brain involved in tremor.² In addition, research at University Health Network in Toronto has examined low-intensity ultrasound and has measured how targeted brain circuits respond to the stimulation.³ 

In summary 

The term focused ultrasound can refer to more than one procedure. High-intensity focused ultrasound is an available but highly specialized treatment that may be considered for a small number of carefully selected people with Parkinson’s. Low-intensity FUS for blood-brain barrier opening or altering brain circuits remains experimental and is currently available only through research. 

Anyone interested in focused ultrasound should speak with their neurologist or movement disorder specialist. They can help determine whether a referral to an advanced therapies clinic or information about a clinical trial may be appropriate for you. 

References: 

1. Study Details | NCT05565443 | MR-guided Focused Ultrasound Plus GCase | ClinicalTrials.gov  ↩︎
2. Low-intensity transcranial ultrasound effects on the ventral intermediate nucleus and zona incerta in Parkinson’s disease tremor – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation  ↩︎
3. Individualized non-invasive deep brain stimulation of the basal ganglia using transcranial ultrasound stimulation | Nature Communications ↩︎