Focused Ultrasound
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Opening the blood-brain barrier in ALS

Sunnybrook researchers make history in conducting a world-first study that has demonstrated the safety of using MRI-guided focused ultrasound to open the blood-brain barrier (BBB) of the motor cortex in patients with ALS. Sunnybrook is the only centre pursuing this kind of work with ALS patients.

Learn more:

» Sunnybrook research helps take future treatment of ALS patients to a new level

» Behind the research: ALS milestone for Sunnybrook researchers

» ‘Let’s make history’: what one man is doing about living with ALS

Frequently asked questions

Is this a cure for ALS?

No. This research is in its early stages and the primary goal is to demonstrate safety and feasibility. If successful, the ultimate goal is to use this novel technique to open the blood-brain-barrier (BBB) and then test the most promising ALS therapeutics. ALS stands for Amyotrophic Lateral Sclerosis and is also known as Lou Gehrig's disease.

Will this help me / my family member?

The goal of the Phase 1 trial was to investigate the safety and feasibility of opening of the BBB in patients with ALS using this non-invasive and novel technique. Although there are no medications being administered in this early stage safety study, it will set the foundation for a future trial using BBB opening and an ALS therapeutic.

What is the blood-brain barrier?

The blood-brain barrier is a protective wrapping around the blood vessels of the brain that keeps it safe from toxins and infectious agents. At the same time, it also prevents the access of medications and therapeutics that may potentially help treat diseases like ALS.

How is focused ultrasound used to open the BBB?

In this phase 1 trial, researchers are investigating the safety, feasibility and tolerability of opening the blood-brain barrier using low-intensity focused ultrasound.

The trial is the first study in ALS patients. Eight patients will have their blood-brain barriers opened temporarily over the motor cortex, which is the part of the brain responsible for movement and is damaged in ALS.

Microscopic bubbles are injected into the patient’s bloodstream through an IV in their hand or arm. MRI-guided low-intensity ultrasound (sound waves) is precisely targeted on small blood vessels where they want the BBB opened. The ultrasound energy repeatedly compresses and expands the microbubbles, causing them to vibrate and gently loosen tight junctions of the cells comprising the BBB, creating a small opening.

If this trial is successful in demonstrating that the motor cortex blood-brain barrier is safely opened in ALS patients, future studies will be able to use this technique to deliver the most promising therapeutics to key areas of the brain of patients with ALS.

What are the risks?

All procedures carry risk. In this procedure, the main risks include bleeding in the brain. Patients are monitored very closely by a large interdisciplinary group including neurosurgeons, an anesthetist, radiologist, neurologist and physicist. The procedure is done incrementally to help reduce risk. Research is completed within the hospital environment with access to care and leading brain health specialists.

Who is this trial for?

Phase 1 of this trial is open to Canadian residents and will involve eight patients with ALS who are 18 years and older. Patients cannot be taking anticoagulants and need to be able to tolerate lying flat in an MRI. For more information or to inquire about eligibility for the trial, please contact Maheleth Llinas at

Who do I contact for more information about this focused ultrasound clinical trial at Sunnybrook?

For more information or to inquire about eligibility for the trial, please contact Maheleth Llinas at