Sunnybrook Magazine – Fall 2018

A world-first clinical trial moves on to a second study

Focused Ultrasound

Sunnybrook researchers once again made history by successfully opening the blood-brain barrier non-invasively, this time in patients with Alzheimer’s disease.

The blood-brain barrier is like plastic wrap coating the small blood vessels of the brain, preventing large compounds from getting into the brain, including possibly effective therapies. Getting through that barrier could help medications reach previously elusive areas of the brain without the need for invasive surgery.

Sunnybrook researchers have now opened the blood- brain barrier by combining focused ultrasound with injected microscopic bubbles in six study participants with Alzheimer’s disease.

After the participant is fitted with a specialized helmet within an MRI, precisely targeted ultrasound waves cause the bubbles to vibrate within the brain’s blood vessels, leading to very precise and temporary openings in the blood-brain barrier.

In the first study of its kind, published in July 2018 in Nature Communications, this technique was found to be safe in a small group of patients with mild to moderate Alzheimer’s disease. In all patients, the blood-brain barrier was safely, repeatedly and temporarily opened, without serious side effects.

This success paves the way for a larger, second-phase clinical trial of 30 patients with Alzheimer’s. If the results continue to be promising, researchers say this technique could potentially change the treatment of patients with a variety of neurological conditions where overcoming the blood-brain barrier is a challenge.