Shorter-wave ultrasound pulses could open up new brain treatments

These new findings from Imperial College London could have implications for how drugs are used to help people living with Alzheimer’s.

Neurological diseases like Alzheimer’s can be difficult to treat with drugs because they are often blocked by the blood brain barrier (BBB), the membrane that surrounds blood vessels in the brain and allows very few molecules to pass to the brain from the blood. This protects the brain from harmful substances but can also hinder drugs getting to where they can act.

One avenue of research involves prying open the BBB to let drugs into the brain. This is done by injecting mice with tiny bubbles, or ‘microbubbles’, before applying long-wave pulses of ultrasound radiation to the brain.

The ultrasound pulses change the pressure in the blood vessel, causing the microbubbles to expand and contract. As they do so, they gently open the BBB.

According to Imperial, the long pulses last at least ten milliseconds at a time, which can cause side effects. The longer the BBB stays open, the more chance there is for tissue damage and for harmful molecules to reach the brain.