Non-invasive ways to stimulate the brain

When the medication to treat Parkinson’s disease symptoms like stiffness, slowness and tremors stops working, some people turn to deep brain stimulation. The procedure requires implanting electrodes deep in the basal ganglia region of the brain to deliver electrical pulses encouraging neurons to fire in a particular pattern.

Although the surgery is effective, it’s too risky for many older people with Parkinson’s who have other serious health conditions.

At McGill University, neuroscientist Matthew Krause is studying a way to deliver electrical stimulation to the same region of the brain, without the need for surgery.

Krause, a research associate, is testing transcranial electrical stimulation. This method involves attaching electrodes to people’s scalps, through a tight-fitting cap, and creating an electrical field. A small battery-powered device then delivers the electrical charge to the electrodes. It creates a tingling feeling on the scalp and an electrical field that interacts with the brain’s own electrical activity.

Positioning the electrodes precisely places will be critical to the method’s success, Krause says.

“Over the last two years, we’ve shown we can change how neurons fire with this transcranial stimulation.”

“What we’re trying to figure out how to set it up correctly to hit the kind of same deep brain structures a surgeon would target, but without drilling into your head.”

Currently, only five to 25 percent of people with Parkinson’s receive deep brain stimulation, and there’s a long waiting list for surgery.

If Krause could find a way to encourage neurons damaged by Parkinson’s disease to fire and connect with other neurons, without surgery, this new method would be accessible to many more people.

“Over the last two years, we’ve shown we can change how neurons fire with this transcranial stimulation,” he says.

Commercial versions of devices that deliver transcranial electrical stimulation are already being touted as improving memory and other performance. Their results are unproven so far, prompting the need for more research.

Krause and his colleague Pedro Vieira are working with animal models to see if this method of stimulating the brain will reduce the motor symptoms of Parkinson’s.

Krause was motivated to start his research by a family friend with Parkinson’s. The friend, who did not want surgery, asked Krause to investigate other therapies.

“It occurred to me that what we were trying to do elsewhere in the brain would also work here,” Krause says. “To the extent that this could give people back a little bit of mobility, a little bit of independence, that would make me happy.”