tDCS for Dementia: What Baycrest’s Brain Stimulation Research Shows

Using a gentle electrical current to influence the brain is not a new idea. Scientists have studied it for close to 200 years. Today, Baycrest researchers are using it to help people living with dementia keep their memory, speech and independence for longer.

Dr. Howard Chertkow and Dr. Tyler Roncero lead this work in Baycrest’s Bresver Neuromodulation & Therapeutics Program. It is one part of Baycrest’s wider neuromodulation research at Baycrest (opens in a new tab).

What is tDCS?

tDCS, short for transcranial direct current stimulation, is a non-invasive treatment that passes a very low, steady electrical current through sponge pads on the scalp. It needs no surgery and is portable. In the future, some people may be able to use it at home under clinical guidance.

What happens during a tDCS session?

A session lasts about 30 minutes, and the person does simple brain exercises, like memory or language tasks, while the current is on. It does not hurt.

Think of it as a workout for the brain. The light current helps brain cells communicate more easily, and the exercises strengthen those pathways.

Why would electrical stimulation help the brain?

Brain cells talk to each other in two connected ways: with chemicals and with electricity. Chemical messengers help decide whether the next cell fires. Electrical signals, like tiny voltage changes and brain waves, carry information through the brain.

Most medicines work on the chemical side. tDCS works on the electrical side, gently changing how easily brain cells fire and how well they work together. The two approaches support struggling brain circuits in different ways, and reaching a circuit through its electrical activity can sometimes be more direct.

What have Baycrest’s tDCS studies found?

Early results are encouraging. In studies with people living with dementia, Dr. Roncero’s team found that:

• People who got real tDCS during brain exercises improved more than people who got placebo (sham) stimulation.
• Brain scans showed higher activity in several regions after stimulation, and the change lasted at least two weeks.
• Families said their loved ones seemed more alert, more engaged and more social at home.

Across the studies, people have shown gains in memory, language and decision-making, plus walking and coordination. Some benefits lasted weeks or even months. The people who found the exercises hardest gained the most, which suggests treatment may work best when it is matched to the person.

Can tDCS help other brain conditions?

Baycrest is testing it for two rare conditions that have few treatment options.

Progressive supranuclear palsy (PSP) is a rare disorder like Parkinson’s that badly affects walking, balance and eye movement. No drug works well for it. With donor funding, Baycrest grew one patient case into a 30-person study. When people with PSP got tDCS while walking, they walked faster, took more steps per minute and froze less often.

Primary progressive aphasia is a rare dementia that affects language. Dr. Chertkow and Dr. Roncero are working with Johns Hopkins University and the University of Pennsylvania on an international tDCS trial for it. The trial is looking at whether tDCS works, who benefits most and how long the gains last.

What is tACS, and how is it different?

Transcranial alternating current stimulation (tACS) uses a current that rises and falls in a rhythm instead of a steady one. Those rhythms may line up better with the brain’s own, and early evidence suggests this could help memory and learning even more.

Baycrest researchers plan to compare tACS and tDCS directly. They are also building computer models to find the best spots on the scalp to aim stimulation, especially near the hippocampus, the brain’s memory centre.

Questions and answers about tDCS

Is tDCS safe?

tDCS uses a very low current, needs no surgery and is considered very safe in research settings. At Baycrest it is given under the guidance of research teams. Talk with your doctor before you try any brain stimulation.

Does brain stimulation with tDCS hurt?

No. Sessions are painless. People do simple brain exercises while the current is on.

Is tDCS an approved treatment for dementia?

Not yet. Baycrest’s results are encouraging, but tDCS for dementia is still being studied in clinical trials.

How can I take part in a tDCS study?

Baycrest lists current studies on its Joining a Clinical Trial page (opens in a new tab) with details on how to take part.

Sources

1. Baycrest. Transcranial Direct Current Stimulation (tDCS) (opens in a new tab). Undated.