Neuromodulation and Dementia Research | How Baycrest Is Leading the Way

Most people want to stay sharp as they age and keep dementia away for as long as they can. Today's dementia drugs can ease some symptoms, but no drug can stop or reverse the disease. That gap is why Baycrest's Rotman Research Institute (opens in a new tab) has made neuromodulation a core research priority.

The work happens in the Bresver Neuromodulation & Therapeutics Program, where neuroscientists, clinicians and engineers work together. Baycrest is also the scientific home of the Canadian Consortium on Neurodegeneration in Aging (CCNA) (opens in a new tab), a network of more than 400 dementia researchers and clinicians across Canada.

What is neuromodulation?

Neuromodulation is a group of methods that use light, gentle electrical current or magnetic fields to stimulate specific parts of the brain.

Your brain sends messages in two ways. One is chemical, and that is the side most drugs work on. The other is electrical: tiny voltage changes, brain waves and small electromagnetic fields. Neuromodulation works on the electrical side. It does not replace medication or healthy habits. It adds another tool.

Dr. Howard Chertkow, a cognitive neurologist and senior scientist at Baycrest, sees several advantages:

• It can be done without surgery.
• Some methods may cost little and work at home.
• It pairs well with exercise, brain training and time with other people.
• It may help manage symptoms, and in some cases slow decline.

What types of neuromodulation is Baycrest testing?

Baycrest is testing four types, and none of them needs surgery.

• Transcranial direct current stimulation (tDCS) sends a very low, steady electrical current through sponge pads on the scalp. A session takes about 30 minutes.
• Transcranial alternating current stimulation (tACS) works like tDCS, but the current rises and falls in a rhythm. It may help the brain's own rhythms for memory and learning.
• Transcranial magnetic stimulation (TMS) uses a magnetic coil near the head to create tiny currents that switch on nerve cells. Many people say it feels like a light tapping.
• Photobiomodulation, or light therapy, shines near-infrared light through the skull to give brain cells more energy, improve blood flow and lower inflammation.

How could light therapy help the brain?

Light therapy may give brain cells more energy and help the brain clear waste, and Baycrest is measuring whether that happens. Dr. Jean Chen, a senior scientist and Canada Research Chair in Neuroimaging of Aging, leads one of the most active light therapy labs in North America. Some light therapy devices are already sold to the public, but few have been properly tested for their effect on the brain.

Using MRI scans, Dr. Chen's team has found that:

• Carefully set light can pass through the skull, most easily where the bone is thin, such as inside the nose.
• The effect spreads through brain networks and reaches deep areas like the thalamus, which helps with movement, attention and the senses.
• Some changes last after the light is turned off.
• Light seems to affect the brain's fluid-clearing system, which removes toxins linked to Alzheimer's disease.

Her team also studies how skin tone and the colour of the light change how much light reaches the brain, so future treatments work for everyone. Baycrest is recruiting adults aged 50 to 80 for a trial of a home light therapy device used for about 20 minutes a day.

We're not just studying the brain; we're teaching it to heal itself.

Dr. Jean Chen, Senior Scientist, Baycrest

Learn more in our article on light therapy for dementia (opens in a new tab).

Can magnetic stimulation help memory and mood?

Baycrest researchers think it might, and they are testing it in older adults with depression and early memory concerns. Long-lasting depression raises the risk of dementia, so treating it may also protect thinking skills.

Dr. Jed Meltzer leads Baycrest's TMS work. His team uses magnetoencephalography (MEG), a scan that records brain activity as it happens. After a stroke, they often see slowed activity near the injury and too much activity on the other side of the brain. With TMS they can calm or boost one area and watch the result. Calming an overactive area on the healthy side can improve speech or movement.

Dr. Meltzer and Dr. Linda Mah are also testing deep TMS, which uses a helmet to reach brain areas tied to mood and memory. One trial targets the anterior cingulate cortex, an area that helps control emotion and focus. It uses a faster schedule that fits six weeks of treatment into one week. Donors fund this work.

Learn more in our article on magnetic stimulation (opens in a new tab).

Does electrical brain stimulation help people with dementia?

Early studies at Baycrest say yes for some people. Dr. Tyler Roncero and Dr. Chertkow found that people living with dementia who got real tDCS during brain exercises improved more than people who got a placebo. Brain scans showed more activity in several areas, and the change lasted at least two weeks. Families said their loved ones seemed more alert and more social at home.

People who found the exercises hardest gained the most. That suggests treatment may work best when it is matched to the person.

The team also studies progressive supranuclear palsy (PSP), a rare condition like Parkinson's that badly affects walking and has no effective drug. Donor funding grew one patient case into a 30-person study. With tDCS while walking, people walked faster, took more steps and froze less often.

Dr. Chertkow and Dr. Roncero are working with Johns Hopkins University and the University of Pennsylvania on an international tDCS trial for primary progressive aphasia, a rare dementia that affects language.

Learn more in our article on electrical stimulation (opens in a new tab).

Can neuromodulation help other brain conditions?

Early research suggests it may help with Parkinson's disease, stroke recovery and late-life depression. These conditions share similar problems in how brain areas connect. Because the methods need no surgery and cost less than many drugs, they could one day reach people in clinics and at home.

How does neuromodulation fit with a healthy lifestyle?

It works alongside healthy habits. Known risks for dementia still matter, including hearing loss, vision loss, depression, inactivity and loneliness. Baycrest's Kimel Family Centre for Brain Health and Wellness runs programs in diet, exercise, brain activity and social connection. Stimulation may add to the benefits of exercise, therapy and brain training, and it may help where drugs fall short.

Who leads neuromodulation research at Baycrest?

Five scientists shared this work in a webinar hosted by Dr. Allison Sekuler. Dr. Linda Mah also leads magnetic stimulation research for mood and memory with Dr. Meltzer.

Watch the neuromodulation webinar (opens a video player)

Questions and answers about neuromodulation

Is neuromodulation an approved treatment for dementia?

Not yet. TMS is approved in Canada to treat depression, but its use for memory and dementia is still being studied. tDCS, tACS and light therapy for dementia are also in research.

Does brain stimulation hurt?

The methods Baycrest studies need no surgery or implants. tDCS sessions are painless, and many people describe TMS as a light tapping on the head.

Will brain stimulation replace dementia drugs?

No. Most drugs work on the brain's chemical signals, while neuromodulation works on its electrical activity. Researchers see them as tools that can be used together, along with healthy habits.

Can I use brain stimulation at home?

Not as a proven treatment yet. Some methods, like tDCS and light therapy, are portable, and Baycrest is testing a home light therapy device in a clinical trial.

How can I join a Baycrest study?

Baycrest lists current studies on its Joining a Clinical Trial page (opens in a new tab) with details on how to take part. Talk with your doctor before you start any new treatment.

Sources

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

Further reading

• Baycrest Foundation: Light therapy for dementia (opens in a new tab)
• Baycrest Foundation: How magnetic stimulation is powering dementia research (opens in a new tab)
• Baycrest Foundation: Electrical stimulation and the future of brain health (opens in a new tab)