December 03, 2024
A recent study by Baycrest reveals that an area of the brain distinct from the stroke lesion may play a significant role in causing the life-altering symptoms survivors are often left with, which can include severe challenges with speech, mobility and cognition. These results provide hope that innovative, non-invasive treatments could help improve or even fully reverse post-stroke symptoms.
Strokes (which more than 100,000 Canadians suffer from every year1) leave behind an area where brain cells have died, called a lesion. However, this cannot explain the widespread consequences of stroke, limiting scientists’ and clinicians’ ability to treat them. The study, titled “Secondary thalamic dysfunction underlies abnormal large-scale neural dynamics in chronic stroke,” published recently in the journal Proceedings of the National Academy of Sciences, reveals that degeneration of the thalamus – an area of the brain distinct from the stroke lesion – is a significant contributor to post-stroke symptoms.
“This is both good and bad news,” said Dr. Jed Meltzer, Baycrest’s Canada Research Chair in Interventional Cognitive Neuroscience and senior author of this study. “The bad news is the impact to the brain caused by stroke is not limited to the lesion seen on a brain scan. The good news is the area that shows abnormal electrical activity outside the lesion might be treatable with innovative new therapies.”
New targeted treatments, such as brain stimulation and medications, could be designed to prevent or even reverse this degeneration to optimize recovery in stroke survivors.
Main findings:
- Damage to brain tissue near the stroke lesion was not the primary cause of abnormal brain electrical activity.
- Instead, these abnormalities were related to the thalamus, a structure located deep in the brain’s centre that acts like a hub connecting numerous brain areas and activities.
- More than the lesion alone, the amount of degeneration in the thalamus predicted the amount of abnormal brain electrical activity measured using magnetoencephalography (MEG), and the individual’s language and cognitive deficits.
Dr. Meltzer, who is also Senior Scientist at the Rotman Research Institute, part of the Baycrest Academy for Research and Education (BARE), and his team, which includes researchers from Baycrest, the Centre for Addiction and Mental Health (CAMH) and Simon Fraser University, examined the brain’s electrical activity using MEG and brain structure using magnetic resonance imaging (MRI) of 18 individuals living with language deficits as a result of stroke.
This work was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC), the Canadian Partnership for Stroke Recovery, the Canada Research Chairs Program, the Krembil Foundation, the CAMH Discovery Fund, the Labatt Family Network and the University of Toronto EMHSeed program.
Sources:
1. https://www.cambridge.org/core/journals/canadian-journal-of-neurological-sciences/article/estimating-the-number-hospital-or-emergency-department-presentations-for-stroke-in-canada/1E0F45CF9DB3D647DACE8D96CE2336A5
About Baycrest
At Baycrest, our vision is a world where every older person lives with purpose, fulfilment and dignity. Baycrest is a global leader in aging and brain health innovation, with over 105 years of expertise in seniors' care and cutting-edge research. Baycrest has been Designated with Exemplary Status by Accreditation Canada, and drives industry-leading care and safety outcomes. As the home of the Centre for Aging + Brain Health Innovation (CABHI) powered by Baycrest, the Baycrest Academy for Research and Education (BARE) and the Canadian Consortium on Neurodegeneration in Aging, Baycrest is at the forefront of dementia research. Affiliated with the University of Toronto, Baycrest's training programs shape the future of care globally, while Baycrest Global Solutions extends its expertise to senior living and healthcare internationally. For more information, visit: baycrest.org.
About the Rotman Research Institute, part of the Baycrest Academy for Research and Education
The Rotman Research Institute (RRI) is a preeminent international centre for the study of aging and human brain function. Through generous support from private donors and funding agencies, the RRI advances our understanding of human brain structure and function in critical areas of clinical, cognitive, and computational neuroscience, including perception, memory, language, attention and decision making. With a primary focus on aging and brain health, including Alzheimer’s and related dementias, research at the RRI and across the Baycrest campus promotes effective care and improved quality of life for older adults through research into age- and disease-related behavioural and neural changes.
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Nnacevski-laird@baycrest.org