Grey area

Dr. Sean Nestor, who did his PhD training in the lab of Dr. Sandra Black, director of the Hurvitz Brain Sciences Research Program at Sunnybrook Research Institute, received the Young Investigator Award from the International Society of Vascular, Cognitive and Behavioural Disorders. He was awarded the honour at the organization’s meeting held Oct. 12 to 15 in Amsterdam, the Netherlands.

He was recognized for his research into whether increased cerebrovascular disease burden, where there are problems with the blood vessels supplying the brain, is linked to greater disruption of grey matter networks in the brain in normally aging people and those with dementia. “The grey matter contains the cell bodies of neurons. We were interested in seeing how the grey matter is networked across the entire brain and how those large-scale networks are disrupted when somebody has more cerebrovascular disease pathology,” says Nestor, who defended his thesis in June and is now doing his psychiatry residency at the University of Toronto.

The research is the first to look at the link between disruption of grey matter networks and cerebrovascular disease in Alzheimer’s disease (AD). Nestor and colleagues found that in normally aging people all grey matter networks showed a link between network disruption and cerebrovascular disease, also called small vessel disease. In people with AD, however, particular networks tended to be targeted more by cerebrovascular disease pathology, “suggesting that cerebrovascular disease may have a specific contribution to dementia,” says Nestor.

While people with AD are apt to have more evidence of cerebrovascular disease on MRI brain scans, it is difficult for researchers to prove the effects of cerebrovascular disease because of the progressive loss of structure and function of neurons, including the death of neurons. “By looking at these specific networks using very sensitive brain imaging methods, we were able to actually show that yes, in AD, beyond the neurodegenerative processes that are occurring, we’re still able to find an effect of small vessel disease relating to disruption of the brain and how it’s networked,” says Nestor.

The goal is to find a way to use grey matter network brain mapping as a way of predicting dementia, or to support a diagnosis of dementia.