Minding the head-heart connection
Conference explores link between diseases of circulatory system and brain
By Alisa Kim
The brain is somewhat of an energy hog. Accounting for just 2% of total body weight, it consumes 20% of the body's blood supply. Blood, rich with food and oxygen, is carried to the brain by blood vessels. Without this supply of oxygen, brain cells die, which is what happens in stroke. But what happens when these brain-nourishing vessels gradually become damaged through the process of aging and conditions like diabetes, high blood pressure and high cholesterol?
The International Society for Vascular, Behavioural and Cognitive Disorders, or VasCog for short, is devoted to understanding how diseased blood vessels contribute to cognitive impairment, depression and behavioural disorders.
The sixth annual VasCog congress was held June 25 to 28 in Toronto. Dr. Sandra Black, a renowned cognitive and stroke neurologist and director of the Brain Sciences Research Program at Sunnybrook Research Institute (SRI), and Dr. Richard Swartz, a brain scientist at SRI and medical director of the Regional Stroke Program at Sunnybrook Health Sciences Centre, co-hosted the event. More than 250 scientists and clinicians from around the world attended the congress.
"It attracted some of the leading thinkers from Asia, Europe and North America [working] at the interface between dementia and stroke. The 'siloed' approaches to these diseases are not working, and with the population aging, dementia and stroke could overwhelm our health care system," says Black. "Hence, the target leaders were there with keen young investigators who want to work at this interface. This conference was a feast of those ready to grapple with these complex interactions."
There were keynote addresses on vascular factors in dementia and the need for increased global attention to brain health. In developing countries, aging populations are growing at an unprecedented rate. Moreover, there are 37 million people worldwide who have Alzheimer's disease, and this number is projected to triple in 30 years. Despite these alarming facts, the brain has received relatively little consideration from the global health perspective, says Black. "What we're seeing is unintended consequences of human survival well beyond reproduction. Now we have to figure out how to improve that survival and maintain people's quality of life. How do we recognize these complex diseases early, and what do we do to delay and mitigate them?"
Other highlights of the congress included debates on whether vascular disease causes Alzheimer's disease, and the significance of microbleeding in the brain in dementia. Microbleeds are leakage of blood in the surrounding brain tissue. Using advanced magnetic resonance imaging at 7 Tesla, with resolution similar to a microscope, researchers from Holland have shown microbleeds are present in 80% of people with Alzheimer's disease. "What does it mean? Does this help us understand clinical expression of disease? We don't know because it depends on how many [bleeds] you have and how widespread they are in the brain. The debate had young and old weighing in, with leading people on opposite sides of the debate. That was really stimulating," says Black.
One of the congress's unique features was the proffering of international perspectives: researchers from Japan, Korea, Hong Kong, Germany, Holland and the U.K., just to name a few, attended. "What was really nice was that they wanted to come and show [their research] in this forum because the interaction is really special when you have a smaller meeting," says Black, who also notes that the cozier atmosphere fostered greater participation from junior investigators during discussions.
New this year were workshops held a few days prior to the congress, an innovation introduced by Black due to the vast amount of knowledge streaming from this field. Black says she looks forward to collaborating with researchers from Asia, spurred by the workshop on harmonizing cognitive assessment tools so they can be used everywhere. "We were struggling with issues like how to do a cognitive assessment in Hong Kong, where literacy rates in certain residential areas are low, and with translating some of the assessment tools from English to Mandarin, Cantonese and Korean. The exciting part is that there's a real willingness to do this together because there's so much we gain by working across borders and ethnicities," says Black.
Planning for the next VasCog congress, which will be held in Tokyo in 2015, is already underway.
Dr. Sandra Black is also the executive director of the Toronto Dementia Research Alliance, site director of the Heart and Stroke Foundation Centre for Stroke Recovery and a professor at the University of Toronto.
Dr. Richard Swartz is also an assistant professor at U of T and director of the U of T Stroke Program.