Grant: Catalyst Grant: Pilot Projects in Aging

The brain changes during both normal and disease-related forms of aging. Many of the consequences of brain aging are well established, including loss of neuron cells as well as issues that affect large and small blood vessels. Small blood vessels deliver nutrients to brain tissues and they clear waste products. Several factors can cause these functions to become impaired in what is broadly known as "small vessel disease" (SVD). To follow are some of the processes that result in SVD: narrowing of the diameter of the upstream arteries, which causes an inflow problem and chokes the small vessels and affects the underlying tissue. Downstream to the small vessels, and on the opposite side of the circulatory system, are veins. They too play a role in the progression of SVD by clogging the outflow of blood. SVD damages tissue, creating brain lesions in the white matter and deep structures in the brain. Interestingly, damage to white matter does not necessarily produce an obvious deficit in the early stages of SVD. It is only when the SVD is more widespread that neurological symptoms, such as mild cognitive impairment and dementia, begin to present. SVD can be thought of as "accelerated aging" so there is motivation to develop tools to characterizes the physiological circumstances surrounding SVD. It is important to determine which aspects of the aging brain's physiology relate most strongly to the functional consequences of SVD. Furthermore, 25% of all strokes due to a blockage are caused by SVD, which demonstrates a link exists between SVD and acute "brain attacks". The objective of this Catalyst Grant Pilot Project is to use a Magnetic Resonance Imaging protocol to investigate differences in brain physiology between adults with SVD and age-matched volunteers. The goal is to develop new imaging tools that can explain behaviours that impact daily activities like cognition and gait. A third group of healthy adults will be recruited to show age-related differences.