The Beat Goes On: Brain Vessel Health
In an ageing population, problems with the brain caused by poor blood flow are increasing.
Poor blood flow is a factor in conditions associated with memory problems, such as Alzheimer’s disease and other forms of dementia. We are developing ways of assessing the health of the brain’s blood vessels using MRI. This allows us to track deterioration of the vessels as we age and opens the possibility of treating associated brain conditions before they become problematic.
The heart keeps pounding a rhythm to the brain. Fortunately, the brain’s blood vessels are elastic, providing protection by soaking up the energy; a process called buffering. We develop ways to measure how, over a lifetime, the force of the heartbeat damages the vessels, causes stiffening and reduces buffering. We measure arterial stiffness in the brain’s blood vessels, both large and small, and link it to blood supply issues in different parts of the brain.
Women’s Brain Health and how it changes with age is an understudied area of research. Oestrogen helps protect against degeneration of the brain’s blood vessels. However, during menopause hormone levels drop which increases the risk of developing problems with brain blood flow, contributing to conditions such as dementia. Using large population datasets, such as the UK Biobank, we investigate the effects of menopause and hormone replacement therapy on brain imaging measures. In smaller cohort studies, we measure how hormones such as oestrogen and progesterone change brain blood flow and arterial stiffness over a monthly cycle. We aim to follow women as they progress through menopause to determine the mechanisms of deterioration in brain blood flow. The research has great potential to change clinical practice and to make a true difference to the lives of half of the population.
We have developed a battery of MR cerebrovascular health measures that are used in many studies in CUBRIC to investigate brain vessel health. These studies are often complimented with retinal vessel measures, as a direct visualisation of brain vessels. Research into populations with conditions such as hypertension, obesity, polycystic ovary syndrome (PCOS) and cystic fibrosis (CF) help disentangle the causes of arterial stiffness and poor blood flow. Inflammation challenges demonstrate how the body’s immune response can accelerate deterioration of the blood vessels. Interventions, such as exercise, blood pressure medication and dietary nitrate help us determine new ways of treating brain vessel issues, slowing the deterioration with age. Combining brain imaging with genetic risk tells us who is likely to have these problems and what the best personalised treatment strategy should be.
