2022 Alzheimer's Association Research Grant (AARG)

Cortical Microinfarcts: A Tool to Study Vascular Contributions to Dementia

How might the detection of small strokes in the brain impact changes related to dementia?

Vasileios-Arsenios Lioutas, M.D.
Beth Israel Deaconess Medical Center
Boston, MA - United States

Background

As individuals age, blood vessels can become damaged, impacting blood flow in the brain and other parts of the body. Studies show that vascular (blood vessel) damage may impact an individual’s risk for many brain diseases. One type of blood vessel disorder, called cerebral small vessel disease (CSVD), affects small blood vessels within the brain. Current studies suggest that CSVD may increase an individual’s risk of Alzheimer’s.

One sign of cerebral small vessel disease is the presence of cerebral microinfarcts (very small areas of brain tissue death) in the brain. These small areas of damage in the brain are due to microscopic strokes. Cerebral microinfarcts are associated with cognitive impairment and dementia, and may represent an important mechanistic link between CSVD and dementia. 

In recent years, high-resolution brain scans (structural magnetic resonance imaging, MRI) have allowed the detection of cerebral microinfarcts in the brains of living individuals. However, the detection process is laborious, time-consuming, and requires extensive training.

Research Plan

Dr. Vasileios-Arsenios Lioutas and colleagues will use a sophisticated computer science technique called machine learning to streamline the process of cerebral microinfarct detection and improve precision and accuracy. They will use data from the Framingham Heart Study, an ongoing, long-term, community-based group of adults. The research team will develop a machine learning technique to automate the detection of cerebral microinfarcts from MRI brain images. In addition, the researchers will determine whether the presence of cerebral microinfarcts is associated with increased presence of cognitive decline over time by studying individuals’  brain scans and cognitive performance from at least two different time points several years apart. Finally, Dr. Lioutas and colleagues will use additional brain scanning techniques (diffusion tensor imaging, DTI, and positron emission tomography, PET) to study the connection between cerebral microinfarcts and biological markers of Alzheimer’s (the accumulation of the proteins beta-amyloid and tau, two hallmark brain changes observed in Alzheimer’s).

Impact

If successful, the results may reveal links between cerebral small vessel disease, cognitive function, and Alzheimer’s-related brain changes. The findings may support the use of cerebral microinfarcts as markers of brain health.