Project Overview

Does SARS-CoV-2 infection increase cognitive decline via myelin loss in older individuals?

Background: One in 4 persons infected with SARS-CoV-2 (the COVID-19 virus) shows cognitive decline. This decline could be related to white matter damage. The white matter is made of axons connecting neurons with each other. The integrity of these connections depends on myelin, a fatty tissue layer which envelops the axons. Healthy myelin is essential for transmission of brain signals. Research shows that SARS-CoV-2 causes myelin loss in mice even when neurons are not impacted by the virus. This means myelin loss may be the reason behind cognitive decline after COVID-19.

Methods: In this project, we will investigate if older individuals with SARS-CoV-2 infection show more myelin loss compared with noninfected individuals. We will measure myelin using magnetic resonance imaging. Myelin will be measured at baseline, 1, and 2 years later. Using the data from this study, we will also determine if participants with brain signs of Alzheimer’s disease or with its
genetic risk factor (apolipoprotein E 4 allele) show more myelin loss and cognitive decline after SARS-CoV-2 infection.

Impact: SARS-CoV-2 infection likely causes cognitive decline by reducing myelin in the white matter of the brain. People with brain signs or genetic risk of Alzheimer’s disease might have more decline in cognition after SARS-CoV-2 infection. If these hypotheses are confirmed, our study can help better understand how viral infections increase the risk of Alzheimer’s disease and other dementias. This knowledge can inform future treatment options.

Principal Investigator

Narlon Cassio Boa Sorte Silva , Concordia University

Partners and Donors

Alzheimer's Association