Introduction: Differences in brain network connectivity may reflect the capability of the neurological substrate to compensate for brain damage and preserve cognitive function (cognitive reserve). We examined the associations between white matter connectivity, brain damage markers, and cognition in a population sample of middle-aged individuals.
Methods: A total of 4759 participants from The Maastricht Study (mean age = 59.2, SD = 8.7, 50.2% male) underwent cognitive testing and diffusion magnetic resonance imaging (dMRI), from which brain volume, structural connectivity, and vascular damage were quantified. Multivariable linear regression was used to investigate whether connectivity modified the association between brain damage and cognition, adjusted for demographic and cardiometabolic risk factors.
Results: More atrophic and vascular brain damage was associated with worse cognition scores. Increasing connectivity moderated the negative association between damage and cognition (χ2 = 8.64, df = 3, p ≤ 0.001); individuals with high damage but strong connectivity showed normal cognition.
Discussion: Findings support the reserve hypothesis by showing that brain connectivity is associated with cognitive resilience.
Keywords: atrophy; brain damage; brain reserve; cerebral small vessel disease; cognition; cognitive reserve; diffusion MRI; epidemiology; executive function; information processing; memory; modifiable risk factors; networks; prevention; structural connectivity.
© 2022 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.