Affiliations: [a] Division of Neuropsychology, Department of Neurology, The University of Alabama at Birmingham, Birmingham, AL, USA
| [b] Alzheimer’s Disease Center, The University of Alabama at Birmingham, Birmingham, AL, USA
| [c] The University of Texas at Dallas, School of Behavioral and Brain Sciences, Center for Vital Longevity, Dallas, TX, USA
Correspondence:
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Correspondence to: Kristen Kennedy, PhD, Center for Vital Longevity, Behavioral and Brain Sciences, The University of Texas at Dallas, 1600 Viceroy Dr., Suite 800, Dallas, TX 75235, USA. Tel.: +1 972 883 3739; Fax: +1 972 883 3520; E-mail: [email protected].
Abstract: Financial capacity (FC) is a cognitively complex activity of daily living that declines in mild cognitive impairment (MCI) and Alzheimer’s disease (AD), limiting an individual’s ability to manage one’s finances and function independently. The neural underpinnings of this decline in function are poorly understood but likely involve age-related and disease-related degradation across structural networks. The purpose of the current study was to determine if altered white matter integrity is associated with declining FC in persons with MCI and AD compared to older controls. Individuals with MCI due to AD (n = 31), mild dementia (n = 39), and cognitively healthy older adults (n = 60) were administered a neuropsychological battery including the FC Instrument, a performance-based measure of FC. All 130 participants also underwent diffusion tensor imaging (DTI) upon which tract-based spatial statistics were performed. Both FC and white matter integrity decreased in accordance with disease severity with little to no effect in healthy elderly, significant effects in MCI, and greater effects in AD. Regional white matter degradation (increased diffusivities and decreased fractional anisotropy) was associated with reduced FC in both MCI and AD groups even after controlling for age, education, and gender. Specifically, in MCI, decreased fractional anisotropy, but not increased diffusivities, was associated with poorer FC in widespread cingulo-parietal-frontal and temporo-occipital areas. In AD, rather than anisotropy, increased mean and axial diffusivities in anterior cingulate, callosum, and frontal areas associated with poorer FC. These findings suggest a severity gradient of white matter degradation across DTI metrics and AD stages that predict declining financial skill and knowledge.
Keywords: Aging, financial management, Alzheimer’s disease, brain, diffusion tensor imaging, magnetic resonance imaging, mild cognitive impairment, white matter connectivity
