Peak width of skeletonized mean diffusivity and its association with age-related cognitive alterations and vascular risk factors

• Published in: Alzheimer's & dementia : diagnosis, assessment & disease monitoring assessment & disease monitoring, 2019-12, Vol.11 (1), p.721-729
• Main Authors: Lam, Bonnie Yin Ka, Leung, Kam Tat, Yiu, Brian, Zhao, Lei, Biesbroek, J. Matthijs, Au, Lisa, Tang, Yumi, Wang, Kai, Fan, Yuhua, Fu, Jian-Hui, Xu, Qun, Song, Haiqing, Tian, Xiaolin, Chu, Winnie Chiu Wing, Abrigo, Jill, Shi, Lin, Ko, Ho, Lau, Alexander, Duering, Marco, Wong, Adrian, Mok, Vincent Chung Tong
• Format: Article
• Language: English
• Subjects: Community subjects; Diffusion tensor imaging; Neuroimaging; Peak width of skeletonized mean diffusivity; Processing speed; Small vessel disease
• ISSN: 2352-8729; 2352-8729
• DOI: 10.1016/j.dadm.2019.09.003

Only two studies investigated the associations between peak width of skeletonized mean diffusivity (PSMD) and age-related cognitive alterations, whereas none of the studies investigated the association with vascular risk factors. We evaluated 801 stroke- and dementia-free elderlies with baseline and 3-year follow-up assessments. Regression analyses were used to assess the association between age-related cognitive functions and PSMD. Simple mediation models were used to study the mediation effect of PSMD between vascular risk factors and age-related cognitive outcomes. PSMD was negatively associated with processing speed at baseline and negatively associated with processing and memory scores at 3-year follow-up. The association between vascular risk factors and age-related cognition was mediated by PSMD, as well as other diffusion tensor imaging markers. PSMD is preferred over other diffusion tensor imaging markers as it is sensitive to age-related cognitive alterations and calculation is fully automated. PSMD is proposed as a research tool to monitor age-related cognitive alterations.