White matter lesions play a role in cognitive decline and dementia. One presumed pathway is through disconnection of functional networks. Little is known about location-specific effects of lesions on functional connectivity. This study examined location-specific effects within anatomically-defined white matter tracts in 1584 participants of the Rotterdam Study, aged 50–95. Tracts were delineated from diffusion magnetic resonance images using probabilistic tractography. Lesions were segmented on fluid-attenuated inversion recovery images. Functional connectivity was defined across each tract on resting-state functional magnetic resonance images by using gray matter parcellations corresponding to the tract ends and calculating the correlation of the mean functional activity between the gray matter regions. A significant relationship between both local and brain-wide lesion load and tract-specific functional connectivity was found in several tracts using linear regressions, also after Bonferroni correction. Indirect connectivity analyses revealed that tract-specific functional connectivity is affected by lesions in several tracts simultaneously. These results suggest that local white matter lesions can decrease tract-specific functional connectivity, both in direct and indirect connections.

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doi.org/10.1016/j.neurobiolaging.2016.12.004, hdl.handle.net/1765/95308
Neurobiology of Aging: age-related phenomena, neurodegeneration and neuropathology
Department of Radiology

Langen, C., Zonneveld, H.I. (Hazel I.), White, T., Huizinga, W., Cremers, L., de Groot, M., … Vernooij, M. (2017). White matter lesions relate to tract-specific reductions in functional connectivity. Neurobiology of Aging: age-related phenomena, neurodegeneration and neuropathology, 51, 97–103. doi:10.1016/j.neurobiolaging.2016.12.004