Fiber-specific variations in anterior transcallosal white matter structure contribute to age-related differences in motor performance

Hamed Zivari Adab; Sima Chalavi; Thiago S Monteiro; Jolien Gooijers; Thijs Dhollander; Dante Mantini; Stephan P Swinnen

doi:10.1016/j.neuroimage.2020.116530

Fiber-specific variations in anterior transcallosal white matter structure contribute to age-related differences in motor performance

Neuroimage. 2020 Apr 1:209:116530. doi: 10.1016/j.neuroimage.2020.116530. Epub 2020 Jan 10.

Authors

Hamed Zivari Adab¹, Sima Chalavi², Thiago S Monteiro², Jolien Gooijers², Thijs Dhollander³, Dante Mantini⁴, Stephan P Swinnen²

Affiliations

¹ Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; Leuven Brain Institute (LBI), KU Leuven, Leuven, Belgium. Electronic address: Hamed.Zivariadab@kuleuven.be.
² Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; Leuven Brain Institute (LBI), KU Leuven, Leuven, Belgium.
³ The Florey Institute of Neuroscience and Mental Health, Melbourne, Australia; The Florey Department of Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.
⁴ Movement Control and Neuroplasticity Research Group, Department of Movement Sciences, Group Biomedical Sciences, KU Leuven, Leuven, Belgium; Brain Imaging and Neural Dynamics Research Group, IRCCS San Camillo Hospital, Venice, Italy.

PMID: 31931154
DOI: 10.1016/j.neuroimage.2020.116530

Abstract

Age-related differences in bimanual motor performance have been extensively documented, but their underlying neural mechanisms remain less clear. Studies applying diffusion MRI in the aging population have revealed evidence for age-related white matter variations in the corpus callosum (CC) which are related to bimanual motor performance. However, the diffusion tensor model used in those studies is confounded by partial volume effects in voxels with complex fiber geometries which are present in up to 90% of white matter voxels, including the bilateral projections of the CC. A recently developed whole-brain analysis framework, known as fixel-based analysis (FBA), enables comprehensive statistical analyses of white matter quantitative measures in the presence of such complex fiber geometries. To investigate the contribution of age-related fiber-specific white matter variations to age-related differences in bimanual performance, a cross-sectional lifespan sample of healthy human adults (N = 95; 20-75 years of age) performed a bimanual tracking task. Furthermore, diffusion MRI data were acquired and the FBA metrics associated with fiber density, cross-section, and combined fiber density and cross-section were estimated. Whole-brain FBA revealed significant negative associations between age and fiber density, cross-section, and combined metrics of multiple white matter tracts, including the bilateral projections of the CC, indicative of white matter micro- and macrostructural degradation with age. More importantly, mediation analyses demonstrated that age-related variations in the combined (fiber density and cross-section) metric of the genu, but not splenium, of the CC contributed to the observed age-related differences in bimanual coordination performance. These findings highlight the contribution of variations in interhemispheric communication between prefrontal (non-motor) cortices to age-related differences in motor performance.

Keywords: Aging; Bimanual coordination; Diffusion MRI; Fixel-based analysis.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adult
Aged
Aging / pathology*
Aging / physiology*
Arm / physiology
Corpus Callosum / diagnostic imaging
Corpus Callosum / pathology*
Cross-Sectional Studies
Diffusion Tensor Imaging
Female
Humans
Male
Middle Aged
Motor Activity / physiology*
Psychomotor Performance / physiology*
Young Adult