title: Bimanual motor deficits in older adults predicted by diffusion tensor imaging metrics of corpus callosum subregions.
abstract: Age-related changes in the microstructural organization of the corpus callosum (CC) may explain declines in bimanual motor performance associated with normal aging. We used diffusion tensor imaging in young (n = 33) and older (n = 33) adults to investigate the microstructural organization of seven specific CC subregions (prefrontal, premotor, primary motor, primary sensory, parietal, temporal and occipital). A set of bimanual tasks was used to assess various aspects of bimanual motor functioning: the Purdue Pegboard test, simultaneous and alternating finger tapping, a choice reaction time test and a complex visuomotor tracking task. The older adults showed age-related deficits on all measures of bimanual motor performance. Correlation analyses within the older group showed that white matter fractional anisotropy of the CC occipital region was associated with bimanual fine manipulation skills (Purdue Pegboard test), whereas better performance on the other bimanual tasks was related to higher fractional anisotropy in the more anterior premotor, primary motor and primary sensory CC subregions. Such associations were less prominent in the younger group. Our findings suggest that structural alterations of subregional callosal fibers may account for bimanual motor declines in normal aging.
authors.affiliation: Motor Control Laboratory, Movement Control and Neuroplasticity Research Group, Biomedical Sciences Group, KU Leuven, Tervuursevest 101, 3001, Heverlee, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Serbruyns
authors.forename: J
authors.initials: J
authors.lastname: Gooijers
authors.forename: K
authors.initials: K
authors.lastname: Caeyenberghs
authors.forename: R L
authors.initials: RL
authors.lastname: Meesen
authors.forename: K
authors.initials: K
authors.lastname: Cuypers
authors.forename: H M
authors.initials: HM
authors.lastname: Sisti
authors.forename: A
authors.initials: A
authors.lastname: Leemans
authors.forename: Stephan P
authors.initials: SP
authors.lastname: Swinnen
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000375:Aging / Q000473:pathology*; D000704:Analysis of Variance; D016880:Anisotropy; D001931:Brain Mapping; D002755:Choice Behavior; D003337:Corpus Callosum / Q000473:pathology*; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D009069:Movement Disorders / Q000175:diagnosis*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D055815:Young Adult