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.

Age-Related Changes in Frontal Network Structural and Functional Connectivity in Relation to Bimanual Movement Control

“…These results are in agreement with a number of previous studies reporting reductions in FA with advancing age (Nusbaum et al, 2001;Sullivan et al, 2001;Abe et al, 2002;O'Sullivan et al, 2004;Serbruyns et al, 2015), with the largest decline evident in the frontal lobes (Grieve et al, 2007;. The main focus of the present study was to explore the relationships between brain structure, neurophysiological function, and behavior.…”

“…Previous studies have shown that skilled bimanual performance heavily relies on intense interactions between the motor areas in both cerebral hemispheres (Gerloff and Andres, 2002), which are likely dependent on coherent WM microstructural organization (Gooijers and Swinnen, 2014). This view has been supported by investigation of the CC microstructure, including interhemispheric tracts connecting homotopic M1s in relation to bimanual movement performance (Fling and Seidler, 2012;Serbruyns et al, 2015). The current study extends this finding by demonstrating that the WM microstructural organization of interhemispheric fiber tracts between heterotopic cortical regions (i.e., nonprimary motor and primary motor regions) also plays an important role in bimanual coordination tasks, particularly when more complex movements are performed by older adults.…”

“…A complex bimanual visuomotor task (BTT) was used, for which the involvement of the DLPFC and PMd has been previously demonstrated (Sisti et al, 2011Gooijers et al, 2013;. To identify the specific contribution of these brain regions for the control of the respective hand movements, we compared iso (1:1) and two noniso interhand frequencies with conversing frequency arrangements (3:1 and 1:3, i.e., left hand three times faster than right hand, and vice versa).…”

“…To identify the specific contribution of these brain regions for the control of the respective hand movements, we compared iso (1:1) and two noniso interhand frequencies with conversing frequency arrangements (3:1 and 1:3, i.e., left hand three times faster than right hand, and vice versa). The goal of the BTT was to accurately track a moving target presented on a screen with a cursor by rotating dials (Sisti et al, 2011Gooijers et al, 2013;. Participants were comfortably seated on a chair with both arms placed on a table situated in front of them.…”

The Changes of the Cognitive and Psychomotor Functions in the Chronic Cannabis Users after a Month of Remission

“…Reduction in GABA release through CB1 receptor activity in related brain regions may be involved in this reduction of psychomotor speed. A study suggested that structural changes of lower regional callosal fibers may be responsible for age-related bimanual motor reduction 48 . Considering that this study, we found faster motor movement after one-month abstinence and this may be due to reversible changes in lower regional callosal fibers induced by cannabis.…”