Cerebellar gray and white matter volume and their relation with age and manual motor performance in healthy older adults
School of Kinesiology, University of Michigan, Ann Arbor, MI, United States; International Normal Aging and Plasticity Imaging Center (INAPIC), University of Zurich, Zurich, Switzerland; University Research Priority Program Dynamics of Healthy Aging, University of Zurich, Switzerland; Division of Neuropsychology, University of Zurich, Zurich, Switzerland; Department of Special Education, King Abdulaziz University, Jeddah, South Africa; Department of Psychology, University of Michigan, Ann Arbor, MI, United States; Neuroscience Graduate Program, University of Michigan, Ann Arbor, MI, United States; Institute of Gerontology, University of Michigan, Ann Arbor, MI, United States
Objectives: Functional neuroimaging and voxel-based morphometry studies have confirmed the important role of the cerebellum in motor behavior. However, little is known about the relationship between cerebellar gray (GMv) and white matter (WMv) volume and manual motor performance in aging individuals. This study aims to quantify the relationship between cerebellar tissue volume and manual motor performance. Experimental design: To gain more insight into cerebellar function and how it relates to the role of the primary motor cortex (M1), we related cerebellar GMv, WMv, and M1v to manual motor performance in 217 healthy older individuals. Left and right cerebellar GMv and WMv, and M1v were obtained using FreeSurfer. The following motor measures were obtained: grip force, tapping speed, bimanual visuomotor coordination, and manual dexterity. Principal observations: Significant positive relationships were observed between cerebellar GMv and WMv and grip strength, right cerebellar WMv and right-hand tapping speed, right cerebellar WMv and dexterity, M1v and grip strength, and right M1v and left-hand dexterity, though effect sizes were small. Conclusions: Our results show that cerebellar GMv and WMv are differently associated with manual motor performance. These associations partly overlap with the brain-behavior associations between M1 and manual motor performance. Not all observed associations were lateralized (i.e., ipsilateral cerebellar and contralateral M1v associations with motor performance), which could point to age-related neural dedifferentiation. The current study provides new insights in the role of the cerebellum in manual motor performance. In consideration of the small effect sizes replication studies are needed to validate these results. © 2015 Wiley Periodicals, Inc.
age; aged; Article; behavior; brain; brain size; dexterity test; female; gray matter; grip strength; human; male; motor performance; primary motor cortex; priority journal; velocity; visuomotor coordination; white matter; aging; cerebellum; gray matter; hand strength; hemispheric dominance; image processing; longitudinal study; motor cortex; nuclear magnetic resonance imaging; organ size; pathology; physiology; white matter; Aged; Aging; Cerebellum; Female; Functional Laterality; Gray Matter; Hand Strength; Humans; Image Processing, Computer-Assisted; Longitudinal Studies; Magnetic Resonance Imaging; Male; Motor Cortex; Motor Skills; Organ Size; White Matter