Fatigue Research Today is a free monthly online journal that collates and summarizes the latest research about Fatigue, including details on chronic fatigue syndrome, exhaustion, causes, diagnosis.

Primary sensorimotor cortex activation with task-performance after fatiguing hand exercise.

Benwell NM, Byrnes ML, Mastaglia FL, Thickbroom GW

Centre for Neuromuscular and Neurological Disorders, University of Western Australia, Queen Elizabeth II Medical Centre, Nedlands, WA, 6009, Australia.

We have compared functional MRI signals in primary sensorimotor cortex (SM1) during a paced motor task of each hand before and after unimanual (right hand) fatiguing exercise. Our aims were to determine whether the degree of activation is different when a motor task is performed after a fatiguing exercise, and whether there are any differences in activation between movement of the fatigued and non-fatigued hands. There was a significant reduction in the number of voxels activated in SM1 in the hemisphere contralateral to movement of both the fatigued hand (38 +/- 5 pre-exercise versus 21 +/- 3 post-exercise; P<0.05) and the non-fatigued hand (32 +/- 4 pre-exercise vs 18 +/- 4 post-exercise; P<0.05). There was no significant difference in the magnitude of the functional magnetic resonance imaging signal before or after exercise, however, the variance increased significantly after exercise (6.0 +/- 0.5 pre-exercise vs 7.3 +/- 0.6 post-exercise; P<0.01). Reduced functional activation in SM1 may reflect increased variability in the activation rather than a reduction in activation of cortical motor networks after fatigue.

Published 2 December 2005 in Exp Brain Res, 167(2): 160-4.
Full-text of this article is available online (may require subscription).

© 2005-2008 Fatigue Research Today. All Rights Reserved.