Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements

► Lesions of frontal lobe motor areas in Rhesus monkeys produce acute deficits in control of ipsilesional dexterous hand movements. ► Ipsilesional hand movement deficits do not persist beyond a few weeks post-lesion. ► Recovery allows the ipsilesional hand to perform better than in pre-lesion fine motor tests. ► Reduced transcallosal inhibition from the damaged motor cortex likely contributes to the improved ipsilesional fine motor skill.