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      Disability, atrophy and cortical reorganization following spinal cord injury

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          Abstract

          The impact of traumatic spinal cord injury on structural integrity, cortical reorganization and ensuing disability is variable and may depend on a dynamic interaction between the severity of local damage and the capacity of the brain for plastic reorganization. We investigated trauma-induced anatomical changes in the spinal cord and brain, and explored their relationship to functional changes in sensorimotor cortex. Structural changes were assessed using cross-sectional cord area, voxel-based morphometry and voxel-based cortical thickness of T 1-weighted images in 10 subjects with cervical spinal cord injury and 16 controls. Cortical activation in response to right-sided (i) handgrip; and (ii) median and tibial nerve stimulation were assessed using functional magnetic resonance imaging. Regression analyses explored associations between cord area, grey and white matter volume, cortical activations and thickness, and disability. Subjects with spinal cord injury had impaired upper and lower limb function bilaterally, a 30% reduced cord area, smaller white matter volume in the pyramids and left cerebellar peduncle, and smaller grey matter volume and cortical thinning in the leg area of the primary motor and sensory cortex compared with controls. Functional magnetic resonance imaging revealed increased activation in the left primary motor cortex leg area during handgrip and the left primary sensory cortex face area during median nerve stimulation in subjects with spinal cord injury compared with controls, but no increased activation following tibial nerve stimulation. A smaller cervical cord area was associated with impaired upper limb function and increased activations with handgrip and median nerve stimulation, but reduced activations with tibial nerve stimulation. Increased sensory deficits were associated with increased activations in the left primary sensory cortex face area due to median nerve stimulation. In conclusion, spinal cord injury leads to cord atrophy, cortical atrophy of primary motor and sensory cortex, and cortical reorganization of the sensorimotor system. The degree of cortical reorganization is predicted by spinal atrophy and is associated with significant disability.

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                Author and article information

                Journal
                Brain
                brainj
                brain
                Brain
                Oxford University Press
                0006-8950
                1460-2156
                June 2011
                17 May 2011
                17 May 2011
                : 134
                : 6
                : 1610-1622
                Affiliations
                1 Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, UCL, WC1N 3BG London, UK
                2 Wellcome Trust Centre for Neuroimaging, UCL Institute of Neurology, UCL, WC1N 3BG London, UK
                3 Spinal Cord Injury Centre, Royal National Orthopaedic Hospital, UCL, HA7 4LP London, UK
                4 Swiss Paraplegic Research, CH-6207 Nottwil, Switzerland
                5 Sobell Department of Motor Neuroscience, UCL Institute of Neurology, UCL, WC1N 3BG London, UK
                Author notes
                Correspondence to: Patrick Freund, Department of Brain Repair and Rehabilitation, UCL Institute of Neurology, UCL, Queen Square, London WC1N 3BG, UK E-mail: p.freund@ 123456ion.ucl.ac.uk
                Article
                awr093
                10.1093/brain/awr093
                3102242
                21586596
                830001fe-00fe-43f2-89ec-c7c308970cec
                © The Author(s) 2011. Published by Oxford University Press on behalf of Brain.

                This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License ( http://creativecommons.org/licenses/by-nc/2.5), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

                History
                : 11 August 2010
                : 13 February 2011
                : 28 March 2011
                Page count
                Pages: 13
                Categories
                Original Articles

                Neurosciences
                spinal cord injury,disability,cortical reorganization,atrophy
                Neurosciences
                spinal cord injury, disability, cortical reorganization, atrophy

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