title: Altered contralateral sensorimotor system organization after experimental hemispherectomy: a structural and functional connectivity study.
abstract: Hemispherectomy is often followed by remarkable recovery of cognitive and motor functions. This reflects plastic capacities of the remaining hemisphere, involving large-scale structural and functional adaptations. Better understanding of these adaptations may (1) provide new insights in the neuronal configuration and rewiring that underlies sensorimotor outcome restoration, and (2) guide development of rehabilitation strategies to enhance recovery after hemispheric lesioning. We assessed brain structure and function in a hemispherectomy model. With MRI we mapped changes in white matter structural integrity and gray matter functional connectivity in eight hemispherectomized rats, compared with 12 controls. Behavioral testing involved sensorimotor performance scoring. Diffusion tensor imaging and resting-state functional magnetic resonance imaging were acquired 7 and 49 days post surgery. Hemispherectomy caused significant sensorimotor deficits that largely recovered within 2 weeks. During the recovery period, fractional anisotropy was maintained and white matter volume and axial diffusivity increased in the contralateral cerebral peduncle, suggestive of preserved or improved white matter integrity despite overall reduced white matter volume. This was accompanied by functional adaptations in the contralateral sensorimotor network. The observed white matter modifications and reorganization of functional network regions may provide handles for rehabilitation strategies improving functional recovery following large lesions.
authors.affiliation: 1] Department of Pediatric Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center, Utrecht, The Netherlands [2] Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center, Utrecht, The Netherlands.
authors.forename: Willem M
authors.initials: WM
authors.lastname: Otte
authors.affiliation: Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center, Utrecht, The Netherlands.
authors.forename: Kajo
authors.initials: K
authors.lastname: van der Marel
authors.affiliation: Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center, Utrecht, The Netherlands.
authors.forename: Maurits P A
authors.initials: MP
authors.lastname: van Meer
authors.affiliation: Department of Neurosurgery, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Peter C
authors.initials: PC
authors.lastname: van Rijen
authors.affiliation: Department of Neurosurgery, Rudolf Magnus Institute of Neuroscience, University Medical Center Utrecht, Utrecht, The Netherlands.
authors.forename: Peter H
authors.initials: PH
authors.lastname: Gosselaar
authors.affiliation: Department of Pediatric Neurology, Rudolf Magnus Institute of Neuroscience, University Medical Center, Utrecht, The Netherlands.
authors.forename: Kees P J
authors.initials: KP
authors.lastname: Braun
authors.affiliation: Biomedical MR Imaging and Spectroscopy Group, Image Sciences Institute, University Medical Center, Utrecht, The Netherlands.
authors.forename: Rick M
authors.initials: RM
authors.lastname: Dijkhuizen
mesh_terms: D000818:Animals; D001522:Behavior, Animal; D056228:Feedback, Sensory; D038421:Hemispherectomy; D008279:Magnetic Resonance Imaging; D008297:Male; D011859:Radiography; D051381:Rats; D017207:Rats, Sprague-Dawley; D020127:Recovery of Function; D066191:Sensorimotor Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D066127:White Matter / Q000000981:diagnostic imaging / Q000503:physiopathology*