title: The Plasticity of Brain Gray Matter and White Matter following Lower Limb Amputation.
abstract: Accumulating evidence has indicated that amputation induces functional reorganization in the sensory and motor cortices. However, the extent of structural changes after lower limb amputation in patients without phantom pain remains uncertain. We studied 17 adult patients with right lower limb amputation and 18 healthy control subjects using T1-weighted magnetic resonance imaging and diffusion tensor imaging. Cortical thickness and fractional anisotropy (FA) of white matter (WM) were investigated. In amputees, a thinning trend was seen in the left premotor cortex (PMC). Smaller clusters were also noted in the visual-to-motor regions. In addition, the amputees also exhibited a decreased FA in the right superior corona radiata and WM regions underlying the right temporal lobe and left PMC. Fiber tractography from these WM regions showed microstructural changes in the commissural fibers connecting the bilateral premotor cortices, compatible with the hypothesis that amputation can lead to a change in interhemispheric interactions. Finally, the lower limb amputees also displayed significant FA reduction in the right inferior frontooccipital fasciculus, which is negatively correlated with the time since amputation. In conclusion, our findings indicate that the amputation of lower limb could induce changes in the cortical representation of the missing limb and the underlying WM connections.
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Guangyao
authors.initials: G
authors.lastname: Jiang
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China ; McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4.
authors.forename: Xuntao
authors.initials: X
authors.lastname: Yin
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Chuanming
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Li
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4.
authors.forename: Lu
authors.initials: L
authors.lastname: Zhao
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, QC, Canada H3A 2B4.
authors.forename: Alan C
authors.initials: AC
authors.lastname: Evans
authors.affiliation: National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.
authors.forename: Tianzi
authors.initials: T
authors.lastname: Jiang
authors.affiliation: Department of Rehabilitation, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Jixiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Radiology, Southwest Hospital, Third Military Medical University, Chongqing 400038, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000293:Adolescent; D000328:Adult; D017668:Age of Onset; D000673:Amputation, Traumatic / Q000503:physiopathology*; D001284:Atrophy; D056324:Diffusion Tensor Imaging; D005260:Female; D007839:Functional Laterality; D066128:Gray Matter / Q000473:pathology* / Q000503:physiopathology; D006801:Humans; D035002:Lower Extremity / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000473:pathology / Q000503:physiopathology; D009412:Nerve Fibers / Q000473:pathology; D009473:Neuronal Plasticity; D066127:White Matter / Q000473:pathology* / Q000503:physiopathology; D055815:Young Adult