title: Supplementary Motor Cortical Changes Explored by Resting-State Functional Connectivity in Brachial Plexus Injury.
abstract: BACKGROUND
  Brachial plexus injury (BPI) is a serious peripheral nerve injury, and clinical outcomes are generally unsatisfactory. It has been reported that cortical plasticity could influence the restoration of motor function. However, the neurologic mechanism of BPI is unclear, which provides a basis for further investigation. The supplementary motor area (SMA) plays an important role in the regulation of motor function. This study aims to explore SMA-whole brain functional connectivity after deafferentation of the brachial plexus.
  
  
  METHODS
  Study subjects included 16 patients with BPI and 8 healthy volunteers. The seed region was defined by a block-design functional magnetic resonance imaging program that used unilateral imaginary hand grasp motion as a task stimulus. Next, the voxel-wise functional connectivity between the predefined region and the other regions of the brain was calculated.
  
  
  RESULTS
  We discovered decreased voxel-wise functional connectivity between the SMA and multiple brain regions, including precuneus, posterior cingulum cortex, and anterior cingulum cortex, that are closely associated with information integration or motor processing in patients with BPI.
  
  
  CONCLUSIONS
  Patients with BPI showed weakened functional connectivity between hand grasp-related areas and the SMA and multiple regions associated with motor processing or information integration. A clear image of the functional status of the brain after deafferentation was provided. On the basis of this discovery, a relationship between changes in neuroimaging measurements and clinical outcomes can be determined in future studies.
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Yechen
authors.initials: Y
authors.lastname: Lu
authors.affiliation: Department of Radiology, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Hanqiu
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Xuyun
authors.initials: X
authors.lastname: Hua
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China; State Key Laboratory of Medical Neuroscience, Fudan University, Shanghai, China. Electronic address: wendongxu@fudan.edu.cn.
authors.forename: Wen-Dong
authors.initials: WD
authors.lastname: Xu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Jian-Guang
authors.initials: JG
authors.lastname: Xu
authors.affiliation: Department of Hand Surgery, Huashan Hospital, Fudan University, Shanghai, China.
authors.forename: Yu-Dong
authors.initials: YD
authors.lastname: Gu
mesh_terms: D000328:Adult; D001917:Brachial Plexus / Q000293:injuries* / Q000503:physiopathology*; D020516:Brachial Plexus Neuropathies / Q000503:physiopathology*; D063132:Connectome / Q000379:methods*; D005260:Female; D006801:Humans; D007092:Imagination; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000503:physiopathology*; D059348:Peripheral Nerve Injuries / Q000503:physiopathology*; D012146:Rest
keywords: Brachial plexus injury; Supplementary motor area; voxel-wise functional connectivity