title: Reduced functional connectivity within the primary motor cortex of patients with brachial plexus injury.
abstract: This study aims at the effects of traumatic brachial plexus lesion with root avulsions (BPA) upon the organization of the primary motor cortex (M1). Nine right-handed patients with a right BPA in whom an intercostal to musculocutaneous (ICN-MC) nerve transfer was performed had post-operative resting state fMRI scanning. The analysis of empirical functional correlations between neighboring voxels revealed faster correlation decay as a function of distance in the M1 region corresponding to the arm in BPA patients as compared to the control group. No differences between the two groups were found in the face area. We also investigated whether such larger decay in patients could be attributed to a gray matter diminution in M1. Structural imaging analysis showed no difference in gray matter density between groups. Our findings suggest that the faster decay in neighboring functional correlations without significant gray matter diminution in BPA patients could be related to a reduced activity in intrinsic horizontal connections in M1 responsible for upper limb motor synergies.
authors.affiliation: Departamento de Matemática y Ciencias, Universidad de San Andrés, Buenos Aires, Argentina; CONICET, Argentina.
authors.forename: D
authors.initials: D
authors.lastname: Fraiman
authors.affiliation: Instituto de Matemática e Estatística, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: M F
authors.initials: MF
authors.lastname: Miranda
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil; Instituto de Neurologia Deolindo Couto, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: F
authors.initials: F
authors.lastname: Erthal
authors.affiliation: Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands.
authors.forename: P F
authors.initials: PF
authors.lastname: Buur
authors.affiliation: Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands.
authors.forename: M
authors.initials: M
authors.lastname: Elschot
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil; Instituto de Neurologia Deolindo Couto, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: L
authors.initials: L
authors.lastname: Souza
authors.affiliation: Leiden Institute for Brain and Cognition, Leiden, The Netherlands; Institute of Psychology, Leiden University, Leiden, The Netherlands; Leiden University Medical Center, Department of Radiology, Leiden, The Netherlands.
authors.forename: S A R B
authors.initials: SA
authors.lastname: Rombouts
authors.affiliation: Leiden University Medical Center, Department of Radiology, Leiden, The Netherlands; Leiden University Medical Center, Department of Neurosurgery, Leiden, The Netherlands.
authors.forename: C A
authors.initials: CA
authors.lastname: Schimmelpenninck
authors.affiliation: Spinoza Centre for Neuroimaging, Amsterdam, The Netherlands; Erwin L. Hahn Institute for Magnetic Resonance Imaging, University Duisburg-Essen, Essen, Germany.
authors.forename: D G
authors.initials: DG
authors.lastname: Norris
authors.affiliation: Leiden University Medical Center, Department of Neurosurgery, Leiden, The Netherlands.
authors.forename: M J A
authors.initials: MJ
authors.lastname: Malessy
authors.affiliation: Instituto de Matemática e Estatística, Universidade de São Paulo, São Paulo, Brazil.
authors.forename: A
authors.initials: A
authors.lastname: Galves
authors.affiliation: Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Brazil; Instituto de Neurologia Deolindo Couto, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil.
authors.forename: C D
authors.initials: CD
authors.lastname: Vargas
mesh_terms: D000328:Adult; D020516:Brachial Plexus Neuropathies / Q000503:physiopathology*; D001931:Brain Mapping; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000503:physiopathology*
keywords: Correlation decay; Functional connectivity; Gray matter; Horizontal connections; Peripheral lesion; Resting state