title: Abnormal functional connectivity and cortical integrity influence dominant hand motor disability in multiple sclerosis: a multimodal analysis.
abstract: Functional reorganization and structural damage occur in the brains of people with multiple sclerosis (MS) throughout the disease course. However, the relationship between resting-state functional connectivity (FC) reorganization in the sensorimotor network and motor disability in MS is not well understood. This study used resting-state fMRI, T1-weighted and T2-weighted, and magnetization transfer (MT) imaging to investigate the relationship between abnormal FC in the sensorimotor network and upper limb motor disability in people with MS, as well as the impact of disease-related structural abnormalities within this network. Specifically, the differences in FC of the left hemisphere hand motor region between MS participants with preserved (n = 17) and impaired (n = 26) right hand function, compared with healthy controls (n = 20) was investigated. Differences in brain atrophy and MT ratio measured at the global and regional levels were also investigated between the three groups. Motor preserved MS participants had stronger FC in structurally intact visual information processing regions relative to motor impaired MS participants. Motor impaired MS participants showed weaker FC in the sensorimotor and somatosensory association cortices and more severe structural damage throughout the brain compared with the other groups. Logistic regression analysis showed that regional MTR predicted motor disability beyond the impact of global atrophy whereas regional grey matter volume did not. More importantly, as the first multimodal analysis combining resting-state fMRI, T1-weighted, T2-weighted and MTR images in MS, we demonstrate how a combination of structural and functional changes may contribute to motor impairment or preservation in MS. Hum Brain Mapp 37:4262-4275, 2016. © 2016 Wiley Periodicals, Inc.
authors.affiliation: Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec, H3H 2R9, Canada.|Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, H3H 2R9, Canada.
authors.forename: Jidan
authors.initials: J
authors.lastname: Zhong
authors.affiliation: Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, H3H 2R9, Canada.|Integrated Program in Neuroscience, McGill University, 3801 University Street, Room 141, Montreal, Quebec, H3A 2B4, Canada.
authors.forename: Julia C
authors.initials: JC
authors.lastname: Nantes
authors.affiliation: Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, H3H 2R9, Canada.|Integrated Program in Neuroscience, McGill University, 3801 University Street, Room 141, Montreal, Quebec, H3A 2B4, Canada.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Holmes
authors.affiliation: Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec, H3H 2R9, Canada.
authors.forename: Serge
authors.initials: S
authors.lastname: Gallant
authors.affiliation: McConnell Brain Imaging Centre, Montreal Neurological Institute, McGill University, Montreal, Quebec, H3H 2R9, Canada.
authors.forename: Sridar
authors.initials: S
authors.lastname: Narayanan
authors.affiliation: Research Institute of the McGill University Health Centre, 2155 Guy Street, 5th Floor, Montreal, Quebec, H3H 2R9, Canada.|Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, H3H 2R9, Canada.|Department of Psychology, McGill University, Montreal, Quebec, H3H 2R9, Canada.
authors.forename: Lisa
authors.initials: L
authors.lastname: Koski
mesh_terms: D000328:Adult; D001284:Atrophy; D001931:Brain Mapping; D002540:Cerebral Cortex / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004185:Disability Evaluation; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D066128:Gray Matter / Q000000981:diagnostic imaging / Q000503:physiopathology; D006225:Hand / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009043:Motor Activity / Q000502:physiology*; D009069:Movement Disorders / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D064847:Multimodal Imaging; D009103:Multiple Sclerosis / Q000150:complications / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D009434:Neural Pathways / Q000000981:diagnostic imaging / Q000503:physiopathology; D009929:Organ Size
keywords: functional connectivity; grey matter volume; logistic regression; magnetization transfer ratio; motor disability; multiple sclerosis; resting state fMRI