title: Reproducibility of Resting State Connectivity in Patients with Stable Multiple Sclerosis.
abstract: Given increasing efforts to use resting-state fMRI (rfMRI) as a biomarker of disease progression in multiple sclerosis (MS) we here explored the reproducibility of longitudinal rfMRI over three months in patients with clinically and radiologically stable MS. To pursue this aim, two approaches were applied in nine rfMRI networks: First, the intraclass correlation coefficient (ICC 3,1) was assessed for the mean functional connectivity maps across the entire network and a region of interest (ROI). Second, the ratio of overlap between Z-thresholded connectivity maps for each network was assessed. We quantified between-session functional reproducibility of rfMRI for 20 patients with stable MS and 14 healthy controls (HC). Nine rfMRI networks (RSNs) were examined at baseline and after 3 months of follow-up: three visual RSNs, the default-mode network, sensorimotor-, auditory-, executive control, and the left and right fronto-parietal RSN. ROI analyses were constrained to thresholded overlap masks for each individual (Z>0) at baseline and follow-up.In both stable MS and HC mean functional connectivity across the entire network did not reach acceptable ICCs for several networks (ICC<0.40) but we found a high reproducibility of ROI ICCs and of the ratio of overlap. ROI ICCs of all nine networks were between 0.98 and 0.99 for HC and ranged from 0.88 to 0.99 in patients with MS, respectively. The ratio of overlap for all networks was similar for both groups, ranging from 0.60 to 0.75.Our findings attest to a high reproducibility of rfMRI networks not only in HC but also in patients with stable MS when applying ROI analysis. This supports the utility of rfMRI to monitor functional changes related to disease progression or therapeutic interventions in MS.
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Daniela
authors.initials: D
authors.lastname: Pinter
authors.affiliation: Donders Institute, Cognitive Neuroscience Department and Centre for Cognitive Neuroimaging, Radboud University Nijmegen, Nijmegen, The Netherlands.
authors.forename: Christian
authors.initials: C
authors.lastname: Beckmann
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Marisa
authors.initials: M
authors.lastname: Koini
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Eva
authors.initials: E
authors.lastname: Pirker
authors.affiliation: The Oxford Centre for Functional MRI of the Brain, Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom.
authors.forename: Nicola
authors.initials: N
authors.lastname: Filippini
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Alexander
authors.initials: A
authors.lastname: Pichler
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Siegrid
authors.initials: S
authors.lastname: Fuchs
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.
authors.forename: Franz
authors.initials: F
authors.lastname: Fazekas
authors.affiliation: Department of Neurology, Medical University of Graz, Graz, Austria.|Division of Neuroradiology, Department of Radiology, Medical University of Graz, Graz, Austria.
authors.forename: Christian
authors.initials: C
authors.lastname: Enzinger
mesh_terms: D000328:Adult; D001921:Brain / Q000502:physiology*; D016022:Case-Control Studies; D018450:Disease Progression; D005260:Female; D059907:Functional Neuroimaging; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009103:Multiple Sclerosis / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology; D009483:Neuropsychological Tests