RT Journal Article
SR Electronic
T1 Increased connectivity of hub networks and cognitive impairment in multiple sclerosis
JF Neurology
JO Neurology
FD Lippincott Williams & Wilkins
SP 2107
OP 2114
DO 10.1212/WNL.0000000000003982
VO 88
IS 22
A1 Kim A. Meijer
A1 Anand J.C. Eijlers
A1 Linda Douw
A1 Bernard M.J. Uitdehaag
A1 Frederik Barkhof
A1 Jeroen J.G. Geurts
A1 Menno M. Schoonheim
YR 2017
UL http://n.neurology.org/content/88/22/2107.abstract
AB Objective: To investigate default-mode network (DMN) and frontoparietal network (FPN) dysfunction in cognitively impaired (CI) patients with multiple sclerosis (MS) because these networks strongly relate to cognition and contain most of the hubs of the brain.Methods: Resting-state fMRI and neuropsychological assessments were performed in 322 patients with MS and 96 healthy controls (HCs). Patients with MS were classified as CI (z score < −2.0 on at least 2 tests; n = 87), mildly cognitively impaired (z score < −1.5 on at least 2 tests and not CI; n = 65), and cognitively preserved (CP; n = 180). Within-network connectivity, connectivity with the rest of the brain, and between-network connectivity were calculated and compared between groups. Connectivity values were normalized for individual means and SDs.Results: Only in CI, both the DMN and FPN showed increased connectivity with the rest of the brain compared to HCs and CP, with no change in within- or between-network connectivity. Regionally, this increased connectivity was driven by the inferior parietal, posterior cingulate, and angular gyri. Increased connectivity with the rest of the brain correlated with worse cognitive performance, namely attention for the FPN as well as information processing speed and working memory for both networks.Conclusions: In CI patients with MS, the DMN and FPN showed increased connectivity with the rest of the brain, while normal within- and between-network connectivity levels were maintained. These findings indicate that cognitive impairment in MS features disturbed communication of hub-rich networks, but only with the more peripheral (i.e., nonhub) regions of the brain.CI=cognitively impaired; CP=cognitively preserved; DMN=default-mode network; EDSS=Expanded Disease Severity Scale; FPN=frontoparietal network; GM=gray matter; GMV=gray matter volume; HC=healthy control; MCI=mildly cognitively impaired; MS=multiple sclerosis; ROI=region of interest; RSN=resting-state network; TE=echo time; TR=repetition time; WM=white matter