Assessing brain connectivity at rest is clinically relevant in early multiple sclerosis.
OBJECTIVE
The present study aims to determine the clinical counterpart of brain resting-state networks reorganization recently evidenced in early multiple sclerosis.


METHODS
Thirteen patients with early relapsing-remitting multiple sclerosis and 14 matched healthy controls were included in a resting state functional MRI study performed at 3 T. Data were analyzed using group spatial Independent Component Analysis using concatenation approach (FSL 4.1.3) and double regression analyses (SPM5) to extract local and global levels of connectivity inside various resting state networks (RSNs). Differences in global levels of connectivity of each network between patients and controls were assessed using Mann-Whitney U-test. In patients, relationship between clinical data (Expanded Disability Status Scale and Multiple Sclerosis Functional Composite Score - MSFC) and global RSN connectivity were assessed using Spearman rank correlation.


RESULTS
Independent component analysis provided eight consistent neuronal networks involved in motor, sensory and cognitive processes. For seven RSNs, the global level of connectivity was significantly increased in patients compared with controls. No significant decrease in RSN connectivity was found in early multiple sclerosis patients. MSFC values were negatively correlated with increased RSN connectivity within the dorsal frontoparietal network (r = -0.811, p = 0.001), the right ventral frontoparietal network (r = - 0.587, p = 0.045) and the prefronto-insular network (r = -0.615, p = 0.033).


CONCLUSIONS
This study demonstrates that resting state networks reorganization is strongly associated with disability in early multiple sclerosis. These findings suggest that resting state functional MRI may represent a promising surrogate marker of disease burden.
Aix-Marseille Univ, CRMBM, UMR 6612, 13005, Marseille, France.
Anthony
A
Faivre
Audrey
A
Rico
Wafaa
W
Zaaraoui
Lydie
L
Crespy
Françoise
F
Reuter
Delphine
D
Wybrecht
Elisabeth
E
Soulier
Irina
I
Malikova
Sylviane
S
Confort-Gouny
Patrick J
PJ
Cozzone
Jean
J
Pelletier
Jean-Philippe
JP
Ranjeva
Bertrand
B
Audoin
D000328:Adult; D000704:Analysis of Variance; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D003071:Cognition; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009043:Motor Activity; D020529:Multiple Sclerosis, Relapsing-Remitting / Q000175:diagnosis* / Q000503:physiopathology / Q000523:psychology; D009415:Nerve Net / Q000503:physiopathology*; D009483:Neuropsychological Tests; D011237:Predictive Value of Tests; D011379:Prognosis; D012044:Regression Analysis; D012146:Rest; D012677:Sensation; D012720:Severity of Illness Index; D055815:Young Adult