Article

Resting brain activity can be modulated by motor tasks to adapt to
function. In multiple sclerosis (MS) patients, altered resting-state functional
connectivity (RS-FC) has been reported and associated with impaired function and
disability; little is known on how RS-FC is modulated by a simple repetitive
motor task. OBJECTIVE: To assess changes in RS-FC in early relapsing-remitting MS
(RRMS) patients associated with repetitive thumb flexions (RTFs). METHODS: A total of 20 right-handed patients with early RRMS and 14 healthy controls
underwent a resting functional magnetic resonance imaging (fMRI) scan, before and
after 25 minutes of alternate 30-s blocks of right RTF and rest. Dual-regression
analysis of resting fMRI data followed the independent component analysis.
Individual spatial maps of coherence between brain areas for 2 networks of
interest, sensorimotor and cerebellar, were compared at the group level and
correlated with measures of both clinical impairment and brain damage. RESULTS:
Significant RTF-induced differences in RS-FC were observed between groups in the
cerebellar network because of increased RS-FC in patients but not in controls. In
the sensorimotor network, the RS-FC after RTF increased in both groups, with no
significant between-group differences. The sensorimotor and the cerebellar RS-FC
were intercorrelated only in patients and only after the RTF. The sensorimotor
RS-FC increase in patients correlated with structural MRI alterations.
CONCLUSIONS: Our study unmasked RS-FC changes of motor-related networks occurring
after a simple repetitive motor task in early RRMS patients only. Evaluation of
altered RSN dynamics might prove useful for anticipating neuroplasticity and for
MRI-informed neurorehabilitation.
CI - (c) The Author(s) 2014.

Langue : ANGLAIS