Article

People with multiple sclerosis (MS) frequently complain of excessive fatigue,
which is the most disabling symptom for half of them. While the few drugs used to
treat MS fatigue are of limited utility, we recently observed the efficacy of a
personalized neuromodulation treatment. Here, we aim at strengthening knowledge
of the brain network changes that occur when MS fatigue increases, using graph
theory. We collected electroencephalographic (EEG; 23 or 64 channels) data in
resting state with eyes open in 27 relapsing-remitting (RR) patients with mild MS
(EDSS </=2), suffering a wide range of fatigue as scored by the modified Fatigue
Impact Scale (mFIS) (2-69, within a total range 0-84). To estimate graph theory
small-world index (SW), we calculated the lagged linear coherence between EEG
cortical eLORETA sources, in the standard frequency bands delta (2-4 Hz), theta
(4-8 Hz), alpha1 (8-10.5 Hz), alpha2 (10.5-13 Hz), beta1 (13-20 Hz), beta2 (20-30
Hz), and gamma (30-45 Hz). We calculated the SW of these undirected and weighted
networks separately in the four left and right frontal (motor) and
parieto-occipito-temporal (sensory) brain networks. A correlative analysis
demonstrated increased fatigue symptoms along with the SW specifically in the
Sensory network of the left dominant hemisphere in the beta1 band (Pearson's r =
0.404, P = .020). Our study indicates a specific involvement of the
dominant-hemisphere sensory network in MS fatigue. It suggests that compensatory
neuromodulation interventions could enhance efficacy in relieving this
debilitating symptom by targeting this area.
CI - (c) The Author(s) 2016.

Langue : ANGLAIS