Increased functional connectivity one week after motor learning and tDCS in stroke patients. (6th January 2017)

• Record Type: Journal Article
• Authors: Lefebvre, Stéphanie; Dricot, Laurence; Laloux, Patrice; Desfontaines, Philippe; Evrard, Frédéric; Peeters, André; Jamart, Jacques; Vandermeeren, Yves
• Is Part Of: Neuroscience. Volume 340(2017)
• Page Start: 424
• Page End: 435
• Publication Date: 2017-01-06
• Subjects: ANOVA analysis of variance -- damH damaged hemisphere -- DAN dorsal attentional network -- FC functional connectivity -- ICA Independent Component Analysis -- LI Learning Index -- M1 primary motor cortex -- NIBS non-invasive brain stimulation -- PI performance index -- PMd dorsal premotor cortex -- qFDR q False Discovery Rate -- ROI region of interest -- rs-fMRI resting-state functional magnetic resonance imaging -- SAT speed/accuracy trade-off -- SMA supplementary motor area -- SMN somatomotor network -- tDCS transcranial direct stimulation -- TMS transcranial magnetic stimulation -- undamH undamaged hemisphere -- VN visual network; transcranial direct current stimulation -- resting-state-fMRI -- functional connectivity -- stroke -- neurorehabilitation; Neurochemistry -- Periodicals; Neurophysiology -- Periodicals; Neurology -- Periodicals; Neurochimie -- Périodiques; Neurophysiologie -- Périodiques; Neurochemistry; Neurophysiology; Electronic journals; Periodicals; Electronic journals; 612.8
• DOI: 10.1016/j.neuroscience.2016.10.066
• Languages: English
• ISSNs: 0306-4522

Abstract

Highlights: Dual-tDCS enhanced motor skill learning and retention in chronic stroke patients (80/85). Dual-tDCS + motor learning increased FC in ipsilesional (pre-)motor cortex @ 1 week (84/85). Both seed and ICA-based analyses showed a FC reorganization following dual-tDCS (80/85). The observed changes of FC lasting well beyond what previously reported after tDCS (83/85). This study promotes tDCS use as efficient add-on intervention in neurorehabilitation (84/85). Abstract: Recent studies using resting-state functional magnetic resonance imaging (rs-fMRI) demonstrated that changes in functional connectivity (FC) after stroke correlate with recovery. The aim of this study was to explore whether combining motor learning to dual transcranial direct current stimulation (dual-tDCS, applied over both primary motor cortices (M1)) modulated FC in stroke patients. Twenty-two chronic hemiparetic stroke patients participated in a baseline rs-fMRI session. One week later, dual-tDCS/sham was applied during motor skill learning (intervention session); one week later, the retention session started with the acquisition of a run of rs-fMRI imaging. The intervention + retention sessions were performed once with dual-tDCS and once with sham in a randomized, cross-over, placebo-controlled, double-blind design. A whole-brain independent component analysis based analysis of variance (ANOVA) demonstrated no changes between baseline and sham sessions in the somatomotor network, whereas a FC increase was observed one week after dual-tDCS compared to baseline (qFDR <0.05, t 63 = 4.15). A seed-based analysis confirmed specific stimulation-driven changes within a network of motor and premotor regions in both hemispheres. At baseline and one week after sham, the strongest FC was observed between the M1 and dorsal premotor cortex (PMd) of the undamaged hemisphere. In contrast, one week after dual-tDCS, the strongest FC was found between the M1 and PMd of the damaged hemisphere. Thus, a single session of dual-tDCS combined with motor skill learning increases FC in the somatomotor network of chronic stroke patients for one week.