Article

OBJECTIVE: To investigate the effects of cathodal transcranial direct current
stimulation (tDCS) and continuous theta burst stimulation (cTBS) on neural
network connectivity and motor recovery in individuals with subacute stroke.
DESIGN: Double-blinded, randomized, placebo-controlled study. SETTING: University
hospital rehabilitation unit. PARTICIPANTS: Inpatients with stroke (N=41; mean
age, 65y; range, 28-85y; mean weeks poststroke, 5; range, 2-10) with resultant
paresis in the upper extremity (mean Fugl-Meyer score, 14; range, 3-48).
INTERVENTIONS: Subjects with stroke were randomly assigned to neuronavigated cTBS
(n=14), cathodal tDCS (n=14), or sham transcranial magnetic stimulation/sham tDCS
(n=13) over the contralesional primary motor cortex (M1). Each subject completed
9 stimulation sessions over 3 weeks, combined with physical therapy. MAIN OUTCOME
MEASURES: Brain function was assessed with directed and nondirected functional
connectivity based on high-density electroencephalography before and after
stimulation sessions. Primary clinical end point was the change in slope of the
multifaceted motor score composed of the upper extremity Fugl-Meyer Assessment
score, Box and Block test score, 9-Hole Peg Test score, and Jamar dynamometer
results between the baseline period and the treatment time. RESULTS: Neither
stimulation treatment enhanced clinical motor gains. Cathodal tDCS and cTBS
induced different neural effects. Only cTBS was able to reduce transcallosal
influences from the contralesional to the ipsilesional M1 during rest.
Conversely, tDCS enhanced perilesional beta-band oscillation coherence compared
with cTBS and sham groups. Correlation analyses indicated that the modulation of
interhemispheric driving and perilesional beta-band connectivity were not
independent mediators for functional recovery across all patients. However,
exploratory subgroup analyses suggest that the enhancement of perilesional
beta-band connectivity through tDCS might have more robust clinical gains if
started within the first 4 weeks after stroke. CONCLUSIONS: The inhibition of the
contralesional M1 or the reduction of interhemispheric interactions was not
clinically useful in the heterogeneous group of subjects with subacute stroke. An
early modulation of perilesional oscillation coherence seems to be a more
promising strategy for brain stimulation interventions.
CI - Copyright (c) 2017 American Congress of Rehabilitation Medicine. Published by
Elsevier Inc. All rights reserved.

Langue : ANGLAIS