Article

Recovery of handgrip is critical after stroke since it is positively
related to upper limb function.
To boost motor recovery, transcranial direct
current stimulation (tDCS) is a promising, non-invasive brain stimulation
technique for the rehabilitation of persons with stroke.
When applied over the
primary motor cortex (M1), tDCS has been shown to modulate neural processes
involved in motor learning. However, no studies have looked at the impact of tDCS
on the learning of a grip task in both stroke and healthy individuals. OBJECTIVE:
To assess the use of tDCS over multiple days to promote motor learning of a grip
task using a learning paradigm involving a speed-accuracy tradeoff in healthy
individuals. METHODS: In a double-blinded experiment, 30 right-handed subjects
(mean age: 22.1+/-3.3 years) participated in the study and were randomly assigned
to an anodal (n=15) or sham (n=15) stimulation group. First, subjects performed
the grip task with their dominant hand while following the pace of a metronome.
Afterwards, subjects trained on the task, at their own pace, over 5 consecutive
days while receiving sham or anodal tDCS over M1. After training, subjects
performed de novo the metronome-assisted task. The change in performance between
the pre and post metronome-assisted task was used to assess the impact of the
grip task and tDCS on learning. RESULTS: Anodal tDCS over M1 had a significant
effect on the speed-accuracy tradeoff function. The anodal tDCS group showed
significantly greater improvement in performance (39.28+/-15.92%) than the sham
tDCS group (24.06+/-16.35%) on the metronome-assisted task, t(28)=2.583, P=0.015
(effect size d=0.94). CONCLUSIONS: Anodal tDCS is effective in promoting grip
motor learning in healthy individuals. Further studies are warranted to test its
potential use for the rehabilitation of fine motor skills in stroke patients.
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Langue : ANGLAIS