Strokes represent, in industrialized countries the leading cause of acquired motor disability
in adults older than 40. Stroke is responsible for France from 150 000 to 200 000 new cases
of hemiplegia each year. These patients will see their deficit to improve during the first 6
months after stroke. This recovery is largely based on brain plasticity mechanisms and the
rehabilitation has as main objective to optimize these mechanisms. However, only 20% of
patients hospitalized in a rehabilitation sector recover a functional upper limb. This lack
of functionality is not only due to overall strength gap but also to the predominance of this
gap on the extension movements of the wrist and fingers.
Meanwhile, work on brain plasticity helped develop new techniques of non-invasive brain
stimulation (Non-invasive Brain Stimulation, NIBS) as the model of coupled stimulations
(Paired Associative Stimulation, PAS) for modulating way over effective brain plasticity. In
previous studies, the investigators have shown over a 30 minutes session lasting facilitation
(60mn) and specific motor evoked potential (MEP) of the Extensor Carpi Radialis (ECR).
Several studies showed an adjuvant effect when GSIN were associated with learning of a motor
task. For PAS, some studies have shown a greater facilitation when the latter is associated
with muscle contraction.
The motor imagery (MI) is imagining a movement without realizing it, it is based on
mechanisms similar to those of the real movement. This technique also showed its effects as
an adjuvant therapy in hemiplegic patients, however, they remain lower than those obtained
after a motor drive. Its use in patients with no motor makes its uniqueness and strength.