Neuro-rehabilitation helps hemaparetic stroke patients confronted with loss of motor skills on one side of their body, to recover some of their motor functions after a cerebrovascular accident.

Nineteen hemiparetic stroke patients (with a motor deficit in the upper limb) participated to this new clinical trial. In order to avoid study bias, the stimulations were performed in a double-blind, randomised fashion. Each patient received a real stimulation as well as a placebo-stimulation during two separate sessions. Because the tDCS was as good as completely imperceptible, it became impossible for patients to determine if they received a true or a placebo-stimulation. During the first stimulation session (real or placebo), the patients learned how to perform a task with a paralysed hand, combining speed and accuracy. One week later, they performed the learned task while the functional MRI scanner recorded their cerebral activity. After one week, this experience was completely done over again with the other stimulation (placebo or real). As in the previous study, the non-invasive cerebral stimulation amplified the motor learning capacity with the paralyzed hand and the long-term memory retention in a spectacular way for patients with a chronic stroke.
Thanks to functional MRI, this second study demonstrates that the combination of motor learning and non-invasive cerebral stimulation improves the efficiency of the cerebral activity. Indeed, one week after the placebo stimulation, the cerebral activations measured via the functional MRI was very diffuse. Large cerebral zones were somehow « recruited » although motor performance was low (poor retention). On the other hand, one week after real stimulation, the cerebral activation was focussed on the essential motor zones, almost identical to a person without stroke-impact although the motor performance was significantly better (enhanced task retention). In other words, the combination of motor learning and tDCS reinforced the essential motor zones and this specific network was reactivated one week after the real intervention.
Source-Eurekalert