The visual amplification of goal-oriented movements counteracts acquired non-use in hemiparetic stroke patients

Background: stroke-induced impairments result from both primary and secondary causes,i.e. damage to the brain and the acquired non-use of the impaired limbs. indeed,stroke patients often under-utilize their paretic limb despite sufficient residual motor function. we hypothesize that acquired non-use can be overcome by reinforcement-based training strategies. methods: hemiparetic stroke patients (n = 20,11 males,9 right-sided hemiparesis) were asked to reach targets appearing in either the real world or in a virtual environment. sessions were divided into 3 phases: baseline,intervention and washout. during the intervention the movement of the virtual representation of the patients' paretic limb was amplified towards the target. results: we found that the probability of using the paretic limb during washout was significantly higher in comparison to baseline. patients showed generalization of these results by displaying a more substantial workspace in real world task. these gains correlated with changes in effector selection patterns. conclusions: the amplification of the movement of the paretic limb in a virtual environment promotes the use of the paretic limb in stroke patients. our findings indicate that reinforcement-based therapies may be an effective approach for counteracting learned non-use and may modulate motor performance in the real world. © 2015 rubio ballester et al.