Posts Tagged direct current stimulation
[ARTICLE] Transcranial Direct Current Stimulation of the Leg Motor Cortex Enhances Coordinated Motor Output During Walking With a Large Inter-Individual Variability
- tDCS can enhance the coordinated motor output during walking in healthy subjects, but there is large inter-individual variability in response.
- Dual-hemispheric tDCS tends to have a larger effect on the coordinated motor output than uni-hemispheric tDCS.
- tDCS did not result in improved coordinated motor output in the paretic leg of chronic stroke survivors.
Background: Transcranial direct current stimulation (tDCS) can augment force generation and control in single leg joints in healthy subjects and stroke survivors. However, it is unknown whether these effects also result in improved force production and coordination during walking and whether electrode configuration influences these effects.
Objective: We investigated the effect of tDCS using different electrode configurations on coordinated force production during walking in a group of healthy subjects and chronic stroke survivors.
Methods: Ten healthy subjects and ten chronic stroke survivors participated in a randomized double-blinded crossover study. Subjects walked on an instrumented treadmill before and after 10 minutes of uni-hemispheric (UNI), dual-hemispheric (DUAL) or sham tDCS applied to the primary motor cortex.
Resultst: DCS responses showed large inter-individual variability in both subject populations. In healthy subjects tDCS enhanced the coordinated output during walking as reflected in an increased positive work generation during propulsion. The effects of DUAL tDCS were clearer but still small (4.4% increase) compared to UNI tDCS (2.8% increase). In the chronic stroke survivors no significant effects of tDCS in the targeted paretic leg were observed.
Conclusionst: DCS has potential to augment multi-joint coordinated force production during walking. The relative small contribution of the motor cortex in controlling walking might explain why the observed effects are rather small. Furthermore, a better understanding of the inter-individual variability is needed to optimize the effects of tDCS in healthy but especially stroke survivors. The latter is a prerequisite for clinical applicability.
Source: Transcranial Direct Current Stimulation of the Leg Motor Cortex Enhances Coordinated Motor Output During Walking With a Large Inter-Individual Variability – Brain Stimulation: Basic, Translational, and Clinical Research in Neuromodulation
[ARTICLE] Anodal tDCS Combined With Radial Nerve Stimulation Promotes Hand Motor Recovery in the Acute Phase After Ischemic Stroke
Background and Objective: The question of the best therapeutic window in which noninvasive brain stimulation (NIBS) could potentiate the plastic changes for motor recovery after a stroke is still unresolved. Most of the previous NIBS studies included patients in the chronic phase of recovery and very few in the subacute or acute phase. We investigated the effect of transcranial direct current stimulation (tDCS) combined with repetitive peripheral nerve stimulation (rPNS) on the time course of motor recovery in the acute phase after a stroke.
Methods: Twenty patients enrolled within the first few days after a stroke were randomized in 2 parallel groups: one receiving 5 consecutive daily sessions of anodal tDCS over the ipsilesional motor cortex in association with rPNS and the other receiving the same rPNS combined with sham tDCS. Motor performance (primary endpoint: Jebsen and Taylor Hand Function Test [JHFT]) and transcranial magnetic stimulation cortical excitability measures were obtained at baseline (D1), at the end of the treatment (D5), and at 2 and 4 weeks’ follow-up (D15 and D30).
Results: The time course of motor recovery of the 2 groups of patients was different and positively influenced by the intervention (Group × Time interaction P = .01). The amount of improvement on the JHFT was greater at D15 and D30 in the anodal tDCS group than in the sham group.
Conclusion: These results show that early cortical neuromodulation with anodal tDCS combined with rPNS can promote motor hand recovery and that the benefit is still present 1 month after the stroke.