Unlocking the Potential of Anodal tDCS: How Brain Stimulation Can Improve Motor Function in Stroke Survivors

Stroke is a leading cause of disability, and motor deficits are the most common impairment after a stroke. To address this issue, researchers have been exploring the use of non-invasive brain stimulation techniques like transcranial direct current stimulation (tDCS) to induce changes in the brain and improve motor function in stroke patients. A recent study looked at the effects of a type of brain stimulation called anodal tDCS on stroke survivors and found that this type of stimulation increased the connectivity (communication) between different parts of the brain involved in movement and sensation.

The study used functional magnetic resonance imaging (fMRI) to investigate the effects of tDCS on the brain. The results showed that for the tDCS group (using a Neuroconn stimulator), significant clusters of increased functional connectivity (FC) were observed in the ipsilesional postcentral area and the ipsilesional superior temporal area. Additionally, the study found that significant changes in global efficiency were only observed for the tDCS group, not the sham group. Furthermore, the study found that brain regions with electric fields exceeding 90th percentile mainly included the primary motor cortex, bilateral frontal gyrus, and the ipsilesional frontal, precentral, and postcentral gyrus.

The authors of the study point out that tDCS is an appealing tool for facilitating motor function rehabilitation in stroke patients, as it is non-invasive and has been shown to induce changes in the brain. They also mention that the underlying mechanism of tDCS on brain activity is not fully understood and that there is large inter-individual variability in the effects of tDCS, which might be explained by differences in brain anatomy. The paper concludes by highlighting the need for further research to understand the underlying mechanisms of tDCS and how it can be used to improve motor function in stroke patients. Overall, the study suggests that anodal tDCS may be helpful for improving brain function after a stroke and that individualised stimulation protocols can be designed based on the individual electric field in the sensorimotor area generated by FEM models.

Reference Paper

Yuan, K. et al. (2023) “Individual electric field predicts functional connectivity changes after anodal transcranial direct-current stimulation in chronic stroke,” Neuroscience Research, 186, pp. 21–32. Available at: https://doi.org/10.1016/j.neures.2022.10.003