The effect of transcranial direct current stimulation combined with functional task training on motor recovery in stroke patients.

BACKGROUND: Motor deficits are common after stroke and are a major contributor to stroke-related disability and the potential for long-lasting neurobiological consequences of stroke remains unresolved. There are only a few treatments available for the improvement of motor function in stroke patients. However, the mechanisms underlying stroke recovery remain poorly understood, and effective neurorehabilitation interventions remain insufficiently proven for widespread implementation. METHODS: Herein, we propose to enhance the effects of brain plasticity using a powerful noninvasive technique for brain modulation consisting of navigated transcranial magnetic stimulation (TMS) priming with transcranial direct current stimulation (tDCS) in combination with motor-training-like constraint-induced movement therapy (CIMT). Our hypothesis is that navigated low-frequency rTMS stimulus priming with precise location provided by neuronavigation on the healthy side of the brain and with anodal tDCS on the affected side combined with CIMT will induce a greater motor function improvement than that obtained with sham tDCS combined with CIMT alone. We predict that the application of this technique will result in a large reduction in cortical excitability and dis-inhibition in the affected hemisphere and lead to improvements in behavioral measures of hand function in stroke patients. DISCUSSION: The proposed study, therefore, is important for several reasons. The results could potentially lead to improved stroke therapeutics, and the approach makes use of 2 potential pathways to modulate brain function. TRIAL REGISTRATION: This study protocol was registered in Clinical Trials Registry (https://clinicaltrials.gov/ct2/show/NCT04646577). ETHICS AND DISSEMINATION: The study has been reviewed and approved by the Human Research Ethics Committee of the King Fahad Specialist Hospital Dammam. The results will be actively disseminated through peer-reviewed journals, conference presentations, social media, broadcast media, print media, the internet and various community/stakeholder engagement activities.

Cognitive function assessment during 2 mA transcranial direct current stimulation in DLPFC in healthy volunteers.

Although cognitive function has been reported to change following the anodal transcranial direct current stimulation (tDCS) but still variable results have been reported in healthy subject and there is paucity of data on the cognitive effects of online tDCS. Therefore, we aimed to assess the online effect of tDCS over the left dorsolateral prefrontal cortex (DLPFC) on cognitive function and obtain safety data in healthy adults. We recruited 36 healthy (20 male) participants for this double-blind, sham-controlled parallel design. We used Stop Signal Task (SST) Go Trial and Pattern Recognition Memory (PRM) tests to evaluate cognitive function during 2 mA (20 min) anodal or sham tDCS stimulation over the left DLPFC. In active conditions, left dorsolateral prefrontal cortex was selected for electrode placement with reference over right supraorbital cortex. All related tasks were done during the online tDCS section in both groups (active/sham). There were statistically significant differences in cognitive function according to the PRM test (P = 0.003), SST (P = 0.021), and SST correct response time on Go Trials (P = 0.02) during active stimulation compared to the sham group. Our results reveal that cognitive performance is affected by a single dose of active online tDCS over DLPFC area compared to sham stimulation. In our study, tDCS is well-tolerated and safe that further supports the safety of tDCS in local healthy population.