The Effects of Transcranial Direct Current Stimulation on Chronic Ankle Instability

Abstract

Background: Inhibitory control refers to a central cognitive capacity involved in the interruption and correction of actions. Dysfunctions in these cognitive control processes have been identified as major maintaining mechanisms in a range of mental disorders such as ADHD, binge eating disorder, obesity, and addiction. Improving inhibitory control by transcranial direct current stimulation (tDCS) could ameliorate symptoms in a broad range of mental disorders. Objective: The primary aim of this pre-registered meta-analysis was to investigate whether inhibitory control can be improved by tDCS in healthy and clinical samples. Additionally, several moderator variables were investigated. Methods: A comprehensive literature search was performed on PubMed/MEDLINE database, Web of Science, and Scopus. To achieve a homogenous sample, only studies that assessed inhibitory control in the go-/no-go (GNG) or stop-signal task (SST) were included, yielding a total of 75 effect sizes from 45 studies. Results: Results of the meta-analysis indicate a small but significant overall effect of tDCS on inhibitory control (g = 0.21) which was moderated by target and return electrode placement as well as by the task. The small effect size was further reduced after correction for publication bias. Conclusion: Based on the studies included, our meta-analytic approach substantiates previously observed differences between brain regions, i.e., involvement of the right inferior frontal gyrus (rIFG) vs. the right dorsolateral prefrontal cortex (rDLPFC) in inhibitory control. Results indicate a small moderating effect of tDCS on inhibitory control in single-session studies and highlight the relevance of technical and behavioral parameters.

Effects of Combining High-Definition Transcranial Direct Current Stimulation with Short-Foot Exercise on Chronic Ankle Instability: A Pilot Randomized and Double-Blinded Study

“…It should be noted that the improvement of 15° inversion in the HD-tDCS group was observed in Week-3 and Week-6, but not in Week-4. This may be due to ongoing adaptation of the participants to the change of SFE training in Week-4 from a bipedal to unipedal stance [ 15 ], a possibility supported by a similar regression observed in the sham group at this timepoint.…”

“…Sample size estimation for this study was based upon the results from two previous studies [ 15 , 19 ]. One study demonstrated that 24 sessions of SFE improved joint position sense in people with CAI as compared to proprioceptive sensory exercise; that is, those who received SFE had 20 ± 14% greater improvement [ 19 ].…”

“…The other study demonstrated that 10 sessions of tDCS targeting M1 in combination with eccentric ankle exercises induced improvement in the performance of dynamic balance test in people with CAI as compared to the sham. Specifically, those who received real tDCS had 8 ± 6% greater improvement compared to those who received sham [ 15 ]. Based upon this data, we estimated that 22 participants total (11 per intervention arm) would provide at least 85% power to detect similar improvements in joint position sensation and balance test performance in the SFE+tDCS group (alpha = 0.05).…”

“…More recently, researchers have examined tDCS as an adjunct to evidenced-based interventions such as physical therapy or balance retraining. Bruce et al [ 15 ] reported that in individuals with CAI, a 4-week intervention comprising eccentric ankle exercises and 10 sessions of anodal tDCS targeting M1, as compared to eccentric exercise combined with sham stimulation, improved cortical excitability as measured by transcranial magnetic stimulation, dynamic balance performance as measured by a hop-to-stabilization test, and muscle activation during dynamic balance test as determined by surface electromyography.…”

Effects of Transcranial Direct Current Stimulation Combined With Physical Training on the Excitability of the Motor Cortex, Physical Performance, and Motor Learning: A Systematic Review

“…Fifteen studies implemented a double-blinded design (Vines et al, 2008;Reis et al, 2009Reis et al, , 2013Williams et al, 2010;Kang and Paik, 2011;Thirugnanasambandam et al, 2011;Goodwill et al, 2013;Hendy and Kidgell, 2013;Kim and Ko, 2013;Fujimoto et al, 2014;Steiner et al, 2016;Rumpf et al, 2017;Baltar et al, 2018;Yosephi et al, 2018;Jafarzadeh et al, 2019), in which both the study personnel and participants were not aware of the types of intervention. Five studies used a single-blinded design (Stagg et al, 2011;Naros et al, 2016;Zandvliet et al, 2018;Bruce et al, 2020;Tseng et al, 2020), and the blinding was not reported in other four studies (Karok and Witney, 2013;Looi et al, 2016;Washabaugh et al, 2016;Chen et al, 2020).…”