Motor cortex excitability in attention-deficit hyperactivity disorder (ADHD): A systematic review and meta-analysis.

BACKGROUND: The core characteristic of attention deficit hyperactivity disorder (ADHD) is a persistent pattern of inattention and/or hyperactivity-impulsivity that causes developmental or functional impairment. Observational studies have investigated neurophysiological features in individuals with ADHD using transcranial magnetic stimulation (TMS) to identify which intracortical mechanisms are associated with the symptoms. This systematic review aimed to assess the quality of these studies and present meta-analyses of the available neurophysiological measures. METHODS: This systematic review searched the PubMed, Scopus, Web of Science, with no date restrictions. The methodological quality of observational studies was assessed utilizing the Agency for Healthcare Research and Quality (AHRQ) criteria for observational studies. The analysis of the mean and standard deviation of the neurophysiological measurements was performed using the RevMan software version 5.0 for the meta-analyses of studies. RESULTS: Nine publications that met the inclusion criteria were evaluated. Most of the AHRQ criteria were satisfied, indicating the good quality of the studies. On comparing subjects with ADHD and controls, the forest plot profiles were similar in respect to the resting motor threshold (RMT), and silent period (SP) but a significant difference was found for short intracortical inhibition (SICI). CONCLUSION: This meta-analysis found reduced SICI in individuals with ADHD, when compared with controls. Given the small number of studies, it is important that further studies be conducted for a more robust conclusion to be formed.

Effects of the addition of transcranial direct current stimulation to virtual reality therapy after stroke: a pilot randomized controlled trial.

BACKGROUND: Upper limb (UL) impairment is the most common disabling deficit following a stroke. Previous studies have suggested that transcranial direct current stimulation (tDCS) enhances the effect of conventional therapies. OBJECTIVE: This pilot double-blind randomized control trial aimed to determine whether or not tDCS, combined with Wii virtual reality therapy (VRT), would be superior to Wii therapy alone in improving upper limb function and quality of life in chronic stroke individuals. METHODS: Twenty participants were randomly assigned either to an experimental group that received VRT and tDCS, or a control group that received VRT and sham tDCS. The therapy was delivered over 15 sessions with 13 minutes of active or sham anodal tDCS, and one hour of virtual reality therapy. The outcomes included were determined using the Fugl-Meyer scale, the Wolf motor function test, the modified Ashworth scale (MAS), grip strength, and the stroke specific quality of life scale (SSQOL). Minimal clinically important differences (MCID) were observed when assessing outcome data. RESULTS: Both groups demonstrated gains in all evaluated areas, except for the SSQOL-UL domain. Differences between groups were only observed in wrist spasticity levels in the experimental group, where more than 50% of the participants achieved the MCID. CONCLUSIONS: These findings support that tDCS, combined with VRT therapy, should be investigated and clarified further.