Review articleMotor cortex excitability in attention-deficit hyperactivity disorder (ADHD): A systematic review and meta-analysis
Section snippets
What this paper adds?
This systematic review shows that individuals with ADHD had lower cortical inhibition than healthy subjects. This finding is an important aspect that should be highlighted in the neurophysiological understanding of ADHD
Literature search
A literature search of the following databases was performed with no date restriction: PubMed, Scopus, Web of Science. The key search terms used were “cortical excitability”, “transcranial magnetic stimulation”, “attention deficit disorder with hyperactivity”, and “motor excitability”. These terms were used in various combinations to find relevant studies. Furthermore, the references of all papers found were checked to find publications not identified in the initial search. The investigation
Results
The flowchart in Fig. 1 details the process used to select studies. The search strategy identified 179 articles however after removing duplicates (n = 33), 146 articles were considered potentially relevant. Of these, 93 did not match the eligibility criteria and 11 were considered appropriate for this review. After reading the full text, nine articles were included in the qualitative analysis, but only six provided data appropriate to the meta-analyses.
Discussion
The findings of this review suggest that SICI is a promising measure to help in the diagnosis of ADHD. However, at present, there are too few studies and the number of participants is too small to draw a reliable conclusion.
This meta-analysis found that patients with ADHD have a reduced SICI compared to controls. No statistically significant difference was found either for the SP or RMT between ADHD patients and controls. In general, taking into account the quality of the studies, these results
Conclusion
This systematic review shows important results of observational studies using TMS in the investigation of neurophysiological parameters in individuals with ADHD compared to healthy subjects. The results show that, in general, the studies on the theme have a good quality regarding the criteria analyzed.
Studies show that there are differences between the neurophysiological parameters of individuals with ADHD compared to healthy subjects. Despite the small number of observational studies that
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