Background: Research continues to develop which investigates the use transcranial magnetic stimulation (TMS) as a novel therapeutic and diagnostic tool in the management of autism spectrum disorder (ASD) without an accompanying intellectual impairment, also known as high functioning ASD (HF-ASD). Additionally, interest has arisen investigating TMS in pediatric cases of HF-ASD due to the neurodevelopmental nature of the disorder, the possibility of greater clinical response in children given the high degree of cortical plasticity in early life, and opportunity for early diagnosis and initiation of treatment. Given these clinical possibilities, a systematic review of the literature investigating the use of TMS in cases of pediatric HF-ASD is warranted
Methods: We conducted a Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) systematic review of literature published through 02/01/2021 which examined control trials and cross over studies investigating TMS as a therapeutic and diagnostic tool in the management of pediatric HF-ASD.
Results: 484 articles were screened, and 14 articles were included for final qualitative synthesis. Heterogeneity between studies was found including study design, clinical outcomes measures, diagnostic variables investigated, TMS parameters and modalities. Notably, inhibitory TMS modalities were the most commonly utilized therapeutic intervention based on the hypothesis of delayed inhibitory neuronal development of ASD. Multiple studies demonstrated positive clinical outcomes in the domains of executive functioning, mood regulation, repetitive behaviors, and social withdrawal. Overall, no serious adverse effects were noted regardless of age, gender, TMS modality or parameters.
Conclusions: TMS is a safe option for diagnosis and treatment of pediatric HF-ASD. However, findings are limited by variability between protocols and modalities. Future studies should include the development of standardized TMS parameters and modalities to enable larger multi-site studies and to create clinical protocols.