Repetitive Transcranial Magnetic Stimulation for Executive Function Deficits in Autism Spectrum Disorder and Effects on Brain Structure and Function
Objectives: To complete a pilot study exploring the novel application of rTMS to DLPFC for treatment of EF deficits in adolescents and young adults with HF-ASD. This pilot study focuses on evaluating the feasibility of implementing our rTMS treatment protocol in HF-ASD. Our primary aims are to: (i) determine if our rTMS protocol can be successfully applied in people with HF-ASD, (ii) examine whether active rTMS improves EF performance in HF-ASD, and (iii) use structural and functional MRI in a pre/post design to identify mechanisms of treatment response .
Methods: We are using a randomized, double-blind, sham-controlled design comparing active (20Hz) vs. sham rTMS applied 5 days per week for 4 weeks bilaterally to DLPFC in young people with HF-ASD (active, N=20 vs. sham, N=20, 16-35 years). Outcome measures of EF performance (measured using Cambridge Neuropsychological Test Automated Battery) are being evaluated before and after the 4-week intervention. Structural and functional neuroimaging measures (MRI/DTI/rs-fMRI and task-based fMRI) will also be acquired at baseline, and at the end of the 4-week rTMS trial in HF-ASD subjects to assess for biomarkers of treatment response.
Results: We have now completed year 1 of our 2-year clinical trial. 20 subjects have now successfully completed our study protocol. Over the past 12 months, we have demonstrated feasibility and tolerability of our rTMS protocol in HF-ASD, having successfully recruited ~2 HF-ASD subjects/month (total N=20) to our study, retaining 100% of randomized subjects, with only transient and mild side-effects reported following rTMS.
Conclusions: At IMFAR 2016, we will present our novel protocol, as well as preliminary data regarding the feasibility of implementing our study protocol in HF-ASD participants. In addition, we will present preliminary neuroimaging results including: associations between baseline measures of cognitive performance and DLPFC structure and DLPFC activation, as well as microstructure of white matter tracts connecting to the DLPFC.