Transcranial Magnetic Stimulation Detects Potential Biomarker for Autism-Related Brain Activity

Published March 2016
Journal of Child and Adolescent Psychopharmacology

One of the challenges of studying autism spectrum disorder (ASD) is a limited understanding about how the brain reacts internally, regardless of external symptoms of diagnosis.

However, new research suggests that transcranial magnetic stimulation (TMS) can serve as a tool for grouping children with ASD according to differences in their brain activity.

Ernest Pedapati, MD, MS, and colleagues Craig Erickson, MD, and Logan Wink, MD, led a team of scientists from Cincinnati Children’s who reported their findings in March 2016 in the Journal of Child and Adolescent Psychopharmacology.

The team delivered intermittent theta burst stimulation (iTBS)—a brief, controlled magnetic pulse that activates brain neurons—to nine children with ASD and nine children without ASD. The ASD group showed a unique and significant decrease in brain excitability after 20 minutes.

These results provide “early evidence for a potential physiological biomarker of cortical plasticity in youth,” the team reports.

Long-term, psychiatrists hope to use these types of biomarkers to guide treatment according to differences in ASD brain activity, Pedapati says. As improved neurological signatures of ASD emerge, clinicians could become more accurate at providing the most effective treatment.

Biomarkers also could help guide patients to the most appropriate drug studies when they do not respond well to existing therapy.

“Some children really do get better, but we lose them in the noise,” Pedapati notes. “This approach uses technology to profile brain activities and brain responses so that they don’t get lost in the noise.”

Fig A:  Linear mixed model estimates with standard errors of post-iTBS motor evoked potential amplitudes. Post-hoc comparison indicated a significant difference at 20 minutes (shown), with ASD demonstrating significantly less facilitation than TDC. ASD, autism spectrum disorder group; Control, typically developing control group; iTBS, intermittent theta burst stimulation.
Click image to view caption.

Citation

Pedapati EV, Gilbert DL, Erickson CA, Horn PS, Shaffer RC, Wink LK, Laue CS, Wu SW. Abnormal Cortical Plasticity in Youth with Autism Spectrum Disorder: A Transcranial Magnetic Stimulation Case-Control Pilot Study. J Child Adolesc Psychopharmacol. 2016 Sep;26(7):625-31.