Serial qEEG as a Neurophysiological Profiling and Treatment Monitoring Tool in dTMS-Treated Autism Spectrum Disorder: A Case Report.

Autism spectrum disorder (ASD) is a neurobiologically heterogeneous neurodevelopmental condition, yet current treatment approaches - predominantly behavioral and communicative - pharmacological option limited to symptomatic relief, with limited benefit for individuals with more severe presentations. Here we report an 8-year-old male with ASD presenting with social withdrawal, anxiety, and self-injurious behavior (SIB), who underwent quantitative electroencephalography(qEEG)-guided deep transcranial magnetic stimulation (dTMS) over 40 sessions. Baseline qEEG demonstrated generalized cortical hyperexcitability - characterized by elevated absolute power across most frequency bands and diffuse coherence elevation - consistent with a maturational lag pattern previously described in ASD. We hypothesized that this profile might offer a neurobiological rationale for BDNF-activating neuromodulatory approach via dTMS. Serial qEEG assessments every 10 sessions enabled quantitative monitoring of treatment response; introduction of the H7 coil from the 21st session associated with subsequent delta reduction and partial resolution of central/posterior high-beta activity. CARS-2 scores decreased from 34 at baseline to 20 at treatment completion - a 41% reduction, representing a shift to the non-autistic range - coinciding with reduced anxiety-related behaviors, improved language, and overall reduction in SIB. This case illustrates the potential dual utility of qEEG as a neurophysiological profiling tool and a quantitative biomarker of treatment response, contributing preliminary evidence for the clinical utility of dTMS in ASD and highlighting the value of neurophysiologically informed, precision-based approach to psychiatric care.