EEG-Based Repetitive Transcranial Magnetic Stimulation for Treatment of Autism Spectrum Disorder

Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder with deficits in social communication and interaction, and repetitive behaviors with restricted interests. Some researchers, using electroencephalography (EEG), had identified a reduction of alpha oscillation in the frontal lobe and long-range underconnectivity between the frontal lobe and other regions in alpha oscillation. Both were related to the core symptoms of autism. Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive neuromodulation technique and has been studied for the treatment of individuals with autism. However, there is no consensus on which frequency is suitable. Here, we present a case of autism who received EEGs as evaluations of brain function and individualized transcranial magnetic stimulations that deliver EEG-based alpha-oscillation frequencies. The results were analyzed by quantitative electroencephalography (qEEG) to evaluate the changes of alpha power and connectivity between the frontal lobe and other regions. The EEG results were also compared with clinical evaluations. BJSTR.

deliver EEG-based alpha-oscillation frequencies based on the calculation of EEGs. The results of EEGs before and after treatments were analyzed by quantitative EEG (qEEG) to identify the changes of the relative power and connectivity which is represented by coherence between tow leads. We also evaluated patient with clinical rating scales.

Case Report
The patient is a 10-year-old boy with a 7-year history of impairments in social interaction and communication. He also sustained repetitive behaviors and restricted interests. His The patient received 25 daily treatments on weekdays in two months with the EEG-based frequency and the power from 60 to 80% of the motor threshold. In addition to baseline EEG, we followed EEG before the 5 th , 15 th , and 25 th treatment and another EEG on 5 months later. EEG-based frequencies were calculated after every acquisition of EEG then applied to the next treatment.
We also evaluated the patient with CARS and AQ when we followed the EEGs. We used Persyst v 13 (Persyst Development Co., Prescott, AZ) to generate qEEG data including relative alpha power of the frontal lobe and alpha-band coherence between frontal and parieto-occipital region. Relative alpha power was calculated by dividing the spectrum power of the alpha-band (8-13Hz) by the summation power of all four frequency bands (delta, theta, alpha, and beta bands). Coherence is defined by the synchronization in a fixed frequency band between two leads with the quantification of the extent to which they share a constant oscillating frequency and phase difference [7]. The coherence is a number between 0 to 1 and a higher number indicates more commonality between two channels in a frequency band. We chose 2-minute EEG for each record to calculate relative power at Fz and coherence between Fp1-P3, Fp1-O1, Fp2-P4, and Fp2-O2. Clinically, his CARS lowered to 40 and AQ lowered to 35 in the follow-up (Table 1). Initially, the relative power of the frontal lobe was 0.12 and increased to 0.45 at the end of treatment with a reduction to 0.33 at the follow-up

Discussion
In the present report, we demonstrate that the changes in qEEGs Furthermore, alpha-band oscillation can regulate the change of neuron firing rate which is related to the processing of information by power and phase with higher power with lower firing rate and trough in phase with higher firing rate. Alpha oscillation serves as a regulating system by inhibitory ability to control the firing rate of neurons. So, it is reasonable that increment in alpha power facilitates the control of neuronal firing [9].
A previous study had identified long-range underconnectivity between the frontal lobe and other regions of the brain [3], and this deficit was related to core symptoms of ASD since the frontal lobe

Declaration of Patient Consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published, and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.