What is Autism?

Autism spectrum disorder (ASD) is a kind of neurodevelopmental disorder that starts in the early stage of development and is mainly characterized by continuous social interaction and social communication ability defects, restricted and repetitive behavior patterns, interests or activities ^[1].

Men are more likely to suffer from this disorder. It is usually a chronic lifelong disease course, which often seriously damages the social function of patients. It is one of the most important diseases leading to children's mental disability and leads to a serious disease burden. In recent years, it has attracted common attention all over the world.

Epidemiology of Autism

According to the latest "Report on the Development of China's Autism Education and Rehabilitation Industry Ⅲ" released by the Wucailu Autism Research Institute in 2019, the incidence of autism has increased year by year. According to the report, the incidence rate of autism in China is 0.7%, and there are currently more than 10 million people with autism spectrum disorders, of which more than 2 million are children under 12 years old.

Etiology of Autism

The etiology and pathogenesis of autism spectrum disorder are still unclear. A large number of studies have shown that autism spectrum disorder is a neurodevelopmental disorder caused by biological factors. Genetic factor is the most important factor, and the heritability is 0.7 ~ 0.9. In addition, environmental factors can increase the risk of individual disease. The interaction between genetic factors and environmental factors can also lead to abnormal brain development. Besides, some neurotransmitter systems (such as serotonin system) or neuropeptides (such as oxytocin) are also abnormal.

Clinical evaluation of Autism

For children with suspicious symptoms of autism spectrum disorder, the following examinations and assessments are recommended: Physical and nervous system examination; Mental examination; Developmental level and intelligence assessment; Laboratory examination; EEG and brain imaging examination (cranial MRI and CT); Genetic examination; Screening and diagnostic evaluation of autism spectrum disorder.

Treatment principle of Austim

The treatment principles of autism spectrum disorder are early diagnosis and early intervention, use scientific and effective treatment methods to intervene, intervention with comprehensive treatment methods and adhere to long-term treatment.

What is TMS?

TMS is a non-invasive neuromodulation technology. The time-varying pulsed magnetic field can penetrate the skull non-invasively, act on the central nervous system, generate induced currents, and cause a series of physiological and biochemical reactions, thereby affecting metabolism and neuronal excitability in the brain so that improve and treat mental and neurological diseases.

Can TMS help Autism？

International consensus statement on the potential of rTMS in the treatment of ASD in 2018^[2]: Data from existing rTMS studies on ASD indicate that rTMS has therapeutic potential. Large, multi-site, double-blind, sham-controlled trials still need to be carried out in order to have a deeper understanding of the neurophysiological heterogeneity of ASD, so as to determine the appropriate treatment options and maximize the clinical outcomes.

International consensus statement on the potential of rTMS in the treatment of ASD in 2018.

Review of TMS Autism clinical trials

A literature review on rTMS in the treatment of autism published in 2018 collected the literature data of rTMS in the treatment of autism from June 2016 to January 2018^[3]. The results showed that:

Stimulation method：Most studies use traditional rTMS protocols.
Stimulation site：The goal of most studies is to stimulate the dorsolateral prefrontal cortex (DLPFC) on both sides or in the left hemisphere using low-frequency stimulation (0.5-1 Hz).
Stimulation sessions: Most studies were stimulated once a week or twice a week, but some studies performed daily treatment for 5-29 consecutive days.
Stimulation coil：Except for Enticott et al. (2014) using H-shaped coils and Annios et al. (2016) using specially designed helmets (containing up to 122 coils), all studies used traditional figure-of-eight coils.

Summary table of TMS targets and parameters.

The results of this meta-analyses showed that rTMS has a significant but moderate impact on repetitive and stereotyped behaviors, social behavior, and the number of errors in executive function tasks, but not other outcomes.

Stimulation protocol ^[4]：

Disease	Stimulation site	Stimulation frequency (Hz)	Stimulation intensity	Stimulation time (s)	Interval time (s)	Total number of pulses
ASD	DLPFC	1	90%MT	10	20	180

Reference

[1] 精神障礙診療規(guī)范（2020 年版）
[2] Cole, E. J. , Enticott, P. G. , Oberman, L. M. , Frampton, G. M. , Casanova, M. F. , & Jackson, S. , et al. (2018). The potential of repetitive transcranial magnetic stimulation for autism spectrum disorder: a consensus statement. Biological Psychiatry, 85, S0006322318315920-.
[3] Barahona-Corrêa J. Bernardo, Ana, V. , Ana, C. , Ricardo, L. , & Oliveira-Maia, A. J. . (2018). Repetitive transcranial magnetic stimulation for treatment of autism spectrum disorder: a systematic review and meta-analysis. Frontiers in Integrative Neuroence, 12, 27-.
[4] Kang, J. , Song, J. , Casanova, M. F. , Sokhadze, E. M. , & Li, X. . (2019). Effects of repetitive transcranial magnetic stimulation on children with Low-function autism. CNS Neuroscience & Therapeutics, 25(11).