Transcranial Direct Current Stimulation by cathode and anode electrodes on the improvement of stereotype behavior and communication of Autism spectrum disorders

Autism is a type of neurodevelopmental disorder that is characterized by deficit verbal communication behaviors. Symptoms of this disorder occur before three years old, and the cause of the disease is unknown. This disorder is more common in boys than in girls. The economic, social, lifestyle and parental education level does not play role in the development of autism. The disorder affects the normal development of the brain in the context of social interactions and communication skills. Children and adults with autism, in verbal and non-verbal communication, social interactions and game-related activities have some troubles. The disorder makes it difficult to communicate with others and the outside world for them. In some cases self-harm and aggression are seen. In these people, repetitive movements (touching, jumping) are unusual responses to people, attachment to objects, or resistance to change, and there may be unusual sensations in the five senses (sight, hearing, odor, smell, and taste). The central core of autism is a disorder in communication. One in every 60 to 70 live births in the world is a person with autism. Study results revealed that pregnant women who are obese or diabetic are more likely to having autism child than other mothers. Direct current stimulation of the brain is a technique that is used to stimulate the different area of the brain in neurologic and psychiatric patients. This study was aimed to evaluate the effect of transcranial direct current stimulation (Tdcs) of the brain to the improvement of stereotype behavior and establishment of communication in children who are suffering from autism spectrum disorder and the duration of its effects.

In this randomized crossover clinical trial, 20 children choosed with an autism spectrum disorder. They referred to the psychiatric centre in 2013-14 in Yazd province and then divided into two-period treatment groups. Stereotype behavior and communication scores of these children measured in the pre-test. The survey did after artificial and actual stimulation and two months later. Data collected by Gilliam autism rating scale (GARS). Group A patients, received artificial stimulation in 5 sessions, and the patient of group B received actual stimulation by Tdcs. After five sessions, the treatment of the two groups replaced. GARS scale is a norm-referenced instrument that assists teachers and clinicians in identifying and diagnosing autism in individuals between 3 to 22 years and in estimating the severity of the child's disorder. This scale calculated by Hemmatiyan et al. in Iran. In their research to assess the construct validity, the Karz questionnaire used simultaneously, and the correlation coefficients of these two questionnaires were 0.08. Comparing 100 healthy children and adolescents determined diagnostic validity through a differential analysis test. The cut point of 52 tests and the sensitivity and scale feature obtained 99% and 100%, respectively. The reliability of this scale was also estimated using Cronbach's alpha coefficient of 0.89.

The result illustrate there was improvement in stereotype behaviors (p<0.05) and communication (p<0.05) in children with autism spectrum disorder after this treatment.

Regarding to the result of this study it seemed that transcranial direct current stimulation could improvement of stereotype behavior and communication in autistic children.