Efeitos da estimulação transcraniana por corrente contínua em crianças com transtorno do processamento auditivo central

Abstract

Central Auditory Processing Disorder (CAPD) is a deficit in the neural processing of auditory stimuli of neurobiological origin, characterized by hearing difficulties resulting from changes in the auditory skills involved in Central Auditory Processing (CAP). In addition, it can be observed that this population has learning difficulties, due to the interrelationship between auditory processing and phonological processing skills. One of the gold standard interventions for this population is Auditory Training (AT), based on the principle of neuroplasticity. Another form of intervention that has been widely investigated is transcranial direct current stimulation (tDCS), which, also based on the principle of neuroplasticity, uses a low-intensity current to modulate cortical activity. In this context, tDCS emerges as a potential non-invasive intervention to modulate neuronal activity and improve cognitive functions in different populations. Therefore, this study aimed to investigate the main effects and efficacy of an intervention protocol based on tDCS on Central Auditory Processing and phonological processing skills in children with CAPD. The work was structured in three studies: The first article is a systematic review with metaanalysis, which sought to analyze the scientific evidence of the efficacy of tDCS in CAPD. The results indicated that anodal tDCS applied to the left temporal cortex showed promise as an intervention in the treatment of CAPD, with positive effects on temporal processing and auditory attention. However, the variability in the types of protocols used stands out; The second article is a blinded, placebo-controlled clinical trial that investigated the effects of tDCS associated with Auditory Training in CAPD. Twentyfour children diagnosed with CAPD participated and were divided into three intervention groups, each subjected to a different type of stimulation: (1) active anodal tDCS (a-tDCS) in the T7 temporal area combined with Auditory Training (AT); (2) isolated a-tDCS in the T7 area; and (3) only AT. The results showed that anodal tDCS applied to the left auditory cortex over 10 sessions increased the effectiveness of auditory training, improving performance in temporal processing and auditory attentional control tasks. The third article is also a blinded, placebo-controlled clinical trial that analyzes the effects of atDCS on phonological awareness, rapid automatized naming, and working memory skills in children with CAPD. The findings indicate that a-tDCS, associated or not with AT, has positive effects on phonological awareness and rapid automatized naming. Thus, it is concluded that tDCS can be used as an adjunct method to accelerate therapeutic intervention in individuals with CAPD and learning disabilities.