Efeitos da estimulação transcraniana combinada com o treinamento cognitivo-linguístico de memória e atenção em crianças com transtorno fonológico: um estudo piloto cruzado, controlado, randomizado e triplo cego

Abstract

Introduction: Transcranial Direct Current Stimulation (tDCS), a non-invasive neuromodulation technique with the potential to induce neuroplastic effects, has shown promising results in modulating cognitive and language functions. However, the application of tDCS in children with specific language disorders remains underrepresented in the current literature, particularly in cases without the presence of other associated medical conditions. Objective: To investigate the effects of tDCS combined with a paired intervention on the cognitive abilities of memory and attention in children with Phonological Disorder (PD). Methods: This pilot, randomized, placebo-controlled, triple-blind, crossover clinical trial was conducted with 16 children aged 7 to 12 years diagnosed with PD. Participants underwent three consecutive weekly sessions of tDCS over four weeks, totaling 12 sessions. Anodal stimulation was applied over the left dorsolateral prefrontal cortex (F3), combined with a standardized cognitive-linguistic training program focused on memory and attention skills. Participants were assessed for cognitive and language functions using the Attention, Oral Language, Executive Functions, and Memory (working, verbal, visual, and semantic) subtests of the NEUPSILIN-Inf – Brief Neuropsychological Assessment Instrument for Children and were evaluated at three time points (T0, T1, and T2). Statistical analyses were performed using R software version 4.5.1, following the intention-to-treat principle. Missing data were handled using Multiple Imputation by Chained Equations (MICE). Considering the crossover design, two analytical approaches were conducted: (1) comparison of changes between T0 and T1 across groups and (2) within-subject analysis comparing the effects of active and sham stimulation. The domains of attention, memory, language, and executive functions were evaluated, in addition to exploratory analyses of individual subtests. Estimates were combined according to Rubin's Rules, and multiple comparisons were adjusted using the False Discovery Rate (FDR) method, adopting a significance level of 5%. Results: The study sample consisted of 16 children, including eight boys and eight girls, aged 7 to 12 years, with a mean age of 8.81 years (SD ± 1.8). Between-group comparison during the first intervention period (T0–T1) demonstrated significantly greater improvement in the attention domain among participants who received active tDCS compared with those who received sham stimulation (p = 0.0085). This finding was corroborated by the within-subject crossover analysis, which also demonstrated superior attentional performance following active stimulation (p = 0.039). Exploratory analyses revealed improvements in auditory attention (p = 0.032) and total attention score (p = 0.033) after active stimulation. Favorable trends were also observed for language and memory, although these findings did not reach statistical significance. Conclusion: The findings suggest that tDCS may primarily enhance attentional processes in children with PD, with potential positive effects on related cognitive functions, including memory and language. These results support the potential of non-invasive neuromodulation as an adjunctive strategy for cognitive rehabilitation, although studies with larger samples are needed to confirm these effects.