The Effects of Transcranial Direct Current Stimulation Before or During Mirror Visual Feedback on Eye-Hand Coordination in Children With Unilateral Cerebral Palsy

Abstract

Background and Aims: Neuroplasticity refers to the reorganization of new neural pathways. Mirror visual feedback is a complementary neurorehabilitation technique that utilizes neuroplasticity and modern technologies such as transcranial direct current stimulation. This study examines the effect of transcranial direct current stimulation before and during mirror visual feedback on eye-hand coordination in children with unilateral cerebral palsy. Methods: A total of 12 children with unilateral cerebral palsy (mean age: 7.57±2.29 years) participated in this randomized, crossover, double-blind, and within-group experimental design. They were randomly exposed to one of 4 interventions: Aodal-tDCS-offline, sham-tDCS-offline, aodal-tDCS-online, and sham-tDCS-online, with a ONE-week interval. The Beery visual-motor integration test was used to assess eye-hand coordination. Data were analyzed using a two-way repeated measures analysis of variance (4×2 factorial design; 4 experimental conditions and 2 time points). Results: The results showed that eye-hand coordination in offline anodal conditions was significantly higher than in other conditions (P<0.05). Additionally, the simple effect of time indicated that the values of eye-hand coordination in offline anodal conditions had significantly increased (P<0.05). In contrast, in online anodal conditions, it had significantly decreased (P=0.003). The results also showed no significant difference in the results between online and offline sham conditions (P<0.05). Conclusion: The results of this research indicate that the sequential combination of mirror visual feedback with transcranial direct current stimulation (offline) yielded better results than other conditions. This is due to the priming stimulation mechanism, in which previous activities create a more effective response to subsequent exercises. However, the simultaneous combination (online) led to decreased performance related to the interference mechanism. Therefore, considering the priming mechanism by occupational therapists can significantly facilitate improvement in motor performance.