## 4 Discussion
One of the most relevant differences between them both is their portability, as while rTMS requires that the subject stays still during the whole stimulation process, the tDCS allows freedom of movement and does not have any noise that may be disturbing when used with children [84; 85; 86; 87]. Both techniques seems to have beneficial effects in improving and accelerating rehabilitation results, when used as an adjuvant therapy [88; 86; 82; 83]. Specifically, tDCS has shown positive effects on paediatric brain damage in functions like balance, gait, and attention, when applied with an excitatory stimulation, with anodal tDCS [30; 46; 89]. tDCS's effects on UL function is still uncertain, as only two studies conducted a 10-session intervention with a cathodal approach, which achieved significant changes only in subjective UL function [47; 48]. Studies in other populations like stroke have presented positive results with anodal tDCS stimulation for UL rehabilitation, which seems more beneficial for UL function and daily living performance [20]. Combined protocols of tDCS and VR have been employed also in stroke, finding better results in dexterity, motor impairment, and quality of life, versus an intervention based on VR exclusively [90; 91; 92]. The main UL function variable, which was used to calculate the sample of our study, is a widely validated scale such as MA-2, evaluating range of movement, accuracy, dexterity, and fluency. This is complemented with an objective kinematic UL evaluation that will allow for the analysis of the velocity and duration of the movement and range of motion of the shoulder, elbow, and wrist providing a wide evaluation of motor performance. Both measures are complemented with a widely validated a test as BBT. One of the main goals of our study is to provide more evidence of the existing relation and functional connectivity between cognitive and motor brain networks and how protocols with direct influence in motor areas such as M1 may have direct cognitive effects that influence the functional improvement [37; 93]. An exhaustive neuropsychological evaluation to assess potential changes in cognitive functions will be applied. The Wechsler Intelligence Scale for Children V (WISC-V) [69] will serve as the cornerstone of our assessment, providing a detailed profile of intelligence across five cognitive domains: verbal comprehension, visuospatial ability, fluid reasoning, working memory, and processing speed. Complementing the WISC-V, the Beery-Buktenica Developmental Test of Visual-Motor Integration (Beery VMI) [70] will gauge visuomotor integration, a crucial skill in academic and daily activities, as the VR will be a key component of the rehabilitation program and might influence its performance. The neuropsychological battery for children (NEPSY-II) [40] will allow for domain-specific inquiries into attention, executive functions, language, and other cognitive faculties, facilitating a nuanced understanding of each child's cognitive profile and will allow for the identification of if there is a determinate profile that is more responsive to the therapy. Attentional capacities will be further explored through the Test for Everyday Attention for Children (TEA-Ch) [71], which probes the various facets of attention crucial for learning and social interactions. Additionally, the Verbal learning test for children Spain-Complutense (TAVECI) [72] will measure memory and learning, vital for academic success and daily life navigation. The Behaviour Rating Inventory for Executive Function 2 (BRIEF-2) [73] will provide insights into executive functions from the perspective of parents and teachers, offering a well-rounded view of the child's cognitive regulation in natural settings. To assess emotional and behavioural aspects, as our protocol may influence the frontal lobe and impact in emotional regulation, the use of the Evaluation System for children and adolescents (SENA) [74] will capture environmental feedback on a wide spectrum of emotional and conduct issues.