Effects of online tDCS and hf-tRNS on reading performance in children and adolescents with developmental dyslexia: a study protocol for a cross sectional, within-subject, randomized, double-blind, and sham-controlled trial.

Background: Developmental Dyslexia (DD) is a brain-based developmental disorder causing severe reading difficulties. The extensive data on the neurobiology of DD have increased interest in brain-directed approaches, such as transcranial direct current stimulation (tDCS), which have been proposed for DD. While positive outcomes have been observed, results remain heterogeneous. Various methodological approaches have been employed to address this issue. However, no studies have compared the effects of different transcranial electrical stimulation techniques (e.g., tDCS and transcranial random noise stimulation, tRNS), on reading in children and adolescents with DD. Methods: The present within-subject, double-blind, and sham-controlled trial aims to investigate the effects of tDCS and hf-tRNS on reading in children and adolescents with DD. Participants will undergo three conditions with a one-week interval session: (A) single active tDCS session; (B) single active hf-tRNS session; and (C) single sham session (tDCS/hf-tRNS). Left anodal/right cathodal tDCS and bilateral tRNS will be applied over the temporo-parietal regions for 20 min each. Reading measures will be collected before and during each session. Safety and blinding parameters will be recordered. Discussion: We hypothesize that tRNS will demonstrate comparable effectiveness to tDCS in improving reading compared to sham conditions. Additionally, we anticipate that hf-tRNS will exhibit a similar safety profile to tDCS. This study will contribute novel insights into the effectiveness of hf-tRNS, expediting the validation of brain-based treatments for DD.

Distance learning during COVID-19 lockdown: Impact on adolescents with specific learning disorders and their parents.

Background: The transition of teaching from in-person to Distance Learning (DL) due to the COVID-19 pandemic led to negative effects on students' psychological wellbeing and academic achievement. The worst consequences have been experienced by students with so-called special educational needs, as well as by their parents. However, very little emphasis has been placed on the effects of DL in students with Specific Learning Disorders (SLD). The present work aimed to evaluate the effects of DL during the COVID-19 lockdown in Italian students with SLD and in their parents. Methods: An online survey was administered to 92 students with SLD and their parents after the COVID-19 lockdown. The survey consisted of four sections: participants' demographic information; perceived stress related to general aspects (i.e., social and family determinants) as well as specific aspects related to DL; attitudes and feelings toward DL; and academic grades before and after DL. Results: Students with SLD perceived stress mainly from social isolation/distancing and DL (p always ≤ 0.0001), especially from online classes and oral exams (p always ≤ 0.0001). Students who did not benefit from appropriate accommodations (i.e., individualized teaching and learning methods) during DL perceived 3 times more DL-related stress than those who used them as in-person learning (OR = 3.00, CI 95%: 1.24-7.28, p = 0.015). Girls perceived more stress from online lessons (OR = 0.40, CI 95%: 0.16-0.96, p = 0.04) and use of devices (OR = 0.33, CI 95%: 0.14-0.80, p = 0.015) than boys. Negative feelings (less motivation, reduced ability to understand lessons, interact, and stay focused) and positive feelings (less anxiety and more self-confidence with its own rate of learning) toward DL emerged. Higher academic grades also was observed after DL (p ≤ 0.0001). Lastly, strong and positive correlations emerged between students' and parents' perceived stress during DL (p always < 0.001). Implications: The present study prompts special considerations for students with special educational needs not only when providing conventional instruction, but especially when it is necessary to suddenly modify teaching approaches.

Effects of a short and intensive transcranial direct current stimulation treatment in children and adolescents with developmental dyslexia: A crossover clinical trial.

Developmental Dyslexia (DD) significantly interferes with children's academic, personal, social, and emotional functioning. Nevertheless, therapeutic options need to be further validated and tested in randomized controlled clinical trials. The use of transcranial direct current stimulation (tDCS) has been gaining ground in recent years as a new intervention option for DD. However, there are still open questions regarding the most suitable tDCS protocol for young people with DD. The current crossover study tested the effectiveness of a short and intensive tDCS protocol, including the long-term effects, as well as the influence of age and neuropsychological processes at baseline on reading improvements. Twenty-four children and adolescents with DD were randomly assigned to receive active tDCS during the first slot and sham tDCS during the second slot or vice versa. Five consecutive daily sessions of left anodal/right cathodal tDCS set at 1 mA for 20 min were administered over the parieto-occipital regions. Reading measures (text, high frequency word, low frequency word, and non-word lists) and neuropsychological measures (visual-spatial and verbal working memory, phoneme blending, and rapid automatized naming tasks) were collected before, immediately after, 1 week and 1 month later the treatment. Our results showed that only the active tDCS condition improved non-word reading speed immediately after and 1 month later the end of the treatment compared with baseline. In addition, the improvement in non-word reading speed was significantly correlated with age and with neuropsychological measures (verbal working memory and phoneme blending) at baseline but only in the active tDCS condition. The current crossover study contributed to enforce previous effects of tDCS, including long-term effects, on non-word reading speed and to understand the effect of age and neuropsychological processes on reading outcomes. Our findings showed that tDCS could be a low-cost and easy-to-implement treatment option with long-term effects for children and adolescents with DD.

Sleep Disturbances in Children with Attentional Deficit Hyperactivity Disorder and Specific Learning Disorders.

Sleep disturbances may be a significant source of distress for children with neurodevelopmental disorders, and consequently also for their families. Crucially, sleep disturbances might be influenced by comorbidity. Attention deficit hyperactivity disorder (ADHD) and specific learning disorder (SLD) often co-occur, and consequently, investigating sleep disturbances in children with comorbidity of ADHD and SLD is essential. Our study aimed at detecting sleep difficulties in a group of 74 children with ADHD, 78 children with SLD, and 76 children with ADHD and SLD by using the Sleep Disturbances Scale for Children. The results showed that sleep difficulties emerge more clearly in children with comorbid ADHD and SLD compared to children with only ADHD or SLD. These sleep difficulties were not due to differences in ages and behavioral/emotional problems. In conclusion, evaluating sleep disturbances is important when assessing and managing children with ADHD, SLD, and particularly with the two comorbid conditions, to better understand their difficulties and develop tailored interventions.

Understanding the Effects of Transcranial Electrical Stimulation in Numerical Cognition: A Systematic Review for Clinical Translation.

Atypical development of numerical cognition (dyscalculia) may increase the onset of neuropsychiatric symptoms, especially when untreated, and it may have long-term detrimental social consequences. However, evidence-based treatments are still lacking. Despite plenty of studies investigating the effects of transcranial electrical stimulation (tES) on numerical cognition, a systematized synthesis of results is still lacking. In the present systematic review (PROSPERO ID: CRD42021271139), we found that the majority of reports (20 out of 26) showed the effectiveness of tES in improving both number (80%) and arithmetic (76%) processing. In particular, anodal tDCS (regardless of lateralization) over parietal regions, bilateral tDCS (regardless of polarity/lateralization) over frontal regions, and tRNS (regardless of brain regions) strongly enhance number processing. While bilateral tDCS and tRNS over parietal and frontal regions and left anodal tDCS over frontal regions consistently improve arithmetic skills. In addition, tACS seems to be more effective than tDCS at ameliorating arithmetic learning. Despite the variability of methods and paucity of clinical studies, tES seems to be a promising brain-based treatment to enhance numerical cognition. Recommendations for clinical translation, future directions, and limitations are outlined.

Gross, Fine and Visual-Motor Skills in Children with Language Disorder, Speech Sound Disorder and Their Combination.

Increasing evidence shows that children with Communication Disorders (CDs) may show gross, fine, and visual-motor difficulties compared to children with typical development. Accordingly, the present study aims to characterize gross, fine and visual-motor skills in children with CDs, distinguishing children with CDs into three subgroups, i.e., with Language Disorders (LD), Speech Sound Disorders (SSD), and LD + SSD. In Experiment 1, around 60% of children with CDs (4 to 7 years; 21 with LD, 36 with SSD, and 90 with LD + SSD) showed clinical/borderline scores in balance skills, regardless of the type of communication deficit. However, children with LD, SSD, and LD + SSD did not differ in gross and fine motor skills. In Experiment 2, a higher percentage of children with CDs (4 to 7 years; 34 with LD, 62 with SSD, 148 with LD + SSD) obtained clinical/borderline scores in Visual Perception skills. Moreover, children with LD + SSD performed significantly worsen in Visual Perception and Fine Motor Coordination skills compared to children with SSD only. Our results underlined that CDs are generally associated with gross motor difficulties and that visual-motor difficulties are related to the type of communication deficit. Paying earlier attention to the motor skills of children with CDs could help clinicians design effective interventions.

Boosting Numerical Cognition in Children and Adolescents with Mathematical Learning Disabilities by a Brain-Based Intervention: A Study Protocol for a Randomized, Sham-Controlled Clinical Trial.

Numbers are everywhere, and supporting difficulties in numerical cognition (e.g., mathematical learning disability (MLD)) in a timely, effective manner is critical for their daily use. To date, only low-efficacy cognitive-based interventions are available. The extensive data on the neurobiology of MLD have increased interest in brain-directed approaches. The overarching goal of this study protocol is to provide the scientific foundation for devising brain-based and evidence-based treatments in children and adolescents with MLD. In this double-blind, between-subject, sham-controlled, randomized clinical trial, transcranial random noise stimulation (tRNS) plus cognitive training will be delivered to participants. Arithmetic, neuropsychological, psychological, and electrophysiological measures will be collected at baseline (T0), at the end of the interventions (T1), one week (T2) and three months later (T3). We expect that tRNS plus cognitive training will significantly improve arithmetic measures at T1 and at each follow-up (T2, T3) compared with placebo and that such improvements will correlate robustly and positively with changes in the neuropsychological, psychological, and electrophysiological measures. We firmly believe that this clinical trial will produce reliable and positive results to accelerate the validation of brain-based treatments for MLD that have the potential to impact quality of life.

Effects of a short, intensive, multi-session tDCS treatment in developmental dyslexia: Preliminary results of a sham-controlled randomized clinical trial.

Developmental Dyslexia (DD) significantly interferes with academic, personal, social and emotional functioning. Nevertheless, established therapeutic options are still scarce. Research has begun to emerge studying the potential action of transcranial direct current stimulation (tDCS) for ameliorating reading. However, there are still open questions regarding the most suitable tDCS protocol in young with DD. The current study tested the effectiveness of a short, intensive and multi-session tDCS protocol and presented preliminary data from a randomized sham-controlled crossover trial. Twenty-seven children and adolescents with DD were randomly assigned to active tDCS or sham tDCS. Active tDCS group received five daily-consecutive sessions of left anodal/right cathodal set at 1mA for 20min over parieto-occipital regions. Reading measures, including text, high frequency word, low frequency word and non-word lists, were recorded before, immediately after the treatment and 1-week later. We found that only the active tDCS group ameliorated non-word reading speed immediately after and 1-week later the end of the treatment compared to the baseline. Some suggestions for the development of future tDCS protocols in children and adolescents with DD are given.

Beyond Reading Modulation: Temporo-Parietal tDCS Alters Visuo-Spatial Attention and Motion Perception in Dyslexia.

Dyslexia is a neurodevelopmental disorder with an atypical activation of posterior left-hemisphere brain reading networks (i.e., temporo-occipital and temporo-parietal regions) and multiple neuropsychological deficits. Transcranial direct current stimulation (tDCS) is a tool for manipulating neural activity and, in turn, neurocognitive processes. While studies have demonstrated the significant effects of tDCS on reading, neurocognitive changes beyond reading modulation have been poorly investigated. The present study aimed at examining whether tDCS on temporo-parietal regions affected not only reading, but also phonological skills, visuo-spatial working memory, visuo-spatial attention, and motion perception in a polarity-dependent way. In a within-subjects design, ten children and adolescents with dyslexia performed reading and neuropsychological tasks after 20 min of exposure to Left Anodal/Right Cathodal (LA/RC) and Right Anodal/Left Cathodal (RA/LC) tDCS. LA/RC tDCS compared to RA/LC tDCS improved text accuracy, word recognition speed, motion perception, and modified attentional focusing in our group of children and adolescents with dyslexia. Changes in text reading accuracy and word recognition speed-after LA/RC tDCS compared to RA/LC-were related to changes in motion perception and in visuo-spatial working memory, respectively. Our findings demonstrated that reading and domain-general neurocognitive functions in a group of children and adolescents with dyslexia change following tDCS and that they are polarity-dependent.

Memory Deficits in Children with Developmental Dyslexia: A Reading-Level and Chronological-Age Matched Design.

Developmental Dyslexia (DD) is considered a multifactorial deficit. Among the neurocognitive impairments identified in DD, it has been found that memory plays a particularly important role in reading and learning. The present study aims to investigate whether short-term memory (STM) and long-term memory (LTM) deficits could be related to poor reading experience or could be causal factors in DD. To verify that memory deficits in DD did not simply reflect differences in reading experience, 16 children with DD were not only compared to 16 chronological age-matched children (CA) but also to 16 reading level-matched children (RL) in verbal, visual-object, and visual-spatial STM and LTM tasks. Children with DD performed as well as RL, but worse than CA in all STM tasks. Considering LTM, the three groups did not differ in Visual-Object and Visual-Spatial Learning tasks. In the Verbal LTM task, DD recalled significantly fewer words than CA but not RL, while CA and RL showed a similar performance. The present results suggest that when reading experience was equated, children with DD and typical readers did not differ in STM and LTM, especially in the verbal modality, weakening claims that memory has a causal effect in reading impairments.

Long-lasting improvement following tDCS treatment combined with a training for reading in children and adolescents with dyslexia.

Noninvasive brain stimulation transiently modulates reading ability in individuals with dyslexia by facilitating the underactive neural pathways in them. However, its long-term effects have not been determined. This study confirmed the ameliorative effects of multiple sessions of transcranial direct current stimulation (tDCS) combined with a training for reading on the reading abilities of children and adolescents with dyslexia and examined whether they are long-lasting. Twenty-six children and adolescents with dyslexia received 3 20-min sessions per week for 6 weeks (18 sessions) of left anodal/right cathodal tDCS, set to 1 mA, over the parieto-temporal regions, combined with training for reading. The participants were randomly assigned to receive active or sham treatment. Reading measures (text, high- and low-frequency words, non-words) were recorded before and immediately after the treatment and 1 and 6 months later. The long-term tolerability to tDCS was also evaluated. The active group received long-lasting benefits in reading. Specifically, the non-word reading efficiency index improved at every time point, as did the low-frequency word reading efficiency index at 1 and 6 months after the end of the treatment. No differences emerged in the sham group. No long-term adverse effects were documented. This study provides evidence of persistent improvements in reading in children and adolescents with dyslexia, constituting a new rehabilitative approach for the remediation of dyslexia.

New Treatment Perspectives in Adolescents With Anorexia Nervosa: The Efficacy of Non-invasive Brain-Directed Treatment.

Poor treatment outcomes are available for anorexia nervosa (AN) and treatment innovations are urgently needed. Recently, non-invasive neuromodulation tools have suggested to have potential for reducing an symptomatology targeting brain alterations. The objective of the study was to verify whether left anodal/right cathodal prefrontal cortex transcranial direct current stimulation (tDCS), may aid in altering/resetting inter-hemispheric balance in patients with AN, re-establishing control over eating behaviors. Twenty-three adolescents with an underwent a treatment as usual (AU), including nutritional, pharmacological, and psychoeducational treatment, plus 18 sessions of tDCS (TDCS+AU = n11; mean age = 13.9, SD = 1.8 years) or a family based therapy (FBT+AU = n12, mean age = 15.1, SD = 1.5 years). Psychopathological scales and the body mass index (BMI) were assessed before and after treatment. After 6 weeks of treatment, the BMI values increased only in the tDCS group, even at 1-month follow-up. Independently of the treatment, all participants improved in several psychopathological measures, included AN psychopathology and mood and anxiety symptoms. Our results demonstrated for the first time a specific effect of the left anodal/right cathodal tDCS treatment protocol on stable weight gain and a superiority compared to an active control treatment for adolescents with AN. Results were interpreted as a possible direct/indirect effect of tDCS in into some pathophysiological mechanisms of AN, involving the mesocortical dopaminergic pathways and the promotion of food intake. This pilot study opens new perspectives in the treatment of an in adolescence, supporting the targeted and beneficial effects of a brain-based treatment.

Reading changes in children and adolescents with dyslexia after transcranial direct current stimulation.

Noninvasive brain stimulation offers the possibility to induce changes in cortical excitability and it is an interesting option as a remediation tool for the treatment of developmental disorders. This study aimed to investigate the effect of transcranial direct current stimulation (tDCS) on reading and reading-related skills of children and adolescents with dyslexia. Nineteen children and adolescents with dyslexia performed different reading and reading-related tasks (word, nonword, and text reading; lexical decision; phonemic blending; verbal working memory; rapid automatized naming) in a baseline condition without tDCS and after 20 min of exposure to three different tDCS conditions: left anodal/right cathodal tDCS to enhance left lateralization of the parietotemporal region, right anodal/left cathodal tDCS to enhance right lateralization of the parietotemporal region, and sham tDCS. In text reading, results showed a significant reduction in errors after left anodal/right cathodal tDCS and an increase in errors after left cathodal/right anodal tDCS. No effect was found in the other reading and reading-related tasks. Our findings indicate for the first time that one session of tDCS modulates some aspects of reading performance of children and adolescents with dyslexia and that the effect is polarity dependent. These single-session results support a potential role of tDCS for developing treatment protocols and suggest possible parameters for tDCS treatment customization in children and adolescents with dyslexia.

Evidence for reading improvement following tDCS treatment in children and adolescents with Dyslexia.

PURPOSE: There is evidence that non-invasive brain stimulation transitorily modulates reading by facilitating the neural pathways underactive in individuals with dyslexia. The study aimed at investigating whether multiple sessions of transcranial direct current stimulation (tDCS) would enhance reading abilities of children and adolescents with dyslexia and whether the effect is long-lasting. METHODS: Eighteen children and adolescents with dyslexia received three 20-minute sessions a week for 6 weeks (18 sessions) of left anodal/right cathodal tDCS set at 1 mA over parieto-temporal regions combined with a cognitive training. The participants were randomly assigned to the active or the sham treatment; reading tasks (text, high and low frequency words, non-words) were used as outcome measures and collected before treatment, after treatment and one month after the end of treatment. The tolerability of tDCS was evaluated. RESULTS: The active group showed reduced low frequency word reading errors and non-word reading times. These positive effects were stable even one month after the end of treatment. None reported adverse effects. CONCLUSIONS: The study shows preliminary evidence of tDCS feasibility and efficacy in improving non-words and low frequency words reading of children and adolescents with dyslexia and it opens new rehabilitative perspectives for the remediation of dyslexia.

Writing abilities in intellectual disabilities: a comparison between Down and Williams syndrome.

Writing is a complex task that requires the integration of multiple cognitive, linguistic, and motor abilities. Until now, only a few studies investigated writing abilities in individuals with Intellectual Disability (ID). The aim of the present exploratory study was to provide knowledge on the organization of writing in two populations with ID, Down syndrome (DS) and Williams syndrome (WS), trying to disentangle different components of the process. A battery tapping diverse writing demands as low-level transcription skills as well as high-level writing skills was proposed to 13 individuals with WS, 12 individuals with DS and 11 mental-age-matched typically developing (TD) children. Results showed that the two groups with genetic syndromes did not differ from TD in writing a list of objects placed in bedroom, in the number of errors in the text composition, in a text copying task and in kind of errors made. However, in a word dictation task, individuals with DS made more errors than individuals with WS and TD children. In a pseudoword dictation task, both individuals with DS and WS showed more errors than TD children. Our results showed good abilities in individuals with ID in different aspects of writing, involving not only low-level transcription skills but also high-level composition skills. Contrary to the pessimistic view, considering individuals with ID vulnerable for failure, our results indicate that the presence of ID does not prevent the achievement of writing skills.

Executive functions in developmental dyslexia.

The present study was aimed at investigating different aspects of Executive Functions (EF) in children with Developmental Dyslexia (DD). A neuropsychological battery tapping verbal fluency, spoonerism, attention, verbal shifting, short-term and working memory was used to assess 60 children with DD and 65 with typical reading (TR) abilities. Compared to their controls, children with DD showed deficits in several EF domains such as verbal categorical and phonological fluency, visual-spatial and auditory attention, spoonerism, verbal and visual short-term memory, and verbal working memory. Moreover, exploring predictive relationships between EF measures and reading, we found that spoonerism abilities better explained word and non-word reading deficits. Although to a lesser extent, auditory and visual-spatial attention also explained the increased percentage of variance related to reading deficit. EF deficits found in DD are interpreted as an expression of a deficient functioning of the Central Executive System and are discussed in the context of the recent temporal sampling theory.

Executive functions in intellectual disabilities: a comparison between Williams syndrome and Down syndrome.

Executive functions are a set of high cognitive abilities that control and regulate other functions and behaviors and are crucial for successful adaptation. Deficits in executive functions are frequently described in developmental disorders, which are characterized by disadaptive behavior. However, executive functions are not widely examined in individuals with intellectual disability. The present study is aimed at evaluating the etiological specificity hypotheses pertaining to executive functions by comparing individuals with intellectual disability of different etiology, as Williams syndrome and Down syndrome, on different aspects of executive functions. To this aim a battery evaluating attention, short-term and working memory, planning, categorization, shifting and inhibition, was administered to 15 children, adolescents and adults with Williams syndrome, to 15 children, adolescents and adults with Down syndrome and to 16 mental-age-matched typically developing children. The two groups with intellectual disability showed impairment in a set of executive functions, as auditory sustained attention, visual selective attention, visual categorization and working memory, and preserved visual sustained attention, auditory selective attention and visual inhibition. However, a distinctive profile has been found between the two syndromic groups on other executive functions. While participants with Down syndrome were poor in shifting and verbal aspects of memory and inhibition, those with Williams syndrome were poor in planning. The specific weakness and straights on executive functions may support the etiological specificity hypothesis accounting for distinctive cognitive development syndrome-specific.

Cochlear implant in the second year of life: lexical and grammatical outcomes.

PURPOSE: The authors studied the effect of the cochlear implant (CI) on language comprehension and production in deaf children who had received a CI in the 2nd year of life. METHOD: The authors evaluated lexical and morphosyntactic skills in comprehension and production in 17 Italian children who are deaf (M = 54 months of age) with a CI and in 2 control groups of children with normal hearing (NH; 1 matched for chronological age and the other whose chronological age corresponded to the duration of CI activation). The authors also compared children with unilateral CI to children with bilateral CI. RESULTS: Children with CI appeared to keep pace with NH children matched for time since CI activation in terms of language acquisition, and they were similar to same-age NH children in lexical production. However, children with CI showed difficulties in lexical comprehension when a task required phonological discrimination as well as in grammar comprehension and production. Children with bilateral CI showed better comprehension than did children with unilateral CI; the 2 groups were similar for production. CONCLUSIONS: Activation of CI in the 2nd year of life may provide children who are deaf with a good opportunity to develop language skills, although some limitations in phonological and morphological skills are still present 3 years after auditory reafferentation.