Dyslexia
Conditions
Keywords
tDCS, transcranial direct current stimulation, transcranial electric stimulation, developmental dyslexia, specific learning disorders, treatment
Brief summary
The present study grounds on the absence of evidence-based treatment in individuals with dyslexia. At this topic, the present study will explore the potential effect of transcranial direct current stimulation (tDCS) over parieto-occipital brain regions, cerebral areas usually disrupted in individuals with dyslexia. tDCS will be administered without concomitantly training. Therefore, the investigators hypothesized that active tDCS over parieto-occipital areas will enhance reading skills in children and adolescents with dyslexia. On the contrary, sham tDCS (placebo) over parieto-occipital areas will not have significant effect on reading. Further, both active and sham tDCS will be safe and well-tolerated.
Detailed description
The study design is randomized stratified, cross-over, double-blind, placebo-controlled. Children and adolescents with dyslexia will be selected and randomly assigned to two different groups: 1. Active tDCS over parieto-occipital areas + sham tDCS over parieto-occipital areas (Active-Sham tDCS); 2. Sham tDCS over parieto-occipital areas + active tDCS over parieto-occipital areas (Sham-Active tDCS). In this project, the investigators will work to understand whether a brain-based intervention, with the use of tDCS without combined training, can enhance reading in individuals with dyslexia. The protocol will allow the investigators to: 1. Testing the efficacy of stand-alone tDCS in enhancing reading in individuals with dyslexia; 2. Testing the critical role of brain regions (parieto-occipital areas) usually involved in reading and disrupted in dyslexia; 3. Predicting outcomes based on reading-related skills; 4. Investigating the safety and tolerability of tDCS; The overarching goal is to provide a scientific foundation for devising new rehabilitation strategies in dyslexia.
Interventions
DEVICEActive tDCS
Active tDCS will be delivered to parieto-occipital areas for five consecutive days. tDCS will be delivered by a battery driven, direct current stimulator through a pair of saline-soaked sponge electrodes kept firm by elastic bands. The electrodes will be placed on the left (anodal) and right (cathodal) parieto-occipital areas, PO7 and PO8 position according to the 10-20 international EEG system for electrode placement. Stimulation intensity will be set at 1 milliampere (mA), the duration of stimulation will be 20 min.
DEVICESham tDCS
Sham tDCS will be delivered to parieto-occipital areas for five consecutive days. tDCS will be delivered by a battery driven, direct current stimulator through a pair of saline-soaked sponge electrodes kept firm by elastic bands. The electrodes will be placed on the left (anodal) and right (cathodal) parieto-occipital areas, PO7 and PO8 position according to the 10-20 international EEG system for electrode placement. Stimulation intensity will be set at 1 milliampere (mA), but the current will be applied for 30 s and will be ramped down without the participants awareness.
Sponsors
Bambino Gesù Hospital and Research Institute
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
TREATMENT
Masking
TRIPLE (Subject, Caregiver, Outcomes Assessor)
Eligibility
Sex/Gender
ALL
Age
9 Years to 18 Years
Healthy volunteers
No
Inclusion criteria
* Children and adolescents with dyslexia (DSM-5, APA 2013) * IQ ≥ 85
Exclusion criteria
* Having a comorbidity with an important medical conditions; * Having neurological diseases; * Having Epilepsy o family history of epilepsy; * Receiving a treatment for dyslexia in the previous three months before the baseline screening;
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Non-word reading speed | up to one month after the end of the intervention | The proportion of patients with change of at least 0.06 sill/sec in the non-word reading speed following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Word reading speed | up to one month after the end of the intervention | The proportion of patients with change in the word reading speed following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Word reading accuracy | up to one month after the end of the intervention | The proportion of patients with change in the word reading accuracy following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Text reading speed | up to one month after the end of the intervention | The proportion of patients with change in the text reading speed following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Text reading accuracy | up to one month after the end of the intervention | The proportion of patients with change in the text reading accuracy following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Non-word reading accuracy | up to one month after the end of the intervention | The proportion of patients with change in the non-word reading accuracy following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Phoneme Blending | up to one month after the end of the intervention | The proportion of patients with change in the index of phoneme blending (more score means better outcome) following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Rapid Automatized Naming of color and letters | up to one month after the end of the intervention | The proportion of patients with change in the accuracy and speed of Rapid Automatized Naming of color and letters following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Lexical Decision | up to one month after the end of the intervention | The proportion of patients with change in the accuracy and speed of Lexical decision following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Questionnaire of safety and tolerability (Questionnaire of adverse effect) | up to one month after the end of the intervention | The proportion of patients with change in the questionnaire of safety and tolerability (Questionnaire of adverse effect; Brunoni et al., 2011) following Active tDCS sessions will be the same than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
| Verbal and visuo-spatial n-back | up to one month after the end of the intervention | The proportion of patients with change in the index of verbal and visuo-spatial working memory (more score means better outcome) following Active tDCS sessions than after Sham tDCS sessions both in ActiveSham tDCS and ShamActive tDCS. |
Countries
Italy
Outcome results
None listed