Transcranial Direct Current Stimulation in the Treatment of Dyslexia.

Not Applicable

Completed

• Conditions: Dyslexia
• Interventions: Device: Active tDCS; Device: Sham tDCS

• Registration Number: NCT04244578
• Lead Sponsor: Bambino Gesù Hospital and Research Institute

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.

Study Timeline

• Study Start: 2016-05-01
• Study First Submitted: 2020-01-25
• Study First Submitted QC: 2020-01-25
• Study First Posted: 2020-01-28
• Primary Completion: 2020-09-01
• Study Completion: 2021-02-01
• Status Verified: 2021-07
• Last Update Submitted: 2021-07-19
• Last Update Posted: 2021-07-23

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 28

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;

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: CROSSOVER

Arm && Interventions

Group	Intervention	Description
Active-Sham tDCS	Active tDCS	Each tDCS sessions will be delivered for 5 days for a total of non consecutive two weeks. The first session will be active tDCS and two months after, a sham tDCS will follow.
Sham-Active tDCS	Sham tDCS	Each tDCS sessions (sham tDCS and active tDCS) will be delivered for 5 days for a total of non consecutive two weeks. The first session will be sham tDCS and two months after, an active tDCS will follow.
Active-Sham tDCS	Sham tDCS	Each tDCS sessions will be delivered for 5 days for a total of non consecutive two weeks. The first session will be active tDCS and two months after, a sham tDCS will follow.
Sham-Active tDCS	Active tDCS	Each tDCS sessions (sham tDCS and active tDCS) will be delivered for 5 days for a total of non consecutive two weeks. The first session will be sham tDCS and two months after, an active tDCS will follow.

Primary Outcome Measures

Name	Time	Method
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 Outcome Measures

Name	Time	Method
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.
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.
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.
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.
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.
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.
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.
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.

Trial Locations

Locations (1)

Bambino Gesù Hospital and Research Institute; 🇮🇹 Roma, Italy