V5/MT Stimulation on Reading and Reading-related Measures in Developmental Dyslexia

Summary

The present study grounds on the absence of evidence-based treatment in individuals with developmental dyslexia (DD). At this topic, the present study will explore the potential effect of transcranial direct current stimulation (tDCS) over left hemispheric direct Lateral Geniculate Nucleus (LGN)-V5/MT pathway, cerebral areas usually disrupted in individuals with DD.

The investigators hypothesized that active tDCS over V5/MT will boost reading skills in children and adolescents with DD. On the contrary, sham (placebo condition) tDCS over V5/MT or active (control condition) tDCS over V1 will not have significant effect in improving reading skills. Further, both active and sham tDCS will be safe and well tolerated.

Conditions

• Developmental Dyslexia

Interventions

DEVICE

Active HD-tDCS over V5/MT

For HD-tDCS a 4 × 1 montage (Kessler et al., 2013), small circular electrodes (diameter 1 cm) will be used with the anode placed centrally with a current intensity of 1 mA for a total of 20 minutes (30 s ramp up/down). Hereby, the anodal electrode modulates the excitability of the targeted area left V5/MT, whereas the other 4 electrodes return electrical currents that flow away from that area. V5/MT will be localised via published procedures and electrode's placement will be done according to the 10-20 International EEG 10-20 System for electrode placement.

DEVICE

Active HD-tDCS over V1

For HD-tDCS a 4 × 1 montage (Kessler et al., 2013), small circular electrodes (diameter 1 cm) will be used with the anode placed centrally with a current intensity of 1 mA for a total of 20 minutes (30 s ramp up/down). Hereby, the anodal electrode modulates the excitability of the targeted area left V1, whereas the other 4 electrodes return electrical currents that flow away from that area. V1 will be localised via published procedures and electrode's placement will be done according to the 10-20 International EEG 10-20 System for electrode placement.

DEVICE

Sham HD-tDCS over V5/MT or V1

Sham HD-tDCS will be delivered over left V5/MT or left V1. The same electrodes placement as well as the stimulation set-up will be used as in the active stimulation conditions, but the current will be applied for 30 s and will be ramped down (0 mA) during the rest of the session without the participants awareness. .

Sponsors & Collaborators

• Bambino Gesù Hospital and Research Institute

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

DOUBLE

Model

CROSSOVER

Eligibility

Min Age

8 Years

Max Age

13 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2023-09-01

Primary Completion

2026-08-31

Completion

2026-08-31

Countries

• Italy

Study Locations