TABLE 3.
TDCS studies in children and adolescents with dyslexia—Latest update on March 2022
| # | Author | Design (control condition) | N | Mean age ± SD [age range] | Target electrode site | Return electrode site/electrode size | Intensity | Duration | Polarity | Outcome measure | Major finding |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | Costanzo et al. (2016a) | RCT double blind (sham controlled) | 19 | 13.7 ± 2.4 [10–17] | Left parietotemporal (mid P7‐TP7) | Right parietotemporal/5 × 5 cm | 1 mA | 20 min (3 single sessions) | Anodal/cathodal | Reading abilities | Anodal left cathodal right temporoparietal tDCS improved reading accuracy. The reverse protocol decreased accuracy |
| 2 | Costanzo et al. (2016b) | RCT double blind (sham controlled) | 18 | 13.2 ± 2.6 [10–17] | Left parietotemporal (mid P7‐TP7) | Right parietotemporal/5 × 5 cm | 1 mA | 18 × 20 min | Anodal | Reading abilities | Reduced reading errors and increased reading speed after active tDCS vs sham up to 1 month |
| 3 | Costanzo et al. (2019) | RCT double blind (sham controlled) | 26 | 13.6 ± 2.4 [10–17] | Left parietotemporal (mid P7‐TP7) | Right parietotemporal/5 × 5 cm | 1 mA | 18 × 20 min | Anodal | Reading abilities | Improved non‐word and low frequency word reading after active tDCS vs sham up to 6 months |
| 4 | Rahimi et al. (2019a) | RCT single blind (sham controlled) | 17 | 10.35 ± 1.36 [9–12] |
|
Right shoulder/5 × 5 cm | 1 mA | 20 min (3 single sessions) | Anodal | Auditory processing and ERP correlates | Improved visual attention processing in active tDCS vs sham |
| 5 | Rahimi et al. (2019b) | RCT single blind (waitlist control) | 45 (tDCS group = 15) | Primary school age 2–5 grade [7–10] | Left dlPFC (F3) | NR/5 × 5 cm | 1.5 mA | 10 × 20 min (daily) | Anodal | Visual sustained attention | Left dlPFC tDCS Improved visual attention processing in active tDCS vs sham in children with a specific learning disorder |
| 6 | Lazzaro et al. (2021a) | RCT double blind (sham controlled) | 26 | 13.80 ± 2.3 [10.8–17.8] | Left TPJ (between P7‐TP7) | Right TPJ (between P8‐TP8)/5 × 5 cm | 1 mA | 18 × 20 min | Anodal/cathodal | Word and pseudoword reading | Anodal left cathodal right TPJ tDCS in the active group improved word reading fluency in dyslexia |
| 7 | Lazzaro et al. (2021b) | RCT single blind (no sham) | 10 | 13.89 ± 2.4 [10.8–16.7] | Left TPJ (between P7‐TP7) | Right TPJ (between P8‐TP8)/5 × 5 cm | 1 mA | 20 min (single session) | Anodal/cathodal | Word and pseudoword reading | Anodal left cathodal right TPJ improved text reading accuracy, word recognition, speed, motion perception, and modified attentional focusing |
Note: tDCS = transcranial direct current stimulation; RCT = randomized controlled trial; SD = standard deviation; ERP = event‐related potentials; dlPFC = dorsolateral prefrontal cortex; F3 = left dorsolateral prefrontal cortex; T3/T4 = left and right temporal cortex; P7 = left parietal‐temporal region; TP7 = left parietal‐central region; P8 = right parietal‐temporal region; TP8 = right parietal‐central region; STG = superior temporal gyrus; TPJ = temporoparietal junction.