Effects of transcranial direct current stimulation combined with speech therapy in two children with autism spectrum disorder: a clinical case series
DOI:
https://doi.org/10.17267/2965-3738bis.2025.e6422Keywords:
Autism Spectrum Disorder, Transcranial Direct Current Stimulation, Speech Therapy, Neuromodulation, Case SeriesAbstract
BACKGROUND: Transcranial direct current stimulation (tDCS) has shown promise as an adjunctive therapy for neurological and developmental conditions, including Autism Spectrum Disorder (ASD). OBJECTIVE: To describe the preliminary effects of a tDCS protocol combined with traditional speech therapy in two children with ASD. METHODS: This case series involved two male children aged 4-5 years diagnosed with ASD. A total of 30 tDCS sessions (1mA, 30 minutes each) were delivered over 10 weeks (CP5–Fp2 montage), combined with language-focused speech therapy. Parents completed the Social Responsiveness Scale (SRS-2) before and after the intervention. RESULTS: Quantitative improvements were observed in social cognition, communication, and motivation, alongside reductions in restrictive behaviors. Qualitative gains included enhanced verbal intention, vocabulary, sentence construction, and emotional regulation. CONCLUSION: These findings support the feasibility and potential therapeutic benefit of combining tDCS with speech therapy in young children with ASD, warranting further investigation in controlled trials.
Downloads
References
1. American Psychiatric Association. Diagnostic and statistical manual of mental disorders: DSM-5-TR. 5th ed. rev. Washington (DC): American Psychiatric Association Publishing; 2022.
2. Maenner MJ, Warren Z, Williams AR, Amoakohene E, Bakian AV, Bilder DA, et al. Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020. MMWR Surveill Summ. 2023;72(2):1–14. https://doi.org/10.15585/mmwr.ss7202a1
3. Organização Pan-Americana da Saúde (OPAS). Transtorno do espectro autista [Internet]. Brasília: OPAS. Available from: https://www.paho.org/pt/topicos/transtorno-do-espectro-autista
4. Brignell A, Chenausky KV, Song H, Zhu J, Suo C, Morgan AT. Communication interventions for autism spectrum disorder in minimally verbal children. Cochrane Database Syst Rev. 2018;(11):CD012324. https://doi.org/10.1002/14651858.CD012324.pub2
5. Yamada Y, Sumiyoshi T. Neurobiological Mechanisms of Transcranial Direct Current Stimulation for Psychiatric Disorders; Neurophysiological, Chemical, and Anatomical Considerations. Front Hum Neurosci. 2021;15:631838. https://doi.org/10.3389/fnhum.2021.631838
6. Yamada Y, Inagawa T, Yokoi Y, Shirama A, Sueyoshi K, Wada A, et al. Efficacy and Safety of Multi-Session Transcranial Direct Current Stimulation on Social Cognition in Schizophrenia: A Study Protocol for an Open-Label, Single-Arm Trial. J Pers Med. 2021;11(4):317. https://doi.org/10.3390/jpm11040317
7. Haouzi P, Sonobe T, Judenherc-Haouzi A. Developing effective countermeasures against acute hydrogen sulfide intoxication: challenges and limitations. Ann N Y Acad Sci. 2016;1374(1):29–40. https://doi.org/10.1111/nyas.13015
8. Salehinejad MA, Ghanavati E, Glinski B, Hallajian AH, Azarkolah A. A systematic review of randomized controlled trials on efficacy and safety of transcranial direct current stimulation in major neurodevelopmental disorders: ADHD, autism, and dyslexia. Brain Behav. 2022;12(9):e2724. https://doi.org/10.1002/brb3.2724
9. Zhou H, Xu Y, Chen L, Yuan J, Guan Z, Liang P. Transcranial direct current stimulation combined with language-cognitive training improves language and cognitive ability in children with language delay. Front Neurol. 2024;15:1412959. https://doi.org/10.3389/fneur.2024.1412959
10. Fregni F, El-Hagrassy MM, Pacheco-Barrios K, Carvalho S, Leite J, Simis M, et al. Evidence-based guidelines and secondary meta-analysis for the use of transcranial direct current stimulation in neurological and psychiatric disorders. Int J Neuropsychopharmacol. 2021;24(4):256–313. https://doi.org/10.1093/ijnp/pyaa051
11. Kang J, Hao P, Gu H, Liu Y, Li X, Geng X. Transcranial direct current stimulation modulate brain complexity and connectivity in children with autism spectrum disorder: insights from entropy analysis Can. Bioengineering (Basel). 2025;12(3):283. https://doi.org/10.3390/bioengineering12030283
12. Chen L, Du B, Li K, Li K, Hou T, Jia F, et al. The effect of tDCS on inhibitory control and its transfer effect on sustained attention in children with autism spectrum disorder: An fNIRS study. Brain Stimul. 2024;17(3):594–606. https://doi.org/10.1016/j.brs.2024.04.019
13. Nikolin S, Huggins C, Martin D, Alonzo A, Loo CK. Safety of repeated sessions of transcranial direct current stimulation: A systematic review. Brain Stimul. 2018;11(2):278–88. https://doi.org/10.1016/j.brs.2017.10.020
14. Krishnan C, Santos L, Peterson MD, Ehinger M. Safety of noninvasive brain stimulation in children and adolescents. Brain Stimul. 2015;8(1):76–87. https://doi.org/10.1016/j.brs.2014.10.012
15. Battisti A, Lazzaro G, Ursumando L, D’Aiello B, Zanna V, Costanzo F, et al. Examining tolerability, safety, and blinding in 1032 transcranial electrical stimulation sessions for children and adolescents with neuropsychiatric and neurodevelopmental disorders. Sci Rep. 2025;15(1):4560. https://doi.org/10.1038/s41598-025-88256-1
16. Mesulam MM, Rader BM, Sridhar J, Nelson MJ, Hyun J, Rademaker A, et al. Word comprehension in temporal cortex and Wernicke area: A PPA perspective. Neurology. 2019;92(3):e224–33. https://doi.org/10.1212/wnl.0000000000006788
17. Sparing R, Dafotakis M, Meister IG, Thirugnanasambandam N, Fink GR. Enhancing language performance with non-invasive brain stimulation--a transcranial direct current stimulation study in healthy humans. Neuropsychologia. 2008;46(1):261-8. https://doi.org/10.1016/j.neuropsychologia.2007.07.009
18. Flöel A, Rösser N, Michka O, Knecht S, Breitenstein C. Noninvasive brain stimulation improves language learning. J Cogn Neurosci. 2008;20(8):1415–22. Cited in: PMID: 18303984
19. Fiori V, Cipollari S, Di Paola M, Razzano C, Caltagirone C, Marangolo P. tDCS stimulation segregates words in the brain: evidence from aphasia. Front Hum Neurosci. 2013;7:269. https://doi.org/10.3389/fnhum.2013.00269
20. Schurz M, Radua J, Aichhorn M, Richlan F, Perner J. Fractionating theory of mind: a meta-analysis of functional brain imaging studies. Neurosci Biobehav Rev. 2014;42:9-34. https://doi.org/10.1016/j.neubiorev.2014.01.009
21. Hagoort P. The neurobiology of language beyond single-word processing. Science. 2019;366(6461):55-8. https://doi.org/10.1126/science.aax0289
22. Uddin LQ, Supekar K, Menon V. Reconceptualizing functional brain connectivity in autism from a developmental perspective. Front Hum Neurosci. 2013;7:458. https://doi.org/10.3389/fnhum.2013.00458
23. Hong SJ, Vos de Wael R, Bethlehem RAI, Lariviere S, Paquola C, Valk SL, et al. Atypical functional connectome hierarchy in autism. Nat Commun. 2019;10(1):1022. https://doi.org/10.1038/s41467-019-08944-1
Downloads
Published
Issue
Section
License
Copyright (c) 2025 Márcia Santos de Oliveira, Sofia Borba de Toledo Ferraz, Emanuelle Lacerda Pinto Barbosa, Hercílio Barbosa da Silva Júnior, Juliana Barbosa Goulardins
This work is licensed under a Creative Commons Attribution 4.0 International License.
This work is licensed under a Creative Commons Attribution 4.0 International License.
