Efficacy of High-Frequency Repetitive Transcranial Magnetic Stimulation (HF-rTMS) as an Adjunct to AI-Enabled Remediation in Children with Dyslexia: Effects on Reading Outcomes, Cortical Excitability, and Functional Network Reorganization in an Ambispective Quasi-Experimental Study
DOI: Pending DOI
Synopsis
Developmental dyslexia often shows incomplete response to conventional remediation, prompting exploration of adjunctive neuromodulatory approaches. This ambispective quasi-experimental study evaluated the efficacy of high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) with AI-enabled remediation in children with dyslexia. Sixty children (6–18 years) received AI-based remedial intervention with three cycles of 5-Hz HF-rTMS targeting key nodes of the dorsal reading network. Significant improvements were observed in reading and phonological processing with sustained benefits up to 24 weeks. Neurophysiological measures showed modulation of cortical excitability, while functional MRI demonstrated increased left-lateralization of language networks. These findings suggest HF-rTMS as a promising adjunct to improve remediation outcomes in dyslexia.
Background
In view of incomplete response to conventional remediation in children with dyslexia, our study aimed to evaluate role of High-Frequency Repetitive Transcranial Magnetic Stimulation (HF-rTMS) as adjunct to AI-enabled remedial intervention (RI) in improving reading abilities. The primary objective was to assess efficacy and compare outcomes with a historical cohort receiving AI-enabled RI alone. Secondary objectives included evaluating persistence of effects at 24 weeks, adverse events, caregiver-reported improvements, and changes in cortical excitability (CE) parameters and functional brain networks on functional MRI during resting-state networks and phonological tasks.
Methods
This ambispective quasi-experimental study (January 2023–January 2025) included children aged 6–18 years with DSM-5–defined dyslexia. Participants received 6 weeks of AI-enabled remediation and 12 weeks of 5-Hz HF-rTMS (three cycles administered 6 weeks apart) targeting P3 (left inferior parietal lobule) and P5 (left superior temporal gyrus).
Assessments included Grade Level Assessment Device (GLAD), Comprehensive Test of Phonological Processing-2 (CTOPP-2), Wide Range Achievement Test-5 (WRAT-5), adverse events monitoring; parent and teacher reported CGI-c (caregiver impression of global change scale) at baseline, 6, 12, and 24 weeks. Cortical excitability parameters—resting motor threshold (RMT), motor evoked potential (MEP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI)—were measured at baseline, 6, 12, and 24 weeks. Resting-state and task-based fMRI were performed in a subset (n = 12) at baseline and 12 weeks.
Results
Sixty children enrolled (mean age 12.31 years, 76.6% males); of whom 55 completed study. Significant improvements observed over baseline at 6 and 12 weeks in mean GLAD scores (baseline-27.15±12.89, 6 week-33.75±13.59, 12 weeks-39.19±15.77 respectively; p<0.001), mean WRAT-5 reading composite scores (baseline-64.20±6.34, 6weeks-67.55±6.48, 12weeks-68.29±6.42 respectively; p<0.001), and all components of CTOPP-2 scores (p<0.001). Compared with the historical cohort (n = 28) that received AI-enabled remedial intervention alone, significant differences emerged at 12 weeks, particularly in GLAD (p < 0.001), WRAT-5 spelling (p = 0.043), and CTOPP-2 phonological awareness composite score (PACS) (p = 0.038). HF-rTMS was well-tolerated with persistence of effect observed at 24 weeks (3 months post intervention).
CE parameters at baseline showed elevated mean RMT of 67.38 ± 17.39, high median (IQR) MEP amplitude of 808 (310–1760), SICI 20.28% (18–24), and LICI 1.7 (1.05–3.22), indicating reduced CE with inefficient network activation. Post intervention RMT increased significantly at 6 weeks (p=0.004), with non-significant trends toward reduced SICI and LICI. fMRI demonstrated increased left-lateralization of language networks, enhanced connectivity of language network with dorsal attention, visual and posterior cerebellar networks, and attenuation of maladaptive anterior cerebellar and insular hyperconnectivity postintervention (Figure 1). These findings correlated with sustained improvements in GLAD, WRAT-5, CTOPP-2 scores at 6, 12, and 24 weeks (p<0.001).
Discussion
Children in our cohort demonstrated severe baseline phonological and reading deficits consistent with established models of dyslexia. Adjunctive HF-rTMS combined with AI-enabled remediation resulted in significant improvements in reading and phonological processing measures, with progressive gains across stimulation cycles and persistence of effects at 24 weeks. While short-term outcomes were comparable to those receiving AI-based remediation alone, significantly greater improvements emerged by 12 weeks in our cohort post-HF-rTMS, suggesting a delayed but additive neuromodulatory effect of rTMS. The intervention was well tolerated, with no serious adverse events. Neurophysiological findings demonstrated modulation of cortical excitability, while functional MRI suggested reorganization of reading-related networks, including increased left-lateralization of language circuits and enhanced integration with attention and visual networks. These changes parallel patterns observed in proficient readers and after successful remediation, supporting a neurobiological basis for the observed behavioural gains. To conclude, HF-rTMS appears to be a promising adjunct to AI-enabled remediation in children with dyslexia, enhancing reading outcomes with sustained benefits and demonstrating associated modulation of cortical excitability and functional language networks.
Disclosures
None
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