Developing and Applying a QEEG-Informed Transcranial Electrical Stimulation Protocol to Remediate Stuttering in Adults Who Stutter

Authors

  • Masoumeh Bayat Geriatric Mental Health Research Center, School of Behavioral Sciences and Mental Health, Iran University of Medical Sciences, Tehran, Iran
  • Reza Boostani Head of Biomedical Engineering Group, Faculty of Electrical and Computer Engineering, Shiraz University, Shiraz, Iran.
  • Mohammadreza Pirmoradi Department of Clinical Psychology, School of Behavioral Sciences and Mental Health, Iran University of Medical Sciences, Tehran, Iran
  • Malihe Sabeti Department of Computer Engineering, Islamic Azad University, North-Tehran Branch, Tehran, Iran
  • Fariba Yadegari Department of Speech and Language Pathology, University of Social Welfare and Rehabilitation Sciences, Tehran, Iran
  • Niloofar Fallahinia Research Center for Bhavioral and Cognitive Sciences, Tehran University of Medical Sciences
  • Mohammad Nami Department of Neuroscience, School of Advanced Medical Sciences and Technologies, Shiraz University of Medical Sciences, Shiraz, Iran

DOI:

https://doi.org/10.15540/nr.13.1.20

Keywords:

QEEG, stuttering, individualized tDCS, power spectrum, phase coherence

Abstract

Introduction. This study investigated whether personalized transcranial direct current stimulation (tDCS) protocols informed by quantitative EEG (qEEG) patterns could enhance treatment outcomes in adults who stutter (AWS), addressing individual variability in neural activity. Methods. Twenty male AWS participated in a double-blind, randomized controlled trial. EEG signals were recorded during speech tasks to differentiate neural substrates of fluent and stuttered speech. Over 10 days, participants received 10 sessions of speech therapy combined with tDCS. The experimental group received personalized tDCS (2 mA for 25 min per session) targeting regions identified through qEEG, while the control group received standard stimulation over FC5. Behavioral outcomes (SSI-4 scores) and EEG metrics were compared pretreatment, posttreatment, and at 3-month follow-up using repeated-measures ANOVA. Results. Both groups exhibited significant reductions in stuttering severity posttreatment. However, the study group maintained greater fluency at follow-up (p < .001). EEG analysis revealed that the study group demonstrated enhanced delta power in the FC5, reduced phase coherence in motor-auditory-somatosensory networks, and greater suppression of high-frequency bands in the personalized group. Conclusion. Personalized, qEEG-informed tDCS protocols yielded more sustainable fluency improvements than conventional tDCS, highlighting the potential of individualized neuromodulation strategies for treating stuttering.

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2026-03-31

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Copyright (c) 2026 Masoumeh Bayat, Reza Boostani, Mohammadreza Pirmoradi, Malihe Sabeti, Fariba Yadegari, Niloofar Fallahinia, Mohammad Nami

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