EEG-defined differences in functional networks following beta-band transcranial alternating current stimulation in patients with disorders of consciousness: a pilot study.
- 1Department of Rehabilitation, The Second Qilu Hospital of Shandong University, 247 Beiyuan Avenue, Jinan, 250033, Shandong, China.
- 2Department of Rehabilitation, The Second Qilu Hospital of Shandong University, 247 Beiyuan Avenue, Jinan, 250033, Shandong, China. [email protected].
Abstract
Background
Severe disruption of cortico-thalamocortical circuits underlies disorders of consciousness (DOC). Beta-band (20 Hz) transcranial alternating current stimulation (tACS) can be used to probe frontal oscillatory synchrony, yet its potential to acutely modulate large-scale network dynamics in DOC is unknown.Methods
We applied 20 Hz tACS (1 mA) for 30 min over the frontal cortex (F3 and F4, International 10-20 system) in 28 patients with DOC. Offline functional near-infrared spectroscopy (fNIRS) was used to quantify hemoglobin (HbO)-based functional connectivity (FC) and graph-theoretical network properties, including small-world properties (clustering coefficient, Cp; path length, Lp) and global efficiency (global efficiency, Eg; local efficiency, Eloc) at pre-stimulation resting-state measurement for 5 min (pre-stim), the first post-stimulation resting-state measurement for 5 min (post-stim1), and the second post-stimulation resting-state measurement for 5 min (post-stim2). Subgroups were defined by baseline video-electroencephalography (vEEG) pathology as moderately abnormal (n = 11) and diffuse slowing (n = 14); 3 patients excluded (incomplete vEEG).Results
Frontal 20 Hz tACS was associated with transient enhancement of FC across the measured cortical network at post-stim1 (pFDR < 0.05), selectively strengthening intra-and interhemispheric and intra-nodal connectivity before resolving by post-stim2. Crucially, the effects were pathology-dependent, and visual-motor integration pathways (right occipital lobe to left motor cortex; right primary somatosensory cortex to left occipital lobe) emerged exclusively in DOC patients with moderately abnormal background but not in those with diffuse slowing. Concurrent acute network reorganization at post-stim1 (all p < 0.05) featured increased Cp, Eg, and Eloc, along with decreased Lp, all normalizing by post-stim2. Clinically, Coma Recovery Scale-Revised scores correlated positively with average FC of HbO (pre-stim: r = 0.47; post-stim2: r = 0.41) and Area Under the Curve (AUC) of Eg (pre-stim: r = 0.44), and negatively with AUC of Lp (pre-stim: r = - 0.41; all p < 0.05).Conclusions
Frontal beta-tACS was associated with state-dependent changes in functional network organization in DOC, with dynamic fNIRS measures that may be useful for tracking these changes. These findings provide preliminary descriptive evidence of short-term network changes associated with beta-tACS and may help guide future controlled studies of targeted neuromodulation in patients with DOC.
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BibTeX
@article{qu2026eegdefined,
title = {{EEG-defined differences in functional networks following beta-band transcranial alternating current stimulation in patients with disorders of consciousness: a pilot study.}},
author = {Sheng Qu and Laigang Huang and Jingjing Shang and Yanqi Qiao and Qiangsan Sun and Fanshuo Zeng},
journal = {Journal of neuroengineering and rehabilitation},
year = {2026},
month = jul,
doi = {10.1186/s12984-026-02102-7},
url = {https://europepmc.org/article/MED/42902320},
note = {CC BY-NC-ND},
}
RIS
TY - JOUR
TI - EEG-defined differences in functional networks following beta-band transcranial alternating current stimulation in patients with disorders of consciousness: a pilot study.
AU - Sheng Qu
AU - Laigang Huang
AU - Jingjing Shang
AU - Yanqi Qiao
AU - Qiangsan Sun
AU - Fanshuo Zeng
PY - 2026
DA - 2026/07/01
JO - Journal of neuroengineering and rehabilitation
DO - 10.1186/s12984-026-02102-7
UR - https://europepmc.org/article/MED/42902320
AB - Background Severe disruption of cortico-thalamocortical circuits underlies disorders of consciousness (DOC). Beta-band (20 Hz) transcranial alternating current stimulation (tACS) can be used to probe frontal oscillatory synchrony, yet its potential to acutely modulate large-scale network dynamics in DOC is unknown.Methods We applied 20 Hz tACS (1 mA) for 30 min over the frontal cortex (F3 and F4, International 10-20 system) in 28 patients with DOC. Offline functional near-infrared spectroscopy (fNIRS) was used to quantify hemoglobin (HbO)-based functional connectivity (FC) and graph-theoretical network properties, including small-world properties (clustering coefficient, Cp; path length, Lp) and global efficiency (global efficiency, Eg; local efficiency, Eloc) at pre-stimulation resting-state measurement for 5 min (pre-stim), the first post-stimulation resting-state measurement for 5 min (post-stim1), and the second post-stimulation resting-state measurement for 5 min (post-stim2). Subgroups were defined by baseline video-electroencephalography (vEEG) pathology as moderately abnormal (n = 11) and diffuse slowing (n = 14); 3 patients excluded (incomplete vEEG).Results Frontal 20 Hz tACS was associated with transient enhancement of FC across the measured cortical network at post-stim1 (pFDR < 0.05), selectively strengthening intra-and interhemispheric and intra-nodal connectivity before resolving by post-stim2. Crucially, the effects were pathology-dependent, and visual-motor integration pathways (right occipital lobe to left motor cortex; right primary somatosensory cortex to left occipital lobe) emerged exclusively in DOC patients with moderately abnormal background but not in those with diffuse slowing. Concurrent acute network reorganization at post-stim1 (all p < 0.05) featured increased Cp, Eg, and Eloc, along with decreased Lp, all normalizing by post-stim2. Clinically, Coma Recovery Scale-Revised scores correlated positively with average FC of HbO (pre-stim: r = 0.47; post-stim2: r = 0.41) and Area Under the Curve (AUC) of Eg (pre-stim: r = 0.44), and negatively with AUC of Lp (pre-stim: r = - 0.41; all p < 0.05).Conclusions Frontal beta-tACS was associated with state-dependent changes in functional network organization in DOC, with dynamic fNIRS measures that may be useful for tracking these changes. These findings provide preliminary descriptive evidence of short-term network changes associated with beta-tACS and may help guide future controlled studies of targeted neuromodulation in patients with DOC.
SN - 1743-0003
ER -