Acute scalp EEG signatures of anterior thalamic DBS in epilepsy:reproducible gamma power enhancement within an aperiodic spectral-state shift
- 1Tampere University
Abstract
Background: Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is an established treatment for drug-resistant epilepsy, but acute scalp-EEG signatures of stimulation remain incompletely characterized. Objective: To identify acute scalp-EEG signatures of ANT-DBS and assess their cross-year reproducibility in a proof-of-concept repeated-session cohort. Methods: Scalp EEG from five patients recorded one year apart (10 sessions) was analyzed during nominal cyclic DBS (1 s ON, ~5 s OFF). DBS ON was compared with the within-cycle OFFmean and consecutive post-offset OFF windows using power spectral density (PSD), spatiotemporal-frequency (STF) analysis, and spectral parameterization. Results: DBS ON showed higher 30-70 Hz gamma power than OFFmean in all sessions (median +0.94 dB), with significant PSD clusters overlapping gamma in 10/10 sessions. STF identified gamma increases as the most reproducible spatiotemporal effect. Exploratory frontal 34-44 Hz and central 56-70 Hz components showed cross-year support, and the broader pattern persisted when 48-52 or 45-55 Hz were excluded before clustering. Lower-frequency effects were more heterogeneous and weakened from early to late OFF windows. Aperiodic parameterization showed lower ON exponent and offset in all sessions (Delta chi = -0.20; Delta b = -0.25). After correction, theta suppression was not preserved, whereas a smaller low-gamma residual remained. Conclusions: ANT-DBS was associated with consistent acute scalp-EEG state signatures comprising raw gamma enhancement, lower aperiodic exponent and offset, and a modest residual low-gamma effect. These hypothesis-generating findings show that scalp EEG can capture acute ANT-DBS state changes, while larger prospective studies are needed to establish clinical relevance.
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BibTeX
@misc{sabbaghi2026acute,
title = {{Acute scalp EEG signatures of anterior thalamic DBS in epilepsy:reproducible gamma power enhancement within an aperiodic spectral-state shift}},
author = {E. Sabbaghi and H. Mattila and E. Siitama and J. Hyttinen and J. Peltola and N. Puthanmadam Subramaniyam},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.16.759433},
url = {https://www.biorxiv.org/content/10.64898/2026.10.16.759433v1},
note = {CC BY},
}
RIS
TY - UNPB
TI - Acute scalp EEG signatures of anterior thalamic DBS in epilepsy:reproducible gamma power enhancement within an aperiodic spectral-state shift
AU - E. Sabbaghi
AU - H. Mattila
AU - E. Siitama
AU - J. Hyttinen
AU - J. Peltola
AU - N. Puthanmadam Subramaniyam
PY - 2026
DA - 2026/10/16
PB - bioRxiv
DO - 10.64898/2026.10.16.759433
UR - https://www.biorxiv.org/content/10.64898/2026.10.16.759433v1
AB - Background: Deep brain stimulation (DBS) of the anterior nucleus of the thalamus (ANT) is an established treatment for drug-resistant epilepsy, but acute scalp-EEG signatures of stimulation remain incompletely characterized. Objective: To identify acute scalp-EEG signatures of ANT-DBS and assess their cross-year reproducibility in a proof-of-concept repeated-session cohort. Methods: Scalp EEG from five patients recorded one year apart (10 sessions) was analyzed during nominal cyclic DBS (1 s ON, ~5 s OFF). DBS ON was compared with the within-cycle OFFmean and consecutive post-offset OFF windows using power spectral density (PSD), spatiotemporal-frequency (STF) analysis, and spectral parameterization. Results: DBS ON showed higher 30-70 Hz gamma power than OFFmean in all sessions (median +0.94 dB), with significant PSD clusters overlapping gamma in 10/10 sessions. STF identified gamma increases as the most reproducible spatiotemporal effect. Exploratory frontal 34-44 Hz and central 56-70 Hz components showed cross-year support, and the broader pattern persisted when 48-52 or 45-55 Hz were excluded before clustering. Lower-frequency effects were more heterogeneous and weakened from early to late OFF windows. Aperiodic parameterization showed lower ON exponent and offset in all sessions (Delta chi = -0.20; Delta b = -0.25). After correction, theta suppression was not preserved, whereas a smaller low-gamma residual remained. Conclusions: ANT-DBS was associated with consistent acute scalp-EEG state signatures comprising raw gamma enhancement, lower aperiodic exponent and offset, and a modest residual low-gamma effect. These hypothesis-generating findings show that scalp EEG can capture acute ANT-DBS state changes, while larger prospective studies are needed to establish clinical relevance.
ER -