Dynamic excitation/inhibition balance preceding seizure onset and its link to functional and structural brain architecture
Bibliographic record
Abstract
BACKGROUND: Altered excitation/inhibition (E/I) balance is a key mechanism in epilepsy, but its dynamic changes before seizure onset remain unclear. The interictal suppression hypothesis suggests that inhibitory input isolates epileptic regions, yet little is known about E/I dynamics in the pre-ictal phase. METHODS: We analyzed high-density EEG recordings from patients with drug-resistant focal epilepsy, each with at least one recorded seizure. Cortical activity was reconstructed using source modeling, and time-resolved changes in the aperiodic exponent-a non-invasive marker of E/I balance-were computed. Directed functional connectivity was assessed via spectral Granger causality. These metrics were correlated with cortical thickness and neurotransmitter receptor density maps. RESULTS: The aperiodic exponent increased progressively in the minutes preceding seizures, reflecting a global shift toward cortical inhibition, with no significant differences between epileptic and non-epileptic regions. Delta and theta power also increased preictally. Epileptic regions showed significantly more outward than inward connectivity, and more outward connectivity than non-epileptic areas. In non-epileptic regions, higher inhibition was associated with greater outward connectivity. Cortical thickness positively correlated with inhibition only in non-epileptic areas. Lower muscarinic receptor density was associated with stronger inhibitory shifts. CONCLUSIONS: Seizure onset is preceded by a widespread shift toward inhibition, possibly representing a compensatory mechanism that fails as ictal thresholds are crossed. This shift is linked to altered connectivity and disrupted structure-function coupling in epileptic regions. The dynamic aperiodic exponent emerges as a promising biomarker for seizure prediction and a potential target for neuromodulation strategies.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.016 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".