Investigating Corticothalamic Network Changes During Interictal Epileptiform Discharges: An SEEG Study
Abstract number :
2.155
Submission category :
3. Neurophysiology / 3E. Brain Stimulation
Year :
2024
Submission ID :
1202
Source :
www.aesnet.org
Presentation date :
12/8/2024 12:00:00 AM
Published date :
Authors :
Presenting Author: Shingo Oana, MD, PhD – University of California, Los Angeles
Saarang Panchavati, BS – UCLA
Atsuro Daida, MD,PhD – UCLA Mattel Children's Hospital
Yipeng Zhang, Dr. – UCLA
Yuanyi Ding, MS – University of California, Los Angeles
Sotaro Kanai, MD, PhD – Tottori University, Faculty of Medicine
Raman Sankar, MD, PhD – University of California, Los Angeles
Aria Fallah, MD, MS – UCLA Mattel Children's Hospital
Vwani Roychowdhury, PhD – UCLA
William Speier, PhD – University of California, Los Angeles,
Hiroki Nariai, MD, PhD, MS – UCLA Mattel Children's Hospital
Rationale: The clinical efficacy of deep brain stimulation (DBS) targeting the anterior nucleus (AN) and centromedian nucleus (CM) of the thalamus has been extensively investigated for the treatment of medication-resistant epilepsy. Several studies have examined dynamic changes in corticothalamic connectivity during seizures using human stereotactic EEG (SEEG) recordings. However, there have been no reports investigating temporal changes in corticothalamic networks during the interictal epileptiform discharges (spikes).
Methods: We analyzed fifteen patients (aged 1.0-28.1 years) with medically resistant focal epilepsy who underwent SEEG recording with thalamic sampling including the AN and CM. A total of 727 interictal spikes were analyzed from the seizure onset zone (SOZ), with each patient having more than 30 spikes. We also analyzed ipsilateral spikes and contralateral spikes not in the SOZ as controls. Using time-frequency analysis, we investigated power changes across various frequency bands: delta (1-4 Hz), theta (4-8 Hz), alpha (8-12 Hz), beta (12-30 Hz), gamma (30-80 Hz), ripple (80-250 Hz), and fast ripple (250-500 Hz). Furthermore, we examined both undirected and directed connectivity using coherence and spectral Granger causality analysis (sGCA) between diverse seizure foci and the thalamic AN and CM. Additionally, subgroup analysis was performed to analyze each power spectrum between the thalamus and anatomical locations such as the frontal, limbic, parietal, and occipital areas.
Results: We observed an increase in power spectrum patterns within the AN and CM during interictal spikes occurred at the SOZ (Figure 1). Coherence between the SOZ and the thalamic nuclei (AN and CM) increased notably in the theta, alpha, beta, and gamma bands during spikes. sGCA showed increased information flow forming two peaks before and after spikes, indicating bidirectional communication between the SOZ and the thalamus (both the AN and CM) across all frequency bands, predominantly in the beta band (Figure 2). In the subgroup analysis, the power increased in both the AN and CM when interictal spikes originated from the SOZ within the frontal lobe. However, this increase was only seen in the AN when spikes originated from the SOZ within the limbic region.
Conclusions: We observed dynamic corticothalamic network interactions between the SOZ and the thalamus during interictal spikes. The findings suggest potential role of responsible neurostimulation targeting interictal spikes to modulate abnormal corticothalamic network involving the SOZ and the thalamus.
Funding: The National Institute of Health, K23NS128318
Neurophysiology