Pulvinar Interictal Activity in Focal Epilepsies
Abstract number :
1.3
Submission category :
4. Clinical Epilepsy / 4B. Clinical Diagnosis
Year :
2025
Submission ID :
1029
Source :
www.aesnet.org
Presentation date :
12/6/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Naoki Ikegaya, MD, PhD – Yokohama City University Graduate School of Medicine
Thandar Aung, MD,MS – University of Pittsburgh Medical School
Aude Jegou, MS – University of Pittsburgh
Steven Salazar, MS – University of Pittsburgh
Arianna Damiani, MS – University of Pittsburgh
Jorge González-Martínez, MD,PhD – University of Pittsburgh Medical School
Rationale: Stereo-electroencephalography (SEEG) has become a dominant approach for evaluating intractable epilepsy. SEEG exploration of the thalamus has contributed to understanding the pathophysiology of epilepsy and has recently aided in surgical decision-making. Among the thalamic sub-nuclei, the pulvinar has been increasingly recognized for its crucial role during ictal periods, such as early seizure involvement and seizure termination. However, the clinical significance of pulvinar activity during interictal periods remains largely unexplored. Here, we describe the characteristics of interictal pulvinar activity in focal epilepsies and evaluate its clinical utility in relation to seizure outcomes after surgery using a prospectively maintained database.
Methods: We reviewed 109 consecutive SEEG cases from Jan 2020 to May 2024, and identified 41 patients with pulvinar exploration. Among them, patients who underwent subsequent resective surgery with at least one year of follow-up were included. We analyzed 20-minute segments of asleep SEEG recordings from pulvinar electrode contact pairs. Interictal epileptiform discharges (IEDs) were visually detected, automatically quantified, and analyzed in relation to clinical characteristics. IED frequency was dichotomized as “Frequent” (more than once per minute) or “Non-Frequent”. Kaplan-Meier analysis was used to statistically evaluate the difference in postoperative seizure outcomes between the groups.
Results: Twenty-one patients (median age: 38 years) were analyzed. IEDs were detected in the pulvinar in 14 of 21 patients. Among them, eight exhibited “Frequent” interictal activity (median: 30 IEDs per 20 minutes). The epileptogenic zone (EZ) was categorized as the medial temporal lobe (MTL) in 8, temporal lobe (TL; including lateral temporal lobe and MTL) in 6, or extratemporal lobe (exTL) in 7. Pulvinar frequent interictal activity was observed in 3 of 8 patients with MTL-EZ, 2 of 6 with TL-EZ, and 3 of 7 with exTL-EZ. Fifteen patients achieved seizure freedom (ILAE class 1). Kaplan-Meier analysis revealed no significant difference in postoperative seizure outcomes between the “Frequent” and “Non-Frequent” groups (p=0.54, log-rank test).
Conclusions: Based on the data collected, epileptiform discharges in the pulvinar were frequently observed during interictal periods. These discharges appeared to reflect certain clinical characteristics of intractable focal epilepsies, but their frequency was not associated with poorer seizure outcomes following resective surgery.
Funding: None
Clinical Epilepsy