Interictal MEG Reveals Altered Excitation-Inhibition Balance in Patients with Focal Epilepsy
Abstract number :
1.242
Submission category :
3. Neurophysiology / 3D. MEG
Year :
2025
Submission ID :
696
Source :
www.aesnet.org
Presentation date :
12/6/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Prabhakararao Eedara, PhD – National Institutes of Health
Yonatan Serlin, MD – National Institutes of Health
Leela Srinivasan, BS – National Institutes of Health
Jeff Stout, PhD – National Institutes of Health
Antonio Triggiani, PhD – National Institutes of Health
William Theodore, MD – National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
Sara Inati, PhD – National Institute of Neurological Disorders and Stroke, NIH, Bethesda, Maryland, USA
Rationale: The healthy brain relies on a precise balance between excitation (E) and inhibition (I) for efficient information processing. Disruptions in this balance have been reported in epilepsy, a neurological disorder marked by recurrent unprovoked seizures. While seizures are associated with excessive excitation, E/I alterations during the interictal (between seizure) period remain unclear. We hypothesize that interictal slowing often seen in patients with epilepsy suggests predominant inhibition, suppressing excessive excitation and thereby seizure onset, as well as potentially correlating with interictal neuropsychiatric dysfunction. Here, we evaluate whether non-invasive biomarkers of increased overall and intermittent low frequency (LF) activity can be detected in MEG recordings from patients with drug resistant focal epilepsy, even in the absence of overt epileptiform activity.
Methods: We acquired six-minute resting state interictal MEG recordings free of overt epileptiform activity from 55 patients (32±10 years, 22 female) with drug resistant focal epilepsy undergoing pre-surgical evaluation at the NIH Clinical Center, and 55 healthy controls (33±10 years, 31 female). We used two approaches to characterize LF activity and measure E/I balance from MEG power spectra: 1) aperiodic components (exponent and offset), which may reflect global E/I alterations; and 2) paroxysmal slow-wave events (PSWEs), defined as epochs with a median power frequency <
Neurophysiology