Interictal Epileptiform Discharges and Focal Epilepsy Surgical Planning
Abstract number :
3.395
Submission category :
9. Surgery / 9A. Adult
Year :
2025
Submission ID :
68
Source :
www.aesnet.org
Presentation date :
12/8/2025 12:00:00 AM
Published date :
Authors :
Presenting Author: Yasho Gondi, MD – Detroit Medical Center/Wayne State University
Jonathan Izygon, MD – Wayne State University/Detroit Medical Center
Shane Sampson, MD – Wayne State University - Detroit Medical Center
Farah Abdelhak, BS – University Of Michigan
Mohammad Emari, DO – Wayne State University/Detroit Medical Center
Sara Younes, MD – Detroit Medical Center/Wayne State University
Charles Hughes, BS – Detroit Medical Center/Wayne State University
Zara Rehman, BS – University Of Case Western Reserve University
Aminah Bharadia, BS – Detroit Medical Center/Wayne State University
Mawadda Abdelhai, BS – Detroit Medical Center/Wayne State University
Rana Elhamzawy, BS – Detroit Medical Center/Wayne State University
Waleed Abood, MD – Detroit Medical Center/Wayne State University
Maysaa Basha, MD – Wayne State University School of Medicine, Detroit, MI
Mona Elsayed, MD – Detroit Medical Center - Wayne State University
Rationale: Interictal epileptiform discharges (IEDs) are the hallmark features of epileptic tissue and are generated by the synchronous activity of a group of neurons. IEDs have characteristic patterns on EEG that may represent distinct pathological processes, predict underling etiologies, and help guide surgical planning and outcome in focal epilepsy.
Methods: We studied sixteen adult patients with focal epilepsy (ages 24-65) who underwent pre-surgical evaluation at the Detroit Medical Center (6 Male had stereoEEG, and 10 Female, 6 of out of 10 had stereoEEG and 4 declined). A retrospective analysis of IEDs recorded from scalp EEG of patients with focal epilepsy aimed to determine the EEG predictive value for IEDs in epilepsy surgery.
Results: We identified different IEDs patterns: (1) possible intrinsic epileptogenicity include Bursts of a) rhythmic sinusoidal spikes in beta range might indicate mesial origin, b) focal enhancement of beta activity or rhythmic alpha range intermixed with high amplitude spikes followed by high amplitude slow waves or brushes of fast activity override high amplitude spikes might indicate FCD, c) Theta rhythmic spikes in waxing and waning amplitudes followed by slow wave might indicate heterotopia. (2) IEDs patterns with possibility of triggered response due to afterdepolarization include a) Localized and isolated monomorphic spike or sharp-slow wave might indicate proper hippocampus origin, b)Spike or sharp-slow wave (exhibited ectopic spikes ipsilateral or contralateral) might indicate hippocampus and para-hippocampus origin, c) focal periodic IEDs or poly spikes-slow wave indicate very irritable and active epileptic focus as seen in FCD, d) bifid spikes (M pattern) or independent ectopic multifocal spikes or irregular slow activity with superimposed short spikes resembling notched delta might indicate cortical gliosis and conduction defect in projection fibers.
Conclusions: These findings explore the multitude of interpretations of IEDs patterns, inviting a new understanding of IEDs and promising applications to the work-up for epilepsy surgery. Interictal EEG patterns provide valuable insight into the presence of epileptic focus and underlying pathology even in the absence of clinical signs and structural lesions. Further studies with larger cohorts are warranted to confirm and validate these findings.
Funding: None
Surgery