Features of intracranial interictal epileptiform discharges associated with memory encoding.

Authors

• Robert J Quon
• Edward J Camp
• Stephen Meisenhelter
• Yinchen Song
• Sarah A Steimel
• Markus E Testorf
• Angeline S Andrew
• Robert E Gross
• Bradley C Lega
• Michael R Sperling
• Michael J Kahana
• Barbara C Jobst

Publication/Presentation Date

11-1-2021

Abstract

OBJECTIVE: Interictal epileptiform discharges (IEDs) were shown to be associated with cognitive impairment in persons with epilepsy. Previous studies indicated that IED rate, location, timing, and spatial relation to the seizure onset zone could predict an IED's impact on memory encoding and retrieval if they occurred in lateral temporal, mesial temporal, or parietal regions. In this study, we explore the influence that other IED properties (e.g., amplitude, duration, white matter classification) have on memory performance. We were specifically interested in investigating the influence that lateral temporal IEDs have on memory encoding.

METHODS: Two hundred sixty-one subjects with medication-refractory epilepsy undergoing intracranial electroencephalographic monitoring performed multiple sessions of a delayed free-recall task (n = 671). Generalized linear mixed models were utilized to examine the relationship between IED properties and memory performance.

RESULTS: We found that increased IED rate, IEDs propagating in white matter, and IEDs localized to the left middle temporal region were associated with poorer memory performance. For lateral temporal IEDs, we observed a significant interaction between IED white matter categorization and amplitude, where IEDs with an increased amplitude and white matter propagation were associated with reduced memory performance. Additionally, changes in alpha power after an IED showed a significant positive correlation with memory performance.

SIGNIFICANCE: Our results suggest that IED properties may be useful for predicting the impact an IED has on memory encoding. We provide an essential step toward understanding pathological versus potentially beneficial interictal epileptiform activity.

Volume

62

Issue

11

First Page

2615

Last Page

2626

ISSN

1528-1167

Published In/Presented At

Quon, R. J., Camp, E. J., Meisenhelter, S., Song, Y., Steimel, S. A., Testorf, M. E., Andrew, A. S., Gross, R. E., Lega, B. C., Sperling, M. R., Kahana, M. J., & Jobst, B. C. (2021). Features of intracranial interictal epileptiform discharges associated with memory encoding. Epilepsia, 62(11), 2615–2626. https://doi.org/10.1111/epi.17060

Disciplines

Medicine and Health Sciences

PubMedID

34486107

Department(s)

Department of Medicine

Document Type

Article