Interictal Epileptiform Discharges are Task Dependent and are Associated with Lasting Electrocorticographic Changes
Abstract
The factors that control the occurrence of interictal epileptiform discharges (IEDs) are not well understood. We suspected that this phenomenon reflects an attention-dependent suppression of interictal epileptiform activity. We hypothesized that IEDs would occur less frequently when a subject viewed a task-relevant stimulus compared with viewing a blank screen. Furthermore, IEDs have been shown to impair memory when they occur in certain regions during the encoding or recall phases of a memory task. Although these discharges have a short duration, their impact on memory suggests that they have longer lasting electrophysiological effects. We found that IEDs were associated with an increase in low-frequency power and a change in the balance between low- and high-frequency oscillations for several seconds. We found that the occurrence of IEDs is modified by whether a subject is attending to a word displayed on screen or is observing a blank screen. In addition, we found that discharges in brain regions in every lobe impair memory. These findings elucidate the relationship between IEDs and memory impairment and reveal the task dependence of the occurrence of IEDs.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jan 01, 2021
- Source ID
- 10.1093/texcom/tgab019
Entities
People
- Barbara C. Jobst
- Bradley C Lega
- Edward J Camp
- George W Culler Iv
- Markus E. Testorf
- Michael J. Kahana
- Michael R Sperling
- Payam Moein
- Robert E Gross
- Robert J Quon
- Sarah A Steimel
- Stephen Meisenhelter
Organizations
- Dartmouth College
- Dartmouth–Hitchcock Medical Center
- Defense Advanced Research Projects Agency
- Emory University
- National Science Foundation
- Thomas Jefferson University
- University of Pennsylvania
- University of Texas Southwestern Medical Center