Meisenhelter Stephen, Quon Robert J, Steimel Sarah A, Testorf Markus E, Camp Edward J, Moein Payam, Culler George W, Gross Robert E, Lega Bradley C, Sperling Michael R, Kahana Michael J, Jobst Barbara C
Department of Neurology, Dartmouth-Hitchcock Medical Center, Lebanon, NH 03766, USA.
Department of Neurology, Geisel School of Medicine at Dartmouth College Hanover, NH 03755, United States.
Cereb Cortex Commun. 2021 Mar 20;2(2):tgab019. doi: 10.1093/texcom/tgab019. eCollection 2021.
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.
控制发作间期癫痫样放电（IEDs）发生的因素尚未完全明确。我们怀疑这种现象反映了对发作间期癫痫样活动的注意力依赖性抑制。我们假设，与观看空白屏幕相比，当受试者观看与任务相关的刺激时，IEDs的发生频率会更低。此外，研究表明，当IEDs在记忆任务的编码或回忆阶段出现在某些区域时，会损害记忆。尽管这些放电持续时间很短，但它们对记忆的影响表明它们具有更持久的电生理效应。我们发现，IEDs与低频功率增加以及低频和高频振荡之间的平衡在数秒内发生变化有关。我们发现，IEDs的发生会因受试者是关注屏幕上显示的单词还是观察空白屏幕而有所改变。此外，我们发现每个脑叶区域的放电都会损害记忆。这些发现阐明了IEDs与记忆损害之间的关系，并揭示了IEDs发生的任务依赖性。
