The Effect of Interictal Epileptiform Discharges on Speed of Picture Naming
Abstract number :
3.354
Submission category :
11. Behavior/Neuropsychology/Language / 11A. Adult
Year :
2022
Submission ID :
2204824
Source :
www.aesnet.org
Presentation date :
12/5/2022 12:00:00 PM
Published date :
Nov 22, 2022, 05:26 AM
Authors :
Joshua LaRocque, MD, PhD – University of Pennsylvania; Simon Henin, PhD – Neurology – NYU School of Medicine; Aaron Struck, MD – Neurology – University of Wisconsin-Madison; Werner Doyle, MD – Neurosurgery – NYU School of Medicine; Orrin Devinsky, MD – Neurology – NYU School of Medicine; Adeen Flinker, PhD – Neurology – NYU School of Medicine; Anli Liu, MD – Neurology – NYU School of Medicine
This abstract is a recipient of the Young Investigator Award
Rationale: Patients with epilepsy (PWE) suffer from language deficits such as word finding difficulty. Recent work demonstrates that IEDs can impair word recall in an anatomically and temporally specific manner.1 Here, we examined the relationship between IEDs and non-mnemonic language function in PWE undergoing iEEG for surgical evaluation while performing a picture-naming task.
Methods: A retrospective analysis of adult PWE undergoing invasive monitoring for epilepsy surgery at New York University Comprehensive Epilepsy Center between the years of 2018 to 2021 was performed. Patients aged 18 to 60 years with subdural electrode coverage over the temporal and/or occipital lobes and who completed a picture naming task were eligible for inclusion. Patients viewed line drawings of common objects, and were instructed to name each object aloud. Responses were recorded, and reaction times (RTs) were automatically calculated based on onset of vocalization. IEDs were identified using a previously published detection algorithm2 and verified by visual review. RTs from trials containing an IED (IED+) vs. trials lacking an IED (IED-) were compared with paired two-tailed t-tests. High gamma activity (HGA), a measure of local neuronal activity, was calculated using Morlet wavelets at 5 Hz intervals between 65 and 170 Hz. Z-scoring before averaging across frequency yielded a single HGA time course for each channel. Task-positive channels for object naming were defined as those with significantly elevated HGA when comparing the 500 ms post-stimulus with corresponding 500 ms pre-stimulus, aiming to capture activity relating to stimulus processing and word-finding rather than articulatory processes.
Results: There were 32 adult PWE included in this analysis. On average, 230 IEDs (177 SD) were detected for each subject. When trials containing IEDs in the first 500 ms post-stimulus were compared with trials lacking IEDs in this time frame, RT was slower in IED+ compared to IED- trials (936 ms vs. 895 ms, p = 0.0065). When analysis of IEDs was restricted to task-positive channels, RT was slower in IED+ compared to IED- trials, though only trending towards significance (978 ms vs. 905 ms, p = 0.06). IEDs in in the 500 ms to 1000 ms post-stimulus window did not have an effect on RT (p > 0.7).
Conclusions: RT for object naming is slower when IEDs occur within a critical window following the stimulus presentation. These results suggest that IEDs could impair word finding, offering a potential therapeutic target to ameliorate word finding difficulty in PWE.
References:_x000D_
1. Horak PC, et al. Interictal epileptiform discharges impair word recall in multiple brain areas. Epilepsia. 2017;58:373-380._x000D_
2. Janca R, et al. Detection of interictal epileptiform discharges using signal envelope distribution modelling: application to epileptic and non-epileptic intracranial recordings. Brain Topogr. 2014; doi:10.1007/s10548-014-0379-1._x000D_
Funding: AES Clinical Research Training Fellowship (JL), ONR N00014-17-1-2961 (SH), R01NS109367 and R01NS115929 (AF), K23NS104252 (AAL)
Behavior