Temporal lobe interictal spikes disrupt encoding and retrieval of verbal memory: A subregion analysis.
Publication/Presentation Date
9-1-2022
Abstract
OBJECTIVE: The medial temporal lobe (MTL) encodes and recalls memories and can be a predominant site for interictal spikes (IS) in patients with focal epilepsy. It is unclear whether memory deficits are due to IS in the MTL producing a transient decline. Here, we investigated whether IS in the MTL subregions and lateral temporal cortex impact episodic memory encoding and recall.
METHODS: Seventy-eight participants undergoing presurgical evaluation for medically refractory focal epilepsy with depth electrodes placed in the temporal lobe participated in a verbal free recall task. IS were manually annotated during the pre-encoding, encoding, and recall epochs. We examined the effect of IS on word recall using mixed-effects logistic regression.
RESULTS: IS in the left hippocampus (odds ratio [OR] = .73, 95% confidence interval [CI] = .63-.84, p < .001) and left middle temporal gyrus (OR = .46, 95% CI = .27-.78, p < .05) during word encoding decreased subsequent recall performance. Within the left hippocampus, this effect was specific for area CA1 (OR = .76, 95% CI = .66-.88, p < .01) and dentate gyrus (OR = .74, 95% CI = .62-.89, p < .05). IS in other MTL subregions or inferior and superior temporal gyrus and IS occurring during the prestimulus window did not affect word encoding (p > .05). IS during retrieval in right hippocampal (OR = .22, 95% CI = .08-.63, p = .01) and parahippocampal regions (OR = .24, 95% CI = .07-.8, p < .05) reduced the probability of recalling a word.
SIGNIFICANCE: IS in medial and lateral temporal cortex contribute to transient memory decline during verbal episodic memory.
Volume
63
Issue
9
First Page
2325
Last Page
2337
ISSN
1528-1167
Published In/Presented At
Camarillo-Rodriguez, L., Leenen, I., Waldman, Z., Serruya, M., Wanda, P. A., Herweg, N. A., Kahana, M. J., Rubinstein, D., Orosz, I., Lega, B., Podkorytova, I., Gross, R. E., Worrell, G., Davis, K. A., Jobst, B. C., Sheth, S. A., Weiss, S. A., & Sperling, M. R. (2022). Temporal lobe interictal spikes disrupt encoding and retrieval of verbal memory: A subregion analysis. Epilepsia, 63(9), 2325–2337. https://doi.org/10.1111/epi.17334
Disciplines
Medicine and Health Sciences
PubMedID
35708911
Department(s)
Department of Medicine
Document Type
Article