TY - JOUR
T1 - Temporal lobe interictal spikes disrupt encoding and retrieval of verbal memory
T2 - A subregion analysis
AU - Camarillo-Rodriguez, Liliana
AU - Leenen, Iwin
AU - Waldman, Zachary
AU - Serruya, Mijail
AU - Wanda, Paul A.
AU - Herweg, Nora A.
AU - Kahana, Michael J.
AU - Rubinstein, Daniel
AU - Orosz, Iren
AU - Lega, Bradley
AU - Podkorytova, Irina
AU - Gross, Robert E.
AU - Worrell, Gregory
AU - Davis, Kathryn A.
AU - Jobst, Barbara C.
AU - Sheth, Sameer A.
AU - Weiss, Shennan A.
AU - Sperling, Michael R.
N1 - Funding Information:
This work was supported by Defense Advanced Research Projects Agency (DARPA) grant N66001‐14‐2‐4032. DARPA was not involved in study design, data collection, data analysis, data interpretation, report writing, or decision to submit for publication. The views, opinions, and/or findings contained in this material are those of the authors and should not be interpreted as representing the official views or policies of the US Department of Defense or the US Government.
Publisher Copyright:
© 2022 International League Against Epilepsy.
PY - 2022/9
Y1 - 2022/9
N2 - 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.
AB - 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.
KW - CA1
KW - dentate gyrus
KW - episodic memory
KW - interictal epileptiform discharges
KW - intracranial EEG
KW - lateral temporal cortex
KW - medial temporal lobe
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U2 - 10.1111/epi.17334
DO - 10.1111/epi.17334
M3 - Article
C2 - 35708911
AN - SCOPUS:85132995231
SN - 0013-9580
VL - 63
SP - 2325
EP - 2337
JO - Epilepsia
JF - Epilepsia
IS - 9
ER -