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Disconnection of hippocampal networks contributes to memory dysfunction in individuals with temporal lobe epilepsy
Author(s) -
Stoub Travis R.,
Chicharro Ada V.,
Grote Christopher L.,
Kanner Andres M.
Publication year - 2019
Publication title -
hippocampus
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.767
H-Index - 155
eISSN - 1098-1063
pISSN - 1050-9631
DOI - 10.1002/hipo.22800
Subject(s) - temporal lobe , psychology , neuroscience , parahippocampal gyrus , entorhinal cortex , verbal memory , hippocampus , white matter , hippocampal formation , epilepsy , visual memory , episodic memory , magnetic resonance imaging , cognition , medicine , radiology
Abstract A deficit in declarative memory function is common among individuals with temporal lobe epilepsy. The purpose of this study is to evaluate the relationship between the volume of the hippocampus, entorhinal cortex along with the surrounding parahippocampal white matter and memory performance in those with temporal lobe epilepsy. T1 weighted MRI scans were acquired using a 3‐D pulse sequence in 50 individuals with temporal lobe epilepsy. Hippocampal and entorhinal cortex volumes were derived by manually tracing consecutive coronal slices aligned perpendicular to the long axis of the hippocampus. In addition, parahippocampal white matter volumes were determined using voxel based morphometry. Finally, declarative memory was assessed using immediate and delayed verbal and visual memory tests from the Wechsler Memory Scale third edition. Significant correlations were seen between right and left hippocampal volumes and delayed verbal memory test scores. In addition, left parahippocampal white matter showed positive correlations with immediate and delayed verbal and visual recall. Furthermore, regression models found that the right hippocampus and left parahippocampal white matter were the best predictors of immediate and delayed verbal and visual memory performance. These results show that a decrease in white matter fibers projecting to the hippocampus may cause a disruption of incoming multi‐modal sensory information, contributing to the memory decline seen in individuals with temporal lobe epilepsy.