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Verbal memory in left temporal lobe epilepsy: Evidence for task‐related localization
Author(s) -
Weintrob David L.,
Saling Michael M.,
Berkovic Samuel F.,
Berlangieri Salvatore U.,
Reutens David C.
Publication year - 2002
Publication title -
annals of neurology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 4.764
H-Index - 296
eISSN - 1531-8249
pISSN - 0364-5134
DOI - 10.1002/ana.10133
Subject(s) - temporal lobe , perirhinal cortex , verbal memory , psychology , temporal cortex , hippocampus , hippocampal sclerosis , voxel , recognition memory , neuroscience , hippocampal formation , epilepsy , cognition , medicine , radiology
We explored the hypothesis that components of verbal memory are subserved by separate temporal lobe structures in patients with temporal lobe epilepsy. Uptake of 18 F‐fluorodeoxyglucose (FDG) measured by positron emission tomography, hippocampal volume, and memory for arbitrarily and semantically related verbal paired associates were examined in 27 patients with left temporary lobe epilepsy. Scores from memory tests performed outside the scanner were regressed against normalized resting FDG uptake at each voxel. Significant regression was seen in the left perirhinal cortex (Talaraich coordinates x, y, z: −29, 10, −34; p < 0.05) for arbitrarily related word pairs. For semantically related paired associates, significant regression was present in the left inferior temporal gyrus (x, y, z: −48, −18, −24; p < 0.05). In subsequent analyses, mean FDG uptake within a spherical region of interest centered on the perirhinal peak predicted performance on both tasks. Mean FDG uptake in a region of interest centered on the inferior temporal peak made an additional, independent contribution to memory for semantically related pairs. Hippocampal volumes did not explain any additional variance in memory scores. Our findings indicate that heterogeneity in the left temporal lobe structures mediating verbal memory function, and support the view that the perirhinal cortex is an important mnemonic substrate.