Open AccessHippocampal involvement in nonpathological déjà vu: Subfield vulnerability rather than temporal lobe epilepsy equivalent
Author(s) -
Pešlová Eva,
Mareček Radek,
Shaw Daniel J.,
Kašpárek Tomáš,
Pail Martin,
Brázdil Milan
Publication year - 2018
Publication title -
brain and behavior
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.915
H-Index - 41
ISSN - 2162-3279
DOI - 10.1002/brb3.996
Subject(s) - hippocampal formation , temporal lobe , déjà vu , subiculum , hippocampus , epilepsy , psychology , medicine , neuroscience , psychiatry , dentate gyrus
Morphological correlates of nonpathological déjà vu ( DV ) have been identified recently within the human brain. Significantly reduced gray matter volume ( GMV ) within a set of cortical and subcortical regions reported in subjects experiencing DV seems to mirror the distribution of GMV reduction in mesial temporal lobe epilepsy ( MTLE ) patients but vary in terms of the hippocampus. Another condition associated with hippocampal GMV reduction and DV alike disturbance in memory processing is schizophrenia ( SCH ). Here, we tested the hypothesis that hippocampal involvement in nonpathological DV resembles more closely the pattern of GMV decrease observed in MTLE compared with that occurring in SCH . Methods Using automated segmentation of the MRI data we compared the medians of GMV within 12 specific hippocampal subfields in healthy individuals that do ( DV +; N = 87) and do not report déjà vu experience ( DV −; N = 26), and patients with MTLE ( N = 47) and SCH ( N = 29). By Pearson correlation, we then evaluated the similarity of MTLE and SCH groups to DV + group with respect to spatial distribution of GMV deviation from DV − group. Results Significant GMV decrease was found in MTLE group in most of the subfields. There were just trends in the hippocampal GMV decrease found in DV + or SCH groups. Concerning the spatial distribution of GMV decrease, we revealed statistically significant correlation for the left hippocampus for SCH vs DV +. Otherwise there was no statistically significant correlation. Conclusions Our findings reveal structural features of hippocampal involvement in nonpathological DV , MTLE , and SCH . Despite our expectations, the pattern of GMV reduction in the DV + relative to the DV − group does not resemble the pattern observed in MTLE any more than that observed in SCH . The highly similar patterns of the three clinical groups rather suggest an increased vulnerability of certain hippocampal subfields; namely, Cornu Ammonis ( CA )4, CA 3, dentate gyrus granular cell layer ( GC ‐ DG ), hippocampal–amygdaloid transition area ( HATA ) and subiculum.