Różne zmiany strukturalne w hipokampie i wzgórzu oraz ich znaczenie dla funkcji poznawczych w jednostronnej epilepsji skroniowej
Differential structural profiles of the hippocampus and thalamus and their cognitive relevance in unilateral mesial temporal lobe epilepsy
W skrócie
Badacze porównali zmiany w mózgu u pacjentów z epilepsją skroniową, skupiając się na dwóch strukturach: hipokampie i wzgórzu. Okazało się, że wzgórze było znacznie zmniejszone u chorych, ale hippokamp miał większy wpływ na problemy z pamięcią i myśleniem. Hippokamp wyjaśniał więcej zaburzeń poznawczych niż wzgórze, zwłaszcza gdy brać pod uwagę, po której stronie mózgu była choroba.
Oryginalny abstract (angielski)
BACKGROUND: Cognitive dysfunction is common in mesial temporal lobe epilepsy (MTLE), yet how much the hippocampus and the thalamus each contribute remains unclear. We compared fine-grained hippocampal and thalamic structure and their cognitive relevance in unilateral MTLE. METHODS: We studied 71 patients with unilateral MTLE (39 with hippocampal sclerosis [HS], 32 without) and 17 controls. FreeSurfer-derived cortical, hippocampal-subfield, and thalamic-nucleus volumes were compared using permutation-based general linear models. In patients, 19 cognitive measures were related to volume using covariate-adjusted partial correlations under seizure-referenced (ipsilateral/contralateral) and anatomical left/right codings. Nested additive models tested the incremental cognitive contributions of hippocampal and thalamic volume. RESULTS: Relative to controls, patients showed widespread thalamic atrophy (34 of 44 nuclei in the full cohort, 32 of 44 in each subgroup), whereas hippocampal subfield atrophy was largely confined to HS and no cortical region survived correction. All 48 corrected volume-cognition associations involved hippocampal subfields; none involved thalamic nuclei. Additive models showed that ipsilateral hippocampal volume explained 7.4%-14.6% of cognitive variance alone and explained an additional 6.8%-18.9% of cognitive variance beyond thalamic volume, whereas global thalamic volume did not add significant corrected incremental variance. Preserving anatomical hemisphere linked verbal comprehension and naming to left hippocampal subfields and working memory predominantly to right subfields. CONCLUSIONS: Hippocampal and thalamic abnormalities showed distinct structural and cognitive profiles in unilateral MTLE. Thalamic atrophy was widespread, whereas hippocampal volume was more closely related to cognition and showed additional variation by HS status and anatomical hemisphere.