| Autor: |
Ortega‐Cruz, Diana, Uceda‐Heras, Alicia, Zhang, Linda, Iglesias, Juan Eugenio, Rabano, Alberto, Strange, Bryan A |
| Zdroj: |
Alzheimer's & Dementia: The Journal of the Alzheimer's Association; Dec2022 Supplement 5, Vol. 18 Issue 5, p1-1, 1p |
| Abstrakt: |
Background: The hippocampus plays a crucial role in memory encoding and retrieval and is highly vulnerable to age‐related pathologic alterations. Hippocampal sclerosis (HS) is a prominent histologic finding in dementia patients which results in worsening of cognitive symptoms but has been so far understudied. Contrary to HS developed in epilepsy, HS of aging specially affects individuals over 85 years old. It is defined by severe neuronal loss and gliosis in CA1 and subiculum areas, which is disproportionate to the expected damage from other pathologies that commonly coexist with HS, such as AD and TDP‐43 pathology. Method: We studied a cohort of dementia patients who underwent follow‐up at the CIEN Foundation (Madrid, Spain) and selected 45 subjects with in vivo MRI and post‐mortem pathological diagnosis. In this neuropathological evaluation, the presence of gliosis without neuronal loss in relevant areas of the hippocampus has been considered a precursor stage of HS, as suggested by previous studies (Hokkannen et al., Brain Pathol 2018). Based on this criterium, a staging system (0‐IV) for HS has been proposed including precursor stages as part of the pathology spectrum. We have explored relations between this staging system and pre‐mortem anatomical differences via analysis of MRI scans. Specifically, we used SPM software to perform voxel‐based morphometry and FreeSurfer to obtain segmentations of hippocampal subfields. Result: We found that the extent of HS measured with this staging system is associated with a bilateral reduction in grey matter density in the hippocampus detectable in vivo. These effects are obtained after controlling for other neuropathologies, indicating an independent contribution of HS to atrophy. Additionally, a reduction in volume is observed at most severe stages of HS in all subfields of the hippocampal cortex, rather than exclusively in CA1 and subiculum. We also found volume differences notable at more than 5 years before death via longitudinal analysis of earlier MRI timepoints. Conclusion: Our results validate this staging system as an accurate description of HS progression and provide hints towards a clinical diagnosis of HS of aging supported by MRI. [ABSTRACT FROM AUTHOR] |
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