Premium
P2‐139: Hippocampal MRI texture is related to hippocampal glucose metabolism
Author(s) -
Sørensen Lauge,
Igel Christian,
Nielsen Mads
Publication year - 2015
Publication title -
alzheimer's and dementia
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.713
H-Index - 118
eISSN - 1552-5279
pISSN - 1552-5260
DOI - 10.1016/j.jalz.2015.06.677
Subject(s) - hippocampal formation , neuroimaging , magnetic resonance imaging , hippocampus , brain size , medicine , hippocampal sclerosis , nuclear medicine , neuroscience , temporal lobe , psychology , pathology , radiology , epilepsy
Therefore, the aim of the present study was to compare atrophy versus hypometabolism discrepancies in SD to that observed in AD in order to highlight similarities and differences in the pathological processes between both diseases. Methods:Sixteen patients with SD, 24 patients with AD and 39 healthy controls matched for age, sex and years of education underwent both structural MRI and 18F-fluorodeoxyglucose PET scans. Images were spatially normalized using dartel in SPM. Age-adjusted Z-score maps were then computed for each patient and each imaging modality using the healthy controls group as a reference. Direct between-modality voxel-wise comparisons were then performed within each patient group. Results:Between-modality analyses highlighted more atrophy than hypometabolism in the medial temporal lobe in both SD and AD (FWE p<.05). By contrast, more hypometabolism than atrophy was found in extended medial and lateral parietal regions, temporo-parietal and frontal areas in AD, and in much more restricted brain regions in SD, i.e. mainly in the prefrontal regions when using a more liberal threshold (p<.001 uncorrected). Conclusions:Interestingly, both neurodegenerative disorders were found to be characterized by stronger atrophy than hypometabolism in the medial temporal lobe. However, unlike in AD, the pattern of hypometabolism only slightly differed from the pattern of atrophy in SD. This likely reflects distinct neuropathological processes in both diseases with much less distant effect of neuronal damage in the hippocampal formation in SD. Yet, the excessive prefrontal hypometabolism in SD might as well reflect diaschisis, or the higher sensitivity of 18F-fluorodeoxyglucose PET than structural MRI to detect the underlying neuropathology. Altogether, these findings suggest that the pathological mechanisms affecting the brain might be more homogeneous in SD than in AD.