Alterations in olfaction‐related brain regions in the ageing population: A structural MRI study
Bibliographic record
Abstract
Abstract Background Ageing plays a major role in neurodegenerative disorders such as Alzheimer’s disease. Olfactory dysfunction can be an early alteration heralding the presence of a neurodegenerative disorder in ageing. Studying alterations in olfaction‐related brain regions might help detection of neurodegenerative diseases at an earlier stage. Objectives: To assess the volume of olfactory cortex and areas associated with odour processing in different age groups in the cognitively healthy population using high resolution 3D structural MRI scans. To test whether normal ageing determines any volumetric alterations of olfactory cortex, hippocampus and other associated areas and whether there are any differential predictive values of these alterations for neurodegenerative disorders. To determine if atrophy of the olfactory cortex occurs prior to atrophy of the hippocampus and other areas involved in some aspects of odour processing in the healthy population. Method Neurologically healthy participants were divided based on their age into three age groups: young (20–35 year; n=53), middle‐aged (36‐65 year; n=66) and elderly (66‐85 year; n=95). T1‐ weighted MRI scans acquired at 1.5T were processed using SPM12. Smoothed images were used to extract the volume of olfaction‐related regions including primary olfactory cortex, hippocampus, parahippocampus and amygdala. Result One‐way ANOVA analyses showed significant decreases in volume between age groups in all olfaction‐related brain regions (p≤0.0001). Post‐hoc multiple comparisons tests showed that significant differences were found between age groups except in the young vs the middle‐aged where no significant differences were found for hippocampal and amygdala volumes. Pairwise comparisons of groups following ANCOVA showed no significant difference in all olfaction‐related brain regions when controlling for age. Adjusting for education showed significant age‐group differences in olfactory cortex and parahippocampus volumes except for hippocampus in all groups, and for the amygdala for young versus middle‐aged groups Conclusion These preliminary data showed significant reduction in the volume of olfaction‐related brain regions with ageing, but hippocampus and amygdala appeared to have a more limited volume reduction than primary olfactory cortex and parahippocampus. The results suggest that monitoring of volume of olfaction‐related brain regions in the ageing population may be valuable to detect risk of neurodegenerative diseases.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".