The study of functional MRI on neuronal activity of primary olfactory cortex in patients with subjective cognitive decline
Notice bibliographique
Résumé
Objective Using olfactory task functional magnetic resonance imaging (fMRI) to investigate the difference in brain olfactory activation between patients with subjective cognitive decline and normal elderly subjects, and to explore the objective image markers for early identification and evaluation the progression from SCD to Alzheimer′s disease (AD). Methods Twenty patients with SCD (SCD group) and twenty matched normal elderly subjects (NC group) were recruited from the community from March 2017 to December 2018. A full neuropsychological scale tests battery, olfactory behavioral tests and olfactory task-fMRI were performed. The differences between olfactory behavior, neuropsychological scales, and task-fMRI brain activation between the two groups were tested. Further, brain regions, which had significantly different activations under task-fMRI, were used as seeds for resting state functional connectivity (FC) analysis. Finally, the correlations between brain activation and olfactory behavior along with clinical neuropsychological scale tests were examined. Results The results of this study showed SCD had a significant decrease in olfactory behavior (olfactory recognition ability) compared with NC (t=-3.042, P<0.01), and there was no statistically significant difference in olfactory threshold. Significant declines were also observed in the SCD self-rating scale (t=6.973, P<0.01), the immediate (t=-4.623, P<0.01) and delayed (t=-2.746, P<0.01) testing of Philadelphia word learning, while the remaining neuropsychological scales were normal. In the olfactory task-fMRI, activation of bilateral primary olfactory cortical regions was significantly reduced in SCD patients, including bilateral entorhinal cortex, amygdala, piriform cortex, anterior olfactory nucleus, and head of the hippocampus. The resting state functional connectivity with the primary olfactory cortex (POC) as the seed showed that the functional connectivity between the olfactory system and the default model network (DMN) of SCD patients was significantly weakened (AlphaSim correction with voxel level P<0.01 and cluster level P<0.05). The Beta value of the left POC was significantly positively correlated with the olfactory threshold and Montreal cognitive assessment (MoCA) (r=0.329, P=0.041; r=0.317, P=0.046). Partial correlation analysis indicated that there was a significantly positive correlation between the FC of the left POC with the right/left inferior frontal gyrus, the left frontal middle gyrus and the right inferior parietal, and the score of immediate Philadelphia word learning test(r=0.411, P=0.008; r=0.400, P=0.011; r=0.329, P=0.003; r=0.454, P=0.003). The FC between the left POC and the right inferior temporal gyrus was negatively correlated with the score of trail making test (TMT) B, and the FC between the left POC and the right inferior was negatively correlated with score of language fluency test (r=-0.317, P=0.047; r=-0.333, P=0.036). The FC between the right POC and the left inferior parietal was positively correlated with the score of immediate Philadelphia word learning (r=0.315, P=0.048), while the FC between right POC and left middle occipital gyrus was negatively corrected with Language Fluency Test (r=-0.403, P=0.01). Conclusion Olfactory function has been impaired in SCD patients with normal standard cognition and phychiatric rating scales, and the changes in the activation of the primary olfactory cortex, such as the entorhinal cortex, may be an early neural circuit damage biomarker for objective evaluation of SCD. Key words: Subjective cognitive decline; Olfactory perception; Magnetic resonance imaging
Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.
Comment cette classification a été obtenuedéplier
Prédiction machine sur la base complète
Imitation des enseignantsNi prévalence calibrée, ni vérité terrain. Validation humaine à venir. Le volet Gemma est une étiquette directe du modèle pour chaque travail de la base, lue sur la notice réduite au titre. Le volet Codex est un classifieur appris des 10 348 étiquettes directes de Codex et calibré sur les taux pondérés de l'échantillon; les champs sans appui suffisant ne portent aucun appel Codex. Le mode candidate est l'union des deux volets; le consensus est leur intersection. Ces sorties portent le statut machine_predicted_unvalidated et ne sont pas des étiquettes humaines.
Scores du classifieur distillé par catégorie (deux têtes)
| Catégorie | Codex | Gemma |
|---|---|---|
| Métarecherche | 0,000 | 0,001 |
| Méta-épidémiologie (sens strict) | 0,000 | 0,000 |
| Méta-épidémiologie (sens large) | 0,000 | 0,000 |
| Bibliométrie | 0,001 | 0,000 |
| Études des sciences et des technologies | 0,000 | 0,000 |
| Communication savante | 0,000 | 0,000 |
| Science ouverte | 0,000 | 0,000 |
| Intégrité de la recherche | 0,000 | 0,000 |
| Charge utile insuffisante (le modèle a refusé de juger) | 0,001 | 0,000 |
Scores machine (provisoires)
Les deux têtes enseignantes du modèle étudiant, lues sur ce travail. Un score ordonne la base pour la relecture; il n'affirme jamais une catégorie, et le statut de validation accompagne chaque rangée tel quel.
Scores de référence d'un modèle non mature (critères de maturité non atteints, 7 itérations). Un score ordonne; il n'affirme jamais une catégorie.
score_only:v0-immature-baseline · tel quel depuis la passe de notation : score_only signifie que le nombre peut ordonner les travaux, et qu'aucune étiquette de catégorie n'en découleClassification
machine, non validéePrédiction automatique; un appel candidat d’une seule source (Gemma direct ou Codex distillé), pas un consensus.
Le détail, modèle par modèle et score par score, se trouve en fin de page sous « Comment cette classification a été obtenue ».