P3‐254: Perivascular Distribution and Variable Progression of Focal White Matter Hyperintensities in Alzheimer’S Disease
Notice bibliographique
Résumé
The origin(s) of white matter hyperintensities (WMH) in Alzheimer’s disease (AD) is not fully understood. Previous studies suggest that parenchymal cerebral vessels (eg arteries and veins) play a role not only in blood circulation, but also in homeostasis of interstitial fluid and toxic metabolite clearance. Specifically the perivascular spaces along the vessels may serve as cerebral lymphatics, and WMH may signify brain lymphatic dysfunction. The purpose of this study was to investigate whether focal WMH were spatially related to intramedullary vessels, and to track their dynamic characteristics by observing any change over one year on MRI. Focal WMH in periventricular and deep white matter were evaluated in 40 AD (age=75) and 20 healthy elderly (age=72) using co-registered 3D-T1 and T2-weighted MR images. A focal WMH was considered as perivascular if it was centered around or overlapped with an intramedullary vessel (Fig1). Intramedullary vessels were defined as linear hypointense signals on appropriately windowed 3D-T1 images. Based on the intramedullary vascular anatomy, a vessel was classified as arteriolar if it was near the cortex or as venular if it connected to the lateral ventricles. Each focal WMH was classified as (enlarging, shrinking or unchanged) between time1 and time 2 (mean 1.3 year apart). A total of 758 focal WMH were identified on the baseline scans from all subjects. 715 (94.3%) focal WMH were perivascular, including 206(28.8%) arteriolar-related and 403(56.4%) venular-related. Of the 715 perivascular focal WMH in the baseline, 209(29.2%) increased, 49(6.9%) decreased and 457(63.9%) were unchanged in size at follow-up (Fig2). These characteristics did not differ between AD and healthy elderly. Focal non-lacunar WMH were mostly centered around intramedullary vessels, suggesting perivascular distribution and were more often associated with venules, than arterioles. The change in size over time raises the possibility the focal WMH may represent perivascular edema/leakage, reflecting underlying dysfunction of perivascular lymphatic drainage. Based on the known increase in arteriolosclerosis and venous collagenosis in aging, we suggest that in aging and dementia small vessel disease may be damaging not only from vascular occlusion but also dysfunction of perivascular clearance of fluid and toxic metabolites. Spatial relationship of focal WMH with intramedullary vessels in MRI Focal WMH change over time T1 and T2 MRI co-registered in the same space showing focal WMH overlapped with intramedullary vessels. Foci can not only increase (A), but also decrease (B) in size over time.
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) | 0,002 | 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 ».