F102. EARLY STAGES OF CONCEPTUAL DISORGANISATION AND REDISTRIBUTION OF CORTICAL HUBS IN UNTREATED FIRST EPISODE PSYCHOSIS; A 7T FMRI STUDY
Notice bibliographique
Résumé
Of the various symptom complexes of established psychosis, network level dysconnectivity has been widely studied in association with positive and negative symptoms. Very few studies have focused on studying the dysconnectivity patterns associated with disorganization, specifically conceptual disorganization (CD), which explains the impairments in both the goal-directed sequencing of thought processes and real-world functioning. Systematic reviews have revealed aberrant connectivity patterns in formal thought disorder (a construct related to CD) at all stages of the illness, suggesting the underlying persistence of CD. However, these studies investigate connectivity patterns between specific regions of interest or resting state networks. No studies have investigated the whole-brain functional correlates of CD in psychosis. We thus sought to investigate the brain regions explaining the severity of CD in patients with first-episode psychosis (FEPs) in comparison with healthy controls (HCs). Participants were recruited as part of a longitudinal neuroimaging project that follows changes in early psychosis during the course of treatment. 31 HC and 38 antipsychotic-naive FEP subjects were included in the study sample. Subjects were assessed using DSM-5 criteria and the 8 item Positive and Negative Syndrome Scale (PANSS-8) and underwent 2 magnetic resonance imaging (MRI) scans at 7T (one T2*-weighted resting-state functional MRI (rs-fMRI) scan, one T1-weighted structural MRI). After preprocessing, whole-brain binarized degree centrality (bDC) maps were computed to characterize the patterns of network connectivity in the two study samples. Statistical analyses included the following: 1) A two-sample t-test comparing connectivity patterns in the HC and FEP groups with bDC maps as the dependent variable, examining the effect of diagnosis accounting for gender as the covariate, 2) Similarly, a two-sample t-test comparing connectivity patterns in the two patient groups (low CD or Low P2, high CD or High P2) with bDC maps as the dependent variable, examining the effect of the severity of symptoms accounting for gender as the covariate. Compared to HCs, the FEPs showed a reduction in hubness of a cluster located in the superior temporal gyrus (rSTG) (right: t = 5.00, p < 0.001). This cluster was functionally connected with clusters in the middle frontal gyrus (left: t = 8.41, p < 0.001; right: t = 7.59, p < 0.001), cerebellum (left: t = 8.02, p < 0.001) and thalamus (left: t = 9.72, p < 0.001). In patients exhibiting high CD severity, increased hubness of a medial superior parietal (mSPL) cluster (left: t = 4.93, p = 0.001) was observed, compared to patients exhibiting low CD severity. This cluster was functionally connected with clusters in the superior temporal (right: t = 8.39, p < 0.001) and middle temporal (right: t = 7.07, p < 0.001) gyri. The summary measure (first eigenvariate) of the mSPL cluster’s centrality showed strong correlation with the severity of CD but no other symptoms. Our observations extend the previous findings of reduced hubness in the superior temporal and insular regions in established schizophrenia to early-stage untreated, active phase of illness. Nevertheless, the increase in peripheral hubness in this first-episode sample was limited to conceptually disorganized patients, indicating the possible role of functional cortical reorganization and re-routing of information transfer in early stages of thought disorder.
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 | 0,000 | 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) | 0,003 | 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 ».