EPA-0448 – Failure of de-activation in the default mode network: a trait marker for schizophrenia?
Notice bibliographique
Résumé
Background Functional imaging abnormality has been proposed as a trait marker or endophenotype for schizophrenia. Although studies examining dorsolateral prefrontal cortex activation in relatives of schizophrenic patients have not had consistent findings, failure of de-activation in the medial frontal cortex may be a promising alternative candidate. Method Twenty-nine patients with schizophrenia, 29 of their siblings and 58 healthy controls underwent fMRI during performance of the n-back working memory task. An ANOVA was fitted to individual whole-brain maps from each set of patient-relative-matched pair of controls. Clusters of significant difference among the groups were used as regions-of-interest to compare mean activations/de-activations between them. Results Four clusters of significant difference were found. The schizophrenic patients, but not the relatives, showed reduced activation compared to the controls in the left lateral frontal cortex, the left basal ganglia and the cerebellum. In contrast, both the patients and the relatives showed significantly reduced de-activation compared to the healthy controls in the medial frontal cortex, with evidence of an intermediate pattern in the relatives. Failure of de-activation was not associated with schizotypy scores or presence of psychotic experiences in the relatives. Conclusions Both schizophrenic patients and their relatives show altered task-related de-activation in the medial frontal cortex. This in turn suggests that default mode dysfunction may function as a trait marker or endophenotype for schizophrenia. Table. 1 . Demographic characteristics of the patinents (n = 29), healthy relatives (n = 29) and controls (n = 58) Schizophrenic patients (n = 29) Healthy relatives (n = 29) Controls (n = 58) p value Sex (male/female) 7/22 12/17 19/39 p = 0.38 Age (SD) (Range) 35.79 (9.55) (19-57) 37-31 (9.03) (19-52) 36.86 (9.91) (19-60) p = 0.82 Pre-morbid IQ (TAP) (SD) (Range) 94.92 (9.56) (77-110) 101.96 (7.80) (83-112) 100.05 (8.09) (81-114) p = 0.03 Current IQ score (WAIS-III score) 92.08 (14.17) (63-121) 108.76 (11.29) (81-122) 104.27 (12.47) (72-128) SCZ (SD) (Range) SCZ GAF score (SD) (Range) 52.41 (12.07) (35-75) - - PANSS score (SD) (Range) 66.55 (14.79) (35-96) - - Positives symptoms 15.44 (4.53) (8-26) Negative symptoms 20.88 (7.33) (7-30) General symptoms 30.92 (8.08) (17-50) Download : Download full-size image Fig. 1 . Brain regions showing a significant effect in the 2-back versus baseline contrast in controls (a), healthy first-degree relatives (b) and in schizophrenic patients (c) Yellow indicates a positive association (activation) with the task. Blue indicates areas where the task led to a decrease in the blood oxygenation level-dependent (BOLD) response (deactivation). Numbers refer to Montreal Neurological Institute (MNI) z coordinates of the slice shown. The right side of each image represents the right side of the brain. Results are thresholdedd at z = 3.5 and corrected for multiple comparisons across space using Gaussian random field methods. Download : Download full-size image Fig. 2 . Clusters of difference between schizophrenic patients (SCZ, n = 29), their first-degree healthy relatives (REL, n = 29) and healthy controls (CTRL, n = 58) (a) Left caudate gryus, globus pallidus and putamen activation, (b) bilateral cerebellar activation, (c) left dorsolateral activation and (d) anterior cingulate deactivation. The right side of each image represents the right side of the brain. Whole brain results are corrected for multiple comparisons across space using Gaussian random field methods. Analyses within ROIs were FDR-corrected for multiple comparisons.
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 | 0,000 |
| 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) | 0,004 | 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 ».