Modèles de synchronie neurale altérée dans le réseau de mode par défaut dans le "trouble du spectre de l'autisme" révélé par magnétoencéphalographie (MEG): Relation avec la symptomatologie clinique

Aperçu: G.M.

La communication entre les différentes zones du cerveau a été observée chez les enfants avec un diagnostic de TSA (dTSA) et d'enfants neurotypiques pendant qu'ils étaient éveillés, mais ne travaillant pas sur une tâche. La magnétoencéphalographie a été utilisée pour mesurer de minuscules champs magnétiques générés naturellement par l'activité cérébrale. Le cerveau des enfants avec dTSA a montré moins de communication entre les zones qui sont importantes pour le traitement de l'information sociale par rapport au cerveau des enfants neurotypiques. La quantité de communication entre ces zones était associée à des difficultés de communication sociales et sociales.

Autism Res. 2017 Dec 18. doi: 10.1002/aur.1908

Patterns of altered neural synchrony in the default mode network in autism spectrum disorder revealed with magnetoencephalography (MEG): Relationship to clinical symptomatology

Lajiness-O'Neill R^1,2, Brennan JR³, Moran JE⁴, Richard AE¹, Flores AM¹, Swick C¹, Goodcase R¹, Andersen T¹, McFarlane K¹, Rusiniak K¹, Kovelman I^2,5, Wagley N^2,5, Ugolini M⁶, Albright J¹, Bowyer SM^6,7,8.

Author information

1

Eastern Michigan University, Ypsilanti, Michigan.

2

Center for Human Growth and Development, University of Michigan, Ann Arbor, Michigan.

3

Department of Linguistics, Ann Arbor, Michigan.

4

Henry Ford Hospital, Detroit, Michigan.

5

Department of Psychology, Ann Arbor, Michigan.

6

University of Massachusetts, Amherst, Massachusetts.

7

Wayne State University, Detroit, Michigan.

8

Oakland University, Rochester, Michigan.

Abstract

Disrupted neural synchrony may be a primary electrophysiological abnormality in autism spectrum disorders (ASD), altering communication between discrete brain regions and contributing to abnormalities in patterns of connectivity within identified neural networks. Studies exploring brain dynamics to comprehensively characterize and link connectivity to large-scale cortical networks and clinical symptoms are lagging considerably. Patterns of neural coherence within the Default Mode Network (DMN) and Salience Network (SN) during resting state were investigated in 12 children with ASD (M_Age  = 9.2) and 13 age and gender-matched neurotypicals (NT) (M_Age  = 9.3) with magnetoencephalography. Coherence between 231 brain region pairs within four frequency bands (theta (4-7 Hz), alpha, (8-12 Hz), beta (13-30 Hz), and gamma (30-80 Hz)) was calculated. Relationships between neural coherence and social functioning were examined. ASD was characterized by lower synchronization across all frequencies, reaching clinical significance in the gamma band. Lower gamma synchrony between fronto-temporo-parietal regions was observed, partially consistent with diminished default mode network (DMN) connectivity. Lower gamma coherence in ASD was evident in cross-hemispheric connections between: angular with inferior/middle frontal; middle temporal with middle/inferior frontal; and within right-hemispheric connections between angular, middle temporal, and inferior/middle frontal cortices. Lower gamma coherence between left angular and left superior frontal, right inferior/middle frontal, and right precuneus and between right angular and inferior/middle frontal cortices was related to lower social/social-communication functioning. Results suggest a pattern of lower gamma band coherence in a subset of regions within the DMN in ASD (angular and middle temporal cortical areas) related to lower social/social-communicative functioning. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.

LAY SUMMARY:

Communication between different areas of the brain was observed in children with ASD and neurotypical children while awake, but not working on a task. Magnetoencephalography was used to measure tiny magnetic fields naturally generated via brain activity. The brains of children with ASD showed less communication between areas that are important for social information processing compared to the brains of neurotypical children. The amount of communication between these areas was associated with social and social communication difficulties.

© 2017 International Society for Autism Research, Wiley Periodicals, Inc.

PMID:29251830

DOI:10.1002/aur.1908

Altered Activity of the Primary Visual Area during Gaze Processing in Individuals with High-Functioning Autistic Spectrum Disorder: A Magnetoencephalography Study

Traduction partielle: G.M.

Neuropsychobiology. 2013 Oct 24;68(3):181-188.

Modification de l'activité de l'aire visuelle primaire pendant le traitement du regard chez les personnes avec des troubles du spectre autistique et un haut niveau de fonctionnement cognitif : une étude de magnétoencéphalographie

Hasegawa N, Kitamura H, Murakami H, Kameyama S, Sasagawa M, Egawa J, Tamura R, Endo T, Someya T.

Source

Department of Psychiatry, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan.

Abstract

Background: 

Les personnes avec des troubles de spectre autistique (TSA) montrent une altération de la capacité à inférer les états mentaux d'autrui à partir de leur regard.  
Ainsi, l'étude des relations entre TSA et le traitement du regard est cruciale pour comprendre les bases neurales de déficiences sociales observées chez les personnes avec TSA. En outre, les caractéristiques des TSA sont observées dans les tâches les plus détaillées de la perception visuelle. Ces caractéristiques visuelles du  TSA ont été bien expliquées en termes de la relation atypique entre le traitement de haut et bas niveau du regard dans les TSA.

Method

We studied neural activity during gaze processing in individuals with ASD using magnetoencephalography, with a focus on the relationship between high- and low-level gaze processing both temporally and spatially. Minimum Current Estimate analysis was applied to perform source analysis of magnetic responses to gaze stimuli. 

Results

The source analysis showed that later activity in the primary visual area (V1) was affected by gaze direction only in the ASD group. Conversely, the right posterior superior temporal sulcus, which is a brain region that processes gaze as a social signal, in the typically developed group showed a tendency toward greater activation during direct compared with averted gaze processing. 

Conclusion

Ces résultats suggèrent que l'activité plus tard dans l'aire visuelle primaire V1 relative au traitement du regard est altérée ou peut-être améliorée chez les personnes avec TSA et un haut niveau de fonctionnement cognitif, ce qui peut sous-tendre la déficience cognitive sociale de ces personnes.

PMID: 24157624