02 mai 2017

La connectivité fonctionnelle de l'état de repos du cerveau est préservée sous anesthésie de Sevoflurane chez les patients

Aperçu: G.M.

Les études de connectivité fonctionnelle jouent un rôle important dans la compréhension de la relation entre les connexions réseau et le phénotype comportemental des personnes avec un trouble envahissant du développement (TED).

L'anesthésie générale est un facteur de confusion dans les études d'imagerie fonctionnelle en raison de son effet sur la connectivité fonctionnelle. L'objectif de cette étude est d'examiner la connectivité fonctionnelle de l'état de repos (RS-FC) sous anesthésie de sévoflurane chez des personnes avec TED.

Les données des sujets ont été comparées aux données de seize témoins sans TED non anesthésiés.

Un total de 13 patients a été étudié. Six réseaux ont été étudiés, le réseau de mode par défaut (DMN), le réseau de contrôle exécutif (ECN), le réseau de salience (SN) ainsi que les réseaux auditifs, visuels et sensori-moteurs.

Les rapports précédents ont suggéré que même des niveaux d'anesthésie légers pourraient réduire les niveaux globaux de fluctuation dans les principaux réseaux de cerveau tels que DMN et ECN. Cependant, ces résultats fournissent des preuves solides que ces réseaux peuvent supporter des niveaux d'activité détectables chez les patients avec TED, même avec des niveaux profonds d'anesthésie.

2017 Apr 26. doi: 10.1089/brain.2016.0448.

Brain Resting State Functional Connectivity is preserved under Sevoflurane Anesthesia in patients with Pervasive Developmental disorders - a pilot study

Venkat Raghavan L¹, Bharadwaj S², Wourms V³, Tan A⁴, Jurkiewicz MT⁵, Mikulis DJ⁶, Crawley AP⁷.

Author information

1: Toronto Western Hospital, 26625, Department of Anesthesia , 399 Bathurst Street , Toronto, Canada , M5T 2S8 ; lashmi.venkatraghavan@uhn.on.ca.
2: Toronto Western Hospital, 26625, Department of Anesthesia, Toronto, Canada ; acharya.suparna@gmail.com.
3: University of Manitoba, 8664, Anesthesia, Winnipeg, Manitoba, Canada ; vpw130@mail.usask.ca.
4: King\'s College Hospital NHS Foundation Trust, 8948, Anesthesia, London, London, United Kingdom of Great Britain and Northern Ireland ; audreytan@me.com.
5: Hospital of the University of Pennsylvia, Division of Neuroradiology, Department of Radiology, Philadelphia, Pennsylvania, United States ; Michael.Jurkiewicz@utorotnto.ca.
6: Toronto Western Hospital, 26625, Joint Department of Medical imaging, Toronto, Canada ; mikulis@mac.com.
7: Toronto Western Hospital, 26625, Joint Department of Medical imaging, Toronto, Ontario, Canada ; crawley@uhnres.utoronto.ca.

Abstract

Background Functional connectivity studies play a huge role in understanding the relationship between the network connections and the behavioral phenotype of patients with Pervasive developmental disorders (PDD). However, some patients with PDD may not tolerate the imaging procedure while awake and they often need general anesthesia. General anesthesia is a confounding factor in functional imaging studies due to its effect on the functional connectivity. The objective of this study is to look at the resting state functional connectivity (RS-FC) under sevoflurane anesthesia in patients with pervasive developmental disorders. Method Adults with PDD scheduled for MRI of the brain under general anesthesia were recruited for the study. Resting state fMRI scans were acquired in all patients on a 3-Tesla scanner at 1 Minimum Alveolar Concentration (MAC) of sevoflurane. During the study period, end-tidal carbon dioxide and blood pressure were maintained at baseline value. Spontaneous BOLD fluctuations were measured, and a seed-voxel analysis done to identify the resting state networks. Subjects' data were compared with data from sixteen non-anesthetised healthy controls.. Results A total of 13 patients was studied. Six networks were investigated, the default mode network (DMN), executive control network (ECN), salience network (SN) as well as the auditory, visual and sensorimotor networks. At 1 MAC sevoflurane anesthesia, RS-FC was preserved in all the networks. Secondary analysis of connectivity showed a decrease in connectivity within the thalamus and an increase in DMN-ECN and DMN-SN cross-network connectivity in the anesthetized patient group compared to healthy controls. Conclusion Previous reports suggested that even mild levels of anesthesia could reduce overall fluctuation levels in major brain networks such as the DMN and ECN. However, our results provide strong evidence that these networks can sustain detectable levels of activity in patients with pervasive developmental disorders even under deep levels of anesthesia.