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Structural and functional connectivity in the default mode network in 22q11.2 deletion syndrome.

Padula MC, Schaer M, Scariati E, Schneider M, Van De Ville D, Debbané M, Eliez S - J Neurodev Disord (2015)

Bottom Line: Connectivity measures were compared between groups and correlated with age.A simultaneous reduction of functional and structural connectivity between core medial nodes of the DMN was observed.No correlations were found between the DMN disconnectivity and expression of prodromal symptoms in 22q11DS.

View Article: PubMed Central - PubMed

Affiliation: Office Médico-Pédagogique, Department of Psychiatry, University of Geneva, Rue David-Dufour 1, Case Postale 50, 1211 Genève 8, Switzerland.

ABSTRACT

Background: The neural endophenotype associated with 22q11.2 deletion syndrome (22q11DS) includes deviant cortical development and alterations in brain connectivity. Resting-state functional magnetic resonance imaging (fMRI) findings also reported disconnectivity within the default mode network (DMN). In this study, we explored the relationship between functional and structural DMN connectivity and their changes with age in patients with 22q11DS in comparison to control participants. Given previous evidence of an association between DMN disconnectivity and the manifestation of psychotic symptoms, we further investigated this relationship in our group of patients with 22q11DS.

Methods: T1-weighted, diffusion, and resting-state fMRI scans were acquired from 41 patients with 22q11DS and 43 control participants aged 6 to 28 years. A data-driven approach based on independent component analysis (ICA) was used to identify the DMN and to define regions of interest for the structural and functional connectivity analysis. Prodromal psychotic symptoms were assessed in adolescents and adults using the positive symptom scores of the Structured Interview of Prodromal Syndromes (SIPS). Connectivity measures were compared between groups and correlated with age. Repeating the between-group analysis in three different age bins further assessed the presence of age-related alterations in DMN connectivity. Structural and functional connectivity measures were then correlated with the SIPS scores.

Results: A simultaneous reduction of functional and structural connectivity between core medial nodes of the DMN was observed. Furthermore, structural connectivity measures significantly increased with age in the control group but not in patients with 22q11DS, suggesting the presence of an age-related alteration of the DMN structural connections. No correlations were found between the DMN disconnectivity and expression of prodromal symptoms in 22q11DS.

Conclusions: These findings indicate the presence of functional and structural DMN disconnectivity in 22q11DS and that patients with 22q11DS fail to develop normal structural connections between medial DMN nodes. This suggests the presence of altered neurodevelopmental trajectories in 22q11DS.

No MeSH data available.


Related in: MedlinePlus

Nine resting-state networks (RSNs), which resulted from the independent component analysis (ICA)
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Fig1: Nine resting-state networks (RSNs), which resulted from the independent component analysis (ICA)

Mentions: Group-level spatial ICA was conducted on the entire sample of participants using the GIFT toolbox (http://mialab.mrn.org/software/gift/index.html). The number of components was fixed at n = 20 and, in accordance with our previous paper [32], 9 of the 20 components resulting from the ICA were visually identified as RSNs (Fig. 1). The remaining 11 components were considered artifacts due to motion or signal from the ventricles. Network identification was performed by visual inspection and confirmed by computing the correlation coefficient between the component and resting-state network templates (http://findlab.stanford.edu/functional_ROIs.html). Among the maps corresponding to the RSNs, only one was identified as the DMN and it comprised different clusters distributed along anterior and posterior medial brain regions and in two lateral regions corresponding to the IPL.Fig. 1


Structural and functional connectivity in the default mode network in 22q11.2 deletion syndrome.

Padula MC, Schaer M, Scariati E, Schneider M, Van De Ville D, Debbané M, Eliez S - J Neurodev Disord (2015)

Nine resting-state networks (RSNs), which resulted from the independent component analysis (ICA)
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4522079&req=5

Fig1: Nine resting-state networks (RSNs), which resulted from the independent component analysis (ICA)
Mentions: Group-level spatial ICA was conducted on the entire sample of participants using the GIFT toolbox (http://mialab.mrn.org/software/gift/index.html). The number of components was fixed at n = 20 and, in accordance with our previous paper [32], 9 of the 20 components resulting from the ICA were visually identified as RSNs (Fig. 1). The remaining 11 components were considered artifacts due to motion or signal from the ventricles. Network identification was performed by visual inspection and confirmed by computing the correlation coefficient between the component and resting-state network templates (http://findlab.stanford.edu/functional_ROIs.html). Among the maps corresponding to the RSNs, only one was identified as the DMN and it comprised different clusters distributed along anterior and posterior medial brain regions and in two lateral regions corresponding to the IPL.Fig. 1

Bottom Line: Connectivity measures were compared between groups and correlated with age.A simultaneous reduction of functional and structural connectivity between core medial nodes of the DMN was observed.No correlations were found between the DMN disconnectivity and expression of prodromal symptoms in 22q11DS.

View Article: PubMed Central - PubMed

Affiliation: Office Médico-Pédagogique, Department of Psychiatry, University of Geneva, Rue David-Dufour 1, Case Postale 50, 1211 Genève 8, Switzerland.

ABSTRACT

Background: The neural endophenotype associated with 22q11.2 deletion syndrome (22q11DS) includes deviant cortical development and alterations in brain connectivity. Resting-state functional magnetic resonance imaging (fMRI) findings also reported disconnectivity within the default mode network (DMN). In this study, we explored the relationship between functional and structural DMN connectivity and their changes with age in patients with 22q11DS in comparison to control participants. Given previous evidence of an association between DMN disconnectivity and the manifestation of psychotic symptoms, we further investigated this relationship in our group of patients with 22q11DS.

Methods: T1-weighted, diffusion, and resting-state fMRI scans were acquired from 41 patients with 22q11DS and 43 control participants aged 6 to 28 years. A data-driven approach based on independent component analysis (ICA) was used to identify the DMN and to define regions of interest for the structural and functional connectivity analysis. Prodromal psychotic symptoms were assessed in adolescents and adults using the positive symptom scores of the Structured Interview of Prodromal Syndromes (SIPS). Connectivity measures were compared between groups and correlated with age. Repeating the between-group analysis in three different age bins further assessed the presence of age-related alterations in DMN connectivity. Structural and functional connectivity measures were then correlated with the SIPS scores.

Results: A simultaneous reduction of functional and structural connectivity between core medial nodes of the DMN was observed. Furthermore, structural connectivity measures significantly increased with age in the control group but not in patients with 22q11DS, suggesting the presence of an age-related alteration of the DMN structural connections. No correlations were found between the DMN disconnectivity and expression of prodromal symptoms in 22q11DS.

Conclusions: These findings indicate the presence of functional and structural DMN disconnectivity in 22q11DS and that patients with 22q11DS fail to develop normal structural connections between medial DMN nodes. This suggests the presence of altered neurodevelopmental trajectories in 22q11DS.

No MeSH data available.


Related in: MedlinePlus