Network-specific cortico-thalamic dysconnection in schizophrenia revealed by intrinsic functional connectivity analyses

Background: Cortico-thalamic connections are thought to be abnormal in schizophrenia due to their important roles in sensory relay and higher cognitive control, both of which are affected by this devastating illness. This study tested the cortico-thalamic dysconnection hypothesis in schizophrenia and further explored corticothalamic network properties using functional connectivity MRI (fcMRI). Methods: Forty-eight participants with schizophrenia and 48 healthy controls underwent resting fMRI scans and clinical evaluations. Six a priori cortical regions of interests (ROIs) were used to derive the six networks: dorsal default mode network (dDMN), fronto-parietal network (FPN), cingulo-opercular network (CON), primary sensorimotor network (SM1), primary auditory network (A1)) and primary visual network (V1). The corticothalamic connectivity for each network was calculated for each participant and then compared between groups. Results: A repeated measures analysis of variance (ANOVA) showed significant group x network interactions (F(5, 90) = 9.5, P < 0.001), which were driven by a significant increase in FC within the SM1 (t(94) = 4.1, P < 0.001) and A1 (t(94) = 4.2, P < 0.001) networks in schizophrenics, as well as a significant decrease within the CON (t(94) = 2.8, P = 0.04). The cortico-thalamic dysconnection did not correlate with symptom severity, representing a state independent abnormality. Conclusion: The network analysis indicates that cortico-thalamic dysconnection in schizophrenia involves multiple networks and shows network specific changes. The findings provide support for dysfunctional thalamus-related networks in schizophrenia and further elaborate their network properties. (C) 2015 Elsevier B.V. All rights reserved.