Original Research ARTICLE
Altered effective connectivity in the default network of the brains of first-episode, drug-naïve schizophrenia patients with auditory verbal hallucinations
- 1Shanghai Key Laboratory of Magnetic Resonance, East China Normal University, China
- 2College of Medicine, Zhejiang University, China
- 3Department of Neurology, First Affiliated Hospital, Zhejiang University, China
- 4New York State Psychiatric Institute (NYSPI), United States
Although the default mode network (DMN) is knowing to be abnormal in schizophrenia patients with auditory verbal hallucinations (AVHs), it is still unclear whether the AVHs occurred to schizophrenia are associated with certain information flow in the DMN. The present study collected resting-state functional magnetic resonance imaging data from 28 first-episode, drug-naïve schizophrenia patients with AVHs, 20 schizophrenia patients without AVHs and 38 healthy controls. We used Granger Causality Analysis (GCA) to examine effective connectivity of two hub regions (posterior cingulate cortex (PCC) and anteromedial prefrontal cortex (aMPFC)) within the DMN. We used two-sample t-tests to compare the difference in effective connectivity between the two patient groups and used Spearman correlation analysis to characterize the relationship between imaging findings and clinical assessments. GCA revealed that compared with non-AVHs group, effective connectivity decreased from aMPFC to the left inferior temporal gyrus (ITG) and from PCC to the left cerebellum posterior lobe, inferior temporal gyrus and right middle frontal gyrus in schizophrenia patients with AVHs. We also found significant correlations between clinical assessments and the mean strengths of connectivity from aMPFC to left ITG and from PCC to left ITG. Moreover, receiver operating characteristic analysis revealed that the effective connectivities above-mentioned had a diagnostic value for distinguishing schizophrenia patients with AVHs from non-AVHs patients. These findings suggest that AVHs in schizophrenia patients may be associated with the aberrant information flows of DMN and left ITG may probably serve as a potential biomarker for the neural mechanisms underlying AVHs in schizophrenia patients.
Keywords: Schizophrenia, Auditory verbal hallucinations, Resting-state functional magnetic resonance imaging (fMRI), Default Mode Network, Granger causality analysis, effective connectivity
Received: 18 Aug 2018;
Accepted: 25 Oct 2018.
Edited by:Chella Kamarajan, SUNY Downstate Medical Center, United States
Reviewed by:Zhen Yuan, University of Macau, China
Valerie Cardenas, Neurobehavioral Research (United States), United States
Copyright: © 2018 Zhao, Li, Feng, Shen, Li, Yi, Huang and Xu. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
* Correspondence: Prof. Dongrong Xu, New York State Psychiatric Institute (NYSPI), New York, United States, email@example.com