The selective impairment of resting-state functional connectivity of the lateral subregion of the frontal pole in schizophrenia.

Yujing Zhou,Chuanjun Zhuo,Chunshui Yu,Di Wang,Wen Qin,Jiajia Zhu,Xiaomei Ma,Yong Liu

doi:10.1371/journal.pone.0119176

Yujing Zhou, Chuanjun Zhuo + Show 6 more

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https://doi.org/10.1371/journal.pone.0119176

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Abstract

ObjectiveAlthough extensive resting-state functional connectivity (rsFC) changes have been reported in schizophrenia, rsFC changes of the frontal pole (FP) remain unclear. The FP contains several subregions with different connection patterns; however, it is unknown whether the FP subregions are differentially affected in schizophrenia. To explore this possibility, we compared rsFC differences of the FP subregions between schizophrenia patients and healthy controls.MethodOne hundred healthy controls and 91 patients with schizophrenia underwent resting-state functional MRI with a sensitivity-encoded spiral-in (SENSE-SPIRAL) imaging sequence to reduced susceptibility-induced signal loss and distortion. The FP was subdivided into the orbital (FPo), medial (FPm), and lateral (FPl) subregions. Mean fMRI time series were extracted for each FP subregion and entered into a seed-based rsFC analysis.ResultsThe FP subregions exhibited differential rsFC patterns in both healthy controls and schizophrenia patients. Direct comparison between groups revealed reduced rsFCs between the bilateral FPl and several cognitive-related regions, including the dorsolateral prefrontal cortex, medial prefrontal cortex, anterior cingulate cortex, posterior cingulate cortex/precuneus, temporal cortex and inferior parietal lobule in schizophrenia. Although the FPl exhibited obvious atrophy, rsFC changes were unrelated to volumetric atrophy in the FPl, to duration of illness, and to antipsychotic medication dosage. No significant differences were observed in the rsFCs of other FP subregions.ConclusionThese findings suggest a selective (the lateral subregion) functional disconnection of the FP subregions in schizophrenia.

Highlights

Schizophrenia is a severe and disabled psychiatric disorder and impairs multiple aspects of brain function, including perception, cognition and emotion [1]
These findings suggest a selective functional disconnection of the frontal pole (FP) subregions in schizophrenia
The mean relative signal intensity (rSI) of all FP regions of interest (ROIs) derived from the SENSE-SPIRAL and the echo-planar imaging (EPI) functional MRI (fMRI) were both higher than 0.5, but the normalized functional images derived from the SENSE-SPIRAL fMRI exhibited a less distortion in the FP and orbitofrontal cortex than those derived from the EPI fMRI (Fig. 1)

Summary

Introduction

Schizophrenia is a severe and disabled psychiatric disorder and impairs multiple aspects of brain function, including perception, cognition and emotion [1]. Most of these functions depend on structural and functional integrity of the prefrontal cortex (PFC). On the basis of neuroimaging studies, the human FP is thought to play a role in processing social and emotional information [4, 5], complex cognition [6,7,8,9,10] and self-referential tasks [11, 12], all of which are impaired in schizophrenia. Structural atrophy of the FP has been found in schizophrenia patients and in young relatives at risk for schizophrenia [19,20,21]

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