Aberrant Functional Connectivity of Resting State Networks in Transient Ischemic Attack

Rong Li,Ling Zhu,Jian Guo,Li He,Shanshan Wang,Ling Zeng,Huafu Chen,Qiyong Gong,Pedro Antonio Valdes-Sosa

doi:10.1371/journal.pone.0071009

Abstract

BackgroundTransient ischemic attack (TIA) is usually defined as a neurologic ischemic disorder without permanent cerebral infarction. Studies have showed that patients with TIA can have lasting cognitive functional impairment. Inherent brain activity in the resting state is spatially organized in a set of specific coherent patterns named resting state networks (RSNs), which epitomize the functional architecture of memory, language, attention, visual, auditory and somato-motor networks. Here, we aimed to detect differences in RSNs between TIA patients and healthy controls (HCs).MethodsTwenty one TIA patients suffered an ischemic event and 21 matched HCs were enrolled in the study. All subjects were investigated using cognitive tests, psychiatric tests and functional magnetic resonance imaging (fMRI). Independent component analysis (ICA) was adopted to acquire the eight brain RSNs. Then one-sample t-tests were calculated in each group to gather the spatial maps of each RSNs, followed by second level analysis to investigate statistical differences on RSNs between twenty one TIA patients and 21 controls. Furthermore, a correlation analysis was performed to explore the relationship between functional connectivity (FC) and cognitive and psychiatric scales in TIA group.ResultsCompared with the controls, TIA patients exhibited both decreased and increased functional connectivity in default mode network (DMN) and self-referential network (SRN), and decreased functional connectivity in dorsal attention network (DAN), central-executive network (CEN), core network (CN), somato-motor network (SMN), visual network (VN) and auditory network (AN). There was no correlation between neuropsychological scores and functional connectivity in regions of RSNs.ConclusionsWe observed selective impairments of RSN intrinsic FC in TIA patients, whose all eight RSNs had aberrant functional connectivity. These changes indicate that TIA is a disease with widely abnormal brain networks. Our results might put forward a novel way to look into neuro-pathophysiological mechanisms in TIA patients.

Highlights

Transient ischemic attack (TIA) is usually defined as a neurologic ischemic disorder without permanent cerebral infarction and lasting neurological deficits [1]
We evaluated the topological differences of the resting state networks (RSNs) between TIA patients and healthy controls, using the method of Independent component analysis (ICA) on functional magnetic resonance imaging (fMRI) data of resting state
There were no significant differences in Hamilton Anxiety Rating Scales (HARS) and Hamilton Depression Rating Scales (HDRS) between two groups

Summary

Introduction

Transient ischemic attack (TIA) is usually defined as a neurologic ischemic disorder without permanent cerebral infarction and lasting neurological deficits [1]. Another research found that TIA patients with carotid artery occlusion may develop persisting impairment in execution and reaction [5]. All these studies have been used the neuropsychological test scores to evaluate the cognitive abnormalities in TIA patients, which may relatively be insensitive to mild cognitive impairment and can not provide any information about the mechanism of such cognitive decline. Transient ischemic attack (TIA) is usually defined as a neurologic ischemic disorder without permanent cerebral infarction. We aimed to detect differences in RSNs between TIA patients and healthy controls (HCs)

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