scholarly journals Aberrant Brain Functional Connectivity Strength and Effective Connectivity in Patients with Type 2 Diabetes Mellitus

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Xi Guo ◽  
Su Wang ◽  
Yu-Chen Chen ◽  
Heng-Le Wei ◽  
Gang-Ping Zhou ◽  
...  

Alterations of brain functional connectivity in patients with type 2 diabetes mellitus (T2DM) have been reported by resting-state functional magnetic resonance imaging studies, but the underlying precise neuropathological mechanism remains unclear. This study is aimed at investigating the implicit alterations of functional connections in T2DM by integrating functional connectivity strength (FCS) and Granger causality analysis (GCA) and further exploring their associations with clinical characteristics. Sixty T2DM patients and thirty-three sex-, age-, and education-matched healthy controls (HC) were recruited. Global FCS analysis of resting-state functional magnetic resonance imaging was performed to explore seed regions with significant differences between the two groups; then, GCA was applied to detect directional effective connectivity (EC) between the seeds and other brain regions. Correlations of EC with clinical variables were further explored in T2DM patients. Compared with HC, T2DM patients showed lower FCS in the bilateral fusiform gyrus, right superior frontal gyrus (SFG), and right postcentral gyrus, but higher FCS in the right supplementary motor area (SMA). Moreover, altered directional EC was found between the left fusiform gyrus and bilateral lingual gyrus and right medial frontal gyrus (MFG), as well as between the right SFG and bilateral frontal regions. In addition, triglyceride, insulin, and plasma glucose levels were correlated with the abnormal EC of the left fusiform, while disease duration and cognitive function were associated with the abnormal EC of the right SFG in T2DM patients. These results suggest that T2DM patients show aberrant brain function connectivity strength and effective connectivity which is associated with the diabetes-related metabolic characteristics, disease duration, and cognitive function, providing further insights into the complex neural basis of diabetes.

2017 ◽  
Vol 52 (10) ◽  
pp. 962-971 ◽  
Author(s):  
Ying Wang ◽  
Shuming Zhong ◽  
Guanmao Chen ◽  
Tao Liu ◽  
Lianping Zhao ◽  
...  

Objectives: Several recent studies have reported a strong association between the cerebellar structural and functional abnormalities and psychiatric disorders. However, there are no studies to investigate possible changes in cerebellar functional connectivity in bipolar disorder. This study aimed to examine the whole-brain functional connectivity pattern of patients with remitted bipolar disorder II, in particular in the cerebellum. Methods: A total of 25 patients with remitted bipolar disorder II and 25 controls underwent resting-state functional magnetic resonance imaging and neuropsychological tests. Voxel-wise whole-brain connectivity was analyzed using a graph theory approach: functional connectivity strength. A seed-based resting-state functional connectivity analysis was further performed to investigate abnormal functional connectivity pattern of those regions with changed functional connectivity strength. Results: Remitted bipolar disorder II patients had significantly decreased functional connectivity strength in the bilateral posterior lobes of cerebellum (mainly lobules VIIb/VIIIa). The seed-based functional connectivity analyses revealed decreased functional connectivity between the right posterior cerebellum and the default mode network (i.e. right posterior cingulate cortex/precuneus and right superior temporal gyrus), bilateral hippocampus, right putamen, left paracentral lobule and bilateral posterior cerebellum and decreased functional connectivity between the left posterior cerebellum and the right inferior parietal lobule and bilateral posterior cerebellum in patients with remitted bipolar disorder II. Conclusion: Our results suggest that cerebellar dysconnectivity, in particular distributed cerebellar–cerebral functional connectivity, might be associated with the pathogenesis of bipolar disorder.


2021 ◽  
pp. E601-E610

BACKGROUND: Despite previous reports on cerebral structures and functional connectivity in patients with myofascial pain (MFP), it is not clear whether alterations in neurovascular coupling occur in these patients. OBJECTIVES: We analyzed the coupling between resting-state cerebral blood flow (CBF) and functional connectivity strength (FCS) for observation of neurovascular coupling in patients with chronic MFP. STUDY DESIGN: Observational study. SETTING: University hospital. METHODS: Resting-state functional magnetic resonance imaging and arterial spin labeling were performed in 23 patients with chronic MFP and 23 healthy controls (HC) for the calculation of FCS and CBF. The whole-brain gray matter CBF-FCS correlations and CBF/FCS ratios of the various voxels of the 2 groups were subsequently compared. RESULTS: Compared with the HC, the patients with MFP experienced a decrease in whole-brain gray matter CBF-FCS coupling. In patients with MFP, a decrease in CBF/FCS was found in the bilateral superior temporal gyri, right parahippocampal gyrus, right hippocampus, caudate nucleus, right medial prefrontal cortex, and the periaqueductal gray matter (PAG), whereas an increase in CBF/FCS was found in the bilateral lingual gyri, posterior cingulate cortex, and bilateral inferior parietal lobules. In addition, the CBF/FCS of the PAG in patients with MFP was significantly negatively correlated with the pain visual analog scale score and pain duration. LIMITATIONS: Alterations in neurovascular coupling in patients with MFP were observed only before treatment. Therefore, there is a lack of data on the alterations that occurred after treatment. CONCLUSION: This study demonstrated for the first time that impairment of neurovascular coupling in the brain may be a potential neuropathological mechanism of chronic MFP. KEY WORDS: Myofascial pain, resting-state functional magnetic resonance imaging, arterial spin labeling, cerebral blood flow, functional connectivity strength, neurovascular coupling


2021 ◽  
Vol 15 ◽  
Author(s):  
Ke Song ◽  
Yong Wang ◽  
Mei-Xia Ren ◽  
Jiao Li ◽  
Ting Su ◽  
...  

Background: Using resting-state functional connectivity (rsFC), we investigated alternations in spontaneous brain activities reflected by functional connectivity density (FCD) in patients with optic neuritis (ON).Methods: We enrolled 28 patients with ON (18 males, 10 females) and 24 healthy controls (HCs; 16 males, 8 females). All subjects underwent functional magnetic resonance imaging (fMRI) in a quiet state to determine the values of rsFC, long-range FCD (longFCD), and short-range FCD (IFCD). Receiver operating characteristic (ROC) curves were generated to distinguish patients from HCs.Results: The ON group exhibited obviously lower longFCD values in the left inferior frontal gyrus triangle, the right precuneus and the right anterior cingulate, and paracingulate gyri/median cingulate and paracingulate gyri. The left median cingulate and paracingulate gyri and supplementary motor area (SMA) were also significantly lower. Obviously reduced IFCD values were observed in the left middle temporal gyrus/angular gyrus/SMA and right cuneus/SMA compared with HCs.Conclusion: Abnormal neural activities were found in specific brain regions in patients with ON. Specifically, they showed significant changes in rsFC, longFCD, and IFCD values. These may be useful to identify the specific mechanism of change in brain function in ON.


2021 ◽  
Vol 12 ◽  
Author(s):  
Xia Yang ◽  
Ya-jing Meng ◽  
Yu-jie Tao ◽  
Ren-hao Deng ◽  
Hui-yao Wang ◽  
...  

Background: Alcohol dependence (AD) is a chronic recurrent brain disease that causes a heavy disease burden worldwide, partly due to high relapse rates after detoxification. Verified biomarkers are not available for AD and its relapse, although the nucleus accumbens (NAc) and medial prefrontal cortex (mPFC) may play important roles in the mechanism of addiction. This study investigated AD- and relapse-associated functional connectivity (FC) of the NAc and mPFC with other brain regions during early abstinence.Methods: Sixty-eight hospitalized early-abstinence AD male patients and 68 age- and education-matched healthy controls (HCs) underwent resting-functional magnetic resonance imaging (r-fMRI). Using the NAc and mPFC as seeds, we calculated changes in FC between the seeds and other brain regions. Over a follow-up period of 6 months, patients were measured with the Alcohol Use Disorder Identification Test (AUDIT) scale to identify relapse outcomes (AUDIT ≥ 8).Results: Thirty-five (52.24%) of the AD patients relapsed during the follow-up period. AD displayed lower FC of the left fusiform, bilateral temporal superior and right postcentral regions with the NAc and lower FC of the right temporal inferior, bilateral temporal superior, and left cingulate anterior regions with the mPFC compared to controls. Among these FC changes, lower FC between the NAc and left fusiform, lower FC between the mPFC and left cingulate anterior cortex, and smoking status were independently associated with AD. Subjects in relapse exhibited lower FC of the right cingulate anterior cortex with NAc and of the left calcarine sulcus with mPFC compared to non-relapsed subjects; both of these reductions in FC independently predicted relapse. Additionally, FC between the mPFC and right frontal superior gyrus, as well as years of education, independently predicted relapse severity.Conclusion: This study found that values of FC between selected seeds (i.e., the NAc and the mPFC) and some other reward- and/or impulse-control-related brain regions were associated with AD and relapse; these FC values could be potential biomarkers of AD or for prediction of relapse. These findings may help to guide further research on the neurobiology of AD and other addictive disorders.


2020 ◽  
Vol 2 (2) ◽  
Author(s):  
Lv Han ◽  
Zhao Pengfei ◽  
Liu Chunli ◽  
Wang Zhaodi ◽  
Wang Xindi ◽  
...  

Abstract To determine the neural mechanism underlying the effects of sound therapy on tinnitus, we hypothesize that sound therapy may be effective by modulating both local neural activity and functional connectivity that is associated with auditory perception, auditory information storage or emotional processing. In this prospective observational study, 30 tinnitus patients underwent resting-state functional magnetic resonance imaging scans at baseline and after 12 weeks of sound therapy. Thirty-two age- and gender-matched healthy controls also underwent two scans over a 12-week interval; 30 of these healthy controls were enrolled for data analysis. The amplitude of low-frequency fluctuation was analysed, and seed-based functional connectivity measures were shown to significantly alter spontaneous local brain activity and its connections to other brain regions. Interaction effects between the two groups and the two scans in local neural activity as assessed by the amplitude of low-frequency fluctuation were observed in the left parahippocampal gyrus and the right Heschl's gyrus. Importantly, local functional activity in the left parahippocampal gyrus in the patient group was significantly higher than that in the healthy controls at baseline and was reduced to relatively normal levels after treatment. Conversely, activity in the right Heschl's gyrus was significantly increased and extended beyond a relatively normal range after sound therapy. These changes were found to be positively correlated with tinnitus relief. The functional connectivity between the left parahippocampal gyrus and the cingulate cortex was higher in tinnitus patients after treatment. The alterations of local activity and functional connectivity in the left parahippocampal gyrus and right Heschl’s gyrus were associated with tinnitus relief. Resting-state functional magnetic resonance imaging can provide functional information to explain and ‘visualize’ the mechanism underlying the effect of sound therapy on the brain.


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