scholarly journals Dynamic Changes of Amplitude of Low-Frequency Fluctuations in Patients With Diabetic Retinopathy

2021 ◽  
Vol 12 ◽  
Author(s):  
Xin Huang ◽  
Zhi Wen ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
Yin Shen

Background: Growing evidence demonstrate that diabetic retinopathy (DR) patients have a high risk of cognitive decline and exhibit abnormal brain activity. However, neuroimaging studies thus far have focused on static cerebral activity changes in DR patients. The characteristics of dynamic cerebral activity in patients with DR are poorly understood.Purpose: The purpose of the study was to investigate the dynamic cerebral activity changes in patients with DR using the dynamic amplitude of low-frequency fluctuation (dALFF) method.Materials and methods: Thirty-four DR patients (18 men and 16 women) and 38 healthy controls (HCs) (18 males and 20 females) closely matched in age, sex, and education were enrolled in this study. The dALFF method was used to investigate dynamic intrinsic brain activity differences between the DR and HC groups.Results: Compared with HCs, DR patients exhibited increased dALFF variability in the right brainstem, left cerebellum_8, left cerebellum_9, and left parahippocampal gyrus. In contrast, DR patients exhibited decreased dALFF variability in the left middle occipital gyrus and right middle occipital gyrus.Conclusion: Our study highlighted that DR patients showed abnormal variability of dALFF in the visual cortices, cerebellum, and parahippocampal gyrus. These findings suggest impaired visual and motor and memory function in DR individuals. Thus, abnormal dynamic spontaneous brain activity might be involved in the pathophysiology of DR.

2021 ◽  
Vol 18 (12) ◽  
pp. 1205-1212
Author(s):  
Yingchan Wang ◽  
Yuchao Jiang ◽  
Dengtang Liu ◽  
Jianye Zhang ◽  
Dezhong Yao ◽  
...  

Objective Abnormalities of static brain activity have been reported in schizophrenia, but it remains to be clarified the temporal variability of intrinsic brain activities in schizophrenia and how atypical antipsychotics affect it.Methods We employed a resting-state functional magnetic resonance imaging (rs-fMRI) and a sliding-window analysis of dynamic amplitude of low-frequency fluctuation (dALFF) to evaluate the dynamic brain activities in schizophrenia (SZ) patients before and after 8-week antipsychotic treatment. Twenty-six schizophrenia individuals and 26 matched healthy controls (HC) were included in this study.Results Compared with HC, SZ showed stronger dALFF in the right inferior temporal gyrus (ITG.R) at baseline. After medication, the SZ group exhibited reduced dALFF in the right middle occipital gyrus (MOG.R) and increased dALFF in the left superior frontal gyrus (SFG.L), right middle frontal gyrus (MFG.R), and right inferior parietal lobule (IPL.R). Dynamic ALFF in IPL.R was found to significant negative correlate with the Scale for the Assessment of Negative Symptoms (SANS) scores at baseline.Conclusion Our results showed dynamic intrinsic brain activities altered in schizophrenia after short term antipsychotic treatment. The findings of this study support and expand the application of dALFF method in the study of the pathological mechanism in psychosis in the future.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Qi Liu ◽  
Peihai Zhang ◽  
Junjie Pan ◽  
Zhengjie Li ◽  
Jixin Liu ◽  
...  

Background.Pattern differentiation is the foundation of traditional Chinese medicine (TCM) treatment for erectile dysfunction (ED). This study aims to investigate the differences in cerebral activity in ED patients with different TCM patterns.Methods.27 psychogenic ED patients and 27 healthy subjects (HS) were enrolled in this study. Each participant underwent an fMRI scan in resting state. The fractional amplitude of low-frequency fluctuation (fALFF) was used to detect the brain activity changes in ED patients with different patterns.Results.Compared to HS, ED patients showed an increased cerebral activity in bilateral cerebellum, insula, globus pallidus, parahippocampal gyrus, orbitofrontal cortex (OFC), and middle cingulate cortex (MCC). Compared to the patients with liver-qi stagnation and spleen deficiency pattern (LSSDP), the patients with kidney-yang deficiency pattern (KDP) showed an increased activity in bilateral brainstem, cerebellum, hippocampus, and the right insula, thalamus, MCC, and a decreased activity in bilateral putamen, medial frontal gyrus, temporal pole, and the right caudate nucleus, OFC, anterior cingulate cortex, and posterior cingulate cortex (P<0.005).Conclusions.The ED patients with different TCM patterns showed different brain activities. The differences in cerebral activity between LSSDP and KDP were mainly in the emotion-related regions, including prefrontal cortex and cingulated cortex.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Xin Huang ◽  
Zhi Wen ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
Han-Dong Dan ◽  
...  

Previous neuroimaging studies demonstrated that visual deprivation triggers significant crossmodal plasticity in the functional and structural architecture of the brain. However, prior neuroimaging studies focused on the static brain activity in blindness. It remains unknown whether alterations of dynamic intrinsic brain activity occur in late blindness (LB). This study investigated dynamic intrinsic brain activity changes in individuals with late blindness by assessing the dynamic amplitude of low-frequency fluctuations (dALFFs) using sliding-window analyses. Forty-one cases of late blindness (LB) (29 males and 12 females, mean age: 39.70±12.66 years) and 48 sighted controls (SCs) (17 males and 31 females, mean age: 43.23±13.40 years) closely matched in age, sex, and education level were enrolled in this study. The dALFF with sliding-window analyses was used to compare the difference in dynamic intrinsic brain activity between the two groups. Compared with SCs, individuals with LB exhibited significantly lower dALFF values in the bilateral lingual gyrus (LING)/calcarine (CAL) and left thalamus (THA). LB cases also showed considerably decreased dFC values between the bilateral LING/CAL and the left middle frontal gyrus (MFG) and between the left THA and the right LING/cerebelum_6 (CER) (two-tailed, voxel-level P<0.01, Gaussian random field (GRF) correction, cluster-level P<0.05). Our study demonstrated that LB individuals showed lower-temporal variability of dALFF in the visual cortices and thalamus, suggesting lower flexibility of visual thalamocortical activity, which might reflect impaired visual processing in LB individuals. These findings indicate that abnormal dynamic intrinsic brain activity might be involved in the neurophysiological mechanisms of LB.


2019 ◽  
Vol 61 (6) ◽  
pp. 813-820 ◽  
Author(s):  
Qing Gao ◽  
Bin Peng ◽  
Xin Huang ◽  
Chen-Xing Qi ◽  
Yan Tong ◽  
...  

Background There is increasing evidence that patients with retinal vein occlusion exhibit cerebral vascular changes and are at an increased risk of stroke. However, it remains unknown whether patients with retinal vein occlusion exhibit changes in intrinsic brain activity. Purpose This study investigated intrinsic brain activity changes in patients with retinal vein occlusion by assessing the amplitude of low-frequency fluctuations. Material and Methods Forty-five patients with retinal vein occlusion (22 men, 23 women, mean age 56.55 ± 6.97 years) and 43 healthy controls (13 men, 30 women; mean age 53.53 ± 8.19 years) closely matched in age, sex, and education level underwent resting-state MRI scans. The amplitude of low-frequency fluctuation method was used to compare intrinsic brain activity between the two groups. Results Compared with healthy controls, patients with retinal vein occlusion exhibited significantly lower amplitude of low-frequency fluctuation values in the left middle occipital gyrus, right middle occipital gyrus, and right calcarine. However, patients with retinal vein occlusion showed significantly higher amplitude of low-frequency fluctuations in the bilateral cerebellum 6, right hippocampus, left insula, and left fusiform (voxel-level P < 0.01, Gaussian random field correction, cluster-level P < 0.05). Conclusion Our results demonstrated that patients with retinal vein occlusion showed abnormal spontaneous neural activities in the visual cortices, cerebellum, and Papez circuit, which might indicate impaired vision, cognition, and emotional function in patients with retinal vein occlusion. These findings offer important insights into the neural mechanism of retinal vein occlusion.


2020 ◽  
Vol 14 ◽  
Author(s):  
Fei-Fei Luo ◽  
Hui Xu ◽  
Ming Zhang ◽  
Yuan Wang

PurposeThree classical methods of resting-state functional magnetic resonance imaging (rs-fMRI) were employed to explore the local functional abnormalities and their effect on spasm ratings in hemifacial spasm (HFS) patients.MethodsThirty HFS patients and 30 matched healthy controls (HCs) were recruited. Rs-fMRI data, neurovascular compression (NVC) degree and spasm severity were collected in each subject. Fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and degree centrality (DC) were calculated in the whole brain voxels. Two sample t-tests were performed to investigate group differences of fALFF, ReHo, and DC. Correlation analysis was performed to assess the relationships between the regional brain abnormalities and clinical variables in HFS.ResultsCompared with HCs, HFS patients exhibited increased fALFF in the left precuneus and right posterior cingulate cortex (PCC), together with increased ReHo in the bilateral PCC and bilateral precuneus. Decreased ReHo was observed in the right middle occipital gyrus (MOG), right superior occipital gyrus (SOG), right cuneus, and right angular gyrus (AG) in HFS patients. Moreover, ReHo in the right PCC were positively correlated with NVC degree and spasm severity in HFS patients, respectively. Mediation analysis revealed that increased ReHo in the right PCC regulated the neurovascular compression degree, and further resulted in increased spasm ratings.ConclusionOur study revealed regional brain dysfunctions from different perspectives and an indirect effect of ReHo in right PCC on spasm ratings predominantly through the alteration of NVC.


2021 ◽  
pp. 028418512110324
Author(s):  
Xiao-Dong Zhang ◽  
Jun Ke ◽  
Jing-Li Li ◽  
Yun-Yan Su ◽  
Jia-Min Zhou ◽  
...  

Background Sjögren’s syndrome (SjS) associated with systemic lupus erythematosus (SjS-SLE) was considered a standalone but often-overlooked entity. Purpose To assess altered spontaneous brain activity in SjS-SLE and SjS using amplitude of low-frequency fluctuation (ALFF). Material and Methods Sixteen patients with SjS-SLE, 17 patients with SjS, and 17 matched controls underwent neuropsychological tests and subsequent resting-state functional magnetic resonance imaging (fMRI) examinations. The ALFF value was calculated based on blood oxygen level dependent (BOLD) fMRI. Statistical parametric mapping was utilized to analyze between-group differences and multiple comparison was corrected with Analysis of Functional NeuroImages 3dClustSim. Then, the ALFFs of brain regions with significant differences among the three groups were correlated to corresponding clinical and neuropsychological variables by Pearson correlation. Results ALFF differences in the bilateral precuneus/posterior cingulate cortex (PCC), right parahippocampal gyrus/caudate/insula, and left insula were found among the three groups. Both SjS-SLE and SjS displayed decreased ALFF in the right parahippocampal gyrus, right insula, and left insula than HC. Moreover, SjS-SLE showed wider decreased ALFF in the bilateral precuneus and right caudate, while the SjS group exhibited increased ALFF in the bilateral PCC. Additionally, patients with SjS-SLE exhibited lower ALFF values in the bilateral PCC and precuneus than SjS. Moreover, ALFF values in the right parahippocampal gyrus and PCC were negatively correlated to fatigue score and disease duration, respectively, in SjS-SLE. Conclusion SjS-SLE and SjS exhibited common and different alteration of cerebral functional segregation revealed by AlFF analysis. This result appeared to indicate that SjS-SLE might be different from SjS with a neuroimaging standpoint.


2021 ◽  
Vol 12 ◽  
Author(s):  
Ruiping Zheng ◽  
Yuan Chen ◽  
Yu Jiang ◽  
Mengmeng Wen ◽  
Bingqian Zhou ◽  
...  

Background: Major depressive disorder (MDD) has demonstrated abnormalities of static intrinsic brain activity measured by amplitude of low-frequency fluctuation (ALFF). Recent studies regarding the resting-state functional magnetic resonance imaging (rs-fMRI) have found the brain activity is inherently dynamic over time. Little is known, however, regarding the temporal dynamics of local neural activity in MDD. Here, we investigated whether temporal dynamic changes in spontaneous neural activity are influenced by MDD.Methods: We recruited 81 first-episode, drug-naive MDD patients and 64 age-, gender-, and education-matched healthy controls who underwent rs-fMRI. A sliding-window approach was then adopted for the estimation of dynamic ALFF (dALFF), which was used to measure time-varying brain activity and then compared between the two groups. The relationship between altered dALFF variability and clinical variables in MDD patients was also analyzed.Results: MDD patients showed increased temporal variability (dALFF) mainly focused on the bilateral thalamus, the bilateral superior frontal gyrus, the right middle frontal gyrus, the bilateral cerebellum posterior lobe, and the vermis. Furthermore, increased dALFF variability values in the right thalamus and right cerebellum posterior lobe were positively correlated with MDD symptom severity.Conclusions: The overall results suggest that altered temporal variability in corticocerebellar–thalamic–cortical circuit (CCTCC), involved in emotional, executive, and cognitive, is associated with drug-naive, first-episode MDD patients. Moreover, our study highlights the vital role of abnormal dynamic brain activity in the cerebellar hemisphere associated with CCTCC in MDD patients. These findings may provide novel insights into the pathophysiological mechanisms of MDD.


2021 ◽  
Author(s):  
Yilei Chen ◽  
Yingjie Kang ◽  
Shilei Luo ◽  
Shanshan Liu ◽  
Bo Wang ◽  
...  

Abstract Background: The underlying neurological mechanism of acupuncture treatment in migraine without aura (MwoA) remains unclear. Therefore, we explored the dynamic alterations of intrinsic brain activity and effective connectivity in patients with MwoA after acupuncture treatment.Methods:The fMRI scans were separately obtained at baseline, after the first and after the 12th acupuncture sessions in 40 patients with MwoA. The acupuncture treatments were finished within 6 weeks as twice a week. 36 matched healthy controls (HCs) were recruited and performed once fMRI scan. The dynamic amplitude of low-frequency fluctuation (dALFF) and dynamic granger causality analysis(GCA) were used to analyze the difference of different time points in patients with MwoA. The correlation analyses were performed in dALFF variability, dynamic effective connectivity (DEC) variability with clinical variables in patients with MwoA.Results:Compared with HCs, Patients with MwoA at baseline showed decreased dALFF variability in regions within rostral ventromedial medulla (RVM), the superior lobe of left cerebellum (Cerebelum_Crus1_L), the right inferior frontal gyrus, triangular part (IFGtriang.R), the right median cingulate and paracingulate gyri (DCG.R), the right precuneus (PCUN.R), and the left inferior parietal, supramarginal and angular gyri (IPL.L), increased dALFF variability only in the left inferior occipital gyrus (IOG.L). After acupuncture treatment, the decreased dALFF variability of the RVM, Cerebelum_Crus1_L , and PCUN.R progressively recovered, the RVM revealed gradually increased DEC variability to the right middle frontal gyrus (MFG.R), the left insula (INS.L), the right precentral gyrus (PreCG.R), and the right supramarginal gyrus (SMG.R). And enhanced DEC variability from the right fusiform gyrus (FFG.R) to RVM. Furthermore, the increased DEC variability were found from Cerebelum_Crus1_L to the left middle occipital gyrus (MOG.L) and the left precentral gyrus (PreCG.L), from PCUN.R to the right thalamus (THA.R). These dALFF variabilities were significantly positive correlated with frequency of migraine attack and negative correlated with disease duration at baseline, dynamic GCA coefficients were significantly positive correlated with Migraine-Specific Quality of Life Questionnaire (MSQ) score, negative correlated with frequency of migraine attack and visual analog scale (VAS) score postacupuncture treatment.Conclusions:Our results provide insight into dynamic alterations from the perspective of dynamic local brain activity and effective connectivity for the understanding mechanisms of cumulative therapeutic effect of acupuncture in patients with MwoA.Trial registration: ChiCTR, ChiCTR1900023105. Registered 11 May 2019, http://www.chictr.org.cn/showproj.aspx?proj=36959.


2020 ◽  
Vol 61 (10) ◽  
pp. 1388-1397
Author(s):  
Yi Cheng ◽  
Li Yan ◽  
Liqun Hu ◽  
Hongyun Wu ◽  
Xin Huang ◽  
...  

Background Previous studies have linked high myopia (HM) to brain activity, and the difference between HM and low myopia (LM) can be assessed. Purpose To study the differences in functional networks of brain activity between HM and LM by the voxel-level degree centrality (DC) method. Material and Methods Twenty-eight patients with HM (10 men, 18 women), 18 patients with LM (4 men, 14 women), and 59 healthy controls (27 men, 32 women) were enrolled in this study. The voxel-level DC method was used to assess spontaneous brain activity. Correlation analysis was used to explore the change of average DC value in different brain regions, in order to analyze differences in brain activity between HM and LM. Results DC values of the right cerebellum anterior lobe/brainstem, right parahippocampal gyrus, and left caudate in HM patients were significantly higher than those in LM patients ( P < 0.05). In contrast, DC values of the left medial frontal gyrus, right inferior frontal gyrus, left middle frontal gyrus, and left inferior parietal lobule were significantly lower in patients with HM ( P < 0.05). However, there was no correlation between behavior and average DC values in different brain regions ( P < 0.05). Conclusion Different changes in brain regions between HM and LM may indicate differences in neural mechanisms between HM and LM. DC values could be useful as biomarkers for differences in brain activity between patients with HM and LM. This study provides a new method to assess differences in functional networks of brain activity between patients with HM and LM.


Sign in / Sign up

Export Citation Format

Share Document