Abnormal Amplitude of Low-Frequency Fluctuations of Intrinsic Brain Activity in Alzheimer's Disease

2014 ◽  
Vol 40 (2) ◽  
pp. 387-397 ◽  
Author(s):  
Xuena Liu ◽  
Siqi Wang ◽  
Xinqing Zhang ◽  
Zhiqun Wang ◽  
Xiaojie Tian ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Brain Activity ◽  
Low Frequency ◽  
Frequency Fluctuations ◽  
Intrinsic Brain Activity

Comparison of intrinsic brain activity in individuals with low/moderate myopia versus high myopia revealed by the amplitude of low-frequency fluctuations

2019 ◽  
Vol 61 (4) ◽  
pp. 496-507 ◽  
Author(s):  
Yi Cheng ◽  
Xin Huang ◽  
Yu-Xiang Hu ◽  
Mu-Hua Huang ◽  
Bo Yang ◽  
...  
Keyword(s):  
White Matter ◽  
High Myopia ◽  
Brain Activity ◽  
Low Frequency ◽  
Anterior Lobe ◽  
Frequency Fluctuation ◽  
Healthy Controls ◽  
Optic Radiation ◽  
Frequency Fluctuations ◽  
Intrinsic Brain Activity

Background Previous neuroimaging studies demonstrated that individuals with high myopia are associated with abnormalities in anatomy of the brain. Purpose The purpose of this study was to explore alterations in the intrinsic brain activity by studying the amplitude of low-frequency fluctuations. Material and Methods A total of 64 myopia individuals (41 with high myopia with a refractive error <–600 diopter [D], 23 with low/moderate myopia with a refractive error between –100 and –600 D, and similarly 59 healthy controls with emmetropia closely matched for age) were recruited. The amplitude of low-frequency fluctuations method was conducted to investigate the difference of intrinsic brain activity across three groups. Results Compared with the healthy controls, individuals with low/moderate myopia showed significantly decreased amplitude of low-frequency fluctuation values in the bilateral rectal gyrus, right cerebellum anterior lobe/calcarine, and bilateral thalamus and showed significantly increased amplitude of low-frequency fluctuation values in left white matter (optic radiation), right prefrontal cortex, and left primary motor cortex (M1)/primary somatosensory cortex (S1). In addition, individuals with high myopia showed significantly decreased amplitude of low-frequency fluctuation values in the right cerebellum anterior lobe/calcarine/bilateral parahippocampal gyrus, bilateral posterior cingulate cortex, and bilateral middle cingulate cortex and significantly increased amplitude of low-frequency fluctuation values in left white matter (optic radiation), bilateral frontal parietal cortex, and left M1/S1. Moreover, we found that the amplitude of low-frequency fluctuation values of the different brain areas was closely related to the clinical features in the high myopia group. Conclusion Our results demonstrated that individuals with low/moderate myopia and high myopia had abnormal intrinsic brain activities in various brain regions related to the limbic system, default mode network, and thalamo-occipital pathway.

scholarly journals Amplitude of low-frequency fluctuations on Alzheimer’s disease with depression: evidence from resting-state fMRI

2020 ◽  
Vol 33 (4) ◽  
pp. e100147
Author(s):  
Yuzhu Mu ◽  
Yumei Li ◽  
Qi Zhang ◽  
Zhongxiang Ding ◽  
Mei Wang ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Resting State ◽  
Brain Activity ◽  
Inferior Frontal Gyrus ◽  
Low Frequency ◽  
Middle Frontal Gyrus ◽  
Left Inferior Frontal Gyrus ◽  
Superior Frontal Gyrus ◽  
Frequency Fluctuations ◽  
Left Middle

BackgroundThe prevalence of Alzheimer’s disease (AD) comorbid with depression is common. However, the mechanisms of AD with depression remain unclear.AimsTo investigate the regional alterations of brain activity of AD with depression in resting-state functional magnetic resonance imaging (rs-fMRI).Methods154 patients with AD who met the inclusion criteria were recruited from the Zhejiang Provincial People’s Hospital from October 2014 to October 2016. According to whether the core symptoms of depression were present, patients were divided into two groups, 22 patients with AD with depression (AD-D) and 52 patients with AD without depression (AD-nD). The amplitude of low frequency fluctuations (ALFF) was compared between two groups by performing independent-samples t-test.ResultsCompared with the AD-D group, increased ALFF values in the bilateral superior frontal gyrus, left middle frontal gyrus and left inferior frontal gyrus were observed in the AD-nD group. The brain activity in the AD-nD group in the bilateral superior frontal gyrus, left middle frontal gyrus and the left inferior frontal gyrus was higher than the AD-D group.ConclusionsResting-state brain functional alterations may be closely bound up with the pathophysiologic features of patients with AD with depressive symptoms.

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