Fractional Amplitude Of Low-frequency Fluctuations Research Articles

Dynamic amplitude of low-frequency fluctuation links dark personalities to malevolent creative behavior.

Malevolent creativity refers to the ability to generate ideas that cause harm to oneself or others. While previous research has touched on how personality traits influence malevolent creative behavior, the neural mechanisms involved remain underexplored. This study investigated the brain patterns associated with malevolent creative behavior and how these patterns are mediated by dark personality traits (Machiavellianism, narcissism, and psychopathy) and positive traits (internalization, symbolization, and honesty-humility). Our findings revealed that Machiavellianism mediated the relationship between the amplitude of low-frequency fluctuation (ALFF) in the left medial superior frontal gyrus (mSFG), pallidum (PAL), and middle temporal gyrus (MTG) and malevolent creative behavior, particularly in actions like hurting people or playing tricks. Psychopathy similarly mediated the link between the ALFF in the right orbital middle frontal gyrus (oMFG), right mSFG, left PAL, and left MTG and malevolent creative behavior. Additionally, Machiavellianism negatively mediated the relationship between the fractional ALFF (fALFF) of the left parahippocampal gyrus (PHG) and hurting people, as well as between the fALFF of the left inferior occipital gyrus (IOG) and playing tricks. The ALFF in the left mSFG and left MTG predicted playing tricks but also negatively predicted internalization and honesty-humility, which in turn reduced engagement in playing tricks. Finally, the fALFF of the left IOG negatively predicted playing tricks and positively predicted internalization, which again decreased playing tricks. These findings highlight the complex interaction between brain activity, personality traits, and malevolent creative behavior, offering a potential path for targeted interventions and further research into this interesting phenomenon.

Abstract 27: The Brain-behaviour Mechanisms of Impaired Linguistic and Cognitive Function Impairments in Stroke Patients with Aphasia

Introduction: The combination of verbal and non-verbal cognitive dysfunction in post-stroke aphasia (PSA) patients may ultimately affect social interactions. However, the underlying neural mechanisms of both verbal and non-verbal cognitive impairment remain unclear. This study aimed to investigate the activity and functional abnormalities of local and remote brain regions and their relationship with cognitive behaviour, to provide more effective guidance in future clinical therapy. Methods: We recruited 46 PSA patients and 40 normal controls(NCs) matched for general characteristics in this study and evaluated their verbal and non-verbal cognitive functions. Functional magnetic resonance imaging(fMRI) was used to examine the fractional amplitude of low-frequency fluctuations(fALFF), regional homogeneity(ReHo), and functional connectivity(FC) in PSA patients. Independent two-sample t-tests were used to identify differences in these measures between two groups. Moreover, partial correlation analyses were performed to determine the correlation between FC from the affected brain regions and language and cognitive performance in PSA patients. Results: This study revealed that PSA patients presented significantly lower fALFF and ReHo values in right cerebellum superior (CRBL.Superior.R), left thalamus(THA.L), and left middle frontal gyrus(MFG.L). Moreover, the FC in the MFG.L-left inferior frontal gyrus, orbital part was significantly lower among PSA patients and was positively correlated with language and cognitive performance(p< 0.05). The CRBL. Superior. R-left caudate nucleus and right lenticular nucleus FC were also decreased and were associated with cognitive function(p< 0.05). In addition, PSA patients were further divided into fluent and nonfluent groups. The results revealed that nonfluent patients performed worse in verbal and non-verbal cognitive performance(p< 0.05) and had weaker performance in the THA.L and left supplementary motor area FC(p< 0.001). Conclusions: This study provides new evidence that abnormal neural activity and functional connectivity within specific brain regions may play crucial roles in language and cognitive processing. The underlying mechanisms of impaired linguistic function accompanied by decline in cognition may be a partial overlap between language and cognitive-related brain networks. In future, combining cognitive and linguistic functions and designing a comprehensive treatment plan will be the focus of rehabilitation.

Decreases in frequency-dependent intrinsic activity of the default mode network are associated with depression and cognition in patients with postacute sequelae of SARS-CoV-2 infection.

A significant proportion of patients who have recovered from COVID-19 suffer from persistent symptoms, referred to as "post-acute sequelae of SARS-CoV-2 infection (PASC)". Abnormal brain intrinsic activity has been observed in PASC patients, but the patterns of frequency-dependent intrinsic activity in the PASC and non-PASC (recovered COVID-19 patients without persistent symptoms) groups and their association with neuropsychiatric sequelae remain unclear in PASC. Twenty-nine PASC patients, 27 non-PASC subjects, and 31 healthy controls (HCs) were recruited. The voxel-level fractional amplitude of low-frequency fluctuation (fALFF) was calculated in different frequency bands (typical frequency band: 0.01-0.10Hz; slow 5: 0.01-0.023Hz; slow 4: 0.023-0.073Hz) to assess regional intrinsic activity patterns within different groups. Correlation analyses were performed to explore the associations between frequency-dependent alterations and clinical variables. Significant frequency-dependent alterations in intrinsic activity patterns were observed in both the PASC and non-PASC groups, primarily involving regions of the default mode network (DMN). The decreased fALFF values of the DMN in different frequency bands were associated with different symptoms in PASC. For example, decreased fALFF in the left precuneus in the typical frequency band was related to general attention impairment in PASC, whereas decreased fALFF in the left superior frontal gyrus appeared in non-PASC. The fALFF alterations in the left precuneus/posterior cingulate gyrus in the slow 5 band were also related to cognitive performance in PASC. Additionally, in the slow 4 band, decreased fALFF in the right angular gyrus was associated with depressive symptoms in the PASC. Our results may provide insights into the potential neural mechanisms underlying symptoms in PASC patients.

Obstructive sleep apnea and structural and functional brain alterations: a brain-wide investigation from clinical association to genetic causality

BackgroundObstructive sleep apnea (OSA) is linked to brain alterations, but the specific regions affected and the causal associations between these changes remain unclear.MethodsWe studied 20 pairs of age-, sex-, BMI-, and education- matched OSA patients and healthy controls using multimodal magnetic resonance imaging (MRI) from August 2019 to February 2020. Additionally, large-scale Mendelian randomization analyses were performed using genome-wide association study (GWAS) data on OSA and 3935 brain imaging-derived phenotypes (IDPs), assessed in up to 33,224 individuals between December 2023 and March 2024, to explore potential genetic causality between OSA and alterations in whole brain structure and function.ResultsIn the cohort study, OSA patients exhibited significantly lower fractional amplitude of low-frequency fluctuation and regional homogeneity in the right posterior cerebellar lobe and bilateral superior and middle frontal gyrus, while showing higher levels in the left occipital lobe and left posterior central gyrus. Decreased fractional anisotropy (FA) but increased apparent diffusion coefficient (ADC) was shown in the bilateral superior longitudinal fasciculus. According to the results of Affiliation file 2: table s6, it is the ADC value of right superior longitudinal fasciculus was shown a positive correlation with the lowest oxygen saturation. In the Mendelian randomization analyses, the area of left inferior temporal sulcus (OR: 0.89; 95% CI: 0.82–0.96), rfMRI connectivity ICA100 edge 893 (OR: 0.88; 95% CI: 0.82–0.96), ICA100 edge 951 (OR: 0.89; 95% CI: 0.82–0.97), and ICA100 edge 1213 (OR: 0.89; 95% CI: 0.82–0.96) were significantly decreased in OSA. Conversely, mean thickness of G-front-inf-Triangul in right hemisphere (OR: 1.14; 95% CI: 1.05–1.23), mean orientation dispersion index in right tapetum (OR: 1.13; 95% CI: 1.04–1.23), and rfMRI connectivity ICA100 edge 258 (OR: 1.13; 95% CI: 1.04–1.22) showed opposite results.ConclusionsNerve fiber damage and imbalances in neuronal activity across multiple brain regions caused by hypoxia, particularly the frontal lobe, underlie the structural and the functional connectivity impairments in OSA.

Research on noise-induced hearing loss based on functional and structural MRI using machine learning methods

Noise-induced hearing loss (NIHL) is a common occupational condition. The aim of this study was to develop a classification model for NIHL on the basis of both functional magnetic resonance imaging (fMRI) and structural magnetic resonance imaging (sMRI) by applying machine learning methods. fMRI indices such as the amplitude of low-frequency fluctuation (ALFF), fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), degree of centrality (DC), and sMRI indices such as gray matter volume (GMV), white matter volume (WMV), and cortical thickness were extracted from each brain region. The least absolute shrinkage and selection operator was used to reduce and select the optimal features. The support vector machine (SVM), random forest (RF) and logistic regression (LR) algorithms, were used to establish the classification model for NIHL. Finally, the SVM model based on combined fMRI indices, achieved the best performance, with area under the receiver operating characteristic curve of 0.97 and an accuracy of 95%. The SVM classification model that integrates fMRI indicators has the greatest potential for identifying NIHL patients and healthy people, revealing the complementary role of fMRI indicators in classification and indicating that it is necessary to include multiple indicators of the brain when establishing a classification model.

Fractional amplitude of low-frequency fluctuations during music-evoked autobiographical memories in neurotypical older adults.

Researchers have shown that music-evoked autobiographical memories (MEAMs) can stimulate long-term memory mechanisms while requiring little retrieval effort and may therefore be used in promising non-pharmacological interventions to mitigate memory deficits. Despite an increasing number of studies on MEAMs, few researchers have explored how MEAMs are bound in the brain. In the current study activation indexed by fractional amplitude of low frequency fluctuations (fALFF) during familiar and unfamiliar MEAM retrieval was compared in a sample of 24 healthy older adults. Additionally, we aimed to investigate the impact of age-related gray matter volume (GMV) reduction in key regions associated with MEAM-related activation. In addition to a T1 structural scan, neuroimaging data were collected while participants listened to familiar music (MEAM retrieval) versus unfamiliar music. When listening to familiar compared to unfamiliar music, greater fALFF activation patterns were observed in the right parahippocampal gyrus, controlling for age and GMV. The current findings for the familiar (MEAM) condition have implications for cognitive aging as persons experiencing age-related memory decline are particularly susceptible to volumetric reduction in the parahippocampal cortex. Post-hoc analyses to explore correlations between brain activity and the content of MEAMs were performed using the text analysis program Linguistic Inquiry and Word Count. Our findings suggest that MEAM-related activation of the parahippocampal cortex is evident in normative older adults. However, it is yet to be determined whether such brain states are attainable in older adult populations diagnosed with mild cognitive impairment and/or prodromal Alzheimer's disease.

Brain function abnormalities and inflammation in HIV-positive men who have sex with men with depressive disorders.

Depressive disorders are highly prevalent among people with HIV (PWH) and are related to aberrant inflammation and immune responses. However, there is currently a lack of investigation into the neurological, inflammatory, endocrine, and immune aspects of HIV-associated depressive disorders (HADD). The study involved 33 HIV-positive men who have sex with men with depressive disorders (HADD group) and 47 without neuropsychiatric disorders (HIV control group). Participants underwent resting-state functional magnetic resonance imaging (rs-fMRI) scans and assessments of peripheral blood. Peripheral blood cytokines, plasma concentrations of hormone and neurotrophic factors, and immune cell levels were determined using liquid chip, enzyme-linked immunosorbent assay, and flow cytometry, respectively. The correlation of imaging alterations with clinical variables and peripheral blood indicators was assessed. Compared to the HIV control group, the HADD group exhibited a higher fractional amplitude of low-frequency fluctuations in the left superior parietal gyrus, lower regional homogeneity in the left precentral gyrus, and reduced voxel-wise functional connectivity for the seed region in the right precentral gyrus with clusters in the right cuneus, etc. Furthermore, the HADD group had higher levels of interferon-gamma, a higher frequency of non-classical monocytes, and higher expression levels of perforin and CD38 on specific cells. These imaging results were significantly correlated with peripheral blood indicators and clinical variables. This rs-fMRI study provides considerable evidence for abnormal intrinsic brain activity in people with HADD. Furthermore, our data also indicate the detrimental effects of depression-related inflammation on PWH. Therefore, it is imperative to increase attention to HADD and implement effective preventive interventions accordingly.

Dynamic Neural Mechanisms Underlying Sustained Motor Training Post-Stroke: An fNIRS Investigation Employing Time-Varying ALFF and Functional Connectivity Analysis.

Motor dysfunction of the upper limbs following a stroke predominantly arises from abnormal motor patterning caused by the disrupted balance of inter-cortical communication within motor-associated cortical regions. Temporal analysis offers a more precise reflection of the cortical functional state in affected patients. This study employed fNIRS to capture hemodynamic responses among 20 stroke patients and 19 healthy controls in both resting and Baduanjin task state. Including computing the coefficient of variation of fractional amplitude of low-frequency fluctuations (fALFF) for each channel, alongside extracting dynamic state metrics. Findings indicate that, during sustained motor tasks, stroke patients exhibit a diminished fALFF variability in targeted cortical regions; these individuals display a higher prevalence of low-intensity states and a lower prevalence of high-intensity states during task execution. These dynamic state attributes are significantly associated with scores on the upper limb motor function scale (FMA-UE), thereby proposing a time-domain perspective for investigating the underlying mechanisms of stroke-induced motor dysfunction.

Neurovascular coupling dysfunction associated with inflammatory factors in sudden sensorineural hearing loss.

The neuropathologic mechanisms of sudden sensorineural hearing loss (SSNHL) are unknown. The aim of this study was to investigate the alterations of neurovascular coupling (NVC) in patients with SSNHL and its association with hematologic inflammatory factors. The amplitude of low-frequency fluctuations (ALFF), fractional amplitude of low-frequency fluctuations (fALFF), regional homogeneity (ReHo), and degree centrality (DC) were calculated in 48 patients with SSNHL and 54 age-, gender-, and education-matched healthy control (HC), and also utilized the arterial spin labeling imaging (ASL) to calculate cerebral blood flow (CBF). Four indices of NVC (CBF-ALFF, CBF-fALFF, CBF-ReHo, and CBF-DC) in the whole brain gray matter as well as the NVC ratio were compared between two groups. In addition, correlation analyses were performed with inflammatory factors for the NVC indexes at the global level and regional level, respectively. The NVC at global level was lower in SSNHL group than in HC, except for CBF-ALFF. At the regional level, most of the brain regions with abnormal NVC in SSNHL patients involved auditory and sensorimotor language centers and limbic system compared to HC. In addition, both at the global and regional levels, NVC metrics were shown to correlate with partial inflammatory factors or hematologic parameters, including platelet-lymphocyte ratio (PLR), neutrophil-lymphocyte ratio (NLR), systemic immunoinflammatory index (SII), blood platelet count (PLT), and lymphocyte count (Lym). From the view of the NVC metrics, these findings provide new perspectives on the neuropathologic mechanisms and clinical treatment of SSNHL.

Altered spontaneous brain activity in children with deprivation amblyopia: a resting-state functional magnetic resonance imaging study

BackgroundTo investigate the alterations in spontaneous brain activity and the similarities and differences between monocular deprivation amblyopia and binocular deprivation amblyopia.MethodsTwenty children with binocular deprivation amblyopia, 26 children with monocular deprivation amblyopia and 20 healthy controls underwent resting-state functional magnetic resonance imaging. The evaluation of altered spontaneous brain activity was conducted using fractional amplitude of low-frequency fluctuations (fALFF). One-way analysis of variance was employed to analyze fALFF values among the three groups. Additionally, the relationship between fALFF values and best corrected visual acuity (BCVA) was analyzed via correlation analysis.ResultsCompared to healthy controls, children with binocular deprivation amblyopia presented increased fALFF values in the left medial superior frontal gyrus, left middle frontal gyrus, left anterior cingulate cortex, left postcentral gyrus and bilateral precentral gyrus, and decreased fALFF values in the right fusiform gyrus. Compared to healthy controls, children with monocular deprivation amblyopia presented increased fALFF values in the right lingual gyrus, right superior frontal gyrus, right middle frontal gyrus, left superior temporal gyrus, triangular part of the left inferior frontal gyrus and bilateral middle temporal gyrus, and decreased fALFF values in the right precuneus. Compared with monocular deprivation amblyopia, fALFF values of binocular deprivation amblyopia were decreased in the triangular part of the left inferior frontal gyrus, right lingual gyrus and right cuneus, and increased in the left precentral gyrus and left postcentral gyrus. No significant correlations were found between the fALFF values of identified regions and the BCVA of amblyopic eyes for either type of amblyopia.ConclusionsChildren with deprivation amblyopia presented alterations in spontaneous activity in multiple brain regions, and these alterations differed between monocular amblyopia and binocular amblyopia. These abnormal spontaneous activities may reflect dysfunctions and compensation related to amblyopia.

Aberrant regional neural fluctuations and functional connectivity in insomnia comorbid depression revealed by resting-state functional magnetic resonance imaging.

Insomnia is a common mental illness seriously affecting people lives, that might progress to major depression. However, the neural mechanism of patients with CID comorbid MDD remain unclear. Combining fractional amplitude of low-frequency fluctuation (fALFF) and seed-based functional connectivity (FC), this study investigated abnormality in local and long-range neural activity of patients with CID comorbid MDD. Here, we acquired resting-state blood oxygenation level dependent (BOLD) data from 57 patients with CID comorbid MDD and 57 healthy controls (HC). Compared with the controls, patients with CID comorbid MDD exhibited abnormal functional activity in posterior cerebral cortex related to the visual cortex, including the middle occipital gyrus (MOG), the cuneus and the lingual gyrus, specifically, lower fALFF values in the right MOG, left cuneus, and right postcentral gyrus, increased FC between the right MOG and the left cerebellum, and decreased FC between the right MOG and the right lingual gyrus. Neuropsychological correlation analysis revealed that the decreased fALFF in the right MOG was negatively correlated with all the neuropsychological scores of insomnia and depression, reflecting common relationships with symptoms of CID and MDD. While the decreased fALFF of the left cuneus was distinctly correlated with the scores of depression related scales. The decreased FC between the right MOG and the right lingual gyrus was distinctly correlated with the scores of insomnia related scales. This study not only widened neuroimaging evidence that associated with insomnia and depressive symptoms of patients with CID comorbid MDD, but also provided new potential targets for clinical treatment.

A preliminary study of fMRI and the relationship with depression and anxiety in Meniere's patients

PurposeTo examine alterations in Blood Oxygen Level-Dependent (BOLD) resting-state functional magnetic resonance imaging (rs-fMRI) signals, utilizing regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuation (fALFF) metrics, within activated brain regions. Additionally, this study aims to explore the relationship between these neural changes and clinical characteristics, as well as emotional states, in patients diagnosed with unilateral Meniere's disease (MD). MethodThe study included 24 patients diagnosed with left Meniere's disease (L-MD), 25 patients diagnosed with right Meniere's disease (R-MD), and 23 healthy control subjects. Resting-state blood‑oxygen-level-dependent functional magnetic resonance imaging (rest-BOLD-fMRI) data were preprocessed. A two-sample t-test was employed to compare the regional homogeneity (ReHo) and fractional amplitude of low-frequency fluctuation (fALFF) between the patient groups and the control group. Brain regions exhibiting significant differences were further analyzed for correlations with disease duration, vertigo severity, vertigo duration, hearing loss grade, and levels of anxiety and depression. ResultsIn patients with L-MD, fALFF values were significantly decreased in the right cerebellar hemisphere, middle occipital gyrus, among other regions. In patients with right-sided Ménière's disease (R-MD), fractional amplitude of low-frequency fluctuation (fALFF) values were elevated in the right middle inferior temporal gyrus and fusiform gyrus. Regional homogeneity (ReHo) values exhibited both increases and decreases in the temporal gyrus, parahippocampal gyrus, occipital gyrus, superior marginal gyrus, anterior central gyrus, and fusiform gyrus. In studies examining relational aspects, the parahippocampal gyrus, inferior temporal gyrus, middle occipital gyrus, superior middle occipital gyrus, superior marginal gyrus, and occipital gyrus demonstrated positive or negative correlations with clinical characteristics and emotional states. ConclusionsPatients with unilateral Meniere's disease (MD) exhibited both increased and decreased activation in various brain regions when compared to control subjects. A correlation was identified between these neural activation patterns and clinical characteristics, as well as emotional state, which holds significant implications for clinical treatment, prognosis, and rehabilitation strategies for MD patients.

Alterations in local activity and whole-brain functional connectivity in human immunodeficiency virus-associated neurocognitive disorders: a resting-state functional magnetic resonance imaging study.

Approximately half of human immunodeficiency virus (HIV) patients experience HIV-associated neurocognitive disorders (HAND); however, the neurophysiological mechanisms underlying HAND remain unclear. This study aimed to evaluate changes in functional brain activity patterns during the early stages of HIV infection by comparing local and global indicators using resting-state functional magnetic resonance imaging (rs-fMRI). A total of 165 people living with HIV (PLWH) but without neurocognitive disorders (PWND), 173 patients with asymptomatic neurocognitive impairment (ANI), and 100 matched healthy controls (HCs) were included in the study. A cross-sectional study of the participants was conducted. The metrics of functional segregation and integration were computed, using graph theory to explore differences across methodologies. Brain functional changes in the PWND and ANI groups were assessed, and correlations between the rs-fMRI metrics, clinical data, and cognitive function were examined. As cognitive function declined, changes reflected by regional homogeneity (ReHo) were primarily observed in the default mode network (DMN). In the DMN and visual network (VIS), amplitude of low-frequency fluctuation (ALFF) decreases were mainly observed in the parieto-occipital lobes, while increases were mainly observed in the limbic network (LIM). Reductions in fractional ALFF (fALFF) were mainly observed in the somatomotor network (SMN) and LIM, while increases were observed in the DMN and LIM. Unlike local indicators, global functional connectivity (FC) significantly decreased in both the PWND and ANI groups compared to the HC group. The ANI group showed partial increases in FC compared to the PWND group, with major changes observed in the DMN, VIS, and LIM. Notably, FC between the right insula and right supramarginal gyrus decreased significantly following HIV infection, while FC between the right caudate nucleus and the left middle frontal gyrus declined further in the ANI group. Graph theory further confirmed the significance of the DMN, and revealed changes in the eigenvector centrality mapping (ECM) values of the frontoparietal network (FPN) and dorsal attention network (DAN). HIV patients exhibit complex changes in both local and global brain activity, regardless of cognitive impairment. Widespread abnormalities primarily involve the DMN, VIS, and LIM. Changes in FC along the fronto-striatal pathway may play a crucial role in the decline of cognitive function in individuals with HAND. Our findings provide new insights that may assist in the early detection of brain damage in the early stages of HIV infection. The use of multiple methodologies may offer a more comprehensive and effective approach, enabling the early detection of brain damage in HIV patients.

Association between functional alterations and specific transcriptional expression patterns in craniocervical dystonia.

Craniocervical dystonia (CCD) is a large-scale network disorder that involves functional changes in multiple brain regions. However, the association between these functional changes and the underlying molecular mechanisms has not been explored. We aimed to characterize the molecular changes associated with the imaging-defined functional architecture of the brain in CCD. Resting-state functional magnetic resonance imaging (rs-fMRI) data were obtained from 146 patients with CCD and 137 healthy controls (HCs). Differences in the amplitude of low-frequency fluctuations (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) were compared between groups. Transcriptomic data were obtained from the Allen Human Brain Atlas to identify the gene expression patterns underlying the affected functional architecture in CCD using partial least squares regression. Compared to HCs, patients with CCD showed common functional alterations, mainly in the left middle occipital gyrus, right middle occipital gyrus, right calcarine, right precentral gyrus, and left postcentral gyrus. These functional alteration patterns were positively associated with 1763 genes (including five risk genes for dystonia) enriched for synaptic signaling, regulation of trans-synaptic signaling, and neuronal systems, while they were negatively associated with 2318 genes (including eight risk genes for dystonia), which were enriched for monoatomic cation transport, DNA damage response and neurodevelopment. Our study reveals a genetic pathological mechanism explaining CCD-related brain functional changes.

Alterations in spontaneous brain activity of maintenance hemodialysis patients with restless legs syndrome: a cross-sectional case-control study

ObjectiveThrough resting state functional magnetic resonance imaging (rs-fMRI) we evaluate the spontaneous brain activity changes of maintenance hemodialysis (MHD) patients with restless legs syndrome (RSL) and analyzed the imaging features and related mechanisms of RLS in patients with MHD.MethodWe select 27 MHD patients with RLS and 27 patients without RSL matched by age, gender, cognitive function. Both groups underwent neuropsychological tests and MRI scans. MRI data analysis was performed to obtain and compare the amplitude of low-frequency fluctuation (ALFF), fractional amplitude of low-frequency fluctuations (fALFF), and regional homogeneity (ReHo) values, which were mALFF, mfALFF, and mReHo. Clinical data were collected and compared. Differentiated indicators and RLS scores conduct Pearson correlation analysis.ResultCompared with the MHD-nRLS group, the MHD-RLS group showed significantly lower mALFF values in the left precentral, right precentral gyrus, and right postcentral gyrus, lower mfALFF values in the left precentral gyrus, right precentral gyrus, left calcarine fissure, left lingual gyrus, left postcentral gyrus, and right postcentral gyrus, and lower mReHo values in the left precentral gyrus, right precentral gyrus, left calcarine fissure, left lingual gyrus, left postcentral gyrus, and right postcentral gyrus, and right postcentral gyrus (P < 0.05). The MHD-RLS group exhibited lower hemoglobin levels (P = 0.001), higher total iron-binding capacity levels (P = 0.011), and higher folic acid levels (P = 0.022). The above indicators were correlated with RLS scores using Pearson correlation analysis, and it was found that the mfALFF value of the right precentral gyrus and the right postcentral gyrus, and the mReHo values of the right precentral gyrus and right postcentral gyrus were negatively correlated with the RLS score (r = -0.567, P = 0.002;r = -0.705, P < 0.001;r = -0.414, P = 0.032; r = -0.410, P = 0.034), and the hemoglobin concentration was negatively correlated with the RLS scores (r = -0.394, P = 0.042).ConclusionPatients with MHD-RLS exhibit abnormal spontaneous brain activity in the right precentral gyrus and right postcentral gyrus within the sensorimotor network, along with lower hemoglobin levels, which may be associated with the pathogenesis and severity of MHD-RLS.

Effects of childhood trauma on sustained attention in major depressive disorder: the mediating role of brain activity and functional connectivity

BackgroundSustained attention deficits were reported more significant in patients with major depressive disorder (MDD) than in healthy controls (HCs), and are pivotal in both the development and aggravation of depression. Childhood trauma is also common in MDD and the exposure to childhood trauma may impede sustained attention and increase the treatment resistance in MDD. However, the underlying neuro-mechanisms link the childhood trauma to sustained attention deficits in MDD remain unclear.MethodsWe collected resting-state functional magnetic resonance imaging data, and measured childhood trauma severity using the Childhood Trauma Questionnaire and sustained attention using the Continuous Performance Test, Identical Pairs version. After excluding subjects with significant head movement, 45 MDDs and 54 HCs were included in the analysis. We compared fractional amplitude of low-frequency fluctuation (fALFF) between the groups, conducted whole-brain correlation analysis between the fALFF and sustained attention in the MDD group, and defined significant regions as the regions of interest for the seed-to-whole brain functional connectivity (FC) analysis. We further performed mediation analyses to investigate the relationships among the childhood trauma, fALFF and FC values, and the level of sustained attention in the MDD group.ResultsCompared with HCs, MDDs exhibited higher fALFF in the right middle frontal gyrus and left inferior frontal gyrus, and lower fALFF in the bilateral insular cortex, left medial orbital superior frontal gyrus and left angular gyrus (ANG.L). Whole-brain correlation analysis showed that impaired sustained attention was associated with increased fALFF in the left postcentral gyrus (PoCG.L), and FC of PoCG.L-left precentral gyrus (PreCG.L) and ANG.L-right superior temporal gyrus (STG.R) in the MDD group. Furthermore, mediation analyses showed that the fALFF in PoCG.L, and FC of PoCG.L-PreCG.L and ANG.L-STG.R mediated the relationship between the childhood trauma and sustained attention in the MDD group.ConclusionThe fALFF in PoCG.L, and FC of PoCG.L-PreCG.L and ANG.L-STG.R might be potential neural substrate in the association between the childhood trauma and poor sustained attention in the MDDs, and might serve as potential intervention targets for the treatment of sustained attention deficits in MDDs with childhood trauma history.

Evaluation of Neurovascular Coupling in Early-Onset and Late-Onset Epilepsy of Unknown Etiology.

Previous studies have shown neurovascular coupling (NVC) dysfunction in epilepsy, suggesting its role in the pathological mechanisms. However, it remains unclear whether NVC abnormalities exist in epilepsy of unknown etiology (EU). To integrate multiparametric MRI to assess NVC and its relationship with cognition in early-onset and late-onset EU patients. Prospective. Ninety-six EU patients (46 early-onset, M/F = 20/26; 50 late-onset, M/F = 29/21) and 60 healthy controls (HCs, M/F = 25/35). 3.0 T, resting-state gradient echo-planar imaging, pseudo-continuous arterial spin labeling (pc-ASL), and T1-weighted brain volume sequence. Functional MRI data were analyzed to assess intrinsic brain activity including amplitude of low-frequency fluctuations (ALFF), fractional ALFF (fALFF), regional homogeneity (ReHo), and functional connectivity strength (FCS), while pc-ASL provided cerebral blood flow (CBF) measurements. Coupling correlation coefficients and ratios of CBF to neural activity were calculated to evaluate global and regional NVC. Two-sample t-test, Analysis of Variance, Kruskal-Wallis test, Chi-square test, Analysis of Covariance, family-wise error/Bonferroni correction, partial correlation analyses. Statistical significance was defined as P < 0.05. Whole-brain analysis revealed increased ALFF values in both patient groups' left precentral and postcentral gyri. Both patient groups had lower global NVC coefficients than HCs, with reduced CBF-ALFF (0.28 vs. 0.30), CBF-fALFF (0.43 vs. 0.45), and CBF-ReHo (0.40 vs. 0.41) in early-onset patients, and lower CBF-fALFF (0.38 vs. 0.45) and CBF-ReHo (0.32 vs. 0.41) in late-onset patients. Regional analysis showed significantly decreased CBF/ALFF ratios in the left precentral and postcentral gyri (T = 3.85 to 5.33). Reduced global NVC in early-onset patients was significantly associated with poorer executive function (r = 0.323), while global coupling in late-onset patients was negatively correlated with disease duration (r = -0.348 to -0.426). This study showed abnormal global and regional NVC in both early-onset and late-onset EU patients, emphasizing the potential role of NVC in the pathophysiological mechanisms of EU. 1 TECHNICAL EFFICACY: Stage 1.

Fractional amplitude of low-frequency fluctuations in right dorsal cingulum bundle associated with depression symptoms in AD patients: effects of donepezil intervention.

Our aim was to investigate the mechanisms of spontaneous brain activity of white matter functional signals in Alzheimer's disease (AD) patients after donepezil intervention. We used resting-state functional magnetic resonance imaging and the fractional amplitude of low-frequency fluctuations (fALFF) approach to investigate changes in spontaneous brain activity of white matter functional signals in AD patients before and after donepezil intervention. A total of 32 subjects participated in the study, including 16 healthy subjects (HCs) and 16 AD patients. The 16 AD patients underwent brain imaging and neuropsychological assessment before and after donepezil. ANOVA and post hoc t-test analysis were used to compare the differences in fALFF between the three groups. Pearson correlations were used to investigate the relationships between abnormal fALFF values and clinical variables in AD patients before and after intervention (P < 0.05). Compared to HCs, AD patients before donepezil intervention had an abnormal fALFF in superior longitudinal fasciculus 2; AD patients after donepezil intervention had an abnormal fALFF in right superior longitudinal fasciculus 1,2 and right dorsal cingulum, Compared with baseline, AD patients after donepezil intervention had an abnormal fALFF in the right dorsal cingulum. Compared with the baseline, AD patients after donepezil intervention had significantly decreased depression scores (P < 0.0003). Our study showed that spontaneous activity of functional signalling in the cholinergic pathway was altered in AD patients after donepezil intervention and that this change was associated with depressive symptoms in AD patients.

Alterations in surface-based amplitude of low-frequency fluctuations primary open-angle glaucoma link to neurotransmitter profiling and visual impairment severity.

The study aimed to examine alterations in surface-based amplitude of low-frequency fluctuations (ALFF) and fractional amplitude of low-frequency fluctuations (fALFF) in primary open-angle glaucoma (POAG) patients using resting-state functional magnetic resonance imaging (rs-fMRI), and to investigate their relationships with visual function and molecular profiling. A total of 70 POAG patients and 45 age- and sex-matched healthy controls (HCs) underwent rs-fMRI scans. The differences between POAG and HCs groups were compared by two-sample t-test. Spearman's correlation analyses assessed the relationship between ALFF/fALFF values and ophthalmic parameters. Spatial correlation analysis of the patients-control difference map with brain imaging data further explores underlying neurobiological mechanisms. POAG patients displayed altered brain activity compared to HCs, including decreased ALFF/fALFF in the visual network and increased in the frontoparietal and default mode networks. They exhibited reduced fALFF in the somatomotor network and increased ALFF in the dorsal and ventral attention networks. These changes are linked to neurotransmitter systems, with fALFF particularly associated with the dopamine system. Moreover, the altered ALFF/fALFF in brain regions related to vision and attention - the occipital lobe, temporal lobe, parietal lobe, paracentral lobule, and frontal lobe correlated with ophthalmic examination parameters. Surface-based ALFF/fALFF in POAG decreased in visual processing regions and increased in brain regions related to cognitive control, working memory, and attention. These changes were linked to neurotransmitter distributions important for emotional stability and mental health, potentially informing treatment approaches for POAG patients.

The relationship between fractional amplitude of low-frequency fluctuations (fALFF) and the severity of neglect in patients with unilateral spatial neglect (USN) after stroke: A functional near-infrared spectroscopy study.

Unilateral spatial neglect (USN) following right hemisphere stroke is more pronounced, severe, and persistent than in the left hemisphere. However, the pathophysiological mechanisms underlying USN remain largely unknown. This study aims to investigate the relationship between the fractional amplitude of low-frequency fluctuations (fALFF) in the right hemisphere of patients with post-stroke USN and the severity of neglect using resting-state functional near-infrared spectroscopy (fNIRS) technology. This could provide new theoretical insights into the subtle changes in the pathophysiology of spontaneous neural activity in brain regions of patients with USN. Seventeen patients with post-stroke USN (USN group) and twenty-four control subjects (control group) were selected. A 22-channel fNIRS system was used to test the hemodynamic signals of the right hemisphere at rest for all subjects. Data preprocessing and analysis were performed using the NIRS-KIT toolbox. Patients in the USN group were assessed using the Behavioral Inattention Test-Conventional (BIT-C) and the Catherine Bergego Scale (CBS). Differences in fALFF values across channels between the two groups were compared, and the fALFF values from channels showing significant differences in the USN group were correlated with scores on scales evaluating the severity of USN. (1) Significant differences in fALFF values were observed between the USN and control groups in specific channels, with channels CH6 and CH11 showing significantly lower fALFF values in the USN group compared to the control group (p < 0.05), while channels CH12, CH16, and CH21 exhibited significantly higher fALFF values in the USN group (p < 0.05). (2) In patients with USN, fALFF values in CH12 were significantly negatively correlated with BIT-C scores (r = -0.4966, p = 0.0443), and fALFF values in CH21 were also significantly negatively correlated with BIT-C scores (r = -0.5270, p = 0.0318). (3) Only the fALFF values in CH21 were significantly positively correlated with CBS scores in patients with USN (r = 0.5512, p = 0.0236). The severity of symptoms of neglect towards the left side in patients with USN may be related to compensatory neural functional activity in the right dorsolateral prefrontal cortex area.