Abnormal Regional Brain Activity Research Articles

Abnormal dynamic brain activity and functional connectivity of primary motor cortex in blepharospasm.

Accumulating evidence indicates that dynamic amplitude of low-frequency fluctuations (dALFF) or dynamic functional connectivity (dFC) can provide complementary information, distinct from static amplitude of low-frequency fluctuations (sALFF) or static functional connectivity (sFC), in detecting brain functional abnormalities in brain diseases. We aimed to examine whether dALFF and dFC can offer valuable information for the detection of functional brain abnormalities in patients with blepharospasm. We collected resting-state functional magnetic resonance imaging data from 46 patients each of blepharospasm, hemifacial spasm (HFS), and healthy controls (HCs). We examined intergroup differences in sALFF and dALFF to investigate abnormal regional brain activity in patients with blepharospasm. Based on the dALFF results, we conducted seed-based sFC and dFC analyses to identify static and dynamic connectivity changes in brain networks centered on areas showing abnormal temporal variability of local brain activity in patients with blepharospasm. Compared with HCs, patients with blepharospasm displayed different brain functional change patterns characterized by increased sALFF in the left primary motor cortex (PMC) but increased dALFF variance in the right PMC. However, differences were not found between patients with HFS and HCs. Additionally, patients with blepharospasm exhibited decreased dFC strength, but no change in sFC, between right PMC and ipsilateral cerebellum compared with HCs; these findings were replicated when patients with blepharospasm were compared to those with HFS. Our findings highlight that dALFF and dFC are complementary to sALFF and sFC and can provide valuable information for detecting brain functional abnormalities in blepharospasm. Blepharospasm may be a network disorder involving the cortico-ponto-cerebello-thalamo-cortical circuit.

Dynamic alterations of amplitude of low-frequency fluctuations in patients with chronic neck pain.

The pathogenesis of neck pain in the brain, which is the fourth most common cause of disability, remains unclear. Furthermore, little is known about the characteristics of dynamic local functional brain activity in cervical pain. The present study aimed to investigate the changes of local brain activity caused by chronic neck pain and the factors leading to neck pain. Using the amplitude of low-frequency fluctuations (ALFF) method combined with sliding window approach, we compared local brain activity that was measured by the functional magnetic resonance imaging (fMRI) of 107 patients with chronic neck pain (CNP) with that of 57 healthy control participants. Five pathogenic factors were selected for correlation analysis. The group comparison results of dynamic amplitude of low-frequency fluctuation (dALFF) variability showed that patients with CNP exhibited decreased dALFF variability in the left inferior temporal gyrus, the middle temporal gyrus, the angular gyrus, the inferior parietal marginal angular gyrus, and the middle occipital gyrus. The abnormal dALFF variability of the left inferior temporal gyrus was negatively correlated with the average daily working hours of patients with neck pain. The findings indicated that the brain regions of patients with CNP responsible for audition, vision, memory, and emotion were subjected to temporal variability of abnormal regional brain activity. Moreover, the dALFF variability in the left inferior temporal gyrus might be a risk factor for neck pain.This study revealed the brain dysfunction of patients with CNP from the perspective of dynamic local brain activity, and highlighted the important role of dALFF variability in understanding the neural mechanism of CNP.

Acupuncture for patients with insomnia disorder using resting-state functional magnetic resonance imaging: a protocol for a randomized controlled trial

BackgroundInsomnia is among the most prevalent of the sleep-related disorders. Insomnia disorder is associated with a brain hyperarousal state manifested by abnormal regional brain activity and resting state functional connectivity. Acupuncture improves sleep quality and modulates the hyperarousal state; however, the underlying neurobiological basis for improved sleep quality is poorly understood. The purpose of this clinical trial is to study the efficacy of acupuncture in the treatment of insomnia disorder. In addition, the neural mechanism by which acupuncture affects insomnia disorder will be explored using resting-state functional magnetic resonance imaging (rs-fMRI) and neuropsychological parameters.Methods and designA randomized, patient- and assessor-blinded trial will be conducted. We will randomize (in a 1:1 ratio) 60 eligible patients with insomnia disorder into a real acupuncture group or a sham acupuncture group. Interventions will be administered three times per week over a 4-week period, with an 8-week follow-up period. The healthy control group will consist of 30 age- and sex-matched healthy individuals who sleep well without any treatment intervention.All participants will undergo neuropsychological and rs-fMRI evaluations. The change in Pittsburgh Sleep Quality Index (PSQI) scores is the primary outcome parameter. The secondary outcome parameters include the Hyperarousal scale (HAS), rs-fMRI measurements, the Fatigue scale-14 (FS-14), the Hamilton depression scale (HAMD), the Hamilton anxiety scale (HAMA), a sleep diary, and an actigraph.Assessment of all parameters will be performed at baseline, post-treatment, and during follow-up. Analyses will be implemented based on intention-to-treat.DiscussionThe study results will be used to clarify the effectiveness and elucidate the mechanism by which acupuncture improves sleep quality in patients with insomnia disorder.Trial registrationChinese Clinical Trials Register, ChiCTR1800015282. Registered on 20 March 2018.

Relapsing-Remitting Multiple Sclerosis Is Associated With Regional Brain Activity Deficits in Motor- and Cognitive-Related Brain Areas.

Objective: To identify the abnormal regional spontaneous brain activity associated with relapsing-remitting multiple sclerosis (RRMS) using fractional amplitude of low-frequency fluctuation (fALFF) analysis and their relationships with clinical features.Methods: A total of 26 RRMS (11 males, 15 females; age, 36.58 ± 10.82 years) and 27 status-matched healthy group (HGs; 12 males, 15 females; age, 35.85 ± 12.05 years) underwent an Expanded Disability Status Scale (EDSS) examination. fALFF was applied to evaluate the abnormal regional brain activity associated with RRMS. Pearson's correlation analysis was applied to calculate the correlations between the signal values of brain areas that exhibited abnormal fALFF values and clinical features. Receiver operating characteristic (ROC) curve was performed to evaluate the sensitivity and specificity of those altered brain areas to distinguish between RRMS and HGs.Results: Compared with HGs, RRMS exhibited higher fALFF in the right cerebellum posterior lobe, left orbitofrontal cortex, left dorsolateral prefrontal cortex, bilateral supplementary motor area, and right fusiform gyrus and lower fALFF values in the left hippocampus and right precuneus. ROC revealed that these areas showed two good and five fair AUC values (0.77 ± 0.03, 0.729~0.822). However, four combinations with more than five brain regions received the same best discriminatory power with a sensitivity of 96.3% and a specificity of 88.5%. EDSS revealed a negative correlation with supplementary motor area (r = −0.395, p = 0.046).Conclusions: RRMS is associated with abnormal regional brain activity deficits of motor- and cognitive-related areas. The fALFF parameter may serve as a potential biological marker to discriminate between the two groups.

Brain regional homogeneity and function connectivity in attenuated psychosis syndrome \u2014based on a resting state fMRI study

BackgroundBy combining regional homogeneity (ReHo) and functional connectivity (FC) analyses, this study aimed to explore brain functional alterations in Attenuated Psychosis Syndrome (APS), which could provide complementary information for the neurophysiological indicators for schizophrenia (SZ) associated brain dysfunction.MethodsTwenty-one APS subjects and twenty healthy controls were enrolled in the data acquisition of demographics and clinical characteristics as well as structural and resting-state functional magnetic resonance imaging (rs-fMRI). ReHo analysis was conducted to determine the peak coordinate of the abnormal regional brain activity. Then, identified brain regions were considered as seed regions and were used to calculate FC between reginal brain voxels and whole brain voxels. Finally, potential correlations between imaging indices and clinical data were also explored.ResultsFour APS and two HC subjects were excluded because the largest dynamic translation or rotation had exceeded 2 mm / 2°. Compared with healthy controls (HCs), APS subjects exhibited higher ReHo values in the right middle temporal gyrus (MTG) and lower ReHo values in the left middle frontal gyrus (MFG), left superior frontal gyrus (SFG), left postcentral gyrus (PoCG), and left superior frontal gyrus, medial (SFGmed). Considered these areas as seed regions, the APS subjects showed abnormal enhancement in functional brain connections, predominantly in the frontal and temporal lobes.ConclusionsWe concluded that the APS subjects had spatially regional dysfunction and remoted synchronous dysfunction in the frontal and temporal lobes of the brain, and changes in ReHo and FC patterns may reveal the mechanism of brain dysfunctions and may serve as an imaging biomarker for the diagnosis and evaluation of SZ.

Abnormal Resting-State Neural Activity and Connectivity of Fatigue in Parkinson's Disease.

Fatigue is a common burdensome problem in patients with Parkinson's disease (PD), but its pathophysiological mechanisms are poorly understood. This study aimed at investigating the neural substrates of fatigue in patients with PD. A total of 17 PD patients with fatigue, 32 PD patients without fatigue, and 25 matched healthy controls were recruited. The 9-item fatigue severity scale (FSS) was used for fatigue screening and severity rating. Resting-state functional magnetic resonance imaging (RS-fMRI) data were obtained from all subjects. Amplitude of low-frequency fluctuations (ALFF) was used to measure regional brain activity, and functional connectivity (FC) was applied to investigate functional connectivity at a network level. PD-related fatigue was associated with ALFF changes in right middle frontal gyrus within the attention network and in left insula as well as right midcingulate cortex within the salience network. FC analysis revealed that above three regions showing ALFF differences had altered functional connectivity mainly in the temporal, parietal, and motor cortices. Our findings do reveal that abnormal regional brain activity within attention and salience network and altered FC of above abnormal regions are involved in neural mechanism of fatigue in patients with PD.

Abnormal Regional Brain Activity During Rest and (Anticipated) Gastric Distension in Functional Dyspepsia and the Role of Anxiety: A H2 15O-PET Study

During gastric distension in hypersensitive functional dyspepsia (FD), activation was found in somatosensory cortex (SI/SII) and ventrolateral prefrontal cortex (vlPFC) but, contrary to controls, not in pregenual anterior cingulate (pACC). The aims of this article were to study (i) cortical activations and deactivations during distension and sham compared with baseline in FD, regardless of sensitivity status; (ii) differences in brain activity between health and FD during "no distension" conditions; and (iii) the relationship between anxiety and brain activity in FD. Brain H(2)(15)O-PET was performed in 25 FD patients (13 hypersensitive) during three conditions: baseline, distension at discomfort threshold, and sham. Brain activity was compared against healthy controls using SPM2. Discomfort threshold was lower; sensation scores in all conditions were higher in patients than controls. (i) Activations were similar to controls, except for a lack of pACC activation during distension in FD. Patients showed no dorsal pons and amygdala deactivation during distension and sham, respectively. (ii) Comparing baseline or sham activity showed the following differences: higher activity in SII/SI, insula, midcingulate (MCC), dorsolateral and ventrolateral PFC in controls; and higher activity in occipital cortex in FD. Differences in left lateral PFC were specific to sham. (iii) Anxiety correlated negatively with pACC and MCC and positively with dorsal pons activity. FD patients failed to activate pACC, to deactivate dorsal pons during distension, and to deactivate amygdala during sham; this may represent arousal-anxiety-driven failure of pain modulation. During baseline and sham, differences between patients and controls were found in sensory as well as affective-cognitive areas.

Evidence for Anomalous Network Connectivity during Working Memory Encoding in Schizophrenia: An ICA Based Analysis

BackgroundNumerous neuroimaging studies report abnormal regional brain activity during working memory performance in schizophrenia, but few have examined brain network integration as determined by “functional connectivity” analyses.Methodology/Principal FindingsWe used independent component analysis (ICA) to identify and characterize dysfunctional spatiotemporal networks in schizophrenia engaged during the different stages (encoding and recognition) of a Sternberg working memory fMRI paradigm. 37 chronic schizophrenia and 54 healthy age/gender-matched participants performed a modified Sternberg Item Recognition fMRI task. Time series images preprocessed with SPM2 were analyzed using ICA. Schizophrenia patients showed relatively less engagement of several distinct “normal” encoding-related working memory networks compared to controls. These encoding networks comprised 1) left posterior parietal-left dorsal/ventrolateral prefrontal cortex, cingulate, basal ganglia, 2) right posterior parietal, right dorsolateral prefrontal cortex and 3) default mode network. In addition, the left fronto-parietal network demonstrated a load-dependent functional response during encoding. Network engagement that differed between groups during recognition comprised the posterior cingulate, cuneus and hippocampus/parahippocampus. As expected, working memory task accuracy differed between groups (p<0.0001) and was associated with degree of network engagement. Functional connectivity within all three encoding-associated functional networks correlated significantly with task accuracy, which further underscores the relevance of abnormal network integration to well-described schizophrenia working memory impairment. No network was significantly associated with task accuracy during the recognition phase.Conclusions/SignificanceThis study extends the results of numerous previous schizophrenia studies that identified isolated dysfunctional brain regions by providing evidence of disrupted schizophrenia functional connectivity using ICA within widely-distributed neural networks engaged for working memory cognition.

Interregional cerebral metabolic associativity during a continuous performance task (Part II) : Differential alterations in bipolar and unipolar disorders

Unipolar and bipolar disorders have often been reported to exhibit abnormal regional brain activity in prefrontal cortex and paralimbic structures compared with healthy controls. We sought to ascertain how regions postulated to be abnormal in bipolar and unipolar disorders were functionally connected to the rest of the brain, and how this associativity differed from healthy controls. Thirty patients with bipolar disorder (BPs), 34 patients with unipolar disorder (UPs), and 66 healthy volunteers (Willis, M.W., Benson, B.E., Ketter, T.A., Kimbrell, T.A., George, M.S., Speer, A.M., Herscovitch, P., Post, R.M., 2008. Interregional cerebral metabolic associativity during a continuous performance task in healthy adults. Psychiatry Research: Neuroimaging 164 (1)) were imaged using F-18-fluorodeoxyglucose and positron emission tomography (FDG-PET) while performing an auditory continuous performance task (CPT). Five bilateral regions of interest (ROIs), namely dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal cortex (INFP), thalamus and cerebellum, were correlated with normalized cerebral metabolism in the rest of the brain while covarying out Hamilton Depression Rating Scale Scores. In bipolar patients compared with controls, metabolism in the left DLPFC and INFP, and bilateral thalamus and insula had more positive and fewer negative metabolic correlations with other brain regions. In contrast, compared with controls, unipolar patients had fewer significant correlative relationships, either positive or negative. In common, bipolar and unipolar patients lacked the normal inverse relationships between the DLPFC and cerebellum, as well as relationships between the primary ROIs and other limbic regions (medial prefrontal cortex, anterior cingulate, and temporal lobes) compared with controls. Associations of DLPFC and INFP with other brain areas were different in each hemisphere in patients and controls. Bipolar patients exhibited exaggerated positive coherence of activity throughout the brain, while unipolar patients showed a paucity of normal interrelationships compared with controls. These abnormal patterns of metabolic associativity suggest marked interregional neuronal dysregulation in bipolar and unipolar illness exists beyond that of mere absolute regional differences from control levels, and provides rationale for using acute and long-term therapies that may re-establish and maintain normal associativity in these devastating illnesses.

Abnormal regional brain activity linked to short-term…

Abnormal regional brain activity linked to short-term…

Abnormal regional brain activity associated with processing emotional stimuli in autistic subjects

Abnormal regional brain activity associated with processing emotional stimuli in autistic subjects