Encephalic Regions Research Articles

Early region-specific impact of adjuvant radiation therapy on cognition and quality of life in adult patients with primary brain tumors.

While treatments for primary brain tumors increase survival, they have cognitive sequelae. Neurocognition's anatomical distribution makes it susceptible to brain damage. This study aims to evaluate the contribution of radiotherapy on short-term cognitive impairment. Using a prospective database of cognitive rehabilitation in adults operated on for primary brain tumors, a retrospective sub-analysis of the contribution of radiotherapy was performed. Thirty-four subdivisions of 12 neurocognitive regions were delineated in 48 irradiated patients and 30 non-irradiated patients. In the first group, the correlation between radiation dose and deterioration was evaluated. In all patients, the impact of tumor and surgical changes on dysfunction was calculated and compared with dose-dependent response. The correlation between cognitive status and radiation dose is especially strong and significant in the left hemisphere and in specific subdivisions such as the posterior hippocampus or the dorsolateral prefrontal cortex, with the left prevailing over posterior dominance. Memory is the most affected domain 1month after radiotherapy, as attention is three months later. The hippocampus is involved in various cognitive domains in addition to memory. The prefrontal subregions and the genu of the corpus callosum are more affected by the relationship with disease and surgical changes than by radiation exposure. Patients ongoing a course of radiotherapy do not benefit from concurrent cognitive rehabilitation. There is a correlation between the dose of radiation received by several encephalic regions and degree of short-term domain-specific cognition decline, considering other factors of risk and cognitive rehabilitation.

Network Reorganization for Neurophysiological and Behavioral Recovery Following Stroke.

Stroke continues to be the main cause of motor disability worldwide. While rehabilitation has been promised to improve recovery after stroke, efficacy in clinical trials has been mixed. We need to understand the cortical recombination framework to understand how biomarkers for neurophysiological reorganized neurotechnologies alter network activity. Here, we summarize the principles of the movement network, including the current evidence of changes in the connections and function of encephalic regions, recovery from stroke and the therapeutic effects of rehabilitation. Overall, improvements or therapeutic effects in limb motor control following stroke are correlated with the effects of interhemispheric competition or compensatory models of the motor supplementary cortex. This review suggests that future research should focus on cross-regional communication and provide fundamental insights into further treatment and rehabilitation for post-stroke patients.

Build a bridge between ECG and EEG signals for atrial fibrillation diagnosis using AI methods

Atrial fibrillation (AF) is a very common type of cardiac arrhythmia. The main characteristic of AF is an abnormally rapid and disordered atrial rhythm causing an atrial dysfunction, which can be visualized on an electrocardiograph (ECG) and distinguished by irregular fluctuations. Despite continuous and considerable efforts to analyze the pathophysiology of AF, it is challenging to determine the underlying pathogenesis of the disease in individual patients. This study aims to build a bridge between ECG and electroencephalogram (EEG) signals to probe the strong influence between human brain activity and AF by AI methods. We first found that the one-second data fragment shows the most excellent performance in our time window configuration. Secondly, in our proposed measurement, most cortical potentials were partly associated with AF. Thirdly, we found that only a few channels of data were sufficient for analysis. Finally, our experiment shows δ wave has the best performance compared to other wave bands. By AI methods, the paper contributes to concluding that δ wave band of EEG is the most associated brain wave type with AF. By EEG signals from typical regions, the central region, parietal and Occipital might be the most associated encephalic regions with AF. The clinical trial registration number for our study is ChiCTR2300068625.

Immunohistochemical distribution of secretagogin in the mouse brain.

Calcium is essential for the correct functioning of the central nervous system, and calcium-binding proteins help to finely regulate its concentration. Whereas some calcium-binding proteins such as calmodulin are ubiquitous and are present in many cell types, others such as calbindin, calretinin, and parvalbumin are expressed in specific neuronal populations. Secretagogin belongs to this latter group and its distribution throughout the brain is only partially known. In the present work, the distribution of secretagogin-immunopositive cells was studied in the entire brain of healthy adult mice. Adult male C57BL/DBA mice aged between 5 and 7 months were used. Their whole brain was sectioned and used for immunohistochemistry. Specific neural populations were observed in different zones and nuclei identified according to Paxinos mouse brain atlas. Labelled cells were found with a Golgi-like staining, allowing an excellent characterization of their dendritic and axonal arborizations. Many secretagogin-positive cells were observed along different encephalic regions, especially in the olfactory bulb, basal ganglia, and hypothalamus. Immunostained populations were very heterogenous in both size and distribution, as some nuclei presented labelling in their entire extension, but in others, only scattered cells were present. Secretagogin can provide a more complete vision of calcium-buffering mechanisms in the brain, and can be a useful neuronal marker in different brain areas for specific populations.

Psychological, physiological, and biochemical correlations after negative emotional videos in college students with and without premenstrual syndrome.

Women with premenstrual syndrome (PMS) suffer heavily from emotional problems, the pathogenesis of which is believed to be related to the hypothalamic-pituitary-adrenal (HPA) axis, autonomic nervous system (ANS) and central nervous system (CNS). We took into account all 3 aspects to observed the psychological, physiological and biochemical correlations under anger and sadness in college students with and without PMS. 33 students with PMS and 24 healthy students participated in the emotion induction experiment, and were required to fill out self-report scales. Their salivary cortisol (SCort), skin conductivity level (SCL), heart rate variability (HRV), blood pressure (BP) and electroencephalogram (EEG) data were collected at the resting stage and 10-15 minutes after each video. Compared to healthy controls, students with PMS showed lower SCort level and higher VLF at rest, and no statistic difference in activities of ANS and HPA axis after emotional videos, but different results in EEG in all conditions. The decreases in SBP during angry video, SCort after angry and neutral videos, and increases in θ band power during sad video were moderately correlated with increases in PMS score. No intergroup differences were found in self-report emotions. Students with PMS had lower activity of HPA axis and possibly higher activity of PNS at rest, and different response patterns in CNS in all conditions. Several EEG frequencies, especially θ band, in specific encephalic regions during emotional videos, as well as declined HPA activities in dealing with angry and neutral stressors, in which γ activity in frontal lobe may play a role, showed moderate correlations with more severe PMS.

Advances in the knowledge and therapeutics of schizophrenia, major depression disorder, and bipolar disorder from human brain organoid research.

Tridimensional cultures of human induced pluripotent cells (iPSCs) experimentally directed to neural differentiation, termed "brain organoids" are now employed as an in vitro assay that recapitulates early developmental stages of nervous tissue differentiation. Technical progress in culture methodology enabled the generation of regionally specialized organoids with structural and neurochemical characters of distinct encephalic regions. The technical process of organoid elaboration is undergoing progressively implementation, but current robustness of the assay has attracted the attention of psychiatric research to substitute/complement animal experimentation for analyzing the pathophysiology of psychiatric disorders. Numerous morphological, structural, molecular and functional insights of psychiatric disorders have been uncovered by comparing brain organoids made with iPSCs obtained from control healthy subjects and psychiatric patients. Brain organoids were also employed for analyzing the response to conventional treatments, to search for new drugs, and to anticipate the therapeutic response of individual patients in a personalized manner. In this review, we gather data obtained by studying cerebral organoids made from iPSCs of patients of the three most frequent serious psychiatric disorders: schizophrenia, major depression disorder, and bipolar disorder. Among the data obtained in these studies, we emphasize: (i) that the origin of these pathologies takes place in the stages of embryonic development; (ii) the existence of shared molecular pathogenic aspects among patients of the three distinct disorders; (iii) the occurrence of molecular differences between patients bearing the same disorder, and (iv) that functional alterations can be activated or aggravated by environmental signals in patients bearing genetic risk for these disorders.

Association of Cerebral Small Vessel Disease Burden with Neuropsychiatric Symptoms in Non-Demented Elderly: A Longitudinal Study.

The links between cerebral small vessel disease (CSVD) burden and neuropsychiatric symptoms (NPS) have not been fully studied. We aimed to explore the associations of the CSVD burden with Neuropsychiatric Inventory (NPI) total scores and its subsyndromes in the elderly without dementia. We investigated 630 non-demented participants from the Alzheimer's Disease Neuroimaging Initiative. All of them had NPI assessments and 3 Tesla MRI scans at baseline and 616 had longitudinal NPI assessments during the follow-up. Linear mixed-effects models were used to investigate the cross-sectional and longitudinal associations of CSVD burden with NPI total scores and its subsyndromes. Higher CSVD burden longitudinally predicted more serious neuropsychiatric symptoms, including NPS (p < 0.0001), hyperactivity (p = 0.0006), affective symptoms (p = 0.0091), and apathy (p < 0.0001) in the total participants. Lacunar infarcts (LIs), white matter hyperactivities (WMHs), and cerebral microbleeds (CMBs) might play important roles in the occurrence of NPS, since they were longitudinally associated with specific neuropsychiatric subsyndromes. LIs contributed to hyperactivity (p = 0.0092), psychosis (p = 0.0402), affective symptoms (p = 0.0156), and apathy (p < 0.0001). WMHs were associated with hyperactivity (p = 0.0377) and apathy (p = 0.0343). However, CMBs were only related to apathy (p = 0.0141). CSVD burden was associated with multiple neuropsychiatric symptoms, suggesting the importance of monitoring and controlling vascular risk factors. Different markers of CSVD were associated with specific subsyndromes of NPS, suggesting that different markers tended to occur in different encephalic regions.

Cerebellar primary central nervous system lymphoma: Case series report.

Introduction and importancePrimary central nervous system lymphoma (PCNSL) is a rare cranial malignant haematological tumour. PCNSL in the cerebellar region is less common than PCNSL in other encephalic regions. A diagnosis of cerebellar PCNSL is relatively difficult to make due to its diverse imaging manifestations. The aim of this case series report is to determine whether surgery could be used to confirm the diagnosis of cerebellar PCNSL and the effect of surgical treatment.MethodsWe report 3 cases of cerebellar PCNSL that underwent neuronavigation microsurgery under general anaesthesia. The operation was performed by author 3 and author 5. One patient underwent left lateral ventricular drainage on the fourth and tenth days after the operation due to postoperative obstructive hydrocephalus. All patients received chemotherapy or radiotherapy after histological confirmation.OutcomesAll patients' tumours were completely removed. One patient developed obstructive hydrocephalus twice during the perioperative period after the operation, was given drainage, and then recovered from the hospital. The other two patients recovered and were discharged smoothly without complications. One patient died 9 months after the operation, and the other two patients survived. The prognosis of 3 patients was related to tumour size and timely follow-up chemo-radiation therapy.ConclusionThe histology of all patients showed diffuse large B-cell lymphoma (GCB phenotype). Suspicious cerebellar PCNSL patients should undergo surgery to confirm the diagnosis, followed by radiotherapy and chemotherapy.

Identification of Prefrontal Cortex and Amygdala Expressed Genes Associated With Sevoflurane Anesthesia on Non-human Primate.

Clinical trials and animal studies have indicated that long-term use or multiple administrations of anesthesia may lead to fine motor impairment in the developing brain. Most studies on anesthesia-induced neurotoxicity have focused on the hippocampus and prefrontal cortex (PFC); however, the role of other vital encephalic regions, such as the amygdala, is still unclear. Herein, we focused on sevoflurane, the most commonly used volatile anesthetic in infants, and performed a transcriptional analysis of the PFC and amygdala of macaques after multiple exposures to the anesthetic by RNA sequencing. The overall, overlapping, and encephalic region-specific transcriptional patterns were separately analyzed to reveal their functions and differentially expressed gene sets that were influenced by sevoflurane. Specifically, functional, protein–protein interaction, neighbor gene network, and gene set enrichment analyses were performed. Further, we built the basic molecular feature of the amygdala by comparing it to the PFC. In comparison with the amygdala’s changing pattern following sevoflurane exposure, functional annotations of the PFC were more enriched in glial cell-related biological functions than in neuron and synapsis development. Taken together, transcriptional studies and bioinformatics analyses allow for an improved understanding of the primate PFC and amygdala.

Platycladus orientalis seed extract as a potential triple reuptake MAO inhibitor rescue depression phenotype through restoring monoamine neurotransmitters

Ethnopharmacology relevancePlatycladus orientalis seeds are recorded in traditional Chinese medicine (TCM) formulations for modulation of mood and physical activity in “Shen Nong Ben Cao Jing” and “Compendium of Materia Medica” and so on. Recently, we identified its extracting components and looked for the potentials in treatment for depression by improving the function of monoamine neurotransmitters. Aim of the studyWe investigated the mechanism of action of the seed extracts of P. orientalis (S4) to rescue depressive behavior in a chronic, unpredicted, mild stress (CUMS)-induced model in rats. Materials and methodsWe used ultra-fast liquid chromatography coupled with triple quadrupole-time of flight tandem mass spectrometry to analyze the chemical constituents in S4. An assay platform in zebrafish and molecular docking were used to analyze if S4 regulated rest/wake behavior and predict the biological targets which correlated with monoamine neurotransmitters. Depressive-behavior tests (body weight, sucrose preference test, tail-suspension test, forced-swimming test) were carried in the CUMS model. After behavior tests and killing, rat brains were separated into the hippocampus, frontier cortex and dorsal raphe nucleus. The main monoamine neurotransmitters and their metabolite concentrations in these three brain regions were measured by rapid resolution liquid chromatography coupled with triple quadrupole tandem mass spectrometry. ResultsForty-one compounds were identified in S4, including fatty acids, terpenoids, amino acids, plant sterols and flavonoids. S4 could increase the total rest time and decrease the waking activity of zebrafish. S4 showed high correlation with adrenaline agonists, 5-hydroxytryptamine (5-HT) reuptake inhibitors and dopamine agonists. CUMS-group rats, compared with controls, had significantly decreased body weight and preference for sucrose water, whereas the immobility time in the tail-suspension test and forced-swimming test was increased. S4 could significantly rescue the increased levels of 5-HT, noradrenaline and dopamine in the prefrontal cortex and dorsal raphe nucleus. ConclusionsWe demonstrated that S4 was a potential inhibitor of MAO reuptake that could rescue depression in a CUMS-model rats by restoring monoamine neurotransmitters in different encephalic regions.

A Resting-State Functional Magnetic Resonance Imaging Study of Abnormal Frontoparietal Network Function in Migraine without Aura.

BackgroundThis study aimed to investigate frontoparietal network (FPN) dysfunction in participants with migraine without aura (MwoA).Material/MethodsWe selected 48 age-, sex-, and education level-matched graduate students (24 participants with MwoA [MwoA group] and 24 healthy controls). RS-fMRI and independent component analysis were used to examine the FPN and to compare abnormal encephalic regional homogeneity values. The Mindful Attention Awareness Scale (MAAS), Self-Rating Anxiety Scale (SAS), Self-Rating Depression Scale (SDS), and Self-Rating Scale of Sleep (SRSS) were used to evaluate attention, anxiety, depression, and sleep, respectively. Pearson’s correlation was applied to evaluate the association between abnormal brain areas and the scores for each scale.ResultsNeural function activity in encephalic regions of FPN showed abnormal changes in the MwoA group. The MwoA group had significantly lower MAAS scores (P<0.001), higher SAS scores (P<0.001), and higher SDS (P=0.06) and SRSS scores (P=0.26). In the MwoA group, functional activity of the right parietal lobule in the left FPN was positively correlated with MAAS scores (P=0.01) and negatively correlated with SAS (P=0.02). The orbital part of left inferior frontal gyrus activity in the right FPN was positively correlated with SDS (P=0.04) and SRSS (P<0.001). Right superior marginal gyrus activity in the right FPN was positively correlated with SDS (P=0.02).ConclusionsAbnormal FPN function was correlated with attention, anxiety, depression, and sleep status in the MwoA group. These results offer further insights into the evaluation and treatment of MwoA.

A PET imaging study of the brain changes of glucose metabolism in patients with temporal lobe epilepsy and depressive disorder

BackgroundThis study aims to compare the difference of the brain changes of glucose metabolism between temporal lobe epilepsy patients (TLE) with major depressive disorder and temporal TLE without major depressive disorder.MethodsA total of 24 TLE patients, who met the inclusion criteria of our hospital, were enrolled in this study. They were divided into a TLE with depression group (n = 11) and a TLE without depression group (n = 13), according to the results of the HAMD-24 Scale. Two groups patients were examined using 18F-FDG PET brain imaging.ResultsThe low metabolic regions of the TLE with depression group were mainly found in the left frontal lobe, temporal lobe and fusiform gyrus, while the high metabolic regions of the TLE with depression group were mainly located in the right frontal lobe, visual joint cortex and superior posterior cingulate cortex. Both of the TLE groups had high metabolic compensation in the non-epileptic area during the interictal period.ConclusionsThere is an uptake difference of 18F-FDG between TLE patients with depression and TLE patients without depression in multiple encephalic regions.

A neuroimaging comparative study of changes in a cellist’s brain when playing contemporary and Baroque styles

The emergence of different styles of Contemporary concert music in the 20th century led to a marked modification of the foundations built on previous styles. This work investigates whether these modifications, which include procedures and technical resources different to those used in the interpretation of previous musical styles, require different encephalic controls to those used in tonal music and if the experience of the musician in these styles influences them. Functional magnetic resonance images of encephalic regions from 13 professional cellists while interpreting Baroque and Contemporary excerpts inside an MRI scanner were acquired. Activation and connectivity encephalic maps show common cortical motor and sensorial regions (Precentral, Postcentral and Supramarginal Gyri) in both interpretation styles, but with different hemispheric intensity levels. However, certain auditory and motor regions only activate during Baroque. Connectivity maps show some exclusive seed-regions; thus, the Heschl's and Superior Frontal Gyri, Planum-Temporal and Caudate appear as prominent seeds when playing Baroque, whereas when playing Contemporary, the main seeds appear in the Cerebellar-Vermis, Insular cortex and Parietal Operculum. The discrepancies found are attributed to different cognitive, sensory and motor demands underlying the musical interpretation of each style, as well as to the musicians’ learning of and training in these styles.

Temporomandibular inflammation mobilizes parvalbumin and FosB/deltaFosB neurons of amygdala and dorsal raphe.

Pathophysiological mechanisms involved in orofacial pain and their relationship with emotional disorders have emerged as an important research area for multidisciplinary studies. In particular, temporomandibular disorders (TMD) have been evaluated clinically from both physiological and psychological perspectives. We hypothesized that an altered neuronal activity occurs in the amygdala and the dorsal raphe nucleus (DR), encephalic regions involved in the modulation of painful and emotional information. Adult male Wistar rats were used in an experimental complete Freund's adjuvant (CFA)-induced temporomandibular joint (TMJ) inflammation model. CFA was applied for 1 or 10 days, and the animals were euthanized for brain samples dissection for FosB/ΔFosB and parvalbumin (PV) immunostaining. Our results were consistent in showing that the amygdala and DR were activated in the persistent inflammatory phase (10 days) and that the expression of PV+ interneurons in the amygdala was decreased. In contrast, in the DR, the expression of PV+ interneurons was increased in persistent states of CFA-induced TMJ inflammation. Moreover, at 10 days of inflammation, there was an increased co-localization of PV+ and FosB/ΔFosB+ neurons in the basolateral and central nucleus of the amygdala. Different nuclei of the amygdala, as well as portions of the DR, were activated in the persistent phase (10 days) of TMJ inflammation. In conclusion, altered activity of the amygdala and DR was detected during persistent inflammatory nociception in the temporomandibular joint. These regions may be essential for both sensory and affective dimensions of orofacial pain.

The role of HINT1 in methamphetamine-induced behavioral sensitization.

Drug addiction is a chronically relapsing disorder in humans yet the underlying mechanism remained unclear. Recent studies suggested that histidine triad nucleotide binding protein1 (HINT1) may play significant roles in diverse neuropsychiatric diseases including drug addiction. In the current study, we used different batches of mice to establish different stages of methamphetamine (METH)-induced behavioral sensitization (BS) to explore the dynamic changes throughout the process of addiction in different brain regions, including the prefrontal cortex (PFC), nucleus accumbens (NAc), caudate putamen (CPu), and hippocampus (Hip). In addition, we used HINT1 knockout (KO) mice to investigate the effect of HINT1 protein deletion on METH-induced BS. We found that in PFC of the METH group mice, the HINT1 expression level initially increased after development phase, and then dropped to the normal level during expression phase. However, there was no statistical difference in the HINT1 expression level in the other three encephalic regions (NAc, CPu, and Hip). The absence of HINT1 could promote METH-mediated addictive behavior to a certain extent, while the significant difference between genotypes only occurred in the development phase. Using the new technique, hip fractures were correctly predicted in 78% of cases compared with 36% when using the T-score. The accuracy of the prediction was not greatly reduced when using SSM and SAM (78% and 74% correct, respectively). Various geometric and BMD distribution traits were identified in the fractured and non-fractured groups.

Direct Impact of Motor Cortical Stimulation on the Blood Oxygen-level Dependent Response in Rats.

Purpose:Neuropathic pain is a complex and distressing chronic illness in modern medicine. Since 1990s, motor cortex stimulation (MCS) has emerged as a potential treatment for chronic neuropathic pain; however, the precise mechanisms underlying analgesia induced by MCS are not completely understood. The purpose of the present study was to investigate the blood oxygen-level dependent (BOLD) response in the brain during MCS.Methods:We inserted a bipolar tungsten electrode into the primary motor cortex (M1) of adult male Wistar rats. Functional magnetic resonance imaging (fMRI) scans were implemented simultaneously with the electrical stimulation of M1 and the BOLD signals taken from the fMRI were used as an index to reflect the response against MCS.Results:Our results demonstrated that the bilateral M1, ipsilateral caudate-putamen, and ipsilateral primary somatosensory cortex to the stimulation spot were activated after the onset of MCS. The BOLD signal time courses were analysed in these regions and similar temporal characteristics were found.Conclusion:By conducting direct cortical stimulation of the rodent brain to investigate its instant effect using fMRI, we identified encephalic regions directly involved in the instant motor cortical stimulation effects in healthy rat models. This result may be essential in establishing a foundation for further research on the underlying neuropathways associated with the MCS effects.

Analysis of EEG signals in children with autism spectrum disorder under positive and negative emotional stimuli

Autism spectrum disorder (ASD, hereafter autism) is a neurodevelopmental disorder. The symptoms of autism, including the core features of social interaction and language communication disorders, repetitive stereotyped behaviors, and limited narrow interest, are most obvious in children 2−3 years old. Research also shows that childhood is the most critical period for autism diagnosis and behavioral intervention. Because emotional recognition ability is of great importance to individual social development, the emotional recognition defect of children with autism has an extremely negative impact on their social interaction ability, thus hindering their social development. Related studies indicate that, under different emotional stimuli, the occipital and temporal lobes of children with autism show a lower activation state, which affects the development of their social cognitive and emotional recognition abilities. An objective evaluation of the development of autistic children’s brain function using an electroencephalogram (EEG) is feasible. This paper analyses testees’ electroencephalograms of several encephalic regions, including frontal, temporal and occipital lobes, along with their emotional performance metrics and cognitive level to investigate the difference in autistic children and typically developing children’s performance and electroencephalograms while they are being induced by videos designed to produce positive or negative emotions. Based on the emotional performance indicators obtained from brainwave power spectrums and cognitive questions, we analyzed the children’s performance under two emotional stimuli. The experiment recruited 80 children, 40 autistic and 40 typically developing children. We processed the power spectrum analysis of testees’ electroencephalograms through fast Fourier transform and explored the effects between the different groups. Our results show that autistic children’s electroencephalograms generally show very high power in the low frequency range (delta, theta) and high frequency range (beta, gamma) but low power in the alpha band. Moreover, different encephalic regions show different features of the power spectrum. By comparing the testees’ emotional performance metrics based on their electroencephalograms’ power spectrums, as well as cognitive levels based on answering questions under two kinds of emotional stimulation, we found that autistic children’s emotional changes are far less than those of typically developing children. In addition, autistic children’s cognition of six aspects, such as emotional and spatial cognition, are both lower than that of typically developing children. Furthermore, under positive emotion conditions, they show more interest and higher engagement, and their correct rate of answering cognition questions is higher than under negative emotion conditions. This research provides an objective basis for intervention training that aims to improve autistic children’s emotional cognitive levels.

Robust brain causality network construction based on Bayesian multivariate autoregression

BackgroundCognitive processes involve information integration among multiple encephalic regions, which can be measured by causal networks. However, the estimation of causal networks by means of some traditional methods with the least square will lead to distorted networks because of the unexpected outlier noise and the small number of signal samples in real applications. New methodIn this work, we adopted Bayesian inference to estimate parameters in a multivariate autoregression model (MVAR), to restrain the influence of outliers. ResultsThrough the simulation study, we observed that our proposed method can efficiently suppress outlier influence and shows stable performance when sample sizes become small. Application to real motor imagery functional magnetic resonance imaging (fMRI) also revealed that the proposed approach can capture the inherent hemispheric lateralization of motor imagery even with a small number of fMRI samples. Comparison with existing methodsWe compared our proposed Bayesian-based Granger analysis with traditional Granger causality analysis. ConclusionsThe analyses conducted in the current work demonstrate the robustness of Bayesian-based Granger analysis to outlier conditions or physiological signals with small sample sizes.

Regional homogeneity analysis of major Parkinson’s disease subtypes based on functional magnetic resonance imaging

ObjectiveRegional homogeneity (ReHo) differences in encephalic regions of Parkinson’s disease (PD) patients of different subtypes were investigated to analyze its clinical significance during disease occurrence. Methods39 PD patients were evaluated in this study, which included 14 cases with the tremor dominant (TD) PD subtype and 23 cases with the postural instability and gait difficulty (PIGD) PD subtype, along with 28 healthy individuals, who were included as the control group. Magnetic resonance imaging (MRI) was performed for all the cases to obtain the rest-state functional magnetic resonance imaging (R-fMRI) data along with structural data. The ReHo values of the three groups were calculated and disparities in brain structures among the three groups were processed by analysis of variance. In addition, t-test analysis was used to evaluate the differences between the groups. In the end, a correlation analysis between the brain areas evaluated for ReHo differences and the clinical symptoms presented by the patients was carried out. ResultsCompared to the control group, brain areas with increased ReHo values in the TD PD subtype group, included the right putamen, right para-hippocampal gyrus, right inferior temporal gyrus, and right orbital superior frontal gyrus, while areas with decreased ReHo values, included the bilateral superior occipital gyrus and bilateral middle occipital gyrus. In contrast with the control group, areas like the right putamen, right superior temporal gyrus, left thalamus, and right superior parietal gyrus in the PIGD PD subtype group presented an increased in ReHo values, while a decreased in ReHo values was found in the right para-hippocampal gyrus, bilateral superior occipital gyrus, and middle occipital gyrus. Compared to the PIGD group, the TD group showed an increase in ReHo values in the right para-hippocampal gyrus. ConclusionsIn the present study, ReHo values increased in the TD PD subtype group of patients, indicating a compensatory performance of slow progressive cognitive decline when compared to the PIGD PD subtype group. Two subtypes of PD manifest ReHo changes in the basal ganglia, thalamus, and in several areas of the cerebral cortex, areas that are likely to correlate with non-motor symptoms, such as cognition and emotions.

Brain Functional Networks in Type 2 Diabetes Mellitus Patients: A Resting-State Functional MRI Study.

BackgroundPrevious diabetes mellitus studies of cognitive impairments in the early stages have focused on changes in brain structure and function, and more recently the focus has shifted to the relationships between encephalic regions and diversification of network topology. However, studies examining network topology in diabetic brain function are still limited.MethodsThe study included 102 subjects; 55 type 2 diabetes mellitus (T2DM) patients plus 47 healthy controls. All subjects were examined by resting-state functional magnetic resonance imaging (rs-fMRI) scan. According to Automated Anatomical Labeling, the brain was divided into 90 anatomical regions, and every region corresponds to a brain network analysis node. The whole brain functional network was constructed by thresholding the correlation matrices of the 90 brain regions, and the topological properties of the network were computed based on graph theory. Then, the topological properties of the network were compared between different groups by using a non-parametric test. Finally, the associations between differences in topological properties and the clinical indicators were analyzed.ResultsThe brain functional networks of both T2DM patients and healthy controls were found to possess small-world characteristics, i.e., normalized clustering coefficient (γ) > 1, and normalized characteristic path length (λ) close to 1. No significant differences were found in the small-world characteristics (σ). Second, the T2DM patient group displayed significant differences in node properties in certain brain regions. Correlative analytic results showed that the node degree of the right inferior temporal gyrus (ITG) and the node efficiencies of the right ITG and superior temporal gyrus of T2DM patients were positively correlated with body mass index.ConclusionThe brain network of T2DM patients has the same small-world characteristics as normal people, but the normalized clustering coefficient is higher and the normalized characteristic path length is lower than that of the normal control group, indicating that the brain function network of the T2DM patients has changed. The changes of node properties were mostly concentrated in frontal lobe, temporal lobe and posterior cingulate gyrus. The abnormal changes in these indices in T2DM patients might be explained as a compensatory behavior to reduce cognitive impairments, which is achieved by mobilizing additional neural resources, such as the excessive activation of the network and the efficient networking of multiple brain regions.