Most recent paper

Sleep Med. 2024 Nov 12;124:727-736. doi: 10.1016/j.sleep.2024.11.012. Online ahead of print.

ABSTRACT

BACKGROUND: The COVID-19 pandemic has led to long-term neurological and psychological effects, including sleep disturbances. While prior studies have identified altered brain function post-COVID-19, specific functional connectivity (FC) patterns predicting sleep quality after recovery remain unclear. This study aims to identify FC patterns associated with sleep quality two months after the first negative COVID-19 antigen test.

METHODS: Using a connectome-based predictive modeling (CPM) approach, we identified the functional connectome regulating sleep quality based on a 164-region parcellation. Significant connections were analyzed using mediation models to examine their role in the relationship between anxiety, depression, and sleep.

RESULTS: FC between the right cerebellar peduncle and the left VIII of the cerebellum, and between the left middle temporal pole (MTP) and left ventral tegmental area (VTA), significantly predicted Pittsburgh Sleep Quality Index (PSQI) scores for sleep disturbances two months post-recovery (q2 = 0.059, MSE = 0.154, p = 0.017, r = 0.350). Mediation analysis showed a significant indirect effect of FC between the left MTP and VTA on the relationship between generalized anxiety and sleep disturbances (indirect effect = 0.013, 95% CI = [0.002, 0.03], pfdr <0.05). FC between the right dorsal raphe nucleus and ipsilateral regions-including occipital, parietal, and temporal areas-predicted PSQI scores for daytime dysfunction (q2 = 0.092, MSE = 0.678, p = 0.025, r = 0.342).

CONCLUSION: Post-COVID-19 brain connectivity and anxiety predict sleep quality. These findings highlight the potential for targeted therapeutic strategies to improve sleep and identify patients at risk for prolonged disturbances through FC biomarkers.

PMID:39549632 | DOI:10.1016/j.sleep.2024.11.012

Geroscience. 2024 Nov 16. doi: 10.1007/s11357-024-01436-1. Online ahead of print.

ABSTRACT

Given the increasing number of older adults in society, there is a growing need for studies on changes in the aging brain. The aim of this research is to investigate the effective connectivity of different age groups using resting-state functional magnetic resonance imaging (fMRI) and graph theory. By examining connectivity in different age groups, a better understanding of age-related changes can be achieved. Lifespan pilot data from the Human Connectome Project (HCP) were used to examine dynamic effective connectivity (dEC) changes across different age groups. The Granger causality method with time windowing was employed to calculate dEC. After extracting graph measures, statistical analyses were performed to compare the age groups. Support vector machine and decision tree classifiers were used to classify the different age groups based on the extracted graph measures. Based on the obtained results, it can be concluded that there are significant differences in the effective connectivity among the three age groups. Statistical analyses revealed disassortativity. The global efficiency exhibited a decreasing trend, and the transitivity measure showed an increasing trend with the advancing age. The decision tree classifier showed an accuracy of 86.67 % with Kruskal-Wallis selected features. This study demonstrates that changes in effective connectivity across different age brackets can serve as a tool for better understanding brain function during the aging process.

PMID:39549197 | DOI:10.1007/s11357-024-01436-1

Biol Psychiatry Cogn Neurosci Neuroimaging. 2024 Nov 13:S2451-9022(24)00337-9. doi: 10.1016/j.bpsc.2024.10.020. Online ahead of print.

ABSTRACT

BACKGROUND: Repetitive transcranial magnetic stimulation (rTMS), combined with exposure and response prevention (ERP), is a promising treatment modality for treatment-refractory obsessive-compulsive disorder (OCD). Yet, not all patients respond sufficiently to this treatment. We investigated whether brain activation during a symptom provocation task could predict treatment response.

METHODS: Sixty-one adults with OCD (22 male/ 39 female) underwent symptom provocation with OCD- and fear-related visual stimuli during fMRI prior to an 8-week combined rTMS and ERP treatment regimen. Participants received one of the three following rTMS treatments as part of a randomized controlled trial: (1) 10Hz rTMS (110% resting motor threshold (RMT)) to the left dorsolateral prefrontal cortex (DLPFC); (2) 10Hz rTMS (110% RMT) to the left pre-supplementary motor area (preSMA); or (3) 10Hz control rTMS (60% RMT) to the vertex. Multiple regression and correlation were used to examine the predictive value of task-related brain activation for treatment response in the following ROIs: dorsomedial prefrontal cortex, amygdala, DLPFC, and preSMA.

RESULTS: The different treatment groups responded equally to treatment. Higher pre-treatment task-related activation of the right amygdala to OCD-related stimuli showed a positive association with treatment response in all groups. Exploratory whole-brain analyses showed positive associations between activation in multiple task-relevant regions and treatment response. Only dorsal anterior cingulate cortex activation to fear-related stimuli showed a negative association with treatment outcome.

CONCLUSIONS: Higher pre-treatment right amygdala activation during symptom provocation predicts better treatment response to combined rTMS and ERP in OCD.

PMID:39547413 | DOI:10.1016/j.bpsc.2024.10.020

Burns. 2024 Nov 2;51(1):107305. doi: 10.1016/j.burns.2024.107305. Online ahead of print.

ABSTRACT

BACKGROUND: Pruritus, a common symptom of burn wounds, arises from skin tissue damage and abnormal tissue healing. Chronic post-burn pruritus (CPBP) is defined as itching that persists for six weeks or more. The brain mechanisms underlying CPBP are not understood adequately. This study aims to explore abnormal brain function in CPBP patients and identify potential pathogenesis of pruritus.

MATERIALS AND METHODS: Twenty patients with CPBP and twenty healthy controls (HCs) participated in the study and underwent resting-state functional magnetic resonance imaging (fMRI) scans. Brain activity was evaluated using regional homogeneity (ReHo), amplitude of low-frequency fluctuations (ALFF), and fractional ALFF (fALFF) measures. Preprocessing of fMRI data involved steps such as slice timing correction, motion correction, and nuisance regression to account for physiological noise and head motion. Statistical analyses included two-sample t-tests to compare ReHo, ALFF, and fALFF values between CPBP patients and HCs, with age as a covariate, and Spearman correlation analysis to explore relationships between brain activity measures and clinical characteristics.

RESULTS: The study revealed significant differences in brain activity between CPBP patients and HCs. CPBP patients exhibited altered higher ReHo in regions including the bilateral middle frontal gyrus, medial superior frontal gyrus, precuneus, left insula, right caudate, and bilateral cerebellar tonsils, with decreased ReHo in the right precentral gyrus. ALFF analysis showed increased activity in the bilateral middle frontal gyrus, medial superior frontal gyrus, right precuneus, and right inferior frontal gyrus, and decreased ALFF in the left precentral gyrus and right postcentral gyrus. fALFF values were notably higher in the bilateral medial superior frontal gyrus and precuneus. Several brain regions with significant differences in ReHo, ALFF, and fALFF were extensively correlated with the burned area and pruritus scale scores.

CONCLUSION: Our data suggest that patients with CPBP show alterations in ReHo, ALFF, and fALFF values primarily in brain regions associated with the default mode network and sensorimotor areas. These results may provide valuable insights relevant to the neuropathology of CPBP.

PMID:39546823 | DOI:10.1016/j.burns.2024.107305

Front Hum Neurosci. 2024 Oct 31;18:1501310. doi: 10.3389/fnhum.2024.1501310. eCollection 2024.

ABSTRACT

Resting-state functional magnetic resonance imaging (RS-fMRI) has been extensively utilized for noninvasive investigation of human brain activity. While studies employing simultaneous recordings of fMRI and electrophysiology have established a connection between the low-frequency fluctuation (< 0.1 Hz) observed in RS-fMRI and the local field potential (LFP), it remains unclear whether the RS-fMRI signal exhibits frequency-dependent modulation, which is a well-documented phenomenon in LFP. The present study concurrently recorded resting-state functional magnetic resonance imaging (RS-fMRI) and local field potentials (LFP) in the striatum of 8 rats before and after a pharmacological manipulation. We observed a highly similar frequency-dependent pattern of amplitude changes in both RS-fMRI and LFP following the manipulation, specifically an increase in high-frequency band amplitudes accompanied by a decrease in low-frequency band amplitudes. These findings provide direct evidence that the enhanced high-frequency fluctuations and reduced low-frequency fluctuations observed in RS-fMRI may reflect heightened neuronal activity.

PMID:39545149 | PMC:PMC11560898 | DOI:10.3389/fnhum.2024.1501310

BMC Complement Med Ther. 2024 Nov 14;24(1):396. doi: 10.1186/s12906-024-04703-y.

ABSTRACT

BACKGROUND: The hypothalamus has been recognized as a core structure in the sleep-wake cycle. However, whether the neuroplasticity of the hypothalamus is involved in the acupuncture treatment of insomnia remains elusive.

METHODS: We recruited 42 patients with chronic insomnia disorder (CID) and 23 matched healthy controls (HCs), with CID patients randomly assigned to receive real acupuncture (RA) or sham acupuncture (SA) for four weeks. Insomnia severity was evaluated using the Pittsburgh Sleep Quality Index (PSQI) score, and the resting-state functional connectivity (rsFC) of the hypothalamus was assessed via functional magnetic resonance imaging (fMRI).

RESULTS: In the cross-sectional investigation, CID patients showed increased rsFC between the medial hypothalamus (MH) and left lateral orbital frontal cortex (LOFC), and bilateral medial orbital frontal cortex (MOFC) compared to HCs. In the longitudinal experiment, PSQI scores significantly decreased in the RA group (p = 0.03) but not in the SA group. Interestingly, the increased MH-LOFC connectivity was found to be reduced following RA treatment. In addition, the altered rsFC of MH-LOFC significantly correlated with clinical improvement in the RA group (r = -0.692, p = 0.006).

CONCLUSION: This randomized neuroimaging study provides preliminary evidence that acupuncture may improve insomnia symptoms by restoring circuits associated with hypothalamic subregions.

TRIAL REGISTRATION: This trial has been registered on the Chinese Clinical Trial Registry ( www.chictr.org.cn ) with the identifier (ChiCTR1800017092). Registered date: 11/07/2018.

PMID:39543627 | PMC:PMC11566913 | DOI:10.1186/s12906-024-04703-y

Neuroimage. 2024 Nov 12;303:120925. doi: 10.1016/j.neuroimage.2024.120925. Online ahead of print.

ABSTRACT

The ongoing brain activity serves as a baseline that supports both internal and external cognitive processes. However, its precise nature remains unclear. Considering that people display various patterns of brain activity even when engaging in the same task, it is reasonable to believe that individuals possess their unique brain baseline pattern. Using spatial independent component analysis on a large sample of fMRI data from the Human Connectome Project (HCP), we found an individual-specific component which can be consistently extracted from either resting-state or different task states and is reliable over months. Compared to functional connectome fingerprinting, it is much more stable across different fMRI modalities. Its stability is closely related to high explained variance and is minimally influenced by factors such as noise, scan duration, and scan interval. We propose that this component underlying the ongoing activity represents an individual-specific baseline pattern of brain activity.

PMID:39542069 | DOI:10.1016/j.neuroimage.2024.120925

Cogn Neurodyn. 2024 Jun;18(3):813-827. doi: 10.1007/s11571-023-09941-3. Epub 2023 Feb 18.

ABSTRACT

The brain structure-function relationship is crucial to how the human brain works under normal or diseased conditions. Exploring such a relationship is challenging when using the 3-dimensional magnetic resonance imaging (MRI) functional dataset which is temporal dynamic and the structural MRI which is static. Partial Least Squares Correlation (PLSC) is one of the classical methods for exploring the joint spatial and temporal relationship. The goal of PLSC is to identify covarying patterns via linear voxel-wise combinations in each of the structural and functional data sets to maximize the covariance. However, existing PLSC cannot adequately deal with the unmatched temporal dimensions between structural and functional data sets. We proposed a new alternative variant of the PLSC, termed within-subject, voxel-wise, and constant-block PLSC, to address this problem. To validate our method, we used two data sets with weak and strong relationships in simulated data. Additionally, the analysis of real brain data was carried out based on gray matter volume hubs derived from sMRI and whole-brain voxel-wise measures from resting-state fMRI for aging effect based on healthy subjects aged 16-85 years. Our results showed that our constant-block PLSC can detect weak structure-function relationships and has better robustness to noise. In fact, it adequately unearthed the true simulated number of significant and more accurate latent variables for the simulated data and more meaningful LVs for the real data, with covariance improvement from 16.19 to 41.48% (simulated) and 13.29-53.68% (real data), respectively. More interestingly in the real data analysis, our method identified simultaneously the well-known brain networks such as the default mode, sensorimotor, auditory, and dorsal attention networks both functionally and structurally, implying the hubs we derived from gray matter volumes are the basis of brain function, supporting diverse functions. Constant-block PLSC is a feasible tool for analyzing the brain structure-function relationship.

PMID:39539980 | PMC:PMC11555187 | DOI:10.1007/s11571-023-09941-3

Front Pharmacol. 2024 Oct 30;15:1454628. doi: 10.3389/fphar.2024.1454628. eCollection 2024.

ABSTRACT

The modulation of social cognition is suggested as a possible mechanism contributing to the potential clinical efficacy of psychedelics in disorders involving socio-emotional and reward processing deficits. Resting-state functional Magnetic Resonance Imaging (rs-fMRI) can be used to detect changes in brain connectivity during psychedelic-induced states. Thus, this pharmacoimaging study investigates the effects of N,N-Dimethyltryptamine (DMT) on functional connectivity in brain areas relevant to social cognition, using a within-subject design in eleven healthy experienced users. The study included both an active and a control condition, conducted at different time points. The active condition involved DMT inhalation, while the control condition did not. Seed-based connectivity was measured for the two core regions involved in theory of mind and emotional processing, respectively, the posterior supramarginal gyrus and the amygdala. DMT increased supramarginal gyrus connectivity with the precuneus, posterior cingulate gyrus, amygdala, and orbitofrontal cortex. Additionally, increased connectivity emerged between the amygdala and orbitofrontal cortex. These results demonstrate that DMT modulates brain connectivity in socio-emotional and affective-value circuits, advancing our understanding of the neural mechanisms underlying the psychedelic experience and its potential therapeutic action.

PMID:39539622 | PMC:PMC11558042 | DOI:10.3389/fphar.2024.1454628

Front Neurosci. 2024 Oct 30;18:1397234. doi: 10.3389/fnins.2024.1397234. eCollection 2024.

ABSTRACT

BACKGROUND: Mindfulness training has been shown to promote positive mental health outcomes and related changes in neural networks such as the default mode network, which has a central node in the posterior cingulate cortex (PCC). Previous work from our group reported on the impact of a novel, neurofeedback augmented mindfulness training (NAMT) task on regulation of PCC hemodynamic activity in typically developing adolescents. The present pilot study aimed to expand on this finding by examining the pre-post changes of the NAMT task on resting-state functional connectivity of the PCC.

METHODS: Thirty-one typically developing adolescents (14.77 ± 1.23 years; 45% female) underwent a resting-state functional magnetic resonance imaging scan both before and after completing the NAMT task. A linear mixed effects model was used to assess for changes in functional connectivity of the PCC across the two resting-state runs.

RESULTS: Data did not support the hypothesized decrease in connectivity between the PCC seed and other DMN regions from pre- to post-NAMT task. However, we observed a significant increase in functional connectivity between the PCC and a cluster encompassing the left hippocampus and amygdala following completion of the NAMT task (run 1 Fisher's Z = 0.16; run 2 Fisher's Z = 0.26).

CONCLUSION: Although preliminary, this finding suggests NAMT has the potential to strengthen connectivity between default mode and salience regions. We speculate that such changed connectivity may facilitate enhanced self-referential and emotional processing in adolescents.

CLINICAL TRIAL REGISTRATION: https://clinicaltrials.gov/, identifier NCT04053582.

PMID:39539491 | PMC:PMC11558881 | DOI:10.3389/fnins.2024.1397234

CNS Neurosci Ther. 2024 Nov;30(11):e70087. doi: 10.1111/cns.70087.

ABSTRACT

STUDY OBJECTIVES: Sleep deprivation (SD) is prevalent in our increasingly round-the-clock society. Optimal countermeasures such as ample recovery sleep are often unfeasible, and brief naps, while helpful, do not fully restore cognitive performance following SD. Thus, we propose that targeted interventions, such as repetitive transcranial magnetic stimulation (rTMS), may enhance cognitive performance recovery post-SD.

METHODS: We recruited 50 participants for two SD experiments. In the first experiment, participants performed a psychomotor vigilance task (PVT) under three conditions: normal sleep (resting wakefulness), after 24 h of SD, and following a subsequent 30-min nap. We analyzed dynamic changes in PVT outcomes and cerebral responses across conditions to identify the optimal stimulation target. Experiment 2 adopted the same protocol except that, after the nap, 10-Hz, sham-controlled, individualized rTMS was administrated. Then, an analysis of variance was conducted to investigate the ability of stimulation to improve the PVT reaction times.

RESULTS: Through task-related functional magnetic resonance imaging, we identified cerebral responses within the right middle frontal gyrus (MFG) as the optimal stimulation target. Subsequent application of individualized 10-Hz rTMS over the right MFG attenuated SD-induced deterioration of vigilance.

CONCLUSION: Our findings suggest that combining a brief nap with individualized rTMS can significantly aid the recovery of vigilance following SD. This approach, through modulating neural activity within functional brain networks, is a promising strategy to counteract the cognitive effects of SD.

PMID:39539093 | PMC:PMC11561304 | DOI:10.1111/cns.70087

Neuroimage Clin. 2024 Nov 2;44:103696. doi: 10.1016/j.nicl.2024.103696. Online ahead of print.

ABSTRACT

BACKGROUND: Working memory (WM) deficits are among the most prominent cognitive impairments in attention deficit hyperactivity disorder (ADHD). While functional connectivity is a prevailing approach in brain imaging of ADHD, alterations in WM-related functional brain networks and their malleability by cognitive training are not well known. We examined whole-brain functional connectivity differences between adults with and without ADHD during n-back WM tasks and rest at pretest, as well as the effects of WM training on functional and structural brain connectivity in the ADHD group.

METHODS: Forty-two adults with ADHD and 36 neurotypical controls performed visuospatial and verbal n-back tasks during functional magnetic resonance imaging (fMRI). In addition, seven-minute resting state fMRI data and diffusion-weighted MR images were collected from all participants. The adults with ADHD continued into a 5-week randomized controlled WM training trial (experimental group training on a dual n-back task, n = 21; active control group training on Bejeweled II video game, n = 21), followed by a posttraining MRI. Brain connectivity was examined with Network-Based Statistic.

RESULTS: At the pretest, adults with ADHD had decreased functional connectivity compared with the neurotypical controls during both n-back tasks in networks encompassing fronto-parietal, temporal, occipital, cerebellar, and subcortical brain regions. Furthermore, WM-related connectivity in widespread networks was associated with performance accuracy in a continuous performance test. Regarding resting state connectivity, no group differences or associations with task performance were observed. WM training did not modulate functional or structural connectivity compared with the active controls.

CONCLUSION: Our results indicate large-scale abnormalities in functional brain networks underlying deficits in verbal and visuospatial WM commonly faced in ADHD. Training-induced plasticity in these networks may be limited.

PMID:39536524 | DOI:10.1016/j.nicl.2024.103696

J Cogn Neurosci. 2024 Nov 9:1-30. doi: 10.1162/jocn_a_02278. Online ahead of print.

ABSTRACT

The dual-stream model of speech processing describes a cortical network involved in speech processing. However, it is not yet known if the dual-stream model represents actual intrinsic functional brain networks. Furthermore, it is unclear how disruptions after a stroke to the functional connectivity of the dual-stream model's regions are related to speech production and comprehension impairments seen in aphasia. To address these questions, in the present study, we examined two independent resting-state fMRI data sets: (1) 28 neurotypical matched controls and (2) 28 chronic left-hemisphere stroke survivors collected at another site. We successfully identified an intrinsic functional network among the dual-stream model's regions in the control group using functional connectivity. We then used both standard functional connectivity analyses and graph theory approaches to determine how this connectivity may predict performance on clinical aphasia assessments. Our findings provide evidence that the dual-stream model of speech processing is an intrinsic network as measured via resting-state MRI and that functional connectivity of the hub nodes of the dual-stream network defined by graph theory methods, but not overall average network connectivity, is weaker in the stroke group than in the control participants. In addition, the functional connectivity of the hub nodes predicted linguistic impairments on clinical assessments. In particular, the relative strength of connectivity of the right hemisphere's homologues of the left dorsal stream hubs to the left dorsal hubs, versus to the right ventral stream hubs, is a particularly strong predictor of poststroke aphasia severity and symptomology.

PMID:39536158 | DOI:10.1162/jocn_a_02278

Front Hum Neurosci. 2024 Oct 29;18:1453638. doi: 10.3389/fnhum.2024.1453638. eCollection 2024.

ABSTRACT

BACKGROUND: Temporal interference (TI) stimulation, an innovative non-invasive brain stimulation approach, has the potential to activate neurons in deep brain regions. However, the dynamic mechanisms underlying its neuromodulatory effects are not fully understood. This study aims to investigate the effects of TI stimulation on dynamic functional connectivity (dFC) in the motor cortex.

METHODS: 40 healthy adults underwent both TI and tDCS in a double-blind, randomized crossover design, with sessions separated by at least 48 h. The total stimulation intensity of TI is 4 mA, with each channel's intensity set at 2 mA and a 20 Hz frequency difference (2 kHz and 2.02 kHz). The tDCS stimulation intensity is 2 mA. Resting-state functional magnetic resonance imaging (rs-fMRI) data were collected before, during, and after stimulation. dFC was calculated using the left primary motor cortex (M1) as the region of interest (ROI) and analyzed using a sliding time-window method. A two-way repeated measures ANOVA (group × time) was conducted to evaluate the effects of TI and tDCS on changes in dFC.

RESULTS: For CV of dFC, significant main effects of stimulation type (P = 0.004) and time (P < 0.001) were observed. TI showed lower CV of dFC than tDCS in the left postcentral gyrus (P < 0.001). TI-T2 displayed lower CV of dFC than TI-T1 in the left precentral gyrus (P < 0.001). For mean dFC, a significant main effect of time was found (P < 0.001). TI-T2 showed higher mean dFC than tDCS-T2 in the left postcentral gyrus (P = 0.018). Within-group comparisons revealed significant differences between time points in both TI and tDCS groups, primarily in the left precentral and postcentral gyri (all P < 0.001). Results were consistent across different window sizes.

CONCLUSION: 20 Hz TI stimulation altered dFC in the primary motor cortex, leading to a significant decreasing variability and increasing mean connectivity strength in dFC. This outcome indicates that the 20 Hz TI frequency interacted with the motor cortex's natural resonance.

PMID:39534013 | PMC:PMC11554487 | DOI:10.3389/fnhum.2024.1453638

Int J Clin Health Psychol. 2024 Oct-Dec;24(4):100517. doi: 10.1016/j.ijchp.2024.100517. Epub 2024 Oct 30.

ABSTRACT

BACKGROUND/OBJECTIVE: Research on the ontogenetic development of brain networks using resting state has shown to be useful for understanding age-associated changes in brain connectivity. This work aimed to analyze the relationship between brain connectivity, age and intelligence.

METHODS: A sample of 26 children and adolescents between 6 and 18 years of both sexes underwent a resting-state functional magnetic resonance imaging study. We estimated the values of fractional Amplitude low-frequency fluctuations (fALFF) and the values of Regional homogeneity (ReHo) in a voxelwise analysis to later correlate them with age and intelligence quotient (IQ).

RESULTS: No significant correlations were found with IQ, but it was found that the fALFF values of the left precentral cortex (premotor cortex and supplementary motor area), as well as the ReHo values of the medial frontal gyrus, and the precentral cortex of the left hemisphere, correlate with age. Conclusions: Hubs related to various "task positive" networks closely related to cognitive functioning would present a development more related to age and relatively independent of individual differences in intelligence. These findings suggest that the premotor cortex and supplementary motor cortex could be a cortical hub that develops earlier than previously reported and that it would be more related to age than to intelligence level.

PMID:39533988 | PMC:PMC11555343 | DOI:10.1016/j.ijchp.2024.100517

Hum Brain Mapp. 2024 Nov;45(16):e70076. doi: 10.1002/hbm.70076.

ABSTRACT

Perfusion changes in white matter (WM) lesions and normal-appearing brain regions play an important pathophysiological role in multiple sclerosis (MS). However, most perfusion imaging methods require exogenous contrast agents, the repeated use of which is discouraged. Using resting-state functional MRI (rs-fMRI), we aimed to investigate differences in perfusion between white matter lesions and normal-appearing brain regions in MS and healthy participants. A total of 41 MS patients and 41 age- and sex-matched healthy participants received rs-fMRI, from which measures of cerebral hemodynamics and oxygenation were extracted and compared across brain regions and study groups using within- and between-group nonparametric tests, linear mixed models, and robust multiple linear regression. We found longer blood arrival times and lower blood volumes in lesions than in normal-appearing WM. Higher blood volumes were found in MS patients' deep WM lesions compared to healthy participants, and blood arrival time was more delayed in MS patients' deep WM lesions than in healthy participants. Delayed blood arrival time in the cortical grey matter was associated with greater cognitive impairment in MS patients. Perfusion imaging using rs-fMRI is useful for WM lesion characterization. rs-fMRI-based blood arrival times and volumes are associated with cognitive function.

PMID:39535849 | PMC:PMC11558553 | DOI:10.1002/hbm.70076

Asian J Psychiatr. 2024 Nov 4;102:104303. doi: 10.1016/j.ajp.2024.104303. Online ahead of print.

ABSTRACT

BACKGROUND: Resting-state functional magnetic resonance imaging (fMRI) studies have shown altered brain activity in major depressive disorder (MDD) and schizophrenia (SZ). Despite differing diagnoses, SZ and MDD share similar features. However, functional brain activity similarities and differences between SZ and MDD remain unclear.

METHODS: Participants with MDD, SZ, and normal controls (n=36 each) underwent resting-state fMRI scans. Amplitude of low-frequency fluctuations (ALFF) was used to analyze the preprocessed rs-fMRI data. One-way ANOVAs and post hoc analyses compared ALFF values in different brain regions. Pearson correlation analysis examined associations with clinical symptoms.

RESULTS: Comparison among the three groups revealed significant differences in ALFF values within the left superior parietal cortex (L-SPC) and bilateral striatum. Through pairwise comparisons, patients with SZ but not patients with MDD were found to exhibit increased striatum ALFF values relative to NC individuals, but decreased in MDD. Meanwhile, L-SPC ALFF values were significantly increased in patients with SZ relative to both normal control individuals and patients with MDD, while no differences in these values were observed between the normal control and MDD groups. The Pearson correlation analyses showed significant positive correlations between ALFF in the striatum and PANSS positive score, but no significant correlation with other symptom severity in SZ and MDD.

CONCLUSION: These findings support the hypothesis of alterations in brain functional activity as a fundamental component of the pathogenesis of MDD and SZ. The observed differences in functional brain activity in the superior parietal cortex and striatum between MDD and SZ provide a neuroimaging basis that can contribute to the differential diagnosis of these debilitating conditions.

PMID:39531911 | DOI:10.1016/j.ajp.2024.104303

Brain Connect. 2024 Nov 12. doi: 10.1089/brain.2023.0087. Online ahead of print.

ABSTRACT

Introduction: The influence of the cerebellum in poststroke aphasia recovery is poorly understood. Despite the right cerebellum being identified as a critical region involved in both language and cognitive functions, little is known about functional connections between the cerebellum and bilateral cortical hemispheres following stroke. This study investigated the relationship between chronic poststroke naming deficits and cerebello-cerebral resting-state functional connectivity (FC). Methods: Twenty-five cognitively normal participants and 42 participants with chronic poststroke aphasia underwent resting-state functional magnetic resonance imaging. Participants with aphasia also underwent language assessment. We conducted regions of interest (ROI)-to-ROI analyses to investigate the FC between the right cerebellar Crus I/II (seed ROI; Cereb1r/Cereb2r) and bilateral cortical language regions and compared these results to cognitively normal controls. Single-subject connectivity parameters were extracted and used as independent variables in a stepwise multiple linear regression model associating Boston Naming Test (BNT) score with FC measures. Results: FC analyses demonstrated correlations between the right cerebellar Crus I/II and both left and right cortical regions for both cognitively normal controls and stroke participants. Additionally, aphasia severity and lesion load had an effect on the cerebello-cerebral network connectivity in participants with aphasia. In a stepwise multiple linear regression, controlling for aphasia severity, time poststroke and lesion load, FC between the right Cereb2-left Cereb1 (standardized beta [std B]= -0.255, p < 0.004), right Cereb2-right anterior MTG (std B = 0.259, p < 0.004), and the right Cereb2-left anterior STG (std B = -0.208, p < 0.018) were significant predictors of BNT score. The overall model fit was R2 = 0.786 (p = 0.001). Conclusion: Functional connections between the right cerebellum and residual bilateral cerebral hemisphere regions may play a role in predicting naming ability in poststroke aphasia.

PMID:39531223 | DOI:10.1089/brain.2023.0087

Trials. 2024 Nov 11;25(1):752. doi: 10.1186/s13063-024-08606-8.

ABSTRACT

BACKGROUND: The therapeutic use of intermittent theta burst stimulation (iTBS) delivered to the left dorsolateral prefrontal cortex (LDLPFC) is a relatively new but promising treatment option for depression. There is a need for more knowledge on the mechanisms involved in its antidepressant effects.

METHODS: This is a single-centre, prospective, randomized, double-blind, placebo-controlled trial with two arms, iTBS and sham iTBS. Adult outpatients with unipolar major depressive disorder of at least moderate severity will undergo cognitive assessment with an N-back task (0-back and 2-back), functional and structural magnetic resonance imaging and assessment of depression severity before and after brain stimulation. Neuronavigated iTBS or sham stimulation will be targeted at the LDPFC once a day for 10 consecutive workdays. ITBS will be delivered with the parameters 120% of resting motor threshold, triplet 50 Hz bursts repeated at 5 Hz; 2 s on and 8 s off, 600 pulses per session with a total duration of 3 min 9 s. The severity of depression will be measured with the Montogomery Aasberg Depression Rating Scale and the Beck Depression Inventory - second edition. In the iTBS group relative to sham, we expect significant antidepressant effects and improved N-back performance, associated with increased integrity in white matter tracts functionally connected with the LDLPFC and emotion regulation areas within the rostral anterior cingulate cortices, alongside potential increases in cortical thickness in these regions. On functional imaging, we expect to observe increased brain activity in the LDPFC during the performance of the N-back condition with higher cognitive load (2-back) in the iTBS group relative to sham.

DISCUSSION: iTBS is a promising, time-efficient, and considered a safe treatment option for depression according to existing evidence. This trial aims to assess the neurocognitive impact of a 2-week, once-daily iTBS compared to sham iTBS, targeting the LDLPFC in depressed adult outpatients. The study investigates the relationships between changes in cerebral measures and cognitive performance on an N-back task in relation to the antidepressant effect following iTBS. This trial delves into the neurocognitive mechanisms of iTBS in depression, potentially offering novel scientific insights into its treatment effects and mechanisms of action.

TRIAL REGISTRATION: ClinicalTrials.gov NCT06534684. Retrospectively registered on August 1st 2024.

PMID:39529199 | PMC:PMC11555895 | DOI:10.1186/s13063-024-08606-8

Neuroscience. 2024 Oct 17:S0306-4522(24)00537-2. doi: 10.1016/j.neuroscience.2024.10.026. Online ahead of print.

ABSTRACT

The aim of this study was to investigate alterations in the resting-state brain functional network characteristics of lifelong premature ejaculation (PE) patients using surface-based degree centrality (DC), and to analyze the correlation between these alterations and clinical symptoms in PE patients. The study included individuals with lifelong PE (patient group, n = 36) and a control group matched by age and education level (control group, n = 22). Resting-state functional magnetic resonance imaging (fMRI) scans were performed on all participants. Surface-based degree centrality analysis was conducted and the differences between the two groups were compared using t-tests. Further, the DC values of brain regions showing significant differences were correlated with clinical symptoms. Compared to the control group, the patient group exhibited significantly reduced degree centrality (DC) values in the left precuneus and significantly increased DC values in the right supplementary motor area (SMA). Furthermore, intravaginal ejaculatory latency time (IELT) and Chinese Index of Premature Ejaculation (CIPE) values were positively correlated with left precuneus DC values and negatively correlated with right SMA DC values. Patients with primary lifelong ejaculation demonstrate abnormalities in key brain network nodes and their connections with relevant brain regions, which are strongly associate with clinical symptoms. These findings enhance our understanding of the neuronal pathological changes in PE patients.

PMID:39426708 | DOI:10.1016/j.neuroscience.2024.10.026