Most recent paper

Annu Int Conf IEEE Eng Med Biol Soc. 2025 Jul;2025:1-5. doi: 10.1109/EMBC58623.2025.11251640.

ABSTRACT

Brain tumors significantly disrupt brain network organization, yet the temporal dynamics of network reorganization following surgical intervention remain poorly understood. This study investigated longitudinal changes in functional brain network properties across pre-surgical, post-surgical, and follow-up time points in glioma patients. Using graph theory analysis of resting-state functional magnetic resonance imaging (fMRI) data, we examined whole-brain network metrics as well as the connections involving perilesional and contralesional regions. Results revealed significant alterations in network topology over time, with distinct patterns of reorganization in perilesional and contralesional regions, suggesting mechanisms of plasticity and recovery in brain network architecture following tumor resection.Clinical Relevance-These findings have significant implications for surgical planning and post-operative care, suggesting the need for therapeutic approaches that consider both local and distant network effects. The demonstrated importance of contralesional adaptation particularly warrants attention in rehabilitation strategies, potentially opening new avenues for targeted interventions in recovery.

PMID:41336078 | DOI:10.1109/EMBC58623.2025.11251640

Annu Int Conf IEEE Eng Med Biol Soc. 2025 Jul;2025:1-5. doi: 10.1109/EMBC58623.2025.11252604.

ABSTRACT

We present a novel topological framework for analyzing functional brain signals using time-frequency analysis. By integrating persistent homology with time-frequency representations, we capture multi-scale topological features that characterize the dynamic behavior of brain activity. This approach identifies 0D (connected components) and 1D (loops) topological structures in the signal's time-frequency domain, enabling robust extraction of features invariant to noise and temporal misalignments. The proposed method is demonstrated on resting-state functional magnetic resonance imaging (fMRI) data, showcasing its ability to discern critical topological patterns and provide insights into functional connectivity. This topological approach opens new avenues for analyzing complex brain signals, offering potential applications in neuroscience and clinical diagnostics.

PMID:41335918 | DOI:10.1109/EMBC58623.2025.11252604

Annu Int Conf IEEE Eng Med Biol Soc. 2025 Jul;2025:1-4. doi: 10.1109/EMBC58623.2025.11253645.

ABSTRACT

In neuroimaging-based Alzheimer's Disease (AD) diagnosis, effectively integrating structural MRI (sMRI) and resting-state functional MRI (rs-fMRI) data while preserving clinical interpretability remains a significant challenge. To address this issue, we propose a novel transformer-based framework that unifies heterogeneous imaging features into coherent region-level representations. Our approach uniquely leverages prior anatomical knowledge to guide attention toward AD-relevant regions while employing a learnable mapping mechanism that transforms sMRI spatial features into biologically meaningful regional representations. We implement a consistency constraint to ensure optimal alignment between structural and functional coupling across modalities, followed by a Bayesian fusion strategy to integrate these aligned multi-modal features. Through comprehensive evaluation on the ADNI dataset, our method demonstrates not only superior diagnostic accuracy compared to existing state-of-the-art approaches but also provides clinically interpretable insights into AD-related brain connectivity patterns. This work represents a significant advancement in multi-modal neuroimaging analysis for AD diagnosis, successfully combining enhanced diagnostic performance with clinical interpretability.

PMID:41335802 | DOI:10.1109/EMBC58623.2025.11253645

Annu Int Conf IEEE Eng Med Biol Soc. 2025 Jul;2025:1-5. doi: 10.1109/EMBC58623.2025.11254461.

ABSTRACT

Tools for aiding in the diagnosis of Autism Spectrum Disorder (ASD) using machine learning (ML) and resting-state rs-fMRI (rs-fMRI) must encompass different phases such as data collection, preprocessing, feature extraction, model training, and validation. Many studies rely on a single preprocessing pipeline or use preprocessed data, which might not be optimal for the task at hand. This study investigates the impact of rs-fMRI preprocessing on the performance of ML models for ASD diagnosis. Using a subset of the Autism Brain Imaging Data Exchange (ABIDE) dataset, 72 subjects were preprocessed with 108 different configurations, and features were extracted to train 13 ML classifiers. Results indicate that preprocessing choices significantly influence model accuracy, with the best configurations achieving up to 95.83% accuracy. However, generalization tests on an extended dataset revealed a substantial performance drop, highlighting challenges in model robustness. Findings emphasize the need for adaptive preprocessing strategies and gender-balanced datasets to improve ASD classification reliability.

PMID:41335785 | DOI:10.1109/EMBC58623.2025.11254461

Annu Int Conf IEEE Eng Med Biol Soc. 2025 Jul;2025:1-6. doi: 10.1109/EMBC58623.2025.11254951.

ABSTRACT

Functional near-infrared spectroscopy (fNIRS) is an optical imaging modality which, similar to fMRI, measures cerebral hemodynamics associated with neural activity. It has several advantages over fMRI, including low cost, portability, compatibility with metal or electrical medical implants, and ease of integration with electroencephalography (EEG) and transcranial magnetic stimulation (TMS). However, fNIRS signal contains a number of confounding components. Physiological noises due to superficial absorption by the scalp and skull are present in all fNIRS data. Additionally, low-frequency oscillations of respiration, cardiac pulse and movements all obscure the underlying cerebral hemodynamic signals. Our previous work has developed an automatic processing pipeline that effectively removes these physiological noise components from data during voluntary tasks (e.g., a motor task) and an endogenous state (e.g., awake resting) [1], [2]. However, to date it has not been known if the noises behave similarly in recordings involving an externally injected stimulus such as TMS. Therefore, in a unique setup of concurrent fNIRS, EEG and TMS (fNET), this study examined the spatial and temporal profiles of fNIRS data and noises during motor, single pulse and repetitive TMS. Specifically, we compared the multichannel short separation recordings with the regularly distanced long separation data in a whole-head montage. The results showed that superficial fluctuations indeed were present in the TMS-concurrent fNIRS recordings and that the noise components behaved similarly across motor task, single pulse and repetitive TMS at individuals' alpha frequency, which warrants removal of such physiological noises.Clinical Relevance- Compared to fMRI, fNIRS offers a much less expensive alternative for measuring cortical hemodynamics. Importantly, fNIRS can provide a clinic accessible options for concurrent measurement with TMS when TMS is given as treatment to patients with depression or other neurological disorders. Our findings indicate that fNIRS data acquired during concurrent TMS are contaminated by superficial fluctuations and that careful removal of these physiological noises from fNIRS data is critical in obtaining accurate images of cerebral activity with fNIRS.

PMID:41335688 | DOI:10.1109/EMBC58623.2025.11254951

Annu Int Conf IEEE Eng Med Biol Soc. 2025 Jul;2025:1-7. doi: 10.1109/EMBC58623.2025.11254960.

ABSTRACT

Diagnosing Parkinson's disease (PD) is particularly challenging due to the intricate and variable nature of its biomarkers, which span motor and non-motor symptoms, differ across individuals, and evolve over time. While machine learning has been used to automate this process, most studies focus on limited biomarkers due to dataset constraints. This study introduces a Federated Learning (FL) framework that integrates electroencephalography (EEG) and resting-state functional magnetic resonance imaging (rs-fMRI) data for improved PD classification. Unlike traditional fusion-based studies integrating multiple biomarkers from the same subject group, the Federated Learning framework processes EEG and fMRI data separately from distinct subject groups. Client nodes treat these as independent datasets and utilize convolutional neural networks (CNNs), Graph CNNs, and ResNet-18 models for analysis. A central server then aggregates insights, simulating a diagnostic center to evaluate the relevance of additional biomarkers for enhanced PD detection utilizing support vector machines (SVM) and federated dynamic model aggregation (Fed-Dyn). Additionally, gender-specific evaluations suggest that male-exclusive models outperform female models in biomarker representation. The study underscores the necessity of demographic-aware frameworks and optimized fusion techniques for early-stage PD detection.Clinical Relevance- This study significantly enhances early PD diagnosis by integrating EEG and fMRI biomarkers through Federated Learning (FL), offering a more comprehensive view of neurodegenerative changes while preserving patient privacy. By addressing gender-specific biomarker differences and tailoring models to diverse patient profiles and disease stages, it supports precision medicine and equitable healthcare. The advanced fusion techniques improve diagnostic accuracy in terms of ROC-AUC score, aiding clinical decision-making and enabling scalable telemedicine solutions. Beyond PD, the framework holds potential for broader neurodegenerative research and sets benchmarks for biomarker-based diagnostics, paving the way for impactful advancements in precision neurology.

PMID:41335685 | DOI:10.1109/EMBC58623.2025.11254960

NMR Biomed. 2026 Jan;39(1):e70208. doi: 10.1002/nbm.70208.

ABSTRACT

Cerebrovascular reactivity (CVR) mapping based on resting-state BOLD fMRI can be widely available for research of vascular health not only in clinical studies but also in open databases. However, as it utilizes spontaneous CO2 fluctuations of blood as endogenous stimuli, resting-state CVR may be prone to low SNR and reproducibility if the CO2 fluctuation of an individual is small. The automatic identification of such poor-quality CVR datasets is crucial for large-scale research. Thus, in this work, we developed an automatic quality control algorithm for resting-state CVR mapping. Utilizing a total of 51 resting-state CVR maps acquired with three scanning protocols in each healthy participant, quality control parameters reflecting common characteristics of poor-quality CVR, including pooled variance of different tissue types, proportion of negative voxels in gray matter, and the sensitivity of the BOLD signal to CVR, were extracted and then combined into one comprehensive quality evaluation index (QEI). We further evaluated its performance by leave-one-out cross-validation and correlation analyses with test-retest reproducibility. Leave-one-out cross-validation showed that QEI was significantly correlated with the reference standard of quality evaluation in all left-out cases (r = 0.766). Correlation analyses with test-retest reproducibility revealed significant positive correlations between the worse QEI and similarity index of CVR maps from two tests (r = 0.809, 0.890, 0.396, and 0.654 for data from four open databases). The proposed QEI performed not only in good agreement with visual inspection but can also adapt in resting-state CVR from multiple age groups and scanning protocols, paving the way for the clinical applications of resting-state CVR mapping technology.

PMID:41334711 | DOI:10.1002/nbm.70208

Res Sq [Preprint]. 2025 Nov 23:rs.3.rs-7881643. doi: 10.21203/rs.3.rs-7881643/v1.

ABSTRACT

Delirium affects up to 50% of hospitalised, older patients and is linked to increased risk of death and long-term cognitive decline. Age-related changes in the ascending arousal system (AAS), including cholinergic and noradrenergic nuclei, may contribute to delirium vulnerability. Static and dynamic functional connectivity, across cortical and subcortical regions, was extracted from preoperative resting-state fMRI from 120 older adults (aged > 65 years old). Participants who developed delirium showed more segregated brain networks, cholinergic hyperconnectivity and noradrenergic hypoconnectivity. Dynamic patterns from these systems separated groups in low-dimensional space, suggesting altered temporal network dynamics. Normative maps of cholinergic gene expression density were associated with increased network segregation. These results suggest that aging-related AAS alterations-particularly compensatory cholinergic overactivity-may drive network changes that increase delirium risk. This work provides new insights into the neural mechanisms linking aging, arousal system dysfunction, and brain network disruption in delirium, mandating re-appraisal of leading delirium theories.

PMID:41333402 | PMC:PMC12668175 | DOI:10.21203/rs.3.rs-7881643/v1

bioRxiv [Preprint]. 2025 Nov 17:2025.09.22.677834. doi: 10.1101/2025.09.22.677834.

ABSTRACT

Understanding how the brain's functional architecture emerges prior to substantial postnatal visual experience is crucial for determining what initial capabilities infants possess and how they learn from their environment. Using resting-state fMRI from 584 neonates in the Developing Human Connectome Project, we provide the first comprehensive systems-level characterization of human visual cortex within hours of birth and across the third trimester of gestation. We discover that newborns possess a sophisticated visual architecture already functionally organized into three distinct pathways (ventral, lateral, and dorsal), each exhibiting posterior-to-anterior hierarchical structure and adult-like topographic organization. This tripartite visual organization differs from the bipartite organization observed in macaques, suggesting this architecture emerges through intrinsic developmental mechanisms rather than being a product of extensive postnatal experience and environmental adaptation. Moreover, pathway segregation, hierarchical ordering, and connectivity maturity all strengthen progressively with gestational age, revealing that visual cortical organization emerges through an active developmental program that unfolds across late gestation. Yet, despite this large-scale structure, individual pathways follow strikingly different maturation trajectories: dorsal areas exhibit a near-adult-like functional organization, even at the earliest gestational timepoints tested, whereas ventral areas remain immature and poised for experience-dependent refinement. These findings reframe our understanding of early visual development by revealing that complex functional networks emerge before substantial visual experience, yet are differentially prepared for plasticity, providing crucial insights into how evolution has optimized the brain for rapid learning while maintaining the flexibility needed for adaptation to diverse environments.

PMID:41332584 | PMC:PMC12667756 | DOI:10.1101/2025.09.22.677834

Physiol Rep. 2025 Dec;13(23):e70674. doi: 10.14814/phy2.70674.

ABSTRACT

Sensory processing disorder (SPD) is a neurodevelopmental condition characterized by impaired sensory discrimination and responsivity. Although the causes and neural correlates of SPD remain poorly understood, prenatal influences should be considered, as the prenatal environment is strongly implicated in the progression of neurodevelopmental disorders. One factor hypothesized to promote SPD is perinatal Western-style diet (WSD) exposure. This study explored the effects of perinatal WSD exposure on the proposed neural correlates of SPD in Japanese macaques. Functional connectivity between sensory and emotional processing areas was assessed at 4 months of age using resting-state functional magnetic resonance imaging (rs-fMRI). A machine learning model successfully predicted perinatal diet group based on functional connectivity strengths, indicating that differences in sensory connectivity exist between diet groups. Intra-somatomotor, visual-auditory, somatomotor-auditory, somatomotor-visual, and intra-visual network connections demonstrated the greatest differences between groups, with primary motor cortex connectivity being the most impacted. Connections to the amygdala were not major contributors to accurate model performance, but amygdala connectivity, especially to the somatomotor network, may still be a weak driver of model performance. These findings suggest that a proposed predictor of SPD, perinatal WSD exposure, impacts the functional connectivity of sensory processing areas relevant in SPD during early infancy.

PMID:41332183 | DOI:10.14814/phy2.70674

Acta Neuropathol Commun. 2025 Dec 1. doi: 10.1186/s40478-025-02183-w. Online ahead of print.

ABSTRACT

While neuroimaging studies have revealed notable white matter damage following mild traumatic brain injury (mTBI), the specific tracts and brain regions affected vary widely across studies. Here, we explored whether the spatial orientation of white matter tracts influences susceptibility to repeated mTBI, predicting that tracts oriented orthogonal to the axis of rotation of the head during impact (within the plane of rotation) would exhibit the most damage. Using a model of repeated rotational mTBI in mice, we acquired advanced diffusion MRI (diffusional kurtosis imaging using oscillating gradient encoding) and resting-state functional MRI (fMRI) data at baseline and 1-week post-injury. Consistent with our prediction, while both diffusivity and diffusional kurtosis decreased in the white matter of injured mice, only diffusional kurtosis revealed microstructural changes confined to tracts oriented orthogonal to the right-left axis of rotation. In addition, both region and subregion analyses showed functional connectivity (FC) deficits between regions connected via tracts running orthogonal to the rotation axis. The orientation-dependent changes in imaging metrics were validated by histopathological analyses. Females showed greater microstructural changes than males using diffusion MRI following injury, while no sex differences were detected by fMRI. Interestingly, the region-specific and subregion-specific FC analyses showed overlapping but non-identical changes in FC suggesting the utility of using both coarse and fine levels of brain parcellation for FC analyses in mTBI. These findings suggest that mTBI imaging studies may benefit from the consideration that damage after mTBI will predominate in tracts that are oriented orthogonal to the axis of rotation produced by the impact and that diffusivity and diffusional kurtosis as well as region and subregion-specific fMRI analyses can detect these changes.

PMID:41327381 | DOI:10.1186/s40478-025-02183-w

J Neurosci Methods. 2025 Nov 29:110646. doi: 10.1016/j.jneumeth.2025.110646. Online ahead of print.

ABSTRACT

BACKGROUND: Parkinson's disease (PD) involves concurrent changes in brain functional activity and white matter microstructure, yet single-modality analyses often fail to capture these complex alterations.

NEW METHODS: We propose a voxel-level dual-stream Swin Transformer fusion framework (DSTFP) to investigate multimodal structure-function relationships in PD. DSTFP employs parallel transformer branches to extract temporal dynamics from resting-state functional MRI (rs-fMRI) and topological features from diffusion tensor imaging (DTI) fractional anisotropy maps. A cross-modal attention fusion module establishes voxel-wise correspondence between functional and structural features.

RESULTS: Applied to the publicly available Parkinson's Progression Markers Initiative (PPMI) dataset, DSTFP discriminates PD, prodromal, and control groups with high robustness. Structural decoupling index (SDI) and structure-function coupling (SFC) analyses of fused features reveal distributed brain regions with characteristic alterations in functional-structural interactions.

COMPARISON WITH EXISTING METHODS: DSTFP outperforms conventional single-modality and baseline multimodal models in both classification accuracy and interpretability, providing more detailed insight into voxel-level structure-function relationships.

CONCLUSIONS: The proposed framework offers a robust, interpretable approach for multimodal neuroimaging analysis in PD. All source code is publicly available to support reproducibility (https://github.com/MAOmgg/DSTFP).

PMID:41325802 | DOI:10.1016/j.jneumeth.2025.110646

Clin Neurol Neurosurg. 2025 Nov 28;261:109277. doi: 10.1016/j.clineuro.2025.109277. Online ahead of print.

ABSTRACT

PURPOSE: The use of neuronavigation with superimposed mapping tools has enabled visualization of key fiber tracts and improved peri-operative planning. However, a limitation of these approaches is their reliance on a static underlying brain atlas, particularly in neurosurgical patients with brain tumors. A tool that enables qualification and quantification of brain region connectivity could refine approaches to surgical resection.

METHODS: We utilized a machine learning imaging platform, Quicktome™, to generate individualized functional parcels and tracts that dynamically adapt to perioperative change. The connectome was derived from a combination of diffusion tensor imaging and resting-state function magnetic resonance imaging. Matrices were generated from the functional MRI of four patients with intracranial neoplasms and the pre- and post-operative parcellation values were compared. The individual correlation and strength of regions were quantified. Hypo- and hyper-connected regions were marked as anomalous.

RESULTS: We present a case series of four patients to illustrate the correlation of the anomaly matrices with post-operative neurological changes. These include: post-operative delirium originating associated with salience network hypoconnectivity; visual hemineglect linked to hypoconnectivity in the dorsal attention network; and quantifiable improvements in the language network following the resolution of expressive aphasia. All differences between pre-and post-operative paired correlation values were statistically significant.

CONCLUSION: We demonstrate a novel approach to quantifying the extent to which anomalies in the functional connectome correlate with post-operative neurological changes. This has relevance in post-operative prognostication, provision of specialist therapy services, and could serve as a useful tool in surgical education and pre-operative planning.

PMID:41325661 | DOI:10.1016/j.clineuro.2025.109277

Pain. 2025 Nov 25. doi: 10.1097/j.pain.0000000000003843. Online ahead of print.

ABSTRACT

Neuropathic chronic low-back pain (neuCLBP) is associated with worse clinical outcomes compared with non-neuropathic or axial CLBP (non-neuCLBP) and has limited effective nonsurgical treatment options, reflecting poor understanding of its underlying pathophysiology. In this study, we compared neuCLBP and non-neuCLBP patients using standardized clinical phenotyping of the neuropathic component alongside multimodal brain functional magnetic resonance imaging (fMRI). We hypothesized that, consistent with the definition of neuropathic pain as pain arising from injury to the somatosensory nervous system, neuCLBP patients would exhibit reduced thalamic volume and/or altered thalamic shape, reduced primary somatosensory cortex (S1) thickness, and altered resting-state functional connectivity of these structures compared with non-neuCLBP patients and pain-free healthy controls. Consistent with previous literature, we observed that neuCLBP patients (n = 28) presented with more severe clinical symptoms than non-neuCLBP patients (n = 28). Structurally, neuCLBP patients exhibited extensive differences in thalamic shape but no significant differences in thalamic volume or S1 gray matter thickness. By contrast, by examining resting-state thalamic connectivity gradient maps, we found that non-neuCLBP patients exhibited the most pronounced alterations in these gradients. This study is the first to combine multimodal fMRI with rigorous, standardized phenotyping to investigate neuCLBP. While our results may be influenced by greater symptom severity in the neuCLBP patients, they indicate that these patients may display distinct central plasticity patterns. The findings also highlight the importance of distinguishing between these clinical phenotypes to reduce heterogeneity in future studies.

PMID:41325555 | DOI:10.1097/j.pain.0000000000003843

Neurosci Appl. 2025 Jun 11;4:105522. doi: 10.1016/j.nsa.2025.105522. eCollection 2025.

ABSTRACT

Electroconvulsive therapy (ECT) has been shown to induce widespread dysregulation of network connectivity in patients with mood disorders. Nevertheless, the extent to which these functional changes contribute to patients' cognitive side-effects or depressive symptoms improvement remains unclear. This study investigated cross-sectional resting-state functional connectivity (rs-FC) differences in patients with mood disorders after their 8th ECT session (ECT group, n = 33) compared to those receiving pharmacological treatment (non-ECT group, n = 36) and healthy controls (n = 34). Furthermore, we explored the association of rs-FC differences with cognitive side-effects and depressive symptom improvements assessed longitudinally in the ECT group. We focused on analyzing rs-FC within- and between the default mode network (DMN), executive control network (ECN), and frontoparietal network (FPN). Additionally, we explored the association between significant rs-FC group differences and verbal memory decline, and depressive symptoms improvement from pre-to post-ECT within the ECT group. ECT-treated patients exhibited hyper-connectivity within the left-hemisphere FPN compared to those on pharmacological treatment, along with hypo-connectivity between ECN and FPN (p-corrected<0.02). Depressive symptoms positively correlated with rs-FC within the right-hemisphere FPN (p-corrected<0.04). Notably, rs-FC differences were unrelated to verbal memory decline or symptom improvement from pre-to post-ECT (p-corrected>0.1). Our findings highlight differences in brain connectivity between remitted patients after ECT and diagnosis-matched patients following standard pharmacological treatment. Further studies are warranted to investigate longitudinal rs-FC effects of ECT to identify biomarkers predictive of treatment response and the risk of cognitive side effects after ECT.

PMID:41323433 | PMC:PMC12664636 | DOI:10.1016/j.nsa.2025.105522

Front Neurol. 2025 Nov 13;16:1666991. doi: 10.3389/fneur.2025.1666991. eCollection 2025.

ABSTRACT

INTRODUCTION: This study aimed to develop an automated approach for assessing upper limb (UL) motor impairment severity in stroke patients using a deep learning framework applied to resting-state functional magnetic resonance imaging (rs-fMRI).

METHODS: Dynamic functional connectivity (dFC) was computed with the ipsilesional primary motor cortex (M1) as a seed and extracted from rs-fMRI data of 69 stroke patients. These dFC features were used to train a three-dimensional convolutional neural network (3D-CNN) for automatic classification of UL motor impairment severity. Patients were divided into two groups according to UL Fugl-Meyer Assessment (UL-FMA) scores: mild-to-moderate impairment (UL-FMA > 20; n = 29, maximum = 66) and severe impairment (0 ≤ UL-FMA ≤ 20; n = 40). UL-FMA scores served as labels for supervised learning.

RESULTS: The model achieved a balanced accuracy of 99.8% ± 0.2%, with a specificity of 99.9% ± 0.2% and a sensitivity of 99.7% ± 0.3%. Several brain regions-including the angular gyrus, medial orbitofrontal cortex, dorsolateral superior frontal gyrus, superior parietal lobule, supplementary motor area, thalamus, cerebellum, and middle temporal gyrus-were linked to UL motor impairment severity.

DISCUSSION: These findings demonstrate that a 3D deep learning framework based on dFC features from rs-fMRI enables highly accurate and objective classification of UL motor impairment in stroke patients. This approach may provide a valuable alternative to manual UL-FMA scoring, particularly in clinical settings with limited access to experienced evaluators.

PMID:41323228 | PMC:PMC12658776 | DOI:10.3389/fneur.2025.1666991

Neuroimage Rep. 2025 Nov 12;5(4):100299. doi: 10.1016/j.ynirp.2025.100299. eCollection 2025 Dec.

ABSTRACT

Cognitive symptoms are common in Parkinson's disease (PD) and have debilitating effects on quality of life and disease trajectory; however, the underlying brain mechanisms remain poorly understood. To address this gap, we investigated the relationship between functional connectivity and cognition at multiple time points using longitudinal functional MRI (fMRI) and cognitive assessments from the Parkinson's Progression Marker Initiative (PPMI). We calculated resting-state functional connectivity across three distinct time points. We analyzed functional connectivity within and between three key cortical brain networks that have been linked with higher-order cognitive function in PD: the frontoparietal network (FPN); the salience network (SAL); and the default mode network (DMN). Global cognitive functioning was assessed with the Montreal Cognitive Assessment (MoCA) at each of the three time points, and this was our primary dependent variable. Linear mixed-effects modeling revealed that decreased FPN-DMN functional connectivity is associated with lower MoCA scores over time. A similar trend was found for SAL-DMN functional connectivity. These relationships were specific to cognition, as there were no significant associations between functional connectivity and motor symptoms, as measured with the Movement Disorders Society-Unified Parkinson's Disease Rating Scale-Part III (MDS-UPDRS-III). These findings suggests that cortical connectivity is associated with and may contribute to the progression of cognitive symptoms in PD. Our findings advance knowledge about cognitive changes in PD and emphasize the importance of functional brain network architecture.

PMID:41322670 | PMC:PMC12657728 | DOI:10.1016/j.ynirp.2025.100299

Imaging Neurosci (Camb). 2025 Nov 26;3:IMAG.a.1027. doi: 10.1162/IMAG.a.1027. eCollection 2025.

ABSTRACT

The long-term impact of COVID-19 on the brain is multifaceted, encompassing structural and functional disruptions. A cohesive theory of the underlying mechanisms of the Post-COVID Syndrome (PCS) remains unknown, primarily due to high variability in findings across independent studies. Here, we present a multimodal, cross-sectional MRI analysis of brain morphology (T1-MRI), tissue microstructure (diffusion-MRI), functional connectivity (functional-MRI), and cerebral blood flow (arterial spin labeling MRI) in COVID-recovered patients (CRPs, N=76) and healthy controls (HCs, N = 51). Although the global brain volumes did not differ between the two groups, CRPs showed focal atrophy in the right basal ganglia and limbic structures, along with cortical thinning in paralimbic regions (prefrontal cortex, insula) (p < 0.05). Diffusion MRI analysis revealed reduced fractional anisotropy and elevated radial diffusivity in the uncinate fasciculus and cingulum. No differences were observed in resting-state functional connectivity (RSFC) and cerebral blood flow between HCs and CRPs (p > 0.05). We further investigated the effect of infection severity by stratifying the CRPs into hospitalized (HP; N = 21) and non-hospitalized (NHP; N = 46) groups. The microstructural damage was linked to infection severity, more pronounced in the HPs (p < 0.05). In HPs, RSFC was diminished between components of the default mode network and the insula and caudate as compared with HCs and NHPs (p < 0.05). Results suggest COVID-19 is associated with selective structural and functional alterations in basal ganglia-limbic-cortical circuits, with stronger effects in severe cases. Overall, our findings both validate previously reported neuroimaging biomarkers and reveal new ones associated with the post-COVID syndrome, motivating future hypothesis-driven studies on behavioral correlates and therapeutic interventions.

PMID:41322364 | PMC:PMC12658774 | DOI:10.1162/IMAG.a.1027

Biol Psychiatry Glob Open Sci. 2025 Sep 30;6(1):100623. doi: 10.1016/j.bpsgos.2025.100623. eCollection 2026 Jan.

ABSTRACT

BACKGROUND: Resting-state functional magnetic resonance imaging (rs-fMRI) is a powerful tool to reveal disrupted brain activity in major depressive disorder (MDD), but most studies have focused solely on low-frequency functional fluctuations, ignoring the fact that brain activity is composed of both low-frequency and high-frequency fluctuations. Therefore, we applied a novel approach, namely the power spectral slope (PSS), which captures the characteristics of both low- and high-frequency fluctuations to evaluate brain activity in MDD.

METHODS: rs-fMRI data were collected from 109 patients with MDD (27.29 ± 7.11 years, 75 women) and 78 normal control participants (26.47 ± 6.19 years, 51 women). A subset of 52 patients with MDD also underwent rs-fMRI scanning after a 12-week antidepressant treatment (escitalopram/duloxetine). Both the baseline between-group comparison and follow-up within-group comparison were performed for PSS. A 2-sample t test was used for baseline comparison with a liberal Gaussian random-field correction. The follow-up comparison was tested with paired t test.

RESULTS: Patients with MDD showed significantly more negative PSS compared with normal control participants in the ventral striatum and temporal pole. After treatment, PSS in the ventral striatum increased significantly toward normalization, whereas the temporal pole's slope remained unchanged. No significant correlations were found between PSS and depression severity scores.

CONCLUSIONS: This study demonstrates that MDD is characterized by more negative PSS in key affective regions. The normalization effect of ventral striatum spectral slope following antidepressant treatment suggests a region-specific response. Taken together, the findings suggest that PSS may serve as a novel brain functional marker for MDD.

PMID:41321422 | PMC:PMC12657283 | DOI:10.1016/j.bpsgos.2025.100623

Biol Psychiatry Glob Open Sci. 2025 Sep 30;6(1):100624. doi: 10.1016/j.bpsgos.2025.100624. eCollection 2026 Jan.

ABSTRACT

Understanding the impact of prenatal cannabis exposure (PCE) on brain development is increasingly important given rising cannabis use during pregnancy. Many existing reviews on this topic are more than 5 years old and may not reflect recent social shifts that could impact cannabis use during pregnancy; they also have not utilized the recently available large longitudinal datasets for more robust and population-representative investigations. In this narrative review, we aim to provide an updated and expanded examination of the associations between PCE and magnetic resonance imaging (MRI)-based brain outcomes from in utero development to adolescence. We included studies published after 2019 that used at least one of the following measures: structural MRI, diffusion-weighted imaging, resting-state fMRI, and/or task-based fMRI. Across 9 studies that met criteria, 1 study focused on MRI outcomes in utero, 2 in infancy, and 6 in early adolescence, and only 3 studies included MRI and behavior outcomes. PCE was linked to differences in frontal, parietal, and temporal areas, spanning from in utero to adolescence across multiple MRI modalities. However, in the current state of the literature, detecting a consistent trend on PCE's impact on MRI findings was not possible. Furthermore, we found several divergences in study design: varying approaches to assessment (e.g., self-report vs. urine toxicology); difficulties in accounting for prenatal exposure to multiple substances; limited information on timing, frequency, potency, or mode of consumption; and the influence of parental or postnatal factors. Future research should implement designs that can rigorously capture the abovementioned elements to permit replication and eventual meta-analyses on this critical topic.

PMID:41321421 | PMC:PMC12663006 | DOI:10.1016/j.bpsgos.2025.100624