Neuroscience & Biobehavioral Reviews

Importance: Glucose metabolic dysregulation in brain is a common feature of late-onset age-associated neurodegenerative disease (A2ND). Prior meta-analyses have identified disease-specific effects compared to healthy, unimpaired individuals. Yet, a unifying A2ND glucose dysregulation spatial signature remains undescribed. Objective: To determine the common signature of dysregulated glucose metabolism on FDG-PET using activation likelihood estimation (ALE) meta-analyses across A2ND. Data Sources: Searches were conducted using MEDLINE, Embase, PsycINFO, Scopus, and Cochrane from inception through July 2025. The search terms included controlled vocabulary and keywords for four neurodegenerative diseases Parkinson Disease, Amyotrophic Lateral Sclerosis, Alzheimer Disease, and Multiple Sclerosis, Fluorodeoxyglucose F18, glucose, and positron-emission tomography (PET). Study Selection: Studies comparing adults with late-onset neurodegenerative diseases to non-diseased controls using FDG-PET to quantify brain glucose uptake and reporting whole-brain coordinate findings in either Talairach or Montreal Neurological Institute space were included. Data Extraction and Synthesis: Three researchers, assisted by an AI screening tool, screened 7275 potential titles and abstracts for inclusion. Full texts were then retrieved for potentially relevant articles and were evaluated by three researchers using prespecified inclusion/exclusion criteria. Main Outcomes and Measures: Cluster peak and subpeak coordinates, cluster-wise t- or Z- values, and annotations indicating the disease of interest, whether the outcome was for hyper- (disease group > control) or hypometabolism (disease group < control), were extracted from included texts and analyzed using ALE. Results: A total of 130 FDG-PET studies were included in the meta-analysis, with a combined sample of 5412 individuals with A2ND and 3549 controls. Meta-analyses revealed dysregulated glucose metabolism as a unifying feature across A2ND which included both hypo- and hypermetabolic patterns. Neuroanatomical metabolic pattern was unique and disease specific. Each A2ND metabolic phenotype was associated with unique and complex patterns of neurological functionalities. Conclusions and Relevance: These data demonstrate dysregulated glucose metabolism as a common A2ND feature, suggesting responsive remodeling of neural bioenergetics. While hypometabolism is a common research focus, due to functional relevance, hypermetabolism may reflect a compensatory, maladaptive, or neuroinflammatory signal, that requires focused investigation. A2ND prevention and treatment efficacy may depend on addressing bidirectional metabolic dysregulation in addition to disease-specific drivers of pathology.

Detecting a sex difference in response to a treatment or intervention, often reported as a "sex-specific effect," requires statistical comparison of the response across sex. Here, we investigated analytical approaches used to test for such effects in the behavioral and brain sciences. Of 200 recent articles containing terms such as sex-specific or gender-dependent in their titles, only 24% presented appropriate evidence supporting the claim: the effect was compared statistically across sex and results consistent with the claim were reported. In most articles (58%), no test was conducted that could have supported the title claim. Only 15% of studies on non-human animals supported the claim with appropriate evidence, which was significantly less frequently than studies on human participants (34%; p = 0.002). The use of appropriate analytical approaches was unrelated to journal rank or the citation impact of the article. We conclude that claims of sex/gender-dependent effects in the behavioral and brain sciences are only infrequently supported by appropriate evidence.

Oscillatory coupling between respiration, heart rate, and cortical function is fundamental to physiological regulation yet remains poorly characterized in humans. Diminished respiratory heart rate variability (RespHRV)--the rhythmic heart rate modulation accompanying respiration--has emerged as a transdiagnostic biomarker of mental and physical health, reduced in anxiety, depression, cardiovascular disease, and aging (Beauchaine & Thayer, 2015; Menuet & Gourine et al., 2025). However, the cortical substrates that coordinate rhythmic cardiovascular-respiratory coupling are not well understood. Our current findings highlight the involvement of the left orbitofrontal cortex (OFC) in oscillatory cardiorespiratory dynamics. In adults aged 50-70 (N = 55; mean age = 60.1 {+/-} 6.0 years; 29 female), across both a slow-paced breathing condition and a random-paced breathing condition, greater heart rate oscillatory power during 9-week breathing training sessions predicted OFC volume increases. OFC changes were most strongly linked with upper low-frequency range power during practice (0.09-0.13 Hz; p < 0.005, cluster-corrected) but were not tightly constrained by precise breathing frequency. These effects covaried with improved attentional and executive performance, including reduced pupil responses to distractors and enhanced working-memory and associative-memory scores. Our findings identify the orbitofrontal cortex as a key site of cortical plasticity linked to rhythmic cardiovascular-respiratory engagement. By delineating how oscillatory body-brain coupling supports cognitive control-related processes, including attentional filtering and memory updating, this work bridges mechanistic neuroscience and translational intervention science, suggesting a frequency-general pathway through which simple breathing practices may enhance neurovisceral integration and cognitive resilience in aging. SummaryO_LIGreater oscillatory heart rate power during breathing training, particularly within the upper low-frequency range (0.09-0.13 Hz), predicted increases in left orbitofrontal cortex (OFC) volume. C_LIO_LIOFC volume increases were associated with improved attentional and executive performance, including reduced pupil reactivity to distractors and enhanced working-memory and associative-memory scores. C_LIO_LIThese findings suggest that rhythmic cardiovascular-respiratory coupling supports cortical plasticity and cognitive resilience, providing a frequency-general mechanism through which breathing practices enhance neurovisceral integration in aging. C_LI

Child maltreatment is a leading cause of pediatric morbidity and mortality, potentially propagated by DNA methylation (DNAm) changes. We conducted an EWAS meta-analysis (n=175, 554,979 Illumina EPICv1/EPICv2 sites) in buccal swabs from three hospital-based studies of children with traumatic injuries, stratified by study group to include 1) any traumatic injury, 2) fractures, and 3) traumatic brain injuries. Empirical bayes-moderated linear models tested differential DNAm with M-values, followed by near-promoter gene set enrichment analysis. Abuse was associated with methylation at 11 sites (q<0.10), including enhancers of neuroblast differentiation-associated AHNAK, immunomodulators SCGB1A1 and CCL26, exon 5 of LAMP1, essential for lysosomal function and cytotoxicity, and RGS7, a GTPase essential for synaptic transmission. Enriched biological processes included cranial skeletal system and connective tissue development, neural structure and function, immune regulation, gene expression, and metabolism. Our findings suggest that early abuse may epigenetically affect both proximal injury responses and longer-lived systemic biological dysregulation.

Background: Cognitive impairment poses a significant challenge to healthcare systems worldwide, impacting patient autonomy, social participation, and quality of life, while placing a considerable burden on caregivers. Non pharmacological interventions, particularly cognitive training and non invasive brain stimulation, have emerged as promising therapeutic strategies. Objective: This study aims to quantify the synergistic effects of transcranial direct current stimulation (tDCS) with cognitive training on cognitive function across a spectrum of pathologies that induce cognitive impairment. Methods: We conducted a systematic review and metaanalysis following PRISMA guidelines. We searched PubMed for randomized controlled trials that investigated the effect of combined tDCS and cognitive training compared with cognitive training alone. The analysis was based on the GRADE framework for systematic reviews and metaanalyses. Results: Across 27 studies including 1,012 participants, tDCS combined with cognitive training showed a small effect compared with cognitive training alone (SMD = 0.36, 95% CI: 0.15 0.56). The effect was found only immediately after the intervention and declined during follow-up. Conclusion: tDCS combined with cognitive training may provide a small, short term benefit for cognitive function, but high heterogeneity across studies and loss of effect at follow up underscore the need for larger, better standardized trials to clarify its clinical value.

BackgroundMindfulness-based interventions (MBIs) have been increasingly adopted in educational settings to support cognitive development in youth. Executive function (EF)--encompassing inhibitory control, working memory, and cognitive flexibility--is a plausible target of MBI given its reliance on attention regulation. However, prior reviews have yielded mixed conclusions, partly due to inconsistent construct definitions and the pooling of heterogeneous outcome measures. ObjectivesTo (1) estimate the pooled effect of MBI on EF in youth aged 3-18 years using only construct-validated, direct EF measures, (2) examine potential moderators including age group, EF domain, and risk of bias, and (3) test dose-response relationships via meta-regression on intervention duration. MethodsWe searched PubMed, PsycINFO, CINAHL, Scopus, and Web of Science from inception to March 2026, supplemented by reference-list searches from two existing systematic reviews and a scoping review. Only English-language publications were eligible. Eligible studies were randomised controlled trials (RCTs) or quasi-RCTs of MBI (excluding yoga-only interventions) in typically developing youth, with at least one direct behavioural or computerised EF outcome. Risk of bias was assessed using Cochrane RoB 2. Hedges g was computed for each study, and pooled using a DerSimonian-Laird random-effects model. Subgroup analyses by age group, EF domain, and risk of bias were conducted, alongside leave-one-out sensitivity analyses, Eggers regression test, trim-and-fill, and Knapp-Hartung-adjusted meta-regression on intervention duration. Evidence certainty was rated using GRADE. ResultsThirteen RCTs (nine school-age, four preschool; total N = 1,560) met inclusion criteria. The pooled effect was g = 0.365 (95% CI 0.264 to 0.465; p < .00001), with negligible heterogeneity (I2 = 0.0%; Q = 6.76, p = .87). Effects were consistent across age groups (school-age g = 0.389; preschool g = 0.318) and EF domains (inhibitory control, working memory, cognitive flexibility; pbetween = .60). Meta-regression on intervention duration (4-20 weeks) was non-significant (p = .79). The effect was robust in leave-one-out analyses, in the low risk-of-bias subgroup (g = 0.361; k = 8), and after trim-and-fill adjustment (g = 0.354). The 95% prediction interval (0.252 to 0.477) was entirely positive. GRADE certainty was rated MODERATE, downgraded once for risk of bias. ConclusionsMBIs appear to produce a small, statistically significant improvement in EF in youth aged 3-18 years, with moderate certainty of evidence per the GRADE framework. The effect is consistent across preschool and school-age samples and across EF domains, with no significant dose-response relationship within the 4-20 week range studied. Emerging mediation evidence suggests that EF improvement may serve as an important pathway through which MBI supports emotion regulation, though this requires replication. Further large-scale, pre-registered RCTs with active control conditions and longitudinal follow-up are warranted.

3,4-methylenedioxymethamphetamine (MDMA) has emerged as a potential treatment for post-traumatic stress disorder (PTSD), generating considerable enthusiasm in the field. However, rapidly changing evidence in a fast-moving field can be challenging to integrate. Here, we present a living systematic review and open-data meta-analytic resource on MDMA treatment for PTSD. In this initial release, six randomized controlled trials comprising 286 participants are included in the database. Our primary model uses inverse-variance random-effects meta-analysis of standardized mean differences on primary outcomes of PTSD. Compared to control conditions, MDMA showed a greater reduction in PTSD symptoms (Hedges' g = -0.71). Meta-regression on both the number of dosing sessions and cumulative dose showed that a higher number of dosing sessions and a higher cumulative dose was related to larger effects of MDMA. Treatment with MDMA as compared to placebo also resulted in higher response (risk ratio (RR) = 1.35) and remission (RR = 2.25) rates. Most studies included in the database had a low risk of bias according to Cochrane guidelines, though these fail to capture pertinent challenges in the field such as expectancy, functional unblinding, potential issues with study conduct, and safety. The current findings were assigned an overall low certainty rating using the GRADE approach. Together, this systematic review and meta-analysis suggests that MDMA-assisted therapy results in short-term decreases in PTSD symptoms across studies to date, though more trials are needed. This living systematic review, meta-analysis, database, and online dashboard (sypres.io) will continue to be updated as evidence emerges, providing a valuable, open, and transparent resource for researchers in a rapidly evolving field.

Self-referential processing is a fundamental cognitive function, and abnormalities in its neural implementation have been reported across a range of psychiatric disorders, leading to the proposal that such alterations may constitute a transdiagnostic neurobiological feature. Yet claiming transdiagnostic requires rigorous evidence. Here, we examined the evidence for such a hypothesis by conducting a systematic review and coordinate-based meta-analysis of psychiatric neuroimaging studies that employed self-referential tasks. The systematic review identified 36 neuroimaging studies across 9 broad categories of psychiatric disorders, suggesting that the neural aberrancy of self-referential processing is indeed of great interest across different diagnosis. Of these, 27 studies were eligible for the ALE meta-analysis. The ALE results revealed hypoactivation of the right precuneus in psychiatric groups relative to health controls, alongside hyperactivation of the right triangular part of the inferior frontal gyrus (IFGtri) during self-referential processing in psychiatric groups. Notably the precuneus and IFGtri are core nodes of the default mode network and the frontal-parietal control network, respectively, suggesting that aberrant self-referential processing across psychiatric disorders may be characterized by disrupted default mode network engagement accompanied by compensatory or maladaptive recruitment of control-related frontal regions. Together, our findings revealed a strong research interest in neural aberrancy of self-referential processing as a transdiagnostic feature. However, available evidence only provided preliminary evidence for such statement. To move forward, the field needs coordinated efforts to systematically accumulate data and collecting new datasets.

Therapeutic brain stimulation holds promise in treating memory dysfunction, but recent clinical trials have produced heterogenous results. Uncertainty in the neuroanatomical target may contribute to this heterogeneity, with over 13 different brain regions targeted to date. To derive a neuroanatomical target, we studied verbal episodic memory changes across 1247 patients in 12 independent datasets, including patients with focal lesions (n = 985), DBS sites (n = 207), and TMS sites (n = 72). We found lesion and stimulation sites causing verbal memory changes converged on a common brain network. In 3 held-out datasets, connectivity to this convergent memory network explained more variance than connectivity to modality-specific maps or other neuroanatomy previously implicated in memory. In a meta-analysis of 21 prior brain stimulation trials for Alzheimer Disease, overlap between stimulation site and our convergent memory network correlated with trial effect size. In conclusion, we find Lesions, DBS, and TMS sites influencing verbal memory converge upon a single memory network, and this network may inform targeting in memory neuromodulation trials.

Attention-Deficit/Hyperactivity Disorder (ADHD) is a prevalent neurodevelopmental condition characterized by persistent deficits in working memory (WM) and executive control. Dysregulation of the Cyclin-dependent kinase 5 (Cdk5)/p35 signaling pathway has been implicated in ADHD pathophysiology due to its impact on neuronal connectivity and dopamine regulation. Using p35 knockout (p35KO) mice--a validated model exhibiting ADHD-like phenotypes--we investigated sex-specific WM performance, task-related neuronal activation patterns, and responses to acute treatment with methylphenidate (MPH) or fluoxetine (FLX), administered alone or in combination. Under basal conditions, p35KO mice of both sexes exhibited significant WM impairment in the Y-maze test compared with wild type (WT) counterparts, whereas recognition memory remained intact. Analysis of neuronal activation (c-Fos-IR) 90 min after testing revealed region-, sex-, and genotype-dependent alterations. Overall, p35KO animals of both sexes showed reduced c-Fos-IR expression in prefrontal cortical regions, while exhibiting increased c-Fos-IR in hippocampal regions. Acute MPH or FLX treatment improved WM in p35KO males, but this benefit was not observed following combined treatment (MPH+FLX). In contrast, p35KO females showed no WM improvement with any treatment. Notably, WT females exhibited a pronounced decline in WM after exposure to MPH, FLX, or their combination, indicating sex-specific pharmacological sensitivity in healthy animals. These findings support an important role of Cdk5/p35 signaling in the functional engagement of prefrontal and hippocampal networks and demonstrate that pharmacological responses in this ADHD model are strongly influenced by sex and neurobiological background, highlighting the importance of incorporating sex as a biological variable in preclinical and translational ADHD research. GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=123 SRC="FIGDIR/small/696253v2_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@12b4330org.highwire.dtl.DTLVardef@14826c3org.highwire.dtl.DTLVardef@1e8f3d8org.highwire.dtl.DTLVardef@e108a2_HPS_FORMAT_FIGEXP M_FIG C_FIG

Transcranial electrical stimulation (tES) can modulate neural dynamics, yet its effects on memory are heterogeneous. Individual differences in cognitive profiles, may well be one of the potential causes by setting boundary conditions on the extent and mode of the tES-induced modulation of network dynamics. In a sham-controlled, within-subject study (N = 42), we compared the effects of tDCS (1.5 mA), tACS ({+/-}1.0 mA at individual theta frequency, ITF), and otDCS (1.5 mA {+/-} 0.5 mA at ITF) over the left posterior parietal cortex on object-location (OL) associative memory, and examined whether six cognitive abilities (figural reasoning, semantic, visuospatial, processing speed, working memory, mnemonic binding) moderate stimulation outcomes. Associative memory recognition improved selectively under theta-otDCS, whereas tDCS and tACS showed no significant group-level effects. Yet all tES protocols exhibited considerable interindividual variability. Relative to cognitive abilities, processing speed moderated tES effects in line with neural efficiency predictions, yielding greater gains in cognitively faster individuals. In contrast, mnemonic binding and figural reasoning moderated benefits in a compensatory manner, with larger improvements in lower-ability individuals. Overall, the effects of tES on associative memory were specific to the tES protocol and outcome measure while being strongly shaped by cognitive profile via complementing magnification and compensation mechanisms.

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are approved for treating type 2 diabetes and obesity and are under investigation as potential treatments for substance use disorders (SUD). GLP-1 RA-induced weight loss is thought to arise from both peripheral effects on gastrointestinal function and central modulation of appetite and reward circuits, though the exact mechanisms are unclear. Functional magnetic resonance imaging (fMRI) studies examining brain responses to reward-related cues can help clarify the central mechanisms through which GLP-1 RAs influence reward-seeking behavior. We systematically reviewed the fMRI literature examining how GLP-1 RAs affect brain responses to reward-related cues. We identified 1,209 records through a comprehensive literature search. After screening, only 11 studies met eligibility criteria. The vast majority assessed reactivity to food-related cues, with only one examining drug-related cues (alcohol), leaving neural mechanisms relevant to SUD largely unexplored. None included non-food emotional stimuli as control conditions. Several methodological limitations emerged. Most studies enrolled 20 or fewer participants per group, limiting statistical power. Treatment protocols varied substantially, with some assessing cue responses after single-dose administration and others after chronic treatment. Heterogeneity in medications used further confounds interpretation. The limited evidence tentatively suggests that acute GLP-1 RA administration may reduce brain reactivity to food cues in appetite and reward regions. However, effects appear inconsistent and may attenuate over time. Future studies should recruit larger samples, standardize agents and dosing, and assess responses to diverse motivationally relevant stimuli.

Chronic neuroinflammation is associated with comorbidities in people with HIV (PWH) on antiretroviral therapy (ART). While cannabis use is associated with reduced neuroinflammation and neurocognitive impairment (NCI) in PWH, the underlying mechanisms are unknown. To address this gap in knowledge, we analyzed monocyte-derived macrophages (MDMs) from a cohort of 50 PWH and 33 people without HIV (mean age: 61.9 years), categorized by frequency of cannabis use (naive/low, moderate, daily). We performed immunocytochemistry, RNA sequencing, and qPCR on MDMs and quantified related biomarkers in donor plasma. In this cohort study, daily cannabis use in PWH was associated with less global neurocognitive deficits, and with an anti-inflammatory immunometabolic-phenotype in MDMs characterized by (1) a metabolic shift from glycolysis to oxidative phosphorylation, (2) higher mitochondrial numbers, (3) altered cytokine profiles (pro-inflammatory downregulation, anti-inflammatory upregulation), and (4) higher brain-derived neurotrophic factor (BDNF) expression. These cellular changes were corroborated by a plasma biomarker profile in PWH including (1) lower levels of growth differentiation factor 15 and soluble triggering receptor expressed on myeloid cells 2, and (2) higher mature BDNF/precursor BDNF ratios that correlated with better cognition. Thus, cannabis use may mitigate NCI in PWH by immunometabolically reprogramming MDM function towards an anti-inflammatory and neuroprotective state. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/709579v1_ufig1.gif" ALT="Figure 1"> View larger version (42K): org.highwire.dtl.DTLVardef@15fb1adorg.highwire.dtl.DTLVardef@189d79corg.highwire.dtl.DTLVardef@aa6a89org.highwire.dtl.DTLVardef@3852f8_HPS_FORMAT_FIGEXP M_FIG C_FIG

BackgroundGlyphosate-based herbicides are among the most widely used agricultural chemicals globally. Concerns regarding their carcinogenic potential, particularly in relation to non-Hodgkins lymphoma (NHL), persist despite multiple prior systematic reviews and meta-analyses. However, these reviews have demonstrated important methodological limitations and inconsistent analytic decisions, limiting confidence in their conclusions. ObjectiveTo conduct a rigorous, up-to-date systematic review and meta-analysis of observational studies examining the association between glyphosate-based herbicide exposure and risk of NHL and its subtypes, while addressing methodological and analytic shortcomings of prior syntheses. MethodsWe searched MEDLINE (1970-February 26, 2026) and EMBASE (inception-February 26, 2026), supplemented by reference list review. Eligible studies included cohort, case-control, and pooled analyses reporting effect estimates (or sufficient data) for glyphosate exposure and NHL incidence. Two reviewers independently assessed risk of bias using the Newcastle-Ottawa Scale (for primary studies) and structured criteria for pooled analyses. Random- and fixed-effects meta-analyses were conducted using inverse-variance methods. Heterogeneity was evaluated using Cochrans Q and I{superscript 2} statistics. Publication bias was assessed using standard and contour-enhanced funnel plots. Sensitivity analyses addressed overlapping cohorts, hazard ratio inclusion, exposure definitions, and model overfitting (events-per-variable considerations). Certainty of evidence was graded using GRADE. ResultsSeventeen publications were identified, representing 20 unique study populations; after accounting for overlap, 10 primary datasets were included in quantitative synthesis. Five studies were assessed as low risk of bias, four as moderate risk, and one as high risk. For ever exposure, the random-effects model across all eligible datasets yielded an odds ratio (OR) of 1.11 (95% CI: 0.98-1.27), with moderate heterogeneity (I{superscript 2}{approx}53%). In sensitivity analyses excluding hazard ratio-only studies and overlapping cohorts, pooled ORs ranged from 1.19 to 1.23, with estimates approaching or reaching statistical significance depending on modeling assumptions. For the highest exposure categories, the random-effects model demonstrated a statistically significant association (OR{approx}1.38; 95% CI: 1.00-1.90), with moderate heterogeneity (I{superscript 2}{approx}61%). Sensitivity analyses excluding selected pooled cohort estimates strengthened the association (OR{approx}1.47; 95% CI: 1.04-2.06). Analyses incorporating alternative cumulative exposure metrics yielded similar significant associations (OR{approx}1.33-1.45) with low or absent residual heterogeneity. Subtype analyses suggested elevated risks particularly for diffuse large B-cell lymphoma and follicular lymphoma in certain datasets. Publication bias assessments revealed evidence of small-study effects in some models, though contour-enhanced analyses suggested that not all asymmetry was attributable to selective publication. Overall certainty of evidence was graded as moderate for highest exposure analyses and low-to-moderate for ever-exposure analyses due to residual heterogeneity and observational design limitations. ConclusionsThis updated synthesis indicates that while associations with ever exposure to glyphosate are modest and sensitive to analytic decisions, higher levels of exposure are consistently associated with increased odds of NHL. Findings are robust across multiple sensitivity analyses addressing overlapping data, exposure classification, and model overfitting. These results support a dose-related association between glyphosate-based herbicide exposure and NHL risk and underscore the need for continued surveillance, improved exposure characterization, and prospective cohort analyses with minimized loss to follow-up and transparent analytic reporting.

Patients with brain tumors involving language-critical regions face surgical limitations when balancing resection with preservation of function. Non-invasive neuromodulation-induced prehabilitation (NIP) aims to guide preoperative neuroplastic reorganization, potentially facilitating larger resections while preserving function. We investigated whether NIP selectively modulates the targeted language network compared with control networks, and whether such modulation is behaviorally safe. We enrolled 26 patients (mean age = 55.9) from the Prehabilita project (Clinical Trial: NCT05844605) with operable brain tumors affecting language or motor regions. Eleven received language-targeted NIP, combining transcranial magnetic stimulation and/or transcranial direct current stimulation with intensive language training. Fourteen patients with NIP targeting non-language networks, primarily motor networks, served controls. Assessments included task-based functional magnetic resonance imaging (tb-fMRI) and a neuropsychological battery assessing language and cognitive domains before and after prehabilitation. Results indicated a group-specific NIP effect on the language network. In the language-targeted group, tb-fMRI revealed reduced overlap between a region of interest centered on the stimulation target and fMRI-derived language activation maps, whereas no comparable changes were observed in controls. No significant modulation effects were detected in the motor network in either group. These findings indicate that NIP can selectively reorganize the language network, with modulation patterns differing in sensorimotor networks. Importantly, language network modulation occurred while preserving language and cognitive performance. These results support NIP targeting higher-order functions such as language as a safe preoperative strategy that may reduce functional constraints on surgery and enable larger and safer resections in patients with tumors involving language-critical regions.

Background Chronic pain is associated with structural and functional brain alterations, particularly within prefrontal, insular, and cingulate cortices. The dorsolateral prefrontal cortex (DLPFC) shows consistent structural abnormalities across chronic pain conditions, whereas findings on intrinsic functional connectivity (FC) remains inconsistent. Anchoring FC analyses to structural alterations may help identify consistent patterns across chronic pain conditions. Methods We employed a voxel-based morphometry (VBM)-guided, seed-based resting-state FC approach. Structural and functional MRI data were obtained from patients with chronic neck pain (CNP; n=21) and healthy controls (HC; n=25). Regions showing significant gray matter volume (GMV) differences were used as seeds for whole-brain FC analysis. Associations with pain intensity and pain-related fear were examined. Findings were further evaluated in an independent cohort with chronic primary pain (CPP; n=38). Results VBM revealed reduced GMV in the left DLPFC in CNP compared with HC, replicated in CPP. Seed-based FC analysis demonstrated reduced connectivity between the left DLPFC and the right hippocampus in CNP, with a similar pattern in CPP. In CNP, GMV in the DLPFC was positively associated with DLPFC-hippocampal connectivity (r = 0.45, 95% CI 0.02 to 0.74, p = 0.043). Reduced DLPFC-hippocampal connectivity was associated with higher activity avoidance (r = -0.50, 95% CI -0.77 to -0.09, p = 0.021), whereas no associations were observed with pain intensity. Conclusions These findings indicate consistent structural and functional alterations across chronic pain cohorts. Reduced DLPFC-hippocampal connectivity may reflect altered interactions between prefrontal and hippocampal circuits involved in pain-related cognitive and affective processes.

BackgroundEarly-life adversity (ELA) is a risk factor for enduring pain in youth and is associated with alterations in brain morphology and function. However, it remains unclear whether ELA-related neurobiological changes contribute to the development of enduring pain in early adolescence. MethodsUsing data from the Adolescent Brain Cognitive Development (ABCD) Study, we examined multimodal magnetic resonance imaging (MRI) markers in children assessed at baseline (ages 9-11 years) and at 2-year follow-up (ages 11-13 years). ELA exposure was defined at baseline to maximise temporal separation between early adversity and later enduring pain. Participants with enduring pain at follow-up (n = 322) were compared to matched pain-free controls (n = 644). Structural MRI, diffusion MRI (fractional anisotropy, mean diffusivity), and resting-state functional connectivity data were analysed. Linear models tested main effects of enduring pain, ELA, and their interaction on brain metrics, controlling for relevant covariates. ResultsELA exposure was associated with smaller caudate and nucleus accumbens volumes, and reduced surface area of the left rostral middle frontal gyrus. No significant effects of enduring pain or ELA-by-enduring pain interaction were observed across grey matter, white matter, or functional connectivity measures. ConclusionsELA was associated with alterations in fronto-striatal regions in late childhood, but these changes were not linked to enduring pain in early adolescence. These findings suggest that ELA-related neurobiological alterations may represent early markers of vulnerability rather than concurrent correlates of enduring pain. Longitudinal follow-up is needed to determine whether these alterations contribute to later chronic pain risk.

BackgroundClinical trajectories in functional neurological disorder (FND) are variable, and the mechanisms underlying this heterogeneity remain poorly understood. ObjectiveThis longitudinal study examined resting-state functional connectivity predictors and mechanisms of symptom change in FND. MethodsThirty-two adults with FND (motor and/or seizure phenotypes) completed baseline questionnaires and a functional MRI (fMRI) session, followed by naturalistic treatment for 6.8{+/-}0.8 months. All participants completed follow-up questionnaires; 28 individuals completed a follow-up fMRI. At each timepoint, three graph-theory network metrics of functional connectivity were computed: weighted-degree (centrality), integration (between-network connectivity), and segregation (within-network connectivity). Analyses adjusted for age, sex, anti-depressants, head motion, time between sessions, and baseline score-of-interest, with cluster-wise correction. Results were contextualized against 50 age-, sex-, and head motion-matched healthy controls (HCs). ResultsBased on patient-reported Clinical Global Impression of Improvement, 59.4% improved, 31.3% were unchanged, and 9.3% worsened. Psychometric scores of core FND symptoms and non-core physical symptoms showed variable trajectories, with no group-level changes. Greater improvement in core FND symptoms was associated with higher baseline between-network integrated connectivity and reduced integration longitudinally within salience, frontoparietal, and default mode network regions. Right anterior insula integration emerged as a prognostic marker and mechanistic site of reorganization, with the most improved participants showing elevated baseline integration compared to HCs. Increased baseline within-network segregated connectivity in dorsal attention network regions correlated with non-core physical symptom improvement. Findings remained significant adjusting for FND phenotype. ConclusionsThis study identified large-scale network interactions as potential prognostic and mechanistically-relevant sites of reorganization related to symptom change in FND.

ObjectiveTo delineate the phenotype of juvenile myoclonic epilepsy (JME) with a focus on obsessive-compulsive personality disorder (OCPD) using multimodal psychiatric, neuropsychological, quantitative EEG (qEEG), and structural MRI markers within a predictive-processing/free-energy framework. MethodsWe prospectively studied 65 patients with JME and 68 matched healthy controls (HC). Participants completed DSM-IV SCID I/II interviews and a neuropsychological battery assessing working memory, psychomotor speed, mental flexibility, divided attention, inhibition, and phasic/tonic alertness; standard EEG and high-resolution structural MRI were acquired. Groups comprised HC and JME subgroups without psychiatric comorbidity, with non-OCPD Axis I/II diagnoses, and with OCPD. Welchs t-tests (FDR-corrected) and Hedges g quantified neuropsychological and alpha-band coherence differences. Surface-based analyses assessed cortical thickness/surface area. Exploratory regressions tested associations of OCPD, seizure freedom, and antiseizure medication (ASM) load with cognition; Kendalls tau tested coherence-cognition associations. ResultsCompared with HC, JME showed broad executive-attentional impairment, most pronounced in patients with psychiatric comorbidity. The OCPD subgroup exhibited particularly large slowing in psychomotor speed, inhibition (reaction time), and tonic alertness versus HC, while OCPD versus non-OCPD JME differences did not survive multiple-comparison correction. qEEG showed increased interhemispheric frontal and decreased temporal alpha coherence in JME, with temporal hypo-coherence strongest in those with psychiatric comorbidity; within JME, OCPD was linked to increased left fronto-temporal alpha coherence. In the MRI subsample, JME-OCPD demonstrated increased cortical thickness in left medial orbitofrontal and anterior cingulate regions (vs HC and vs JME without OCPD) and additional posterior occipito-temporal clusters versus HC. Regression and coherence-cognition associations were weak and non-significant after FDR correction. SignificanceJME features syndrome-level executive-attentional dysfunction and altered fronto-temporal network organization. Comorbid OCPD marks a subgroup with accentuated cognitive slowing and distinct medial prefrontal/cingulate structural and left fronto-temporal connectivity signatures, aligning with predictive-processing accounts of rigid, over-precise high-level priors. Key pointsJME is linked to broad executive-attentional impairment versus healthy controls. Psychiatric comorbidity amplifies cognitive deficits in JME. JME with OCPD shows particularly large slowing/inhibitory-control deficits versus controls, while OCPD vs non-OCPD differences within JME are modest. Alpha-band EEG coherence indicates altered network organization in JME and an OCPD-related increase in left fronto-temporal coherence within JME Surface-based MRI suggests an OCPD-related structural phenotype in JME, involving medial orbitofrontal/anterior cingulate cortical thickening

Background: Spinal cord injury (SCI) is associated with widespread reorganisation of cortical sensorimotor circuits. Persistent complications such as spasticity and neuropathic pain suggest that homeostatic plasticity, which normally helps stabilise and constrain activity-dependent changes in sensorimotor circuits, may be disrupted after SCI. Homeostatic plasticity can be probed using repeated blocks of transcranial direct current stimulation (tDCS); in healthy individuals, two closely spaced excitatory blocks typically leads to an inhibitory response, reflected as a reduction in corticomotor excitability. Objective: To determine whether individuals with SCI show reduced homeostatic suppression of corticospinal excitability in response to repeated anodal tDCS, compared with healthy controls. Methods: Twenty adults with thoracic or below SCI and 20 healthy controls completed three counterbalanced sessions. Each session comprised two 10-minute blocks of 2 mA tDCS separated by 5 minutes, with the second block always being anodal tDCS over left primary motor cortex. The first block was either anodal, cathodal, or sham tDCS, yielding 3 condition types: anodal-anodal, cathodal-anodal, and sham-anodal. To assess corticomotor excitability, transcranial magnetic stimulation-evoked motor evoked potentials (MEPs) were elicited at baseline, after priming, and every 5 minutes for 60 minutes after the second block. The primary outcome was percent change in MEP amplitude from baseline. Results: In the anodal-anodal condition, the SCI group showed greater facilitation than controls over 0-30 minutes (estimate = 83.09, 95% CI 49.75 to 116.43, p < 0.001), suggestive of a weaker homeostatic response. The cathodal-anodal condition led to a significant overall facilitatory effect with no between-group difference, while the sham-anodal condition showed no change in MEP amplitude relative to baseline. Within the SCI group, exploratory subgroup analysis suggests that those with neuropathic pain and a traumatic injury showed greater facilitation in the anodal-anodal condition than those without these features, indicative of a weaker homeostatic response. Conclusions: SCI is associated with impairment in the homeostatic regulation of corticomotor excitability following repeated excitatory brain stimulation. Disrupted plasticity stabilisation may be relevant to persistent symptoms such as neuropathic pain.