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PubMed2026

Pregnancy diet based on ancestral patterns increases growth in subcortical fetal brain regions.

Evidence on the biological basis for maternal nutrition effects on fetal and newborn neurodevelopment remains limited. This randomized controlled trial in Ecuador tested a maternal dietary pattern-derived from empirical studies of nutrition in human evolution and adapted locally-on offspring growth and brain development. Pregnant women (n = 215) in their first trimester were randomized to: 1) control (n = 104); or 2) Mikhuna ("nourish" in Kichwa) intervention (n = 111). The intervention, from 12 wk gestation to birth, consisted of a weekly food delivery (8 eggs, 500 g fish, and a variety of sustainably sourced fruits and vegetables) and a behavior change communication strategy encouraging diet diversity and limiting highly processed foods. Longitudinal data collection occurred at 12 wk, 21 wk, 35 wk gestation, and 2 wk postpartum, and included ultrasound imaging of fetal bone and brain parameters, maternal dietary intakes, anthropometry, socioeconomic and demographic variables, and other biomarkers. At close of intervention, a significantly higher percentage of women met the minimum dietary diversity threshold in Mikhuna (74.5%) vs. control groups (55.8%) (P = 0.004). Generalized linear regression models showed significant differences in Mikhuna compared to control for: corpus callosum length 0.19 cm (95% CI [0.02, 0.35]), gangliothalamic ovoid height 0.15 cm (95% CI [0.03 to 0.26]), and femur length -0.10 cm (95% CI [-0.19, -0.02]) from 21 wk to 35 wk; and corpus callosum Z 0.56 (95% CI [0.03, 1.09]) and femur length Z -0.21 (95% CI [-0.42, 0.00]) at 35 wk. The Mikhuna intervention increased the growth of subcortical fetal brain structures, which have established roles in motor control, cognition, and signal transmission.

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PubMed2026

Effectiveness of hyperbaric oxygen in traumatic brain injury patients: A systematic review and meta-analysis.

BACKGROUND: Traumatic brain injury (TBI) is the most common neurological disorder and a leading cause of global mortality and disability. Although growing evidence suggests potential benefits of Hyperbaric Oxygen Therapy (HBOT) for TBI, its efficacy remains controversial. METHODS: We systematically searched PubMed, Embase, Cochrane Library, and Web of Science from inception to March 2026. Randomized controlled trials (RCTs) evaluating HBOT versus any comparator including sham, standard care and no treatment in adults with TBI were included. Two independent reviewers screened records, extracted data, and assessed risk of bias using the Cochrane Risk of Bias tool. Heterogeneity was assessed using the I² statistic. Effect sizes were pooled using random/fixed-effects models per heterogeneity results. RESULTS: 8 studies involving 570 participants were included. HBOT significantly improved computerized cognitive performance (SMD = 0.23, 95% CI: 0.07-0.40, p = 0.004, I² = 0%), executive function and processing speed (SMD = -0.59, 95% CI: -0.93 to -0.26, p = 0.0005, I² = 30%), memory function (SMD = 0.33, 95% CI: 0.03-0.63, p = 0.03, I² = 0%), and sleep quality (MD = 1.98, 95% CI: 0.07-3.88, p = 0.04, I² = 65%). No significant benefits were observed for Glasgow Outcome Scale (RR = 1.57, 95% CI: 0.55-4.44, I² = 87%), PTSD symptoms (MD = -3.05, 95% CI: -7.05-0.95, I² = 67%), neurobehavioral symptoms (MD = -9.06, 95% CI: -32.13-14.00, I² = 97%), and emotional distress (SMD = 0.25, 95% CI: -0.32-0.81, I² = 85%). Most adverse events were mild and transient. CONCLUSION: HBOT demonstrates domain‑specific benefits for cognitive function and sleep quality in TBI patients, predominantly those with mild TBI. However, evidence for PTSD, neurobehavioral symptoms, and emotional distress remains uncertain. Furthermore, the applicability of current evidence to moderate-to-severe TBI populations is restricted.

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PubMed2026

Individual differences in brain dynamics across a social cognition network induced by cortico-cerebellar tDCS in adults with autism spectrum disorder (ASD).

Autism spectrum disorder (ASD) is a neurodevelopmental condition with core diagnostic domains of social communication impairments, restricted interests and repetitive behaviors. Idiosyncratic brain organization is a potential hallmark of ASD. Previous transcranial direct current stimulation (tDCS) studies often targeted dorsolateral prefrontal cortex, with changes oin brain dynamics averaged across the cohort. We utilized a magnetoencephalographic (MEG) array to characterize individual differences in brain dynamics induced by cortico-cerebellar tDCS across nodes of a social cognition network. A randomized, sham-controlled, double-blind, within-subject clinical trial was conducted in a cohort of 24 young adults with ASD or high autistic traits. Two separate sessions of computerized social learning activities were combined with verum/sham tDCS, with anodal electrode over right temporoparietal junction (TPJ) and cathode on right deltoid. Following stimulation, theta- and alpha-band activity were evaluated within nodes of a social cognition network: bilateral TPJ, fusiform, medial prefrontal cortex and Crus I/II of cerebellum. Idiosyncratic participant-specific up- and down-regulation of theta- and alpha-band activity occurred across the network. Activity in right Crus I/II, a region inundated by the stimulation current, strongly correlated with the change of activity summed across all cerebral cortical nodes in theta- but not alpha-band. Intrinsic theta-band activity is believed to mediate input/output relationships in cerebellar cortex and to drive synaptic plasticity. These results suggest that theta-band stimulation of cerebellar cortex might be an effective therapy for individuals on the autism spectrum who present with cerebellar hyperactivity.

Humans↗

PubMed2026

Deep brain stimulation for Tourette syndrome: a systematic review and meta-analysis.

Deep brain stimulation (DBS) has emerged as a promising neuromodulatory therapy for patients with refractory Tourette syndrome (TS). Various brain targets-including the globus pallidus internus (GPi) and several thalamic nuclei-have been explored, yet the comparative efficacy of DBS in different targets remain unclear. This meta-analysis aims to evaluate the clinical efficacy of DBS in TS and assess symptom improvements across different stimulation targets. A systematic search of PubMed, Embase, and Web of Science identified studies published between October 2014 and September 2025. Study quality was assessed using the French and Gronseth classification system. Outcomes of interest included pre- and postoperative scores on the Yale Global Tic Severity Scale (YGTSS) and Yale-Brown Obsessive Compulsive Scale (YBOCS). A total of 22 studies involving 358 patients were included in this meta-analysis. Mean YGTSS scores decreased from 69.19 ± 18.04 preoperatively to 35.88 ± 17.23 postoperatively. There was an average 48% reduction in YGTSS scores. DBS led to a substantial reduction in tic severity (YGTSS: GPi, SMD = 2.29, P < 0.00001; thalamus, SMD = 2.33, P < 0.0001). Within the GPi subgroup, stimulation of the anteromedial GPi (amGPi) resulted in significantly better benefits (SMD = 3.01, P < 0.00001) compared to the posterior-ventrolateral GPi (pvlGPi), which did not reach statistical significance (SMD = 1.23, P = 0.05). YBOCS scores decreased from a mean of 17.38 ± 6.15 preoperatively to 9.16 ± 4.12 postoperatively. The average reduction in YBOCS scores was 47%. Obsessive-compulsive disorder (OCD) symptoms also showed significant improvement following DBS (overall YBOCS, SMD = 0.94, P < 0.00001; amGPi, SMD = 1.49, P = 0.004; pvlGPi, SMD = 0.72; P = 0.006). DBS is an effective and target-sensitive intervention for TS, alleviating both motor tics and obsessive-compulsive symptoms. Compared to therapies such as pvlGPi and thalamic-DBS, amGPi-DBS may demonstrate greater therapeutic potential compared with pvlGPi-DBS, suggesting its potential advantage in modulating the associated circuits involved in the pathophysiology of TS.

Humans↗

PubMed2026

Spatial transcriptomics of Ciona adult brains reveals functional zonalization and insights into neural gland function.

The ascidian Ciona is a pivotal chordate model for illuminating the evolutionary origins of the vertebrate brain. Here, spatial transcriptomics of the adult Ciona neural complex, combined with image-based computational super-resolution mapping, resolved distinct tissue domains including the cerebral ganglion, neural gland, ciliated funnel, neural gland duct/dorsal strand, and body wall muscle. Within the cerebral ganglion, high-resolution mapping revealed clear molecular zonalization separating the cortex and medulla, alongside regional specialization within the cortex itself. The neural gland exhibited localized enrichment of genes associated with extracellular matrix and cell-cell interactions. These spatial features suggest that the neural gland functions as a homeostatic and signaling interface, reminiscent of primitive vertebrate meninges or choroid plexus. Overall, this spatially defined gene expression map provides a foundational framework for understanding functional regionalization in the tunicate brain and its evolutionary relationship to vertebrate nervous systems.

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PubMed2026

How to assess different types of abstract concepts in brain disorders: A systematic review.

The clinical evaluation of semantic knowledge has predominantly relied on tools targeting concrete concepts, whereas abstract knowledge has historically received limited attention despite its importance in everyday communication. Only a few instruments have explored the internal subdivision of abstract knowledge, likely due to the intrinsic difficulty of defining specific types of concepts or dimensions, resulting in a fragmented and heterogeneous neuropsychological assessment framework that limits our understanding of this domain. This systematic review examined the tools used to assess various types of abstract concepts in clinical populations. A literature search has been performed on the electronic databases of PubMed and Google Scholar (last update: October 2025). A total of 17 tests is reviewed, differing in the test characteristics, i.e. ranging from automatic to controlled processes and varying in ecological validity, the type of stimuli employed, and the abstract dimensions explored. Most studies have focused on neurodegenerative patients, while comparatively few have examined other clinical conditions. The risk of bias of the reviewed studies was assessed using an ad hoc developed instrument. This review highlights the need for future research to extend investigations to additional abstract domains and clinical populations, while also identifying key challenges related to stimulus selection and the determination of the most appropriate assessment framework.

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PubMed2026

Occupationally relevant vibrations and the brain: frequency-dependent proteomics signatures in a rat model.

INTRODUCTION: Occupational exposure to whole-body vibration (WBV), particularly in agricultural environments, has been associated with adverse cognitive and physiological effects. This study examined the neurophysiological impact of WBV in a rat model at 4 Hz and 30 Hz, frequencies representative of off-road and on-road vehicle operation. METHODOLOGY: Forty-four Sprague-Dawley rats were assigned to control (0 Hz), low-frequency (4 Hz), or high-frequency (30 Hz) vibration conditions. After three days of exposure, brain tissues were collected and analyzed using mass spectrometry-based proteomics to identify differentially expressed proteins. RESULTS: Proteomic profiling revealed distinct, frequency-dependent alterations in brain protein expression. Compared with controls, 32 cognition-related proteins were differentially regulated at 4 Hz and 29 at 30 Hz, with 13 differing between the two vibration conditions. Principal component analysis showed clear separation among groups, indicating unique proteomic signatures for each exposure frequency. Functional enrichment and protein-protein interaction analyses demonstrated involvement of synaptic plasticity, cytoskeletal organization, calcium regulation, and neurotransmitter release. Exposure to 4 Hz was associated with the upregulation of proteins involved in calcium homeostasis and synaptic integrity, suggesting potential disruption of cognitive processes. In contrast, 30 Hz increased the expression of proteins related to axonal guidance and neuroprotection, indicating a less clearly adverse response that may reflect adaptive or potentially beneficial effects. DISCUSSION: These findings provide new insight into biological mechanisms underlying WBV-induced cognitive changes and underscore the importance of vibration frequency in shaping neurophysiological outcomes. They also establish a foundation for future studies integrating proteomics with behavioural assessments in animals and humans.

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PubMed2026

Cognitive-metabolic relationship in temporal lobe epilepsy: A systematic review.

OBJECTIVE: To summarize the current literature on neurometabolic dysfunction identified through brain imaging and its cognitive correlates in temporal lobe epilepsy (TLE). BACKGROUND: Cognitive decline contributes to chronic disability in TLE. The pathophysiology of cognitive decline in TLE is poorly understood, limiting therapeutic advances. Characterizing metabolic changes in patients with TLE and cognitive impairment may identify biomarkers and inform new treatment strategies. DESIGN/METHODS: We conducted a systematic review of five major databases, gathering studies published through December 2024, in accordance with PRISMA guidelines. We included all observational studies describing associations between metabolic imaging findings and cognitive measures in TLE. RESULTS: Of 1449 reports, 38 met the inclusion criteria, encompassing 1161 patients with TLE aged 5-66 years. Twenty-two studies applied fluorodeoxyglucose (18F-FDG) positron emission tomography (PET) to assess interictal brain glucose metabolism. Two studies utilized PET with other tracers to assess more specific metabolic aspects. Fourteen studies used proton magnetic resonance spectroscopy (1H-MRS) to quantify local concentrations of brain metabolites. Impairment of verbal memory was consistently associated with left temporal lobe metabolite changes. Non-memory cognitive impairments correlated with changes in glucose metabolism, N-acetylaspartate, and gamma-aminobutyrate in both temporal and extratemporal areas. CONCLUSION: 18F-FDG PET remains the most widely used imaging modality to assess cognitive-metabolic correlates in TLE, while other PET tracers and 1H-MRS are potentially underexplored. Verbal memory impairment correlates robustly with left temporal dysmetabolism. Cognitive impairment in TLE is multifaceted and correlates with measurable changes in metabolism in both temporal and extratemporal regions. While our synthesis was restricted by some methodological limitations, these neurometabolic signatures may hold promise as potential biomarkers for identifying risk of cognitive decline and highlight avenues for future research.

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PubMed2026

The Thyroid-Brain Network: Exploring Inflammation, Immune Mechanisms and Common Triggers in Thyroid-Related Neurological Dysfunction.

Autoimmune thyroid diseases (AITD), including Hashimoto's thyroiditis and Graves' disease, represent the most prevalent endocrine disorders worldwide, affecting hundreds of millions with profound but often under recognized neurological consequences. There are emerging lines of evidence establishing inflammation and immunity as the critical missing link connecting peripheral thyroid dysfunction to central nervous system manifestations. Thyroid hormones function as essential neuromodulators governing neurodevelopment, synaptic plasticity, and cognitive processing through integrated genomic and non-genomic mechanisms, with region-specific cerebral metabolic disturbances correlating with distinct neuropsychiatric symptoms. The immunological perspective reveals that AITD propagates neuroinflammation through convergent pathways: molecular mimicry enabling cross-reactivity between thyroid and neural antigens, cytokine-mediated disruption of neurotransmitter metabolism, HMGB1-driven glial activation, and blood-brain barrier compromise facilitating immune cell infiltration. The thyroid-gut-microbiota axis emerges as a critical mediator wherein dysbiosis perpetuates both thyroid autoimmunity and neuroinflammation through impaired serotonin precursor availability and increased intestinal permeability. Mitochondrial dysfunction represents an energetic common denominator, as thyroid hormone dysregulation directly impairs oxidative phosphorylation, producing region-specific cerebral metabolic disturbances. Simultaneous compromise of monoamine systems, cholinergic signaling abnormalities, and glutamate excitotoxicity creates a particularly toxic neurochemical state in untreated thyroid dysfunction. Common triggers such as psychological stress, gut dysbiosis, and mitochondrial impairment may activate interconnected pathways that simultaneously compromise thyroid and brain function, revealing that these disorders share fundamental mechanistic origins. These insights have been discussed in the current review to enhance the understanding of thyroid-brain function, the core mechanisms and consequences of functional deficits.

Journal Article↗

PubMed2026

Artificial intelligence (AI) uses in stereotactic radiosurgery (SRS): diagnosis with brain metastasis (BM) - A systematic review.

BACKGROUND: Brain metastases (BM) are the most common intracranial tumors in adults, and stereotactic radiosurgery (SRS) has become a mainstay of management. However, several diagnostic challenges persist in the SRS pathway, particularly the differentiation of radiation necrosis (RN) from true tumor progression, which conventional MRI and even advanced imaging techniques often cannot reliably resolve. Recent advances in artificial intelligence (AI) offer the potential to address these diagnostic limitations. This systematic review synthesizes current literature on AI applications for MRI-based diagnostic decision support in BM patients undergoing SRS, with a focus on radiomics and deep learning tools for distinguishing RN from progression, classifying molecular and histologic subtypes, and predicting treatment response. METHODS: A systematic review was performed in accordance with PRISMA guidelines. PubMed, Web of Science, and Scopus were searched using a targeted query combining terms related to AI, brain metastasis, diagnosis or imaging, and SRS. After screening 483 records and applying strict inclusion and exclusion criteria, 18 studies published between 2015 and 2025 were included. Data were extracted on study design, cohort characteristics, imaging modality, AI methodology, validation strategy, and reported diagnostic performance. RESULTS: Among the 18 included studies, AI models demonstrated strong performance across diagnostic tasks in the BM-SRS pathway. The differentiation of RN from true tumor progression was the most extensively studied application, addressed by 14 of 18 studies, with reported AUCs ranging from 0.71 to 0.94. Support vector machines, random-forest ensembles, convolutional neural networks, and transformer-based multimodal architectures were widely used. The literature evolved from single-sequence radiomic classifiers in 2018 to multimodal deep learning frameworks fusing imaging with clinical and genomic data in 2025. Contrast-enhanced T1-weighted MRI was the dominant imaging input, and texture-based radiomic features (GLCM, GLSZM, GLDM, and wavelet-derived features) were the most consistently predictive. The highest-performing models reached AUCs of 0.85-0.91 through multimodal integration of imaging with clinical and genomic features, and consistently outperformed expert neuroradiologist read on matched cases. Remaining studies addressed longitudinal segmentation-based detection of local failure and adverse radiation effects, BRAF mutation status in melanoma BM, early Gamma Knife treatment response, and primary tumor histology classification, with more variable performance. CONCLUSION: AI models, particularly those integrating MRI-derived radiomic features with clinical and genomic data, show high accuracy in supporting diagnostic decisions for BM patients treated with SRS. The post-SRS differentiation of radiation necrosis from true tumor progression has reached the greatest level of maturity and is closest to clinical translation, with potential to reduce unnecessary biopsies, personalize surveillance intervals, and rationalize treatment-pathway decisions. Other diagnostic applications, including molecular subtyping and primary tumor histology classification, remain exploratory and require further multicenter validation. Integration of AI tools into multidisciplinary tumor-board workflows, combined with prospective validation and standardized reporting, will be essential to realize the full clinical benefits of AI in SRS for brain metastases.

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PubMed2026

Thrombus Metabolism-Based Molecular Subtyping for Prognostic Risk Stratification in Acute Ischemic Stroke: A Preliminary Study.

AIMS: To preliminarily characterize metabolic molecular subtypes of cerebral thromboemboli and evaluate their clinical significance in anterior circulation acute ischemic stroke due to large vessel occlusion (AIS-LVO). METHODS: Untargeted metabolomics was performed on thromboemboli retrieved from 36 patients with anterior circulation AIS-LVO using ultra-performance coupled liquid chromatography with quadrupole time-of-flight mass spectrometry (UPLC-Q-TOF-MS). Unsupervised hierarchical clustering was employed to identify distinct metabolic molecular subtypes, and their associations with stroke etiology, radiographic severity, and functional outcomes were analyzed. RESULTS: Two distinct thrombus metabolic molecular subtypes (C1 and C2) were identified based on 12 metabolites significantly associated with both short-term (7-day ∆NIHSS) and long-term (90-day mRS) functional outcomes. The C1 subtype, predominantly cardioembolic, exhibited enhanced lipid metabolism, whereas the C2 subtype, primarily atherothrombotic, demonstrated increased folate metabolism. Patients with C1 thromboemboli presented more severe admission ischemic lesions (as indicated by ASPECTS) and experienced poorer short-term and long-term outcomes. A six-metabolite signature derived from LASSO regression was identified for exploratory discrimination of thrombus metabolic subtypes, etiological subtypes, and 90-day outcomes. CONCLUSION: This preliminary exploratory study identifies two metabolically distinct thrombus molecular subtypes with clinical implications in anterior circulation AIS-LVO, providing a novel basis for risk stratification and personalized secondary prevention and warrants further investigation.

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PubMed2026

Risk Factors for Long-Term Health-Related Quality-of-Life and Mental Health Outcomes in Traumatic Brain Injury: A Systematic Review and Meta-Analysis.

Traumatic brain injury (TBI) often leads to long-term disability, including persistent mental health issues and lower health-related quality of life (HRQoL). Early interventions can improve recovery, but because resources limit routine monitoring of all patients, trauma care remains largely symptom-driven. The combination of long-term disability and limited capacity for routine follow-up highlights the need for risk-stratified follow-up care and reliable evidence on early prognostic factors. However, the existing literature is sparse and methodologically heterogeneous, limiting the clinical applicability of findings. We therefore conducted a systematic review and meta-analysis to identify early risk factors for poorer long-term mental health and HRQoL outcomes. A systematic search of seven electronic databases identified studies of adult patients with TBI, with outcomes assessed at least 6 months postdischarge. Two authors independently screened the studies, assessed the risk of bias, and extracted the data. We pooled effect estimates using a random-effects meta-analysis and calculated 95% prediction intervals. A narrative synthesis was applied when meta-analysis was not feasible. The review was registered with PROSPERO (CRD42024576912) and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Of the 8,104 articles screened, 64 studies met the inclusion criteria (n = 334,672). Most studies (58%) had a low risk of bias. Female sex, socioeconomic disadvantage, psychiatric history, assaultive-related injuries, and previous TBI were consistently associated with worse long-term outcomes. Across meta-analyses, assault-related injuries more than doubled the odds of post-traumatic stress disorder (odds ratio [OR] = 2.72; 95% confidence interval [CI]: 2.01-3.66, I2 = 0%). Higher odds were also observed among females (OR = 1.33; 95% CI: 1.11-1.59, I2 = 0%), individuals with prior TBI (OR = 1.56; 95% CI: 1.07-2.27, I2 = 0%), and those with psychiatric history (OR = 2.38; 95% CI: 1.83-3.10, I2 = 48%). We found that female sex (OR = 1.72; 95% CI: 1.38-2.16, I2 = 58%), prior TBI (OR = 1.52; 95% CI: 1.25-1.85, I2 = 0%), and psychiatric history (OR = 3.25; 95%CI: 1.86-5.69, I2 = 98%) were associated with higher odds of depression. Furthermore, higher pooled anxiety scores were observed in females and in individuals with a psychiatric history. The study identified several readily available factors present before or at discharge that are associated with poor long-term HRQoL and mental health outcomes. Leveraging these factors in follow-up protocols, prediction modeling, and clinical decision support systems may facilitate risk-stratified postdischarge care for TBI patients.

Humans↗

PubMed2026

Complexity in disguise: a systematic review of fractal analysis in psychiatric neuroimaging.

OBJECTIVES: Psychiatric diagnosis and fractal studies are complex processes that extend beyond clinical evaluation and require careful methodological considerations in neuroimaging. Over the years, fractals have helped reduce these complexities in research, but they still cannot grant clinical diagnoses. Thus, the main objective was a systematic review exploring the potential applications of fractal analysis in characterizing psychiatric conditions through neuroimaging techniques-including both functional and structural MRI. MATERIALS AND METHODS: A systematic literature review was conducted on PubMed, identifying thirty-nine original studies that met the inclusion criteria. Areas showing statistical significance (p < 0.05) were reported. These studies were categorized according to DSM-V classification and examined for the description of psychiatric conditions through the fractal analysis. RESULTS: The review primarily focuses on young adults with psychiatric conditions compared to control groups. Schizophrenia and Autism Spectrum Disorder are major areas of investigation, and fractal dimension (FD) is the primary analysis method used to reflect brain patterns. Studies that calculated whole-brain FD may have underestimated local abnormalities due to the inclusion of a high percentage of tissue, potentially resulting in overlooked findings. Notably, abnormalities in the frontal cortex represent a common neurobiological feature across several psychiatric conditions. CONCLUSIONS: The findings from this systematic review shed light on the use of fractal analysis to quantify complex brain patterns in both psychiatric patients and healthy individuals. However, it is essential to recognize the need for further research to elucidate a fractal analysis protocol that allows for optimal extraction of psychiatric insights. KEY POINTS: Question Fractal analysis applied to structural and functional MRI help characterize brain alterations across psychiatric conditions. Findings This review shows consistent fractal patterns across multiple psychiatric disorders, especially in frontal regions. Despite heterogeneous methodologies, results highlight shared structural and functional abnormalities. Clinical relevance Fractal analysis may offer complementary characterization of subtle brain organization across psychiatric disorders. Its potential clinical utility-such as improving diagnostic characterization, earlier detection, among others-remains limited by the current absence of a standardized protocol.

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PubMed2026

Assessing the effects of non-invasive transcranial electrical stimulation (tACS and tDCS) on electrophysiological sleep parameters - a systematic review.

Transcranial electrical stimulation (tES), including transcranial direct current stimulation (tDCS) and transcranial alternating current stimulation (tACS), is considered a safe method to modulate cortical activity and endogenous brain oscillations. Given the therapeutic potential of tES across various clinical conditions and the central role of sleep in restoration and memory consolidation, numerous studies have investigated its effects on sleep and sleep-related parameters, yielding inconsistent results. This systematic review provides an up-to-date synthesis of 51 studies assessing the impact of tES on objectively measured electrophysiological sleep outcomes in both healthy individuals and clinical populations. The reviewed studies demonstrate heterogeneous effects, reflecting substantial variability in study designs. Nonetheless, consistent trends emerge, including reduced NREM1 and increases in total sleep time, NREM2, and NREM3 following tES. Moreover, slow-oscillatory tES increased slow-wave power during sleep. Here we show that tES, particularly slow-oscillatory tES, may positively influence sleep architecture and continuity by modulating endogenous brain oscillations. However, due to heterogeneous stimulation protocols, inconsistent findings, the limited number of significant effects and substantial risk of bias the current evidence remains inconclusive. Well-designed, large-scale trials targeting specific sleep outcomes are needed to clarify the therapeutic potential of tES.

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PubMed2026

The efficacy of non-invasive brain stimulation interventions in obsessive-compulsive disorder management: A network meta-analysis of randomized controlled trials.

Non-invasive brain stimulation (NIBS) has been widely used as an alternative treatment for obsessive compulsive disorder (OCD). However, the most effective NIBS parameters are unclear. To compare the efficacy of NIBS in OCD. We conducted a systematic review and network meta-analyses (NMA) to combine direct and indirect comparisons of NIBS.Systematic searches were conducted in Cochrane CENTRAL, EMBASE, PubMed, and Web of Science from inception to June 20, 2025. Forty-two randomized sham-controlled trials (n = 1456) were included. All statistical analyses were conducted with R statistical software. Bayesian NMAs mainly using the BUGSnet package and gemtc package. Five NIBS protocols produced statistically significant reductions in Yale-Brown Obsessive Compulsive Scale (Y-BOCS) scores compared with sham stimulation: high-frequency rTMS over the FzFCz (Hf-rTMS-FzFCz; MD -11.77, 95% CrI -20.62 to -3.09), low-frequency rTMS over F3F4 (Lf-rTMS-F3F4; MD -9.93, 95% CrI -18.07 to -1.65), low-frequency rTMS over FCz (Lf-rTMS-FCz; MD -3.25, 95% CrI -6.06 to -0.40), high-frequency deep TMS over FzFC (Hf-dTMS-FzFC; MD -6.48, 95% CrI -12.32 to -0.50), and 2 mA anodal tDCS over F3 with cathodal over Fp2 (MD -9.34, 95% CrI -16.01 to -3.03).For secondary outcomes, high-frequency deep rTMS over FzFCz produced the largest reduction both in depressive symptoms (SMD -1.24, 95% CrI -1.92 to -0.55) and anxiety scores (SMD -1.88, 95% CrI -2.62 to -1.11), but had no effect on Clinical Global Impression-Severity (CGI-S) scores.Specific NIBS protocols are safe and effective adjunctive treatments for OCD, with promising yet inconclusive improvements in comorbid depressive symptoms. Further high-quality, head-to-head trials are needed.

Humans↗

PubMed2026

Neurocorrelates of nocturnal enuresis in pre-adolescent children.

INTRODUCTION: Nocturnal enuresis (NE) is a common neurodevelopmental condition, yet its underlying neural mechanisms remain unclear. This study leverages the large-scale Adolescent Brain Cognitive Development (ABCD) dataset to identify structural and functional brain correlates associated with active symptoms and the resolution of bedwetting. METHODS: Using cross-sectional data from 3472 participants aged 9-10 years, children were categorized into three groups: active nocturnal enuresis (ANE, n = 225), history of nocturnal enuresis (HNE, n = 1171), and healthy control groups (CG, n = 2076). Multimodal neuroimaging protocol evaluated macrostructural properties via structural MRI (sMRI), microstructural white matter integrity via diffusion MRI (dMRI), and functional connectivity via resting-state fMRI (fMRI). Group differences were evaluated using linear models within an ANCOVA framework, adjusting for intracranial volume and handedness with False Discovery Rate (FDR) correction. RESULTS: Compared to controls, the ANE group exhibited a significant volume deficit in the right caudate, decreased sulcal depth in the left insula, and lower internal correlation within the Cingulo-Opercular Network (CON). Conversely, the dry HNE group demonstrated significant structural adaptations, including bilaterally larger putamen volumes and increased right caudate volume compared to the ANE group. The HNE group also showed increased microstructural density (decreased mean diffusivity) in the bilateral hippocampus and an increased cortical surface area in the left insula. Both NE groups demonstrated persistently reduced functional coupling within the CON. CONCLUSIONS: Nocturnal enuresis appears to be associated with a potential complex central signaling deficits. Reduced internal correlation within the CON across both active and former bedwetters indicates a potential for impairment in processing internal homeostatic bladder signals during sleep.

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PubMed2026

How the microbiome shapes epigenetic trained memory in neuroinflammation: Implications for neurodegenerative diseases.

Neurodegenerative diseases are increasingly recognized as disorders involving immune dysregulation. However, the mechanisms underlying this dysfunction remain poorly characterized. Trained immunity has recently emerged as a potential contributor to immune dysregulation, particularly in neuroinflammation and neurodegenerative diseases, where trained immunity is the epigenetic reprogramming of innate immune responses following an initial inflammatory stimulus, which increases responses to subsequent exposures. In parallel, although the brain has traditionally been viewed as an immune-privileged organ, growing evidence indicates that peripheral immune activity exerts significant influence on neuroinflammation in the brain. A major driver of peripheral immunity is the microbiome. Therefore, this perspective aims to present a conceptual framework for a relationship between the microbiome, trained immunity, and neurodegenerative diseases. We first summarize evidence of trained immunity in the brain and its role in neurodegeneration. Next, we highlight the role of the microbiome in peripheral immune modulation and in trained immunity. Finally, we propose potential mechanisms through which the microbiome may induce or modulate trained immunity in the brain. These include: 1) immunogenic microbial metabolites that cross the blood-brain barrier and alter host cell epigenetics; 2) migration of peripherally trained myeloid cells into the brain; 3) viral infection-induced trained immunity that may predispose to neurodegeneration. Together, this perspective suggests that microbiome-induced trained immunity offers a novel mechanism linking peripheral immune regulation with neuroinflammation and neurodegeneration with implications for therapeutic targeting of epigenetic modification as a molecular prevention strategy for progression of neurodegeneration.

Humans↗

PubMed2026

Auditory brainstem response in the identification of cochlear synaptopathy in aged rodents: a systematic review with meta-analysis.

PURPOSE: This systematic review and meta-analysis evaluated the diagnostic performance of auditory brainstem response (ABR) for identifying age-related cochlear synaptopathies in rodents. METHOD: Following PRISMA guidelines, searches were conducted in PubMed/MEDLINE, Cochrane Library, Scopus, Embase, Web of Science, SciELO, LILACS, and gray literature. Studies evaluating CS in naturally aged rodents using short-latency auditory evoked potentials (AEPs) were included. Study selection, data extraction, risk-of-bias (JBI Critical Appraisal Checklist for Analytical Cross-Sectional Studies), and certainty of the evidence (GRADE® system) assessment were conducted independently by two reviewers. Meta-analyses were performed using a random-effects model, with standardized mean differences and 95% confidence intervals. ABR wave I amplitudes were analyzed for click (80 and 90 dB SPL) and tone-burst stimuli stratified by frequency. RESULTS: Among 3,008 identified records, 12 studies were included in the review and five in the meta-analysis. All included studies used ABR measures to investigate CS, with wave I amplitude being the most frequently evaluated biomarker. Meta-analysis demonstrated a significant reduction in ABR wave I amplitude in aged rodents compared with young controls for both click- and tone-burst-evoked responses. Tone-burst ABR showed no significant differences among the evaluated frequencies. These findings should be interpreted with caution due to the limited number of studies and the methodological heterogeneity, which may have reduced statistical power and comparability. CONCLUSIONS: The evidence supports ABR wave I amplitude as a sensitive electrophysiological marker of age-related CS in rodents. Nevertheless, further studies with standardized protocols are needed to strengthen its diagnostic utility and improve comparability across studies.

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