Differences In Brain Structure Research Articles

Body dysmorphic disorder.

Body dysmorphic disorder (BDD) is an obsessive-compulsive disorder-related psychiatric condition characterized by an intense preoccupation with perceived physical flaws that are not observable by others. BDD affects ~2% of the adult population but is underdiagnosed, partly owing to limited clinician awareness, and undertreated, partly due to limited access to treatment. Research on the aetiology of BDD is scarce but likely involves an interplay between genetic and environmental factors. A few studies suggest functional and structural brain differences (compared with controls) in the regions involved in visual and emotional processing, although firm conclusions about the pathophysiology of the disorder cannot be made at this stage. Diagnosis requires the presence of repetitive behaviours or mental acts typically aimed at checking, correcting or concealing perceived flaws. The disorder typically has its onset before 18 years of age, with a female preponderance in youth but no major gender disparity in adults. Quality of life is markedly impaired across multiple domains and suicide risk is considerable. Evidence-based treatments include cognitive behavioural therapy and selective serotonin reuptake inhibitors. Future research should focus on understanding the biological and environmental factors that increase the risk of BDD, and on improving access to effective treatments, thereby addressing a critical gap in care for this often misunderstood and overlooked disorder.

Investigating sex-related differences in brain structure and function in bipolar I disorder using multimodal MRI

BackgroundPast research has highlighted that bipolar I disorder is associated with significant changes in brain structure and function. Notably, the manifestation and progression of bipolar I disorder have been known to differ between males and females. However, the relationship between sex-related differences and bipolar I disorder diagnosis affecting these changes was not fully understood. This study aimed to investigate the sex-by-diagnosis interactions concerning the structural and functional features of the brain in individuals with bipolar I disorder.MethodsBoth structural and functional MRI data were obtained from 105 individuals with bipolar I disorder (36 males and 69 females) and 210 healthy controls (72 males and 138 females). Voxel-wise analyses of gray matter volume and functional connectivity were conducted using a general linear regression model. This model included age, sex, diagnosis, and a sex-by-diagnosis interaction as predictors to explore potential sex-related differences in the brain features of participants with bipolar I disorder.ResultsThe gray matter volume analysis revealed significant sex-by-diagnosis interactions in six brain regions: the left caudate (p < 0.001), left thalamus (p < 0.001), right caudate (p = 0.003), right thalamus (p < 0.001), left anterior cingulate gyrus (p = 0.022), and left middle/posterior cingulate gyrus (p = 0.015). Using these regions as seeds, we detected a significant sex-by-diagnosis interaction in the functional connectivity alteration between the left thalamus and right angular gyrus (p = 0.019).ConclusionsOur findings revealed a noteworthy sex-by-diagnosis interaction, with male individuals with bipolar I disorder displaying larger gray matter volume and altered functional connectivity in the limbic system compared to female individuals with bipolar I disorder and healthy participants. These results hint at potential sex-related differences in the pathophysiology of the limbic system in bipolar I disorder, which may have significant implications for understanding the underlying mechanisms in bipolar I disorder. Our findings could contribute to developing more personalized treatment approaches for individuals with bipolar I disorder.

Neuroanatomy, episodic memory and inhibitory control of persian-kurdish simultaneous bilinguals

We assessed simultaneous bilinguals and monolinguals on inhibitory control and episodic memory, and assessed their grey matter volumes in brain regions known to be involved in language processing, executive control and memory. Bilinguals outperformed monolinguals on episodic memory, and performance on the memory and inhibition tasks were correlated, only in the bilingual group. This suggests that the bilingualism-related benefits on memory are related to individual differences in executive control. We found larger grey matter volumes in bilinguals in left pars opercularis and in bilateral SFG, caudate nuclei, and parasubiculum. Episodic memory performance was correlated with volumes of bilateral posterior hippocampi, again only in the bilinguals, again suggesting that bilingualism may be driving this effect. Finally, we found positive structural covariance between the volumes of the bilateral parasubiculum and that of important components of the executive control network. We provide a novel, mechanistic explanation accounting for observed behavioural advantage and brain structural differences: bilingualism may boost the prefrontal cortex-hippocampal neural circuitry commonly underlying both executive control and memory, via cascade and reverberant effects, leading to synergistic benefits in both cognitive domains. This new framework has important implications for protective effects on cognition and brain health in relation to second language learning.

Sex differences in the antinociceptive effect of codeine and its peripheral but not central metabolism in adult mice

Codeine is a natural opiate extracted from opium poppy (Papaver somniferum) and used to alleviate mild to moderate pain. The analgesic effect of this molecule results from its metabolism into morphine which is an agonist of the mu opioid receptor. Morphine's major metabolite morphine-3-glucuronide induces both thermal and mechanical hypersensitivies while codeine-6-glucuronide has been proposed to be antinociceptive. However, sex differences in codeine antinociceptive effect and pharmacokinetics were barely studied. To this purpose, we injected male and female mice with codeine (2.5, 5, 10, 20 and 40 mg/kg) and thermal hypersensitivity was assessed 30 min after injection using the Tail Immersion Test. Moreover, both peripheral and central metabolism of codeine were evaluated respectively in the blood or pain-related brain structures in the central nervous system. The amounts of codeine and its metabolites were quantified using the isotopic dilution method by liquid chromatography coupled to a mass spectrometer. Our results show that codeine induces a greater antinociceptive effect in males than females mice independently of the estrous cycle. Moreover, major sex differences were found in the peripheral metabolism of this molecule, with higher amounts of pronociceptive morphine-3-glucuronide and less antinociceptive codeine-6-glucuronide in females than in males. Concerning the central metabolism of codeine, we did not find significant sex differences in pain-related brain structures. Collectively, these findings support a greater codeine antinociceptive effect in males than females in mice. These sex differences could be influenced by a higher peripheral metabolism of this molecule in female mice rather than central metabolism.

Biological, psychological, and socio-structural underpinnings of dissociative identity disorder

Abstract. Epidemiological studies revealed the prevalence and diverse symptoms of dissociative identity disorder (DID), emphasizing diagnostic complexities. Debates over its etiology, ranging from trauma to fantasy predisposition, highlight the need for ongoing research and varied therapeutic approaches. Neuroimaging has uncovered distinct structural and functional brain differences in DID patients, contributing to our understanding of its neurological basis. Despite therapeutic progress, including behavioral and pharmacological interventions, effectively DID treatments remain challenging. Integrating biological, psychological, and sociocultural perspectives is crucial for advancing DID diagnosis and treatment.

Volumetric Analysis of Motor Cortex and Basal Ganglia in Pediatric Celiac Disease Patients Using volBrain: Implications for Neurological Dysfunction-Preliminary Results.

Celiac disease (CD) is a common immune-mediated, chronic systemic disorder that is treated with a strict, life-long gluten-free diet (GFD). In addition to gastrointestinal manifestations, CD also presents with a variety of extraintestinal symptoms, including significant neurological and neuropsychiatric symptoms. Among these neurological manifestations, motor dysfunctions are particularly notable. The aim of this study is to investigate the potential volumetric differences in brain structures, particularly the motor cortex and basal ganglia, between pediatric CD patients and healthy controls using the volBrain software AssemblyNet version 1.0. This prospective study included pediatric patients with CD who complained of neurological symptoms and were scheduled for brain magnetic resonance imaging (MRI). All children had been previously diagnosed with CD and their adherence to GFD was evaluated using the Biagi score. Brain MRIs were performed on all included patients to obtain volumetry at the onset of the disease. For volumetric and segmentation data, the volBrain software was used. In total, 12 pediatric patients with CD were included, with a median duration of a GFD of 5.3 years at the time of the MRI examination. There were no statistically significant differences between patients compliant with the GFD and those non-compliant in terms of age or duration of GFD. Volumetric analysis revealed deviations in all patients analyzed, which involved either a decrease or increase in the volume of the structures studied. Despite the limited number of patients in this study, the initial findings support previously described neurological manifestations in patients with CD. Newly developed MRI tools have the potential to enable a more detailed analysis of disease progression and its impact on the motor cortex.

Synesthesia is linked to large and extensive differences in brain structure and function as determined by whole-brain biomarkers derived from the HCP (Human Connectome Project) cortical parcellation approach.

There is considerable interest in understanding the developmental origins and health implications of individual differences in brain structure and function. In this pre-registered study we demonstrate that a hidden subgroup within the general population-people with synesthesia (e.g. who "hear" colors)-show a distinctive behavioral phenotype and wide-ranging differences in brain structure and function. We assess the performance of 13 different brain-based biomarkers (structural and functional MRI) for classifying synesthetes against general population samples, using machine learning models. The features in these models were derived from subject-specific parcellations of the cortex using the Human Connectome Project approach. All biomarkers performed above chance with intracortical myelin being a particularly strong predictor that has not been implicated in synesthesia before. Resting state data show widespread changes in the functional connectome (including less hub-based connectivity). These brain-based individual differences within the neurotypical population can be as large as those that differentiate neurotypical from clinical brain states.

Structural MRI findings in the brain related to pain distribution in chronic overlapping pain conditions: An explorative case-control study in females with fibromyalgia, temporomandibular disorder-related chronic pain and pain-free controls.

Few neuroimaging studies have investigated structural brain differences associated with variations in pain distribution. To explore structural differences of the brain in fibromyalgia (FM), temporomandibular disorder pain (TMD) and healthy pain-free controls (CON) using structural and diffusion MRI. A case-control exploratory study with three study groups with different pain distribution were recruited: FM (n = 16; mean age [standard deviation]: 44 [14] years), TMD (n = 17, 39 [14] years) and CON (n = 10, 37 [14] years). Participants were recruited at the University Dental Clinic in Malmö, Sweden. T1-weighted and diffusion MRIs were acquired, clinical and psychosocial measures were obtained. Main outcome measures were subcortical volume, cortical thickness, white matter microstructure and whole brain grey matter intensity. Patients with FM had smaller volume in the right thalamus than patients with TMD (p = .020) and CON (p = .030). The right thalamus volume was negatively correlated to pain intensity (r = -0.37, p = .022) and pain-related disability (r = -0.45, p = .004). The FM group had lower cortical thickness in the right anterior prefrontal cortex than CON (p = .005). Cortical thickness in this area was negatively correlated to pain intensity (r [37] = - 0.48, p = .002). This study suggests that thalamus grey matter alterations are associated with FM and TMD, and that anterior prefrontal cortex grey matter alterations are associated with FM but not TMD. Studies on chronic overlapping pain conditions are needed in relation to possible nociplastic pain mechanisms in the brain and central nervous system.

Exploring the Impact of Sex and Gender in Brain Function: Implications and Considerations.

Sex and gender are crucial variables in understanding brain development and disease. Biological sex is determined by genetic and hormonal factors, whereas gender is a multidimensional construct shaped by social and cultural influences. The interplay of these factors contributes to sex-specific susceptibilities and disease progression in psychiatric and neurological disorders. However, sex and gender are often considered as a single variable, which can lead to biased data analysis and interpretation. This commentary aims to analyze how sex and gender influence brain structure and function, with implications for personalized medicine, research, and the development of gender-sensitive clinical guidelines. Findings from various studies employing neuroimaging techniques and animal models are discussed, as well as the impact of biological sex, gender, environmental, cultural, and social factors on brain development, organization, and behavior. Evidence suggests that sex differences in brain structure and function are not only genetically determined but arealso influenced by gender-related experiences and societal contexts. Importantly, discrepancies between male and female brains are reduced in gender-equal societies. Preclinical studies play a pivotal role in determining the influence of biological sex, independent of gender, in different disease models. The findings underscore the need to consider both sex and gender in research and clinical practice to avoid biases and promote equitable health outcomes. Moving forward, we advocate for gender-sensitive approaches to be integrated into brain research and in clinical guidelines to achieve personalized and precision medicine.

More similarity than difference: comparison of within- and between-sex variance in early adolescent brain structure.

Background Adolescent neuroimaging studies of sex differences in the human brain predominantly examine mean differences between males and females. This focus on between-groups differences without probing relative distributions and similarities may contribute to both conflation and overestimation of sex differences and sexual dimorphism in the developing human brain. Methods We aimed to characterize the variance in brain macro- and micro-structure in early adolescence as it pertains to sex at birth using a large sample of 9-11 year-olds from the Adolescent Brain Cognitive Development (ABCD) Study (N=7,723). Specifically, for global and regional estimates of gray and white matter volume, cortical thickness, and white matter microstructure (i.e., fractional anisotropy and mean diffusivity), we examined: within- and between-sex variance, overlap between male and female distributions, inhomogeneity of variance via the Fligner-Killeen test, and an analysis of similarities (ANOSIM). For completeness, we examined these sex differences using both uncorrected (raw) brain estimates and residualized brain estimates after using mixed-effects modeling to account for age, pubertal development, socioeconomic status, race, ethnicity, MRI scanner manufacturer, and total brain volume, where applicable. Results The overlap between male and female distributions was universally greater than the difference (overlap coefficient range: 0.585 - 0.985) and the ratio of within-sex and between-sex differences was similar (ANOSIM R range: -0.001 - 0.117). All cortical and subcortical volumes showed significant inhomogeneity of variance, whereas a minority of brain regions showed significant sex differences in variance for cortical thickness, white matter volume, fractional anisotropy, and mean diffusivity. Inhomogeneity of variance was reduced after accounting for other sources of variance. Overlap coefficients were larger and ANOSIM R values were smaller for residualized outcomes, indicating greater within- and smaller between-sex differences once accounting for other covariates. Conclusions Reported sex differences in early adolescent human brain structure may be driven by disparities in variance, rather than binary, sex-based phenotypes. Contrary to the popular view of the brain as sexually dimorphic, we found more similarity than difference between sexes in all global and regional measurements of brain structure examined. This study builds upon previous findings illustrating the importance of considering variance when examining sex differences in brain structure.

Sex Differences in Human Brain Structure at Birth

BackgroundSex differences in human brain anatomy have been well-documented, though remain significantly underexplored during early development. The neonatal period is a critical stage for brain development and can provide key insights into the role that prenatal and early postnatal factors play in shaping sex differences in the brain.MethodsHere, we assessed on-average sex differences in global and regional brain volumes in 514 newborns aged 0–28 days (236 birth-assigned females and 278 birth-assigned males) using data from the developing Human Connectome Project. We also assessed sex-by-age interactions to investigate sex differences in early postnatal brain development.ResultsOn average, males had significantly larger intracranial and total brain volumes, even after controlling for birth weight. After controlling for total brain volume, females showed significantly greater total cortical gray matter volumes, whilst males showed greater total white matter volumes. After controlling for total brain volume in regional comparisons, females had significantly increased white matter volumes in the corpus callosum and increased gray matter volumes in the bilateral parahippocampal gyri (posterior parts), left anterior cingulate gyrus, bilateral parietal lobes, and left caudate nucleus. Males had significantly increased gray matter volumes in the right medial and inferior temporal gyrus (posterior part) and right subthalamic nucleus. Effect sizes ranged from small for regional comparisons to large for global comparisons. Significant sex-by-age interactions were noted in the left anterior cingulate gyrus and left superior temporal gyrus (posterior parts).ConclusionsOur findings demonstrate that sex differences in brain structure are already present at birth and remain comparatively stable during early postnatal development, highlighting an important role of prenatal factors in shaping sex differences in the brain.

A stroke organoids-multiomics platform to study injury mechanism and drug response

Stroke is one of the top causes of death and disability worldwide, and its pathogenesis and mechanism have not been fully elucidated. Several agents have shown protective effects against stroke in animal models; however, few studies have shown obvious effects in clinical practice. This might be due to differences in brain structure and physiological function between humans and rodents. In this study, we established a hypoxic stroke model in human-induced pluripotent stem cell (hiPSC)-derived brain organoids to simulate the hypoxic stroke caused by ischemia. Then, by combining proteomics, single-cell transcriptome analysis, and histopathological analysis, a significant increase of three types of astrocytes was identified and they showed different responses to hypoxic environments; also the main type of astrocyte that cause brain tissue hyperplasia in ischemia brains was identified. In addition, the cortical excitatory neurons had signs of apoptosis and aging after hypoxia both in vivo and in vitro. Most importantly, we identified a possible role of a traditional Chinese medicine formula called DengZhanShengMai capsule in ischemic and hypoxic stroke treatment through regulation of lipid metabolism related biological functions. These results indicate that the combination of brain organoids and multiomics method is helpful for developing a new strategy to direct study stroke, and could provide a promising platform for drug screening of stroke in the future.

Hormone Replacement Therapy and Alzheimer's Disease: Current State of Knowledge and Implications for Clinical Use.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder responsible for over half of dementia cases, with two-thirds being women. Growing evidence from preclinical and clinical studies underscores the significance of sex-specific biological mechanisms in shaping AD risk. While older age is the greatest risk factor for AD, other distinct biological mechanisms increase the risk and progression of AD in women including sex hormones, brain structural differences, genetic background, immunomodulation and vascular disorders. Research indicates a correlation between declining estrogen levels during menopause and an increased risk of developing AD, highlighting a possible link with AD pathogenesis. The neuroprotective effects of estrogen vary with the age of treatment initiation, menopause stage, and type. This review assesses clinical and observational studies conducted in women, examining the influence of estrogen on cognitive function or addressing the ongoing question regarding the potential use of hormone replacement therapy (HRT) as a preventive or therapeutic option for AD. This review covers recent literature and discusses the working hypothesis, current use, controversies and challenges regarding HRT in preventing and treating age-related cognitive decline and AD. The available evidence indicates that estrogen plays a significant role in influencing dementia risk, with studies demonstrating both beneficial and detrimental effects of HRT. Recommendations regarding HRT usage should carefully consider the age when the hormonal supplementation is initiated, baseline characteristics such as genotype and cardiovascular health, and treatment duration until this approach can be more thoroughly investigated or progress in the development of alternative treatments can be made.

Cortical Surface Area Profile Mediates Effects of Childhood Disadvantage on Later-Life General Cognitive Ability.

Childhood disadvantage is associated with lower general cognitive ability (GCA) and brain structural differences in midlife and older adulthood. However, the neuroanatomical mechanisms underlying childhood disadvantage effects on later-life GCA remain poorly understood. Although total surface area (SA) has been linked to lifespan GCA differences, total SA does not capture the nonuniform nature of childhood disadvantage effects on neuroanatomy, which varies across unimodal and transmodal cortices. Here, we examined whether cortical SA profile-the extent to which the spatial patterning of SA deviates from the normative unimodal-transmodal cortical organization-is a mediator of childhood disadvantage effects on later-life GCA. In 477 community-dwelling men aged 56-72 years old, childhood disadvantage index was derived from four indicators of disadvantages and GCA was assessed using a standardized test. Cortical SA was obtained from structural magnetic resonance imaging. For cortical SA profile, we calculated the spatial similarity between maps of individual cortical SA and MRI-derived principal gradient (i.e., unimodal-transmodal organization). Mediation analyses were conducted to examine the indirect effects of childhood disadvantage index through cortical SA profile on GCA. Around 1.31% of childhood disadvantage index effects on later-life GCA were mediated by cortical SA profile, whereas total SA did not. Higher childhood disadvantage index was associated with more deviation of the cortical SA spatial patterning from the principal gradient, which in turn related to lower later-life GCA. Childhood disadvantage may contribute to later-life GCA differences partly by influencing the spatial patterning of cortical SA in a way that deviates from the normative cortical organizational principle.

Shared and distinct alterations in brain morphology in children with ADHD and obesity: Reduced cortical surface area in ADHD and thickness in overweight/obesity

ObjectiveTo investigate shared versus distinct differences in brain structure among children with ADHD and obesity, we examined the morphology of regions implicated in cognitive control and reward function in a single cross-sectional cohort of children with and without ADHD and overweight/obesity (OV/OB). MethodParticipants included 471 children ages 8–12 years with ADHD (n = 244; 58 OV/OB) and neurotypical (NT) controls (n = 227; 81 OV/OB) classified as healthy-weight (HW; BMI %ile 5th to <85th) vs. having OV/OB (BMI %ile≥85th). Structural MRI was performed to obtain measures of cortical and subcortical morphology and compared across ADHD × BMI groups. ResultsSurface area was generally lower in ADHD vs. NT including in anterior cingulate cortex (ACC), dorsolateral prefrontal cortex (dlPFC), medial (m)PFC, and primary motor (M1) cortex. In contrast, cortical thickness was generally lower in OV/OB vs. HW for ACC, dlPFC, orbitofrontal cortex (OFC), mPFC, and supplementary motor cortex (SMC). Furthermore, ADHD × OV/OB interactions were observed for the ACC and OFC, with the lowest ACC volume in the ADHD + OV/OB group and the highest OFC surface area in the NT + OV/OB group. Subcortical volumes did not differ between groups. ConclusionsOur findings reveal distinct alterations in cortical morphology in association with ADHD and overweight, with cortical surface area reduced in ADHD vs. thickness reduced in OV/OB. Additionally, the findings provide evidence of combined effects of ADHD × OV/OB in brain regions integral to cognition and motivation. Our results support further investigation of causes and correlates of shared and distinct ADHD- and OV/OB-associated differences in developing frontocingulate morphology.

Differences in brain structure and cognitive performance between patients with long-COVID and those with normal recovery

BackgroundThe pathophysiology of protracted symptoms after COVID-19 is unclear. This study aimed to determine if long-COVID is associated with differences in baseline characteristics, markers of white matter diffusivity in the brain, and lower scores on objective cognitive testing. MethodsIndividuals who experienced COVID-19 symptoms for more than 60 days post-infection (long-COVID) (n = 56) were compared to individuals who recovered from COVID-19 within 60 days of infection (normal recovery) (n = 35). Information regarding physical and mental health, and COVID-19 illness was collected. The National Institute of Health Toolbox Cognition Battery was administered. Participants underwent magnetic resonance imaging (MRI) with diffusion tensor imaging (DTI). Tract-based spatial statistics were used to perform a whole-brain voxel-wise analysis on standard DTI metrics (fractional anisotropy, axial diffusivity, mean diffusivity, radial diffusivity), controlling for age and sex. NIH Toolbox Age-Adjusted Fluid Cognition Scores were used to compare long-COVID and normal recovery groups, covarying for Age-Adjusted Crystallized Cognition Scores and years of education. False discovery rate correction was applied for multiple comparisons. ResultsThere were no significant differences in age, sex, or history of neurovascular risk factors between the groups. The long-COVID group had significantly (p < 0.05) lower mean diffusivity than the normal recovery group across multiple white matter regions, including the internal capsule, anterior and superior corona radiata, corpus callosum, superior fronto-occiptal fasciculus, and posterior thalamic radiation. However, the effect sizes of these differences were small (all β<|0.3|) and no significant differences were found for the other DTI metrics. Fluid cognition composite scores did not differ significantly between the long-COVID and normal recovery groups (p > 0.05). ConclusionsDifferences in diffusivity between long-COVID and normal recovery groups were found on only one DTI metric. This could represent subtle areas of pathology such as gliosis or edema, but the small effect sizes and non-specific nature of the diffusion indices make pathological inference difficult. Although long-COVID patients reported many neuropsychiatric symptoms, significant differences in objective cognitive performance were not found.

Investigating the genetic relationship of intracranial and subcortical brain volumes with depression and other psychiatric disorders

Abstract Depression is one of the most common mental health disorders worldwide, yet its neurobiological mechanisms remain poorly understood. Structural brain differences in subcortical limbic regions are thought to be implicated in the pathology of depression. We leveraged genome-wide association studies (GWAS) summary-level data to explore the molecular pathways underlying the relationship between genetic risk for depression and intracranial and subcortical brain volumes measured via magnetic resonance imaging. At the whole-genome level, we identified a negative genetic correlation (rG) between depression and the volume of the ventral diencephalon (rG = -0.08), which remained significant after adjusting for multiple testing. We observed nominal (P &amp;lt; 0.05) positive genetic correlations between depression and the volumes of the caudate nucleus (rG = 0.06) and the putamen (rG = 0.06), while hippocampal volume displayed a negative genetic correlation (rG = -0.06) with depression. Pairwise GWAS analyses uncovered 104 genome segments with genetic variants influencing the aetiology of depression and at least one brain volume at the local genetic level. Gene association analyses of these genomic segments suggest putative links with dopamine neurotransmission, mesocorticolimbic functional connectivity, GABAergic transmission, and the insulin signalling pathway. Sensitivity analyses showed that the volume of the ventral diencephalon is also negatively correlated with bipolar disorder and schizophrenia; however, most of the genes associated with depression and brain volumes are specific for depression and do not replicate when investigating bipolar disorder or schizophrenia with brain volumes. We observed negative phenotypic correlations between depression and intracranial and subcortical brain volumes. Overall, our findings contribute to our understanding of the neurobiology of depression and suggest that, besides the known role of the hippocampus, other subcortical structures might also play essential roles in the aetiology of depression.

Structural brain characteristics of epilepsy patients with comorbid migraine without aura

Migraine is a common bi-directional comorbidity of epilepsy, indicating potential complex interactions between the two conditions. However, no previous studies have used brain morphology analysis to assess possible interactions between epilepsy and migraine. Voxel-based morphometry (VBM), surface-based morphometry (SBM), and structural covariance networks (SCNs) can be used to detect morphological changes with high accuracy. We recruited 30 individuals with epilepsy and comorbid migraine without aura (EM), along with 20 healthy controls (HC) and 30 epilepsy controls (EC) without migraine. We used VBM, SBM, and SCN analysis to compare differences in gray matter volume, cortical thickness, and global level and local level graph theory indexes between the EM, EC, and HC groups to investigate structural brain changes in the EM patients. VBM analysis showed that the EM group had gray matter atrophy in the right temporal pole compared with the HC group (p < 0.001, false discovery rate correction [FDR]). Furthermore, the headache duration in the EM group was negatively correlated with the gray matter volume of the right temporal pole (p < 0.05). SBM analysis showed cortical atrophy in the left insula, left posterior cingulate gyrus, left postcentral gyrus, left middle temporal gyrus, and left fusiform gyrus in the EM compared with the HC group (p < 0.001, family wise error correction). We found a positive correlation between headache frequency and the cortical thickness of the left middle temporal gyrus (p < 0.05). SCN analysis revealed no differences in global parameters between the three groups. The area under the curve (AUC) of the nodal betweenness centrality in the right postcentral gyrus was lower in the EM group compared with the HC group (p < 0.001, FDR correction), and the AUC of the nodal degree in the right fusiform gyrus was lower in the EM group compared with the EC group (p < 0.001, FDR correction). We found clear differences in brain structure in the EM patients compared with the HC group. Accordingly, migraine episodes may influence brain structure in epilepsy patients. Conversely, abnormal brain structure may be an important factor in the development of epilepsy with comorbid migraine without aura. Further studies are needed to investigate the role of brain structure in individuals with epilepsy and comorbid migraine without aura.

Frontostriatal salience network expansion in individuals in depression

Decades of neuroimaging studies have shown modest differences in brain structure and connectivity in depression, hindering mechanistic insights or the identification of risk factors for disease onset1. Furthermore, whereas depression is episodic, few longitudinal neuroimaging studies exist, limiting understanding of mechanisms that drive mood-state transitions. The emerging field of precision functional mapping has used densely sampled longitudinal neuroimaging data to show behaviourally meaningful differences in brain network topography and connectivity between and in healthy individuals2–4, but this approach has not been applied in depression. Here, using precision functional mapping and several samples of deeply sampled individuals, we found that the frontostriatal salience network is expanded nearly twofold in the cortex of most individuals with depression. This effect was replicable in several samples and caused primarily by network border shifts, with three distinct modes of encroachment occurring in different individuals. Salience network expansion was stable over time, unaffected by mood state and detectable in children before the onset of depression later in adolescence. Longitudinal analyses of individuals scanned up to 62 times over 1.5 years identified connectivity changes in frontostriatal circuits that tracked fluctuations in specific symptoms and predicted future anhedonia symptoms. Together, these findings identify a trait-like brain network topology that may confer risk for depression and mood-state-dependent connectivity changes in frontostriatal circuits that predict the emergence and remission of depressive symptoms over time.

Comparative study on structural and functional brain differences in mild cognitive impairment patients with tinnitus.

Tinnitus may be associated with various brain changes. However, the degenerative changes in patients with tinnitus have not been extensively investigated. We aimed to evaluate degenerative, structural, and functional brain changes in patients with mild cognitive impairment (MCI) who also suffer from tinnitus. This study included participants aged 60 to 80 years with MCI and a hearing level better than 40 dB. The participants were classified into two groups: MCI with tinnitus (MCI-T) and MCI without tinnitus (MCI-NT). All patients underwent Tinnitus Handicap Inventory (THI), 3 T brain MRI, F18-florapronol PET, and F18-FDG PET. The MCI-T group exhibited higher β-amyloid deposition in the superior temporal gyrus, temporal pole, and middle temporal gyrus compared to the MCI-NT group (p < 0.05 for all). Additionally, the MCI-T group showed increased metabolism in the inferior frontal gyrus, insula, and anterior cingulate cortex (ACC) (p < 0.005 for all). The THI score was strongly correlated with increased volume in the insula, ACC, superior frontal gyrus, supplementary motor area, white matter near the hippocampus, and precentral gyrus (p < 0.05 for all). Moreover, the MCI-T group demonstrated higher metabolic activity in the default mode network (DMN) and lower activity in the executive control network (ECN) (p < 0.05 for all). In the MCI-T group, the posterior DMN was positively correlated with the visual network and negatively with the ECN, whereas in the MCI-NT group, it correlated positively with the ECN. The MCI-T group exhibited greater β-amyloid accumulation in the auditory cortex and more extensive changes across various brain networks compared with the MCI-NT group, potentially leading to diverse clinical symptoms such as dementia with semantic deficits or depression. Tinnitus in MCI patients may serve as a biomarker for degenerative changes in the temporal lobe and alterations in brain network dynamics.