Lower Gray Matter Volume Research Articles

Glucometabolic Changes Are Associated with Structural Gray Matter Alterations in Prodromal Dementia.

Glucometabolic changes, such as high glycemic load (GL) diet and insulin resistance (IR), are potential risk factor of Alzheimer's disease (AD). Yet, the effect of these factors on brain alterations that contribute to AD pathology has not been clearly demonstrated. We aimed to assess the relationship of GL and IR with gray matter volumes involved in prodromal dementia. GL and Triglyceride-Glucose (TyG) index, an IR surrogate marker, were calculated in 497 participants who underwent magnetic resonance imaging (MRI). The gray matter volumes most related to prodromal dementia/mild cognitive impairment (diagnosed in 18/158 participants during the 7-year follow-up) were identified using a data-driven machine learning algorithm. Higher GL diet was associated with reduced amygdala volume. The TyG index was negatively associated with the hippocampus, amygdala, and putamen volumes. These results suggest that GL and IR are associated with lower gray matter volumes in brain regions involved in AD pathology.

Common and distinct fronto-striatal volumetric changes in heroin and cocaine use disorders.

Different drugs of abuse impact the morphology of fronto-striatal dopaminergic targets in both common and unique ways. While dorsal striatal volume tracks with addiction severity across drug classes, opiates impact ventromedial prefrontal cortex (vmPFC) and nucleus accumbens (NAcc) neuroplasticity in preclinical models, and psychostimulants alter inhibitory control, rooted in cortical regions such as the inferior frontal gyrus (IFG). We hypothesized parallel grey matter volume changes associated with human heroin or cocaine use disorder: lower grey matter volume of vmPFC/NAcc in heroin use disorder and IFG in cocaine use disorder, and putamen grey matter volume to be associated with addiction severity measures (including craving) across both. In this cross-sectional study, we quantified grey matter volume (P < 0.05-corrected) in age/sex/IQ-matched individuals with heroin use disorder (n = 32, seven females), cocaine use disorder (n = 32, six females) and healthy controls (n = 32, six females) and compared fronto-striatal volume between groups using voxel-wise general linear models and non-parametric permutation-based tests. Overall, individuals with heroin use disorder had smaller vmPFC and NAcc/putamen volumes than healthy controls. Bilateral lower IFG grey matter volume patterns were specifically evident in cocaine versus heroin use disorders. Correlations between addiction severity measures and putamen grey matter volume did not reach nominal significance level in this sample. These results indicate alterations in dopamine-innervated regions (in the vmPFC and NAcc) in heroin addiction. For the first time we demonstrate lower IFG grey matter volume specifically in cocaine compared with heroin use disorder, suggesting a signature of reduced inhibitory control, which remains to be tested directly using select behavioural measures. Overall, results suggest substance-specific volumetric changes in human psychostimulant or opiate addiction, with implications for fine-tuning biomarker and treatment identification by primary drug of abuse.

P.63 Comparison of brain volume reduction in boys with Duchenne muscular dystrophy treated with different corticosteroid regimes

Recent studies show lower gray matter volumes and altered white matter networks in boys with Duchenne Muscular Dystrophy (DMD) compared with healthy controls, suggesting a lack of dystrophin impacts brain structures. However, the majority of boys with DMD are chronically treated with corticosteroids (CS), which are known to cross the blood-brain barrier and cause brain atrophy. Unraveling the impact of CS treatment on the brain of boys with DMD is key to understand brain involvement in this disease. This study compared two groups of DMD boys treated with a different CS regimen with 2 healthy control groups. 3D T1-weighted images were obtained on a 3T Philips system at two different sites. Scans from 20 DMD patients (13.0±3.1y) on a 10 days on/10 days off prednisolone schedule and 20 age-matched controls (13.2±1.8y) were obtained at the LUMC Leiden, the Netherlands. Additionally scans of 20 age-matched DMD patients (12.8±3.0y) on a daily deflazacort regime and 20 age-matched controls (13.1±3.2y) were acquired at the UZ Leuven, Belgium. All 80 scans were processed using FSL software to calculate intracranial (ICV), total brain (TBV), grey matter (GMV), white matter (WMV) and CSF volumes. In addition, volumes of the hippocampus, amygdala, thalamus, nucleus accumbens, caudate nucleus, globus pallidus and putamen were calculated. To control for intracranial volume differences, relative volumes were compared between controls and DMD per center using univariate analyses of variances in SPSS and considered significant at p<0.05. Both DMD groups showed a significant lower relative GMV, and higher relative CSF volume compared to their control groups. Interestingly, a significantly lower relative WMV (33.81% vs 35.45%, p=.002) and relative volume of the globus pallidus (0.25% vs 0.22%, p<.001) was found in the deflazacort group compared with their control group, but not in the prednisolone group. This study suggest that different CS regimes lead to different regional brain volume reductions in patients with DMD.

The genetic influence of the DRD3 rs6280 polymorphism (Ser9Gly) on functional connectivity and gray matter volume of the hippocampus in patients with first-episode, drug-naïve schizophrenia

The D3 dopamine receptor (DRD3) plays a major role in cognitive function and is a candidate gene for schizophrenia. DRD3 is widely distributed in the hippocampus, but whether there are potential associations between the rs6280 genotype, the hippocampus, and cognitive function in first-episode, drug-naïve (FES) patients and healthy controls (HCs) is still poorly understood. First, using functional and structural magnetic resonance imaging data, we calculated the gray matter volume (GMV) and functional connectivity (FC) of the hippocampus. Then, we examined the possible interaction effect of the DRD3 genotype and the disease on the FC and GMV of the hippocampus in 52 FES patients and 51 HCs. Finally, the correlation between the FC and GMV in the hippocampus, influenced by rs6280, and the cognitive performance of subjects was analyzed. A significant interaction effect of diagnostic group by genotype of rs6280 on the GMV of the left hippocampus was found, with lower GMV in FES patients that were C carriers compared with TT homozygotes; the opposite pattern was found in the genetic subgroups of HCs. In the FES group, C carriers performed significantly worse on reasoning and problem-solving tests than TT homozygotes. The left hippocampal GMV positively correlated with reasoning and problem-solving performance in TT homozygotes, but this correlation disappeared in FES patients that were C carriers and in genetic subgroups of HCs. Together, these results suggest that FES patients that are C carriers of rs6280 have lower GMV in the hippocampus, resulting in greater cognitive impairment.

Cerebrovascular reactivity in multiple sclerosis is restored with reduced inflammation during immunomodulation

Cerebrovascular reactivity (CVR) reflects the capacity of the brain’s vasculature to increase blood flow following a vasodilatory stimulus. Reactivity is an essential property of the brain’s blood vessels that maintains nutrient supplies in the face of changing demand. In Multiple Sclerosis (MS), CVR may be diminished with brain inflammation and this may contribute to neurodegeneration. We test the hypothesis that CVR is altered with MS neuroinflammation and that it is restored when inflammation is reduced. Using a breath-hold task during functional Magnetic Resonance Imaging (MRI), we mapped grey matter and white matter CVRs (CVRGM and CVRWM, respectively) in 23 young MS patients, eligible for disease modifying therapy, before and during Interferon beta treatment. Inflammatory activity was inferred from the presence of Gadolinium enhancing lesions at MRI. Eighteen age and gender-matched healthy controls (HC) were also assessed. Enhancing lesions were observed in 12 patients at the start of the study and in 3 patients during treatment. Patients had lower pre-treatment CVRGM (p = 0.04) and CVRWM (p = 0.02) compared to HC. In patients, a lower pre-treatment CVRGM was associated with a lower GM volume (r = 0.60, p = 0.003). On-treatment, there was an increase in CVRGM (p = 0.02) and CVRWM (p = 0.03) that negatively correlated with pre-treatment CVR (GM: r = − 0.58, p = 0.005; WM: r = − 0.60, p = 0.003). CVR increased when enhancing lesions reduced in number (GM: r = − 0.48, p = 0.02, WM: r = − 0.62, p = 0.003). Resolution of inflammation may restore altered cerebrovascular function limiting neurodegeneration in MS. Imaging of cerebrovascular function may thereby inform tissue physiology and improve treatment monitoring.

Brain Morphological and Functional Changes in Adenomyosis with Pain: A Resting State Functional Magnetic Resonance Imaging Study.

The absence of clinically objective methods to evaluate adenomyosis-associated pain and the poor understanding of its pathophysiology lead to treatment limitations. We conducted a resting-state functional magnetic resonance imaging study with 49 patients with pain-related adenomyosis and 30 pain-free controls to investigate brain morphological alterations and regional dysfunctions in patients with pain-related adenomyosis. These patients had significantly higher scores for anxiety and depression than the control group (p < 0.05). They also had a lower gray matter volume (GMV) in the bilateral insula, left angular gyrus, precuneus, left inferior temporal gyrus, and left postcentral gyrus (p < 0.05, AlphaSim corrected). Similarly, decreased voxel-mirrored homotopic connectivity was observed in the bilateral insula, posterior cingulate cortex, middle frontal gyrus, and postcentral gyrus in the adenomyosis patient group (p < 0.05, AlphaSim corrected). Regional homogeneity showed significant differences mainly in the bilateral cerebellum, left inferior frontal gyrus, medial prefrontal cortex, and posterior cingulate gyrus. Correlation analysis showed that the degree of depression in patients with adenomyosis was negatively correlated with the GMV of the left angular gyrus. The results show that these patients exhibited changes in multiple brain regions associated with pain as well as emotion perception and processing.

Immunohistochemical analysis of caspase expression in the brains of individuals with obesity or overweight.

Mechanisms underlying the negative effects of obesity on the brain are still unknown. Obesity is associated with oxidative stress in the brain and neuroinflammation that promotes neurodegenerative diseases. Chronic low-grade neuroinflammation in obesity could be associated with lower volumes of gray matter and lower neuronal density. If neuroinflammation mediated by the expression of cytokines and chemokines leads to apoptosis, this can be assessed by examining caspase expression. The aim of this study was to compare the expression of caspases in the 16 brains of donors with obesity/overweight (n=8; Body Mass Index [BMI]=31.6±4.35kg/m2; 2 females; Age=52.9±4.76years) and normal weight (n=8; BMI=21.8±1.5kg/m2; 3 females; Age=37.8±19.2years). Sixteen human brain samples were processed. Serial paraffin sections were examined by anti-caspase immunochemistry (caspase-3, caspase-4, caspase-6, caspase-1, caspase-8, and caspase-9 antibodies). Postmortem samples of cerebral cortex tissue were captured as photomicrographs and the images obtained were analyzed using ImageJ software to obtain the percentage of positive caspase expression. Nonparametric Mann-Whitney U tests were performed to compare caspase expression between samples from donors with obesity/overweight and normal weight. Taking into consideration the immunohistochemistry results, the Search Tool for the Retrieval of Interacting Genes was used to model molecular interactions. Results showed that brain samples from individuals with obesity/overweight exhibited significantly greater values of positive expression for Caspase-1 (U=16.5, p=0.05, Cohen d=0.89) and -8 (U=15, p=0.03, Cohen d=0.99) than those from donors with normal weight. This study contributes to the knowledge about the inflammatory effects of obesity/overweight on brain, suggesting theactivation of the alternative inflammasome pathway in which interact caspase-1 and -8.

Brain, cognitive, and physical disability correlates of decreased quality of life in patients with Huntington’s disease

PurposeFollowing a case–control design, as a primary objective, this study aimed to explore the relationship between quality of life (QoL) scores and gray matter (GM) volumes in patients with Huntington’s disease (HD). As a secondary objective, we assessed the relationship between QoL scores and other important behavioral, clinical and demographical variables in patients with HD and HD patients’ caregivers.MethodsWe recruited 75 participants (25 HD patients, 25 caregivers, and 25 controls) and assessed their QoL using the World Health Organization Quality of Life scale-Brief Version (WHOQOL-BREF). Participants were also assessed with general cognitive functioning tests and clinical scales. In addition, we acquired MRI scans from all participants.ResultsOur results showed that patients exhibited significantly lower scores in all four QoL domains (physical health, psychological wellbeing, social relationships, and relationship with the environment) compared to caregivers and controls. Caregivers showed lower scores than controls in the physical health and the environmental domains. In HD patients, lower scores in QoL domains were associated with lower GM volumes, mainly in the precuneus and the cerebellum. Moreover, in HD patients, physical disability and GM volume reduction were significant predictors of QoL decrease in all domains. For caregivers, years of formal education was the most important predictor of QoL.ConclusionsHD patients exhibit greater GM volume loss as well as lower QoL scores compared to caregivers and controls. However, caregivers displayed lower scores in QoL scores than controls, with years of education being a significant predictor. Our results reflect a first attempt to investigate the relationships among QoL, GM volumes, and other important factors in an HD and HD caregiver sample.

Processing speed mediates the relationship between brain structure and semantic fluency in aging

The present study has investigated how brain structure and processing speed contribute to age-related changes in semantic fluency. Groups of younger (N = 37) and older healthy participants (N = 40) completed a semantic fluency test and digit symbol test, and rested while diffusion tensor imaging (DTI) was performed. Group comparisons and correlational analysis revealed that age-related decline in semantic fluency was associated with reduction in gray matter volume in widespread fronto-temporal regions. Age-related decline in semantic fluency was also associated with decline in white matter integrity in brain tracts connecting these brain regions. Critically, hierarchical regression analysis suggested that low processing speed fully mediated the negative effects of lower gray matter volume and white matter integrity on semantic fluency. The present findings provide a support for the processing speed theory in relation to age related decline in semantic fluency, and also provide a reference for improving cognitive decline.

Altered gray matter volume in children with newly diagnosed type 1 diabetes mellitus.

Type 1 diabetes mellitus (T1DM) affects the development of cognitive function in children, which may be due to deficits in brain structures or functions. It is unclear whether children with T1DM experience alterations in the gray matter (GM) structure at the initial stages of the disease. This study investigated GM structure alterations in children with newly diagnosed T1DM. Based on 3D T1-weighted MR images, we investigated the gray matter volume (GMV) of 35 newly diagnosed T1DM children and 35 age- and sex-matched healthy controls using voxel-based morphometry. The brain regions with significant differences in GMV between the newly diagnosed T1DM children and the controls were extracted and the correlation with clinical data was assessed. Compared with the control group, children with newly diagnosed T1DM had a lower GMV in the right inferior and middle temporal gyri, right lingual gyrus, and left superior frontal gyrus. In T1DM subjects, the GMV of the right middle temporal gyrus was positively correlated with IQ but was negatively correlated with HbA1c. Our findings provide compelling evidence that GM abnormalities occur during early disease stages in T1DM children, which may be a potential neurobiological mechanism underlying cognitive deficits. Using an efficient method to analyze gray matter changes in T1DM is very important. The anterior, posterior, and temporal brain regions are susceptible to T1DM in children. Recent glucose variability may affect regional gray matter volume in children with newly diagnosed T1DM. Structural changes were documented in the gray matter of the brain even at the early stages of the disease in children with T1DM.

Differences in Brain Volume by Tooth Loss and Cognitive Function in Older Japanese Adults

BackgroundWe investigated the association between tooth loss and structural brain volume and its mediating effect on the association between tooth loss and cognitive function in older Japanese. MethodsA cross-sectional study was conducted by using the data of 494 randomly sampled community-dwelling individuals aged 65–84 years living in Tokamachi City, Japan. Total brain volume (TBV), gray matter volume (GMV), white matter volume (WMV), and hippocampal volume (HV) were measured with magnetic resonance imaging. The association of self-reported number of teeth (≥20, 1–19, and 0) with cognitive function assessed with the Japanese version of the Quick Mild Cognitive Impairment screen and structural brain volume was examined. Causal mediation analysis was performed to evaluate the mediating effect of structural brain volume. Age, sex, socioeconomic status, health behavior, comorbid conditions, and total intracranial volume were adjusted. ResultsRespondents with no teeth showed lower cognitive function (coefficient = −4.01; 95% confidence interval [CI]: −7.19, −0.82), lower TBV (coefficient = −10.34; 95% CI: −22.84, 2.17), and lower GMV (coefficient = −6.92; 95% CI: −14.84, 0.99) than those with ≥20 teeth (P for trends were 0.003, 0.035, and 0.047, respectively). The number of teeth was not significantly associated with WMV or HV. GMV showed a significant mediating effect on the association between the number of teeth and cognitive function (coefficient = −0.38; 95% CI: −1.14, −0.002, corresponding to 9.0% of the total effect), whereas TBV did not. ConclusionsGMV was suggested to mediate the relationship between tooth loss and lower cognitive function.

The neural substrates of sex differences in balanced time perspective: A unique role for the precuneus.

Sex differences in various aspects of behaviour and cognition have been widely observed. Few studies, however, have explored potential sex differences in maintaining a balanced time perspective or their underlying neural correlates. To address these questions, two studies were conducted. In Study 1, time perspective was assessed in 1913 college students (796 males and 1117 females), revealing that females had a significantly more balanced time perspective relative to males. In Study 2, 58 males and 47 females underwent an assessment of time perspective and structural brain imaging. Voxel-based morphometry analysis and cortical thickness analysis were conducted to explore associations between the structural imaging data and balanced time perspective. Compared with males, females demonstrated a more balanced time perspective in the context of lower grey matter volume in the bilateral precuneus, right cerebellum, right putamen and left supplementary motor area. Analysis of cortical thickness failed to reveal any significant sex differences. Furthermore, lower grey matter volume of bilateral precuneus was associated with more balanced time perspective among all participants. Our findings point to a critical role for the precuneus in modulating a balanced time perspective, and extend our understanding of sex differences in human cognition. Future studies are required to determine whether sex differences in balanced time perspective are predictive of functional outcomes in daily life.

Convergent and divergent gray matter volume abnormalities in unaffected first-degree relatives and ultra-high risk individuals of schizophrenia

High-risk populations of schizophrenia can be mainly identified as genetic high-risk based on putative endophenotypes or ultra-high-risk (UHR) based on clinically manifested symptoms. Previous studies have consistently shown brain structural abnormalities in both genetic high-risk and UHR individuals. In this study, we aimed to disentangle the convergent and divergent pattern of gray matter alterations between UHR and unaffected first-degree relatives from genetic high-risk individuals. We used structural MRI scans and voxel-based morphometry method to examine gray matter volume (GMV) differences among 23 UHR subjects meeting the Structured Interview for Prodromal Syndromes (SIPS) criteria, 18 unaffected first-degree relatives (UFDR), 26 first-episode schizophrenia patients (FES) and 54 healthy controls (CN). We found that a number of brain regions exhibited a monotonically decreasing trend of GMV from CN to UFDR to UHR to FES. Compared with CN, the UHR subjects showed significant decreases of GMV similar to the patients in the inferior temporal gyrus, fusiform gyrus, middle occipital gyrus, insula, and limbic regions. Moreover, the UHR transformed subgroup had significantly lower GMV than UHR non-transformed subgroup in the right inferior temporal/fusiform gyrus. On the other hand, the UFDR subjects only showed significant GMV decreases in the inferior temporal gyrus and fusiform. Moreover, we found GMV in the occipital lobe was negatively correlated with the UHR subjects’ composite positive symptom of SIPS, and GMV in the cerebellum was positively correlated with FES subjects’ symptom severity. Our results suggest that GMV deficits and regional dysfunction are evident prior to the onset of psychosis and are more prominent in the UHR than the UFDR individuals.

Gray Matter Brain Alterations in Type 1 Diabetes - Findings Based on Detailed Phenotyping of Neuropathy Status.

This study investigated brain structure in patients of type 1 diabetes with diabetic peripheral neuropathy (DPN) and type 1 diabetes with neuropathic pain and the associations to clinical, peripheral, and cognitive measurements. Sixty individuals with type 1 diabetes and 20 healthy controls were included in the study. Nineteen individuals with type 1 diabetes and neuropathic pain, 19 with type 1 diabetes and DPN, 18 with type 1 diabetes without DPN, and 20 healthy controls were included in the brain analyses. We utilized structural brain magnetic resonance imaging to investigate total and regional gray matter volume. Significant lower gray matter volume was found in type 1 diabetes with neuropathic pain and in type 1 diabetes without DPN compared to healthy controls (p=0.024 and p=0.019, respectively). Lower insula volume was observed in all three diabetes groups (all p≤0.050). Thalamus and hippocampus volume was lower in type 1 diabetes with neuropathic pain, cerebellum volume was lower in type 1 diabetes with DPN, and somatosensory cortex volume was lower in type 1 diabetes without DPN (all p≤0.018). Attenuated memory was associated with lower gray matter volume in type 1 diabetes with DPN. No associations were found between gray matter volume and clinical/peripheral measurements. We demonstrated lower gray matter volume in individuals with type 1 diabetes regardless of the presence of DPN and neuropathic pain. Hence, central gray matter alteration was not associated with peripheral alterations.

Association between somatosensory sensitivity and regional gray matter volume in healthy young volunteers: a voxel-based morphometry study.

Two-point discrimination (2PD) test reflects somatosensory spatial discrimination ability, but evidence on the relationship between 2PD and cortical gray matter (GM) volume is limited. This study aimed to analyze the relationship between cortical GM volume and 2PD threshold in young healthy individuals and to clarify the characteristics of brain structure reflecting the individual differences in somatosensory function. 2PD was measured in 42 healthy (20 females) volunteers aged 20-32years using a custom-made test system that can be controlled by a personal computer. The 2PD of the right index finger measured with this device has been confirmed to show good reproducibility. T1-weighted images were acquired using a 3-T magnetic resonance imaging scanner for voxel-based morphometry analysis. The mean 2PD threshold was 2.58 ± 0.54mm. Whole-brain multiple regression analysis of the relationship between 2PD and GM volume showed that a lower 2PD threshold (i.e. better somatosensory function) significantly correlated with decreased GM volume from the middle temporal gyrus to the inferior parietal lobule (IPL) in the contralateral hemisphere. In conclusion, a lower GM volume in the middle temporal gyrus and IPL correlates with better somatosensory function. Thus, cortical GM volume may be a biomarker of somatosensory function.

Variable Voxel-based Morphometry Observations of Gray Matter Differences in Fibromyalgia: Individual Differences or Methodological Inconsistency?

Fibromyalgia is a prevalent chronic pain condition characterized by widespread pain and sensory hypersensitivity. While much remains to be learned about the neurobiological underpinnings of this condition, alterations to the central nervous system appear to be heavily implicated in fibromyalgia's pathophysiology. Previous research examining brain structural abnormalities among fibromyalgia patients has yielded inconsistent findings. Thus, we followed previous voxel-based morphometry methods in magnetic resonance imaging to examine brain gray matter differences in females (n=17) with fibromyalgia and female healthy controls (n=17). We hypothesized that, relative to healthy control participants, fibromyalgia participants would exhibit lower gray matter volume in regions consistently implicated in pain processing and, specifically, fibromyalgia: the anterior cingulate cortex and the medial prefrontal cortex. Previously reported peak coordinates are located in both the anterior cingulate cortex (ACC) and medial prefrontal cortex (mPFC), but interpretation of these locations is varied. Therefore, we first examined a large region of interest that encompassed both the mPFC and ACC, followed by a whole brain analysis. Group differences were analyzed with two-sample t-tests, controlling for total intracranial volume. No significant differences in regional or whole brain gray matter volumes were detected between fibromyalgia patients and healthy controls. These results add to an existing body of disparate findings regarding brain gray matter volume differences in fibromyalgia, and suggest structural differences previously detected among fibromyalgia patients should be rigorously examined for reproducibility and support the need for additional meta-analyses. Absent significant differences may also suggest that individual differences, rather than methodological variability, account for contradictory results. Grant support from K99DA040154.

Structural and Functional Correlates of Higher Cortical Brain Regions in Chronic Refractory Cough

Chronic refractory cough significantly impairs the psychological and social aspects of quality of life. Loss of inhibitory control is suggested as a potential central neurobiological mechanism underlying chronic refractory cough. Do structural and functional changes related to chronic cough occur in higher cortical brain regions? The structural and resting-state functional alterations in the brains of 15 patients with chronic refractory cough and 15 age- and sex-matched healthy control participants were evaluated. Gray matter volumes of the whole brain were measured using voxel-based morphometry based on T1-weighted MRI. Intrinsic functional connectivity within large-scale brain networks was examined on resting-state functional MRI. Correlation analyses were performed to examine the relationships of these brain changes with duration, severity, and impact of cough. Compared with healthy control participants, patients with chronic refractory cough demonstrated a lower gray matter volume in the left frontal cluster and enhanced functional connectivity within the left frontoparietal network, which were associated with greater cough scores. Furthermore, enhanced functional connectivity within the left frontoparietal network was associated with a greater psychological and social impact of coughing. Lower left frontal gray matter volume was associated with longer cough duration. Structural and functional alterations in the left frontal brain regions may be implicated in the psychological and social impact and disease duration of chronic refractory cough. Our findings provide new perspectives on developing interventional approaches targeting the cognitive modulation of chronic coughing.

Brain magnetic resonance imaging findings and brain volumetric differences in a large series of benign rolandic epilepsy.

Several studies with a small sample size have investigated the relationship between structural and functional changes on MRI and the clinical and natural history of BRE. We aim to assess the frequency of incidental epileptogenic lesions on brain MRI in a large cohort of patients diagnosed with BRE and to assess the difference in volumetric brain measurements in BRE patients compared to healthy controls. The case-control study includes 214 typical BRE cases and 197 control children with non-epileptic spells. Brain MRIs were evaluated for abnormalities which were classified into normal and abnormal with or without epileptogenic lesions with categorization of epileptogenic lesions. Brain segmentation was also performed for a smaller group of BRE patients and another healthy control group. Pearson's chi-squared test and two-tailed independent samples t-test were used. In patients with BRE, 7% had an epileptogenic lesion on their MRI. The frequency of epileptogenic lesion in the control group was 10.2% and not significantly different from those with BRE (p= 0.2). Significantly higher intracranial and white matter volumes were found in BRE patients compared to the healthy group while lower gray matter volume was found in BRE patients. Cortical and subcortical regions showed either higher or lower volumes with BRE. Interestingly, altered subcallosal cortex development which has a known association with depression was also found in BRE. Our findings confirm the absence of any association between specific brain MRI abnormalities and BRE. However, the altered cortical and subcortical development in BRE patients suggests a microstructural-functional correlation.

Relationships between Personality Traits and Brain Gray Matter Are Different in Risky and Non-risky Drivers.

Personality traits such as impulsivity or sensitivity to rewards and punishments have been associated with risky driving behavior, but it is still unclear how brain anatomy is related to these traits as a function of risky driving. In the present study, we explore the neuroanatomical basis of risky driving behavior and how the level of risk-taking influences the relationship between the traits of impulsivity and sensitivity to rewards and punishments and brain gray matter volume. One hundred forty-four participants with different risk-taking tendencies assessed by real-life driving situations underwent MRI. Personality traits were assessed with self-report measures. We observed that the total gray matter volume varied as a function of risky driving tendencies, with higher risk individuals showing lower gray matter volumes. Similar results were found for volumes of brain areas involved in the reward and cognitive control networks, such as the frontotemporal, parietal, limbic, and cerebellar cortices. We have also shown that sensitivity to reward and punishment and impulsivity are differentially related to gray matter volumes as a function of risky driving tendencies. Highly risky individuals show lower absolute correlations with gray matter volumes than less risk-prone individuals. Taken together, our results show that risky drivers differ in the brain structure of the areas involved in reward processing, cognitive control, and behavioral modulation, which may lead to dysfunctional decision-making and riskier driving behavior.

Brainstem atrophy is linked to extrapyramidal symptoms in frontotemporal dementia

Extrapyramidal (EP) symptoms are a known feature in a subpopulation of patients with behavioral variant frontotemporal dementia (bvFTD). Concomitant EP symptoms with FTD-like neuropsychiatric symptoms are also core features in progressive supranuclear palsy (PSP) and corticobasal degeneration (CBD). This complicates the early diagnosis of these disorders. Our retrospective register study aimed to discover imaging (MRI and FDG-PET) biomarkers to differentiate PSP, CBD, and bvFTD patients with extrapyramidal symptoms (EP +) from bvFTD patients without EP symptoms (EP-). The records of 2751 patients were screened for the diagnoses and presence of EP symptoms. A total of 222 patients were submitted to imaging analysis and applicable imaging data were recovered from 139 patients. Neuroimaging data were analyzed using Freesurfer software. In the whole cohort, EP + patients showed lower volumes of gray matter compared to EP- patients in the putamen (p = 0.002), bilateral globus pallidum (p = 0.002, p = 0.042), ventral diencephalon (p = 0.002) and brain stem (p < 0.001). In the bvFTD subgroup, there was volumetric difference between EP + and EP− patients in the brain stem. FDG-PET scans in the bvFTD patient subgroup showed that EP + patients had comparative hypometabolism of the superior cerebellar peduncle (SCP) and the frontal lobes. We discovered that EP symptoms are linked to brainstem atrophy in bvFTD patients and the whole cohort. Also, evident hypometabolism in the SCP of bvFTD EP + patients was detected as compared to bvFTD EP− patients. This could indicate that the EP symptoms in these diseases have a more caudal origin in the brainstem than in Parkinson’s disease.