Reduced Brain Volume Research Articles

Brain cortical assessment by MRI in fetuses with left congenital diaphragmatic hernia Brain development in left congenital diaphragmatic hernia.

To evaluate fetal brain development using MRI (magnetic resonance imaging) in CDH (congenital diaphragmatic hernia). 52 isolated left CDH and 104 control fetuses were imaged using MRI. Brain morphometry (Biparietal diameter - BPD, brain fronto-occipital diameter - BFOD, third ventricle, posterior ventricles, transcerebellar diameter - TCD, anteroposterior and craniocaudal cerebellar vermis diameter - AP and CC) and cortical structures (bilateral cingulate fissure - CF, insular fissure - IF, insular depth - ID) were compared with controls using Mann-Whitney test . Median gestational age at MRI was comparable (p=0.95), as well as was the median biparietal diameter (p=0.737). Among morphometric parameters only the brain fronto-occipital diameter was significantly smaller in CDH (p= 0.001) and the third ventricle was significantly greater in CDH (<0.0001). Among cortical structures, the cingulate and insular fissure were significantly deeper in CDH fetuses (p<0.0001), as the insular depth ID was smaller in CDH (p< 0.03). CDH fetuses have a smaller fronto-occipitaldiameter, reduced insular depth, and deeper cingulate and insular fissure, and greater third ventricle width as compared to controls. These findings suggest that left CDH may have an impact on fetal brain development with an overall reduction of brain volume. This article is protected by copyright. All rights reserved.

The histostereological teratogenic effects of in-utero exposure to varied doses of lamotrigine on the developing fetal brain in albino rats (Rattus Norvegicus)

The histoqualitative teratogenic effects of lamotrigine, a second-line anticonvulsant medicine, on the developing fetal brain structures when exposed in utero in a time- and dose-dependent manner remain unclear. On the other hand, lamotrigine is currently being widely prescribed as a first-line medicine in the management of maternal conditions like epileptic seizures and bipolar disorders, among others. The preferential use of lamotrigine is attributed to the considerations of its efficacy, tolerability, and minimal teratogenic effects on fetal organs like the brain, among others, though with insufficient supportive data. The aim of this study was therefore to evaluate the histo-quantitative effects of lamotrigine on the developing fetal brain structures when exposed in utero at varying dosages during different trimesters. The study adopted a post-test only experimental study design where a sample size of 30 sexually mature albino rat dams of the species (Rattus norvegicus) weighing between 250 + 30 grams was used. The rats were divided into two broad groups: 3 control rats and 27 dosage rats. The data collected was coded in Excel spreadsheets and analyzed in SPSS. Results were expressed as the mean + standard error of the mean (SEM), and values with a P &lt; 0.05 were considered to be significant. Study findings depicted a reduction in brain weights, length, width, volumes, and volume densities of cortical and subcortical layers in a dose- and time-dependent manner. High lamotrigine dosages, especially during the first and second trimesters, were observed to be associated with significant mean reductions in the brain weights, length, width, volumes, and volume densities of the developing fetal brain structures. Therefore, further studies with higher primates closer to the human species as well as clinical trials are recommended to rule out the safety index of lamotrigine during pregnancy.

The Spectrum of Neurological and Sensory Abnormalities in Gaucher Disease Patients: A Multidisciplinary Study (SENOPRO).

Gaucher disease (GD) has been increasingly recognized as a continuum of phenotypes with variable neurological and sensory involvement. No study has yet specifically explored the spectrum of neuropsychiatric and sensory abnormalities in GD patients through a multidisciplinary approach. Abnormalities involving the nervous system, including sensory abnormalities, cognitive disturbances, and psychiatric comorbidities, have been identified in GD1 and GD3 patients. In this prospective study, named SENOPRO, we performed neurological, neuroradiological, neuropsychological, ophthalmological, and hearing assessments in 22 GD patients: 19 GD1 and 3 GD3. First, we highlighted a high rate of parkinsonian motor and non-motor symptoms (including high rates of excessive daytime sleepiness), especially in GD1 patients harboring severe glucocerebrosidase variants. Secondly, neuropsychological evaluations revealed a high prevalence of cognitive impairment and psychiatric disturbances, both in patients initially classified as GD1 and GD3. Thirdly, hippocampal brain volume reduction was associated with impaired short- and long-term performance in an episodic memory test. Fourthly, audiometric assessment showed an impaired speech perception in noise in the majority of patients, indicative of an impaired central processing of hearing, associated with high rates of slight hearing loss both in GD1 and GD3 patients. Finally, relevant structural and functional abnormalities along the visual system were found both in GD1 and GD3 patients by means of visual evoked potentials and optical coherence tomography. Overall, our findings support the concept of GD as a spectrum of disease subtypes, and support the importance of in-depth periodic monitoring of cognitive and motor performances, mood, sleep patterns, and sensory abnormalities in all patients with GD, independently from the patient's initial classification.

Biopsychological trait markers supporting the stress-diathesis model in functional neurological disorders. (S51.010)

<h3>Objective:</h3> To shed light on the underlying neurobiological mechanisms of functional neurological disorders (FND), we analysed the relationship between potential dysregulation of the Hypothalamic-Pituitary Adrenal (HPA) axis, trauma history, and structural brain abnormalities. <h3>Background:</h3> Stress is a well-known risk factor to develop FND. Only little is known about the biological stress regulation, and what might be the role of predisposing biological and psychosocial risk factors. <h3>Design/Methods:</h3> We set out to study the HPA axis analysing the cortisol awakening response and diurnal baseline cortisol in 86 patients with mixed functional neurological symptoms compared to 76 healthy controls. We then examined the association between cortisol regulation and severity and duration of traumatic life events. Finally, we analysed volumetric brain alterations in brain regions particularly sensitive to psychosocial stress, acting on the assumption of the neurotoxic effect of prolonged cortisol exposure. <h3>Results:</h3> Overall, patients had a significantly flatter cortisol awakening response (<i>P</i> &lt; 0.001) and reported longer (<i>P</i> = 0.01) and more severe (<i>P</i> &lt; 0.001) emotional neglect as compared to heathy controls. Moreover, volumes of bilateral hippocampus and amygdala were found to be reduced in patients. Using a partial least squares correlation, we found that in patients, emotional neglect plays a role in the multivariate pattern between trauma history and HPA axis dysfunction, whilst cortisol did not relate to reduced brain volumes. <h3>Conclusions:</h3> In summary, this study supports a stress-diathesis model for FND and showed an association between different attributes of trauma history and abnormalities in HPA-axis function. Moreover, we suggest that reduced hippocampal- and amygdalar volumes represent a biological ‘trait marker’ for FND patients, which might contribute to a reduced resilience to stress. <b>Disclosure:</b> Mrs. Weber has nothing to disclose. Mrs. Bühler has nothing to disclose. Mr. Loukas has nothing to disclose. Dr. Aybek has received personal compensation in the range of $500-$4,999 for serving as an officer or member of the Board of Directors for Swiss Movement Disorder Foundation. The institution of Dr. Aybek has received research support from Swiss National Science Foundation.

Fragile-X-associated Tremor/Ataxia Syndrome in a Woman with Full Mutation: A Case Report (P5-11.009)

<h3>Objective:</h3> To describe the first case of FXTAS in a full mutation woman without Fragile X syndrome. <h3>Background:</h3> Fragile-X-associated tremor/ataxia syndrome (FXTAS) is caused by expanded trinucleotide (CGG) repeats between 55–199 (premutation) in the <i>Fragile X Mental Retardation 1 (FMR1) gene</i>. Core clinical features of FXTAS include cerebellar ataxia, intention tremor and Parkinsonism. In contrast, a full mutation of CGG repeats&gt;200 repeats with methylation of the gene leads to fragile X syndrome, which is characterized by early intellectual disability, autistic features, and seizures. <i>FMR1</i> premutation carrier women presenting as FXTAS have been reported. This is the first report of a woman with a full mutation presenting with FXTAS. <h3>Design/Methods:</h3> N/A <h3>Results:</h3> A 65-year-old woman presented with problems with dexterity and shuffling gait. The patient also complained of urinary urgency, constipation, anxiety, depression, and mild cognitive complaints. The patient’s son was diagnosed with fragile X syndrome at 14 months. Neurological exam of the patient showed parkinsonism, action tremor and limb ataxia. MRI brain demonstrated chronic ischemic small vessel disease and mildly reduced brain volume. <i>FMR1 CGG</i> repeat sizes were 20 and &gt;200. The 20 repeat allele was seen on the active X chromosome (representing non-random X-inactivation), while the &gt;200 repeat allele was fully methylated on Southern blot. Testing for Parkinson’s disease-associated genes were negative. <h3>Conclusions:</h3> This is the first report of a woman with a <i>FMR1</i> full mutation presenting with signs and symptoms of FXTAS. Several cases of FXTAS have been reported in <i>FMR1</i> full mutation men with fragile X syndrome due to mosaicism of repeat sizes and the presence of a premutation allele. Full mutation adults with complete methylation have not been reported to have FXTAS. The clinical presentation of this case might be due to size or methylation mosaicism in brain. Alternatively, one could also consider a different disease mimicking FXTAS. <b>Disclosure:</b> Dr. Kazanci has nothing to disclose. The institution of Dr. Berry-Kravis has received research support from NIH. The institution of Dr. Berry-Kravis has received research support from Ovid. The institution of Dr. Berry-Kravis has received research support from Zynerba. The institution of Dr. Berry-Kravis has received research support from Roche. The institution of Dr. Berry-Kravis has received research support from CDC. The institution of Dr. Berry-Kravis has received research support from FRAXA Research Foundation. The institution of Dr. Berry-Kravis has received research support from GeneTx. The institution of Dr. Berry-Kravis has received research support from Angelman Syndrome Foundation. The institution of Dr. Berry-Kravis has received research support from Acadia. The institution of Dr. Berry-Kravis has received research support from GW. The institution of Dr. Berry-Kravis has received research support from Anavex. The institution of Dr. Berry-Kravis has received research support from Rett Syndrome Research Trust. The institution of Dr. Berry-Kravis has received research support from Ultragenyx. The institution of Dr. Berry-Kravis has received research support from Mallinckrodt. The institution of Dr. Berry-Kravis has received research support from Together Strong Foundation. The institution of Dr. Berry-Kravis has received research support from Orphazyme. The institution of Dr. Berry-Kravis has received research support from Ionis. The institution of Dr. Berry-Kravis has received research support from Taysha. The institution of Dr. Berry-Kravis has received research support from Erydel. The institution of Dr. Berry-Kravis has received research support from Tetra. The institution of Dr. Berry-Kravis has received research support from Neuren. The institution of Dr. Berry-Kravis has received research support from FRAXA Research Foundation. Dr. Hall has received personal compensation in the range of $10,000-$49,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for American Academy of Neurology. Dr. Hall has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Elsevier - Parkinsonism and Related Disorders. Dr. Hall has received personal compensation in the range of $500-$4,999 for serving as an Editor, Associate Editor, or Editorial Advisory Board Member for Annals of Neurology. The institution of Dr. Hall has received research support from Parkinson’s Foundation. The institution of Dr. Hall has received research support from CHDI. The institution of Dr. Hall has received research support from Biohaven. The institution of Dr. Hall has received research support from Neurocrine. The institution of Dr. Hall has received research support from Uniqure. Dr. Hall has received personal compensation in the range of $500-$4,999 for serving as a Study section with NIH.

Exploring New Imaging Biomarkers: 3D Conformational Analysis Of The Medulla And Upper Cervical Spinal Cord In People With Relapsing Multiple Sclerosis (P11-3.015)

<h3>Objective:</h3> Explore three-dimensional (3D) medulla-upper cervical spinal cord (MUCSC) conformational imaging metrics as biomarkers in multiple sclerosis (MS). <h3>Background:</h3> Measures of spinal cord atrophy are associated with MS disease progression but have yet to emerge as reliable biomarkers of treatment efficacy. 3D MUCSC conformational analysis is a new technique that may provide additional information about neurodegenerative changes in MS beyond conventional magnetic resonance imaging metrics. In the placebo-controlled Phase 3 TEMSO trial (NCT00134563), teriflunomide 14 mg/day lowered the risk of disability worsening and reduced brain volume loss in participants with relapsing MS. 3D MUCSC conformational analysis of the TEMSO dataset has not been explored. <h3>Design/Methods:</h3> TEMSO baseline and 2-year end of study follow-up 3D T1-Magnetization Prepared Rapid Gradient Echo (MP-RAGE) images acquired primarily at 1.5T were assessed for quality, then segmented and analyzed using in-house proprietary software. Change from baseline in MUCSC volume, local curvature and surface texture were summarized with descriptive statistics. <h3>Results:</h3> Quality assessments led to the exclusion of 481 of the 799 TEMSO participants, comprising 64.0%, 62.1%, and 54.5% of participants in the placebo, 7 mg/day, and 14 mg/day arms, respectively. Mean age and disease duration were lower for placebo participants versus teriflunomide arms. No between-group differences were apparent for mean (SD) change from baseline in MUCSC volume (−86±236, −85±218, and −75±218 mm³ for placebo, 7 mg/day, and 14 mg/day arms, respectively), mean curvature (0.01±0.06, 0.02±0.07, and 0.02±0.07 mm), or surface texture (−15.6±28.0, −21.3±26.6, and −19.0±24.2 triangle count). <h3>Conclusions:</h3> 3D conformational analysis of MP-RAGE images from the TEMSO trial showed no discernable between-group differences for MUCSC surface features or volume; however, imbalanced exclusion of participants during quality assessment likely introduced attrition bias. Further development of 3D conformational metrics as MS biomarkers may better illuminate mechanisms related to neurodegenerative changes and treatment efficacy. <b>Disclosure:</b> Miss Moog has nothing to disclose. Janneke Van Wingerden has received personal compensation for serving as an employee of Sanofi Genzyme. Dr. Sanofi has received personal compensation for serving as an employee of Sanofi. Dr. Sanofi has received personal compensation for serving as an employee of Sanofi. Dr. Sanofi has stock in Sanofi. Dr. Sanofi has stock in Sanofi. Dr. Geertsen has received personal compensation for serving as an employee of Sanofi. Dr. Rawlings has received personal compensation for serving as an employee of Sanofi. Dr. Rawlings has stock in Sanofi. Dr. Okuda has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Alexion. Dr. Okuda has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Biogen. Dr. Okuda has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Celgene. Dr. Okuda has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Genzyme. Dr. Okuda has received personal compensation in the range of $500-$4,999 for serving as a Consultant for EMD Serono. Dr. Okuda has received personal compensation in the range of $500-$4,999 for serving as a Consultant for TG Therapeutics. Dr. Okuda has received personal compensation in the range of $500-$4,999 for serving as a Consultant for VielaBio.

Aging-related volume changes in the brain and cerebrospinal fluid using artificial intelligence-automated segmentation

ObjectivesTo verify the reliability of the volumes automatically segmented using a new artificial intelligence (AI)-based application and evaluate changes in the brain and CSF volume with healthy aging.MethodsThe intracranial spaces were automatically segmented in the 21 brain subregions and 5 CSF subregions using the AI-based application on the 3D T1-weighted images in healthy volunteers aged > 20 years. Additionally, the automatically segmented volumes of the total ventricles and subarachnoid spaces were compared with the manually segmented volumes of those extracted from 3D T2-weighted images using the intra-class correlation and Bland–Altman analysis.ResultsIn this study, 133 healthy volunteers aged 21–92 years were included. The mean intra-class correlations between the automatically and manually segmented volumes of the total ventricles and subarachnoid spaces were 0.986 and 0.882, respectively. The increase in the CSF volume was estimated to be approximately 30 mL (2%) per decade from 265 mL (18.7%) in the 20s to 488 mL (33.7%) in ages above 80 years; however, the increase in the volume of total ventricles was approximately 20 mL (< 2%) until the 60s and increased in ages above 60 years.ConclusionsThis study confirmed the reliability of the CSF volumes using the AI-based auto-segmentation application. The intracranial CSF volume increased linearly because of the brain volume reduction with aging; however, the ventricular volume did not change until the age of 60 years and above and then gradually increased. This finding could help elucidate the pathogenesis of chronic hydrocephalus in adults.Key Points• The brain and CSF spaces were automatically segmented using an artificial intelligence-based application.• The total subarachnoid spaces increased linearly with aging, whereas the total ventricle volume was around 20 mL (< 2%) until the 60s and increased in ages above 60 years.• The cortical gray matter gradually decreases with aging, whereas the subcortical gray matter maintains its volume, and the cerebral white matter increases slightly until the 40s and begins to decrease from the 50s.

Counter-gradient variation and the expensive tissue hypothesis explain parallel brain size reductions at high elevation in cricetid and murid rodents

To better understand functional morphological adaptations to high elevation (> 3000 m above sea level) life in both North American and African mountain-associated rodents, we used microCT scanning to acquire 3D images and a 3D morphometric approach to calculate endocranial volumes and skull lengths. This was done on 113 crania of low-elevation and high-elevation populations in species of North American cricetid mice (two Peromyscus species, n = 53), and African murid rodents of two tribes, Otomyini (five species, n = 49) and Praomyini (four species, n = 11). We tested two distinct hypotheses for how endocranial volume might vary in high-elevation populations: the expensive tissue hypothesis, which predicts that brain and endocranial volumes will be reduced to lessen the costs of growing and maintaining a large brain; and the brain-swelling hypothesis, which predicts that endocranial volumes will be increased either as a direct phenotypic effect or as an adaptation to accommodate brain swelling and thus minimize pathological symptoms of altitude sickness. After correcting for general allometric variation in cranial size, we found that in both North American Peromyscus mice and African laminate-toothed (Otomys) rats, highland rodents had smaller endocranial volumes than lower-elevation rodents, consistent with the expensive tissue hypothesis. In the former group, Peromyscus mice, crania were obtained not just from wild-caught mice from high and low elevations but also from those bred in common-garden laboratory conditions from parents caught from either high or low elevations. Our results in these mice showed that brain size responses to elevation might have a strong genetic basis, which counters an opposite but weaker environmental effect on brain volume. These results potentially suggest that selection may act to reduce brain volume across small mammals at high elevations but further experiments are needed to assess the generality of this conclusion and the nature of underlying mechanisms.

Effects of memantine on mania-like phenotypes exhibited by Drosophila Shaker mutants.

Increased glutamate levels and electrolytic fluctuations have been observed in acutely manic patients. Despite some efficacy of the non-competitive NMDA receptor antagonist memantine (Mem), such as antidepressant-like and mood-stabilizer drugs in clinical studies, its specific mechanisms of action are still uncertain. The present study aims to better characterize the Drosophila melanogaster fly Shaker mutants (SH), as a translational model of manic episodes within bipolar disorder in humans, and to investigate the potential anti-manic properties of Mem. Our findings showed typical behavioral abnormalities in SH, which mirrored with the overexpression of NMDAR-NR1 protein subunit, matched well to glutamate up-regulation. Such molecular features were associated to a significant reduction of SH brain volume in comparison to Wild Type strain flies (WT). Here we report on the ability of Mem treatment to ameliorate behavioral aberrations of SH (similar to that of Lithium), and its ability to reduce NMDAR-NR1 over-expression. Our results show the involvement of the glutamatergic system in the SH, given the interaction between the Shaker channel and the NMDA receptor, suggesting this model as a promising tool for studying the neurobiology of bipolar disorders. Moreover, our results show Mem as a potential disease-modifying therapy, providing insight on new mechanisms of action.

Loss of MBNL1-mediated retrograde BDNF signaling in the myotonic dystrophy brain

Reduced brain volume including atrophy in grey and white matter is commonly seen in myotonic dystrophy type 1 (DM1). DM1 is caused by an expansion of CTG trinucleotide repeats in the 3’ untranslated region (UTR) of the Dystrophia Myotonica Protein Kinase (DMPK) gene. Mutant DMPK mRNA containing expanded CUG RNA (DMPK-CUGexp) sequesters cytoplasmic MBNL1, resulting in morphological impairment. How DMPK-CUGexp and loss of MBNL1 cause histopathological phenotypes in the DM1 brain remains elusive. Here, we show that BDNF-TrkB retrograde transport is impaired in neurons expressing DMPK-CUGexp due to loss of cytoplasmic MBNL1 function. We reveal that mature BDNF protein levels are reduced in the brain of the DM1 mouse model EpA960/CaMKII-Cre. Exogenous BDNF treatment did not rescue impaired neurite outgrowth in neurons expressing DMPK-CUGexp, whereas overexpression of the cytoplasmic MBNL1 isoform in DMPK-CUGexp-expressing neurons improved their responsiveness to exogenous BDNF. We identify dynein light chain LC8-type 2, DYNLL2, as an MBNL1-interacting protein and demonstrate that their interaction is RNA-independent. Using time-lapse imaging, we show that overexpressed MBNL1 and DYNLL2 move along axonal processes together and that MBNL1-knockdown impairs the motility of mCherry-tagged DYNLL2, resulting in a reduced percentage of retrograde DYNLL2 movement. Examination of the distribution of DYNLL2 and activated phospho-TrkB (pTrkB) receptor in EpA960/CaMKII-Cre brains revealed an increase in the postsynaptic membrane fraction (LP1), indicating impaired retrograde transport. Finally, our neuropathological analysis of postmortem DM1 tissue reveals that reduced cytoplasmic MBNL1 expression is associated with an increase in DYNLL2 and activated pTrkB receptor levels in the synaptosomal fraction. Together, our results support that impaired MBNL1-mediated retrograde BDNF-TrkB signaling may contribute to the histopathological phenotypes of DM1.

Association of prediabetes with reduced brain volume in a general elderly Japanese population.

Diabetes frequently results in cognitive impairment, but it is less clear if brain health is adversely affected during the prediabetic stage. Our aim is to identify possible changes in brain volume as measured by magnetic resonance imaging (MRI) in a large elderly population stratified according to level of "dysglycemia." This is a cross-sectional study of 2144 participants (median age 69years, 60.9% female) who underwent 3-T brain MRI. Participants were divided into 4 dysglycemia groups based on HbA1c levels (%): normal glucose metabolism (NGM) (< 5.7%), prediabetes (5.7 to < 6.5%), undiagnosed diabetes (6.5% or higher), and known diabetes (defined by self-report). Of the 2144 participants, 982 had NGM, 845 prediabetes, 61 undiagnosed diabetes, and 256 known diabetes. After adjustment for age, sex, education, body weight, cognitive status, smoking, drinking, and disease history, total gray matter volume was significantly lower among participants with prediabetes (0.41% lower, standardized β = - 0.0021 [95% CI - 0.0039, - 0.00039], p = 0.016), undiagnosed diabetes (1.4% lower, standardized β = - 0.0069 [95% CI - 0.012, - 0.002], p = 0.005), and known diabetes (1.1% lower, standardized β = - 0.0055 [95% CI - 0.0081, - 0.0029], p < 0.001) compared to the NGM group. After adjustment, total white matter volume and hippocampal volume did not differ significantly between the NGM group and either the prediabetes group or the diabetes group. Sustained hyperglycemia may have deleterious effects on gray matter integrity even prior to the onset of clinical diabetes. • Sustained hyperglycemia has deleterious effects on gray matter integrity even prior to the onset of clinical diabetes.

Brain reserve contributes to distinguishing preclinical Alzheimer’s stages 1 and 2

BackgroundIn preclinical Alzheimer’s disease, it is unclear why some individuals with amyloid pathologic change are asymptomatic (stage 1), whereas others experience subjective cognitive decline (SCD, stage 2). Here, we examined the association of stage 1 vs. stage 2 with structural brain reserve in memory-related brain regions.MethodsWe tested whether the volumes of hippocampal subfields and parahippocampal regions were larger in individuals at stage 1 compared to asymptomatic amyloid-negative older adults (healthy controls, HCs). We also tested whether individuals with stage 2 would show the opposite pattern, namely smaller brain volumes than in amyloid-negative individuals with SCD. Participants with cerebrospinal fluid (CSF) biomarker data and bilateral volumetric MRI data from the observational, multi-centric DZNE-Longitudinal Cognitive Impairment and Dementia Study (DELCODE) study were included. The sample comprised 95 amyloid-negative and 26 amyloid-positive asymptomatic participants as well as 104 amyloid-negative and 47 amyloid-positive individuals with SCD. Volumes were based on high-resolution T2-weighted images and automatic segmentation with manual correction according to a recently established high-resolution segmentation protocol.ResultsIn asymptomatic individuals, brain volumes of hippocampal subfields and of the parahippocampal cortex were numerically larger in stage 1 compared to HCs, whereas the opposite was the case in individuals with SCD. MANOVAs with volumes as dependent data and age, sex, years of education, and DELCODE site as covariates showed a significant interaction between diagnosis (asymptomatic versus SCD) and amyloid status (Aß42/40 negative versus positive) for hippocampal subfields. Post hoc paired comparisons taking into account the same covariates showed that dentate gyrus and CA1 volumes in SCD were significantly smaller in amyloid-positive than negative individuals. In contrast, CA1 volumes were significantly (p = 0.014) larger in stage 1 compared with HCs.ConclusionsThese data indicate that HCs and stages 1 and 2 do not correspond to linear brain volume reduction. Instead, stage 1 is associated with larger than expected volumes of hippocampal subfields in the face of amyloid pathology. This indicates a brain reserve mechanism in stage 1 that enables individuals with amyloid pathologic change to be cognitively normal and asymptomatic without subjective cognitive decline.

Increased Resting-State Functional Connectivity as a Compensatory Mechanism for Reduced Brain Volume in Prediabetes and Type 2 Diabetes.

To investigate the contribution of alterations in brain structure and function to cognitive function and their interactions in individuals with diabetes and patients with type 2 diabetes mellitus (T2DM). This population-based study included 2,483 participants who underwent structural MRI (n = 569 with normal glucose metabolism [NGM], n = 1,353 with prediabetes, and n = 561 with T2DM) and cognitive testing. Of these, 2145 participants also underwent functional MRI (n = 496 NGM, n = 1,170 prediabetes, and n = 479 T2DM). Multivariate linear regression models were used to assess the association of brain volume and functional connectivity with cognition, as well as the association of brain volume and functional connectivity. Compared with NGM participants, those with T2DM had lower brain volume in a wide range of brain regions and stronger functional connectivity between the bilateral thalamus and brain functional network (visual network and default mode network), and those with prediabetes had lower brain volume in specific local regions (subcortical gray matter volume and subcortical subregions [bilateral thalamus, bilateral nucleus accumbens, and right putamen]) and stronger functional connectivity between the right thalamus and visual network. Cognition was associated with greater right thalamus volume and lower functional connectivity between the right thalamus and visual network. Functional connectivity between the right thalamus and visual network was associated with lower right thalamus volume. Cognition was associated with greater brain volume and lower functional connectivity in T2DM. Increased functional connectivity may indicate a compensatory mechanism for reduced brain volume that begins in the prediabetic phase.

Neuropsychiatric symptoms and their neural correlates in individuals with mild cognitive impairment.

Neuropsychiatric symptoms are common in subjects with MCI and associated with higher risk of progression to AD. The cognitive and neuroanatomical correlates of neuropsychiatric symptoms in MCI have not been fully elucidated. In this study, we sought to evaluate the association between neuropsychiatric symptoms, cognitive function, regional tau deposition, and brain volumes in MCI subjects. A total of 233 MCI and 305 healthy comparisons were selected from the ADNI-3 cohort. All the subjects underwent a comprehensive neuropsychological assessment, volumetric MR brain scan, and Flortaucipir PET for in vivo assessment of regional tau deposition. Prevalence of neuropsychiatric symptoms was evaluated by means of the NPI questionnaire. Multivariate analyses of variance were used to detect differences in cognitive and imaging markers in MCI subjects with and without neuropsychiatric symptoms. 61.4% MCI subjects showed at least one neuropsychiatric symptom, with the most prevalent ones being depression (26.1%), irritability (23.6%), and sleep disturbances (23.6%). There was a significant effect of neuropsychiatric symptoms on cognitive tests of frontal and executive functions. MCI subjects with neuropsychiatric symptoms showed reduced brain volumes in the orbitofrontal and posterior cingulate cortices, while no effects were detected on regional tau deposition. Posterior cingulate cortex volume was the only predictor of global neuropsychiatric burden in this MCI population. Neuropsychiatric symptoms occur early in the AD trajectory and are mainly related to defects of control executive abilities and to the reduction of gray matter volume in the orbitofrontal and posterior cingulate cortices. A better understanding of the cognitive and neuroanatomical mechanisms of neuropsychiatric symptoms in MCI could help develop more targeted and efficacious treatment alternatives.

Extra cup of tea intake associated with increased risk of Alzheimer's disease: Genetic insights from Mendelian randomization.

Observational studies report inconclusive effects of tea consumption on the risk of Alzheimer's disease (AD), and the mechanisms are unclear. This study aims to investigate the effects of genetically predicted tea intake (cups of tea consumed per day) on AD, brain volume, and cerebral small vessel disease (CSVD) using the two-sample Mendelian randomization (MR) method. Summary statistics of tea intake were obtained from UK Biobank (N = 447,485), and AD was from the International Genomics of Alzheimer's Project (N = 54,162). Genetic instruments were retrieved from UK Biobank using brain imaging-derived phenotypes for brain volume outcomes (N > 33,224) and genome-wide association studies for CSVD (N: 17,663-48,454). In the primary MR analysis, tea intake significantly increased the risk of AD using two different methods (ORIVW = 1.48, 95% CI: [1.14, 1.93]; ORWM = 2.00, 95% CI: [1.26, 3.18]) and reached a weak significant level using MR-Egger regression (p < 0.1). The result passed all the sensitivity analyses, including heterogeneity, pleiotropy, and outlier tests. In the secondary MR analysis, per extra cup of tea significantly decreased gray matter (βWM = -1.63, 95% CI: [-2.41, -0.85]) and right hippocampus volume (βWM = -1.78, 95% CI: [-2.76, -0.79]). We found a nonlinear association between tea intake and AD in association analysis, which suggested that over-drinking with more than 13 cups per day might be a risk factor for AD. Association analysis results were consistent with MR results. This study revealed a potential causal association between per extra cup of tea and an increased risk of AD. Genetically predicted tea intake was associated with a decreased brain volume of gray matter and the right hippocampus, which indicates that over-drinking tea might lead to a decline in language and memory functions. Our results shed light on a novel possible mechanism of tea intake to increase the risk of AD by reducing brain volume.

Antipsychotics and structural brain changes: could treatment adherence explain the discrepant findings?

Progressive structural brain changes are well documented in schizophrenia and have been linked to both illness progression and the extent of antipsychotic treatment exposure. Literature reporting longitudinal changes in brain structure in individuals with schizophrenia is selectively reviewed to assess the roles of illness, antipsychotic treatment, adherence and other factors in the genesis of these changes. This narrative review considers literature investigating longitudinal changes in brain structure in individuals with schizophrenia. The review focusses on structural changes in the cortex, basal ganglia and white matter. It also examines effects of medication non-adherence and relapse on the clinical course of the illness and on structural brain changes. Studies investigating structural magnetic resonance imaging changes in patients treated with long-acting injectable antipsychotics are reviewed. Temporal changes in brain structure in schizophrenia can be divided into those that are associated with antipsychotic treatment and those that are not. Changes associated with treatment include increases in basal ganglia and white matter volumes. Relapse episodes may be a critical factor in illness progression and brain volume reductions. Medication adherence may be an important factor that could explain the findings that brain volume reductions are associated with poor treatment response, higher intensity of antipsychotic treatment exposure and more time spent in relapse. Improved adherence via long-acting injectable antipsychotics and adherence focussed psychosocial interventions could maximize protective effects of antipsychotics against illness progression.

Prevalence and risk factors of brain atrophy and associated confusion state among adults from three hospitals in northern Tanzania.

brain atrophy is the reduction of brain volume often accompanied with cognitive changes. Despite the availability of computerized-tomography (CT) scanners in Tanzania, little is known about the magnitude of brain atrophy, its associated confusion state and the risk factors in adults. This study aimed to fill those knowledge gaps. a retrospective cross-sectional hospital-based survey was conducted in northern Tanzania using a sample size of 384 CT images of adults who underwent brain CT scans in three referral hospitals. CT images were evaluated using a diagonal brain fraction (DBF) method to determine the presence of brain atrophy. Data for other covariates were also collected. we report a prevalence of 60.67% for brain atrophy and 35% for the associated confusion state. Association between confusion state and brain atrophy was statistically significant (χ2 = 21.954, p<0.001). Brain atrophy was prognosticated by: age (adjusted OR: 1.11; 95% CI [1.05, 1.20], p<0.001), smoking (adjusted OR: 6.97; 95% CI [2.12, 26.19], p<0.001), alcohol-consumption (adjusted OR: 11.87; 95% CI [3.44, 40.81], p<0.001), hypertension (adjusted OR: 61.21; 95 CI [15.20, 349.43], p<0.001), type-2 diabetes mellitus (adjusted OR: 15.67; 95% CI [5.32, 52.77], p<0.001) and white matter demyelination (adjusted OR: 13.45; 95% CI [4.66, 44.25], p<0.001). there is high prevalence of brain atrophy and associated confusion state among hospitalized adults in northern Tanzania. Reported prognostic factors for brain atrophy such as age, smoking, alcohol consumption, hypertension, type-2 diabetes mellitus and white matter demyelination could help focus interventions in this area.

A case-control study on the driving factors of childhood brain volume loss: What pediatricians must explore.

The brain volume loss also known as brain atrophy is increasingly observed among children in the course of performing neuroimaging using CT scan and MRI brains. While severe forms of brain volume loss are frequently associated with neurocognitive changes due to effects on thought processing speed, reasoning and memory of children that eventually alter their general personality, most clinicians embark themselves in managing the neurological manifestations of brain atrophy in childhood and less is known regarding the offending factors responsible for developing pre-senile brain atrophy. It was therefore the goal of this study to explore the factors that drive the occurrence of childhood brain volume under the guidance of brain CT scan quantitative evaluation. This study was a case-control study involving 168 subjects with brain atrophy who were compared with 168 age and gender matched control subjects with normal brains on CT scan under the age of 18 years. All the children with brain CT scan were subjected to an intense review of their birth and medical history including laboratory investigation reports. Results showed significant and influential risk factors for brain atrophy in varying trends among children including age between 14-17(OR = 1.1), male gender (OR = 1.9), birth outside facility (OR = 0.99), immaturity (OR = 1.04), malnutrition (OR = 0.97), head trauma (OR = 1.02), maternal alcoholism (OR = 1.0), antiepileptic drugs & convulsive disorders (OR = 1.0), radiation injury (OR = 1.06), space occupying lesions and ICP (OR = 1.01) and birth injury/asphyxia (OR = 1.02). Pathological reduction of brain volume in childhood exhibits a steady trend with the increase in pediatric age, with space occupying lesions & intracranial pressure being the most profound causes of brain atrophy.

Neurostructural associations with traumatic experiences during child- and adulthood

Adverse experiences can lead to severe mental health problems, such as posttraumatic stress disorder (PTSD), throughout the lifespan. In individuals with PTSD, both global and local brain volume reductions have been reported—especially in the amygdala and hippocampus—while the literature on childhood maltreatment suggests a strong dependency on the timing of adverse events. In the present study, we pooled data from two studies to contrast the effects of reported trauma exposure during neurodevelopmentally sensitive periods in early life with trauma exposure during adulthood. A total of 155 women were allocated into one of six age-matched groups according to the timing of traumatization (childhood vs adulthood) and psychopathology (PTSD vs trauma-exposed healthy vs trauma-naïve healthy). Volumes of the amygdala and hippocampus were compared between these groups. Six additional exploratory regions of interest (ROI) were included based on a recent meta-analysis. Amygdala volume was strongly dependent on the timing of traumatization: Smaller amygdala volumes were observed in participants with childhood trauma and PTSD compared to the healthy control groups. In contrast, larger amygdala volumes were observed in both groups with trauma exposure during adulthood compared to the trauma-naïve control group. Hippocampal volume comparisons revealed no statistically significant differences, although the descriptive pattern was similar to that found for the amygdala. The remaining exploratory ROIs showed significant group effects, but no timing effects. The timing might be an important moderator for adversity effects on amygdala volume, potentially reflecting neurodevelopmental factors. Albeit confounded by characteristics like trauma type and multiplicity, these findings pertain to typical childhood and adulthood trauma as often observed in clinical practice and speak against a simple association between traumatic stress and amygdala volume.

Structural and Functional Neural Correlates in Individuals with Excessive Smartphone Use: A Systematic Review and Meta-Analysis.

Background: Despite known association of internet addiction with a reduced brain volume and abnormal connectivity, the impact of excessive smartphone use remains unclear. Methods: PubMed, Embase, ClinicalTrial.gov, and Web of Science databases were systematically searched from inception to July 2022 using appropriate keywords for observational studies comparing differences in brain volumes and activations between excessive smartphone users and individuals with regular use by magnetic resonance imaging. Results: Of the 11 eligible studies retrieved from 6993 articles initially screened, seven and six evaluated brain volumes and activations, respectively. The former enrolled 421 participants (165 excessive smartphone users vs. 256 controls), while the latter recruited 276 subjects with 139 excessive smartphone users. The results demonstrated a smaller brain volume in excessive smartphone users compared to the controls (g = −0.55, p < 0.001), especially in subcortical regions (p < 0.001). Besides, the impact was more pronounced in adolescents than in adults (p < 0.001). Regression analysis revealed a significant positive association between impulsivity and volume reduction. Regarding altered activations, the convergences of foci in the declive of the posterior lobe of cerebellum, the lingual gyrus, and the middle frontal gyrus were noted. Conclusions: Our findings demonstrated a potential association of excessive smartphone use with a reduced brain volume and altered activations.