Semantic segmentation of cerebrospinal fluid and brain volume with a convolutional neural network in pediatric hydrocephalus-transfer learning from existing algorithms

Background

For the segmentation of medical imaging data, a multitude of precise but very specific algorithms exist. In previous studies, we investigated the possibility of segmenting MRI data to determine cerebrospinal fluid and brain volume using a classical machine learning algorithm. It demonstrated good clinical usability and a very accurate correlation of the volumes to the single area determination in a reproducible axial layer. This study aims to investigate whether these established segmentation algorithms can be transferred to new, more generalizable deep learning algorithms employing an extended transfer learning procedure and whether medically meaningful segmentation is possible.

Methods

Ninety-five routinely performed true FISP MRI sequences were retrospectively analyzed in 43 patients with pediatric hydrocephalus. Using a freely available and clinically established segmentation algorithm based on a hidden Markov random field model, four classes of segmentation (brain, cerebrospinal fluid (CSF), background, and tissue) were generated. Fifty-nine randomly selected data sets (10,432 slices) were used as a training data set. Images were augmented for contrast, brightness, and random left/right and X/Y translation. A convolutional neural network (CNN) for semantic image segmentation composed of an encoder and corresponding decoder subnetwork was set up. The network was pre-initialized with layers and weights from a pre-trained VGG 16 model. Following the network was trained with the labeled image data set. A validation data set of 18 scans (3289 slices) was used to monitor the performance as the deep CNN trained. The classification results were tested on 18 randomly allocated labeled data sets (3319 slices) and on a T2-weighted BrainWeb data set with known ground truth.

Results

The segmentation of clinical test data provided reliable results (global accuracy 0.90, Dice coefficient 0.86), while the CNN segmentation of data from the BrainWeb data set showed comparable results (global accuracy 0.89, Dice coefficient 0.84). The segmentation of the BrainWeb data set with the classical FAST algorithm produced consistent findings (global accuracy 0.90, Dice coefficient 0.87). Likewise, the area development of brain and CSF in the long-term clinical course of three patients was presented.

Conclusion

Using the presented methods, we showed that conventional segmentation algorithms can be transferred to new advances in deep learning with comparable accuracy, generating a large number of training data sets with relatively little effort. A clinically meaningful segmentation possibility was demonstrated.

The association between MRI brain volumes and computerized cognitive scores of people with multiple sclerosis

BACKGROUND

Computerized cognitive assessment facilitates the incorporation of multi-domain cognitive monitoring into routine clinical care. The predictive validity of computerized cognitive assessment among people with multiple sclerosis (PwMS) has scarcely been investigated.

OBJECTIVE

To explore the associations between brain volumes and cognitive scores from a computerized cognitive assessment battery (CAB, NeuroTrax) among PwMS.

METHODS

PwMS were evaluated with the CAB and underwent brain MRI within 40 days. Cognitive assessment yielded age- and education-adjusted scores in 9 cognitive domains: memory, executive function, attention, information processing speed, visual spatial, verbal function, motor skills, problem solving, and working memory. The global cognitive score (GCS) is the average of all domain scores. MRI brain and lesion volumes were assessed with icobrain ms, a fully automated tissue and lesion segmentation and quantification software.

RESULTS

91 PwMS were included [Age: 52.1 ± 11.7 years, 64 (70%) female, EDSS: 3.4 ± 2.0, 79 (87%) with a relapsing remitting course]. Significant correlations were found between the GCS and whole brain, white matter, grey matter, thalamic, lateral ventricles, hippocampal and lesion volumes (Correlation coefficients: 0.46, 0.40, 0.25, 0.42, -0.36, 0.21, -0.3, respectively). Regression analysis revealed that lateral ventricles and thalamic volumes were the most consistent predictors of all cognitive domain scores.

CONCLUSION

Computerized cognitive scores were significantly associated with quantified MRI. These findings support the predictive validity of multi-domain computerized cognitive assessment for people with multiple sclerosis.

Parsing differences in amygdala volume among individuals with and without social and generalized anxiety disorders across the lifespan

Structural differences in the amygdala (AMG) are implicated in anxiety and observed among individuals with generalized (GAD) and social anxiety (SAD) disorders. Findings have been mixed, perhaps because studies rarely examine differences between GAD and SAD, test comorbidity, or examine age-related differences. We tested AMG volume differences among a sample of adults and youth with/without SAD and GAD. Participants (N = 242; ages 7-60 years) completed an MRI scan, diagnostic interviews, and anxiety symptom measures. Groups were formed from diagnostic interviews: 1) Typically developing (TD; n = 91); 2) GAD (n = 53); 3) SAD (n = 35); and 4) comorbid SAD/GAD (n = 63). We used analysis of covariance with a bonferroni correction to examine group differences in AMG volume. The SAD and comorbid SAD/GAD groups exhibited increased bilateral AMG volume compared to the TD group. GAD and TD groups did not differ from each other in AMG size. The SAD, but not the comorbid SAD/GAD group, displayed greater right AMG size relative to the GAD group. SAD and comorbid SAD/GAD groups did not differ from the GAD group in left AMG volume. SAD and SAD/GAD groups did not exhibit different bilateral AMG size. Linear regression analyses demonstrated that greater social anxiety but not generalized anxiety symptom severity was associated with enlarged AMG volume. Age was not associated with AMG volume and nor did age moderate any group or symptom effects. Future longitudinal studies should examine whether larger AMG volume is a unique biomarker for SAD across the lifespan.

Neurocognitive Functions and Brain Volume in Patients with Endogenous Cushing's Syndrome Before and After Curative Surgery

INTRODUCTION

Cushing's syndrome (CS) leads to various neuropsychiatric manifestations due to structural and functional changes of the brain and contributes significantly in the impairment of health-related quality of life.

AIM AND OBJECTIVE

This study is conducted with aims to evaluate neurocognitive functions and brain volume in patients with endogenous Cushing's syndrome before and after curative surgery.

METHODS

The diagnosis of CS was made by clinical features, abnormal cortisol dynamics, ACTH levels, and imaging studies. Neuropsychiatric tests (Beck depression Index, Spatial span test, PGI memory scale, Color trail test, Verbal fluency test), and Brain volume (Bi-caudate and third ventricular diameter) were done before and after curative surgery.

RESULTS

Fifteen patients of CS were included for the study; all patients underwent curative surgery, neuropsychiatric assessment, and brain volume measurements. Nine patients were followed successfully till remission and repeat evaluation of these patients was done. Depression was the most common neuropsychiatric illness. Severity of depression positively correlated with 0800 h plasma cortisol and ACTH. Patients with higher severity of depression had maximum improvement after curative surgery. Significant decrease in the third ventricular, as well as bicaudate diameter, was observed after curative surgery (P < 0.01).

CONCLUSION

Neuropsychiatric functions and structural brain changes reverse after curative surgery in patients with endogenous CS, however, long term follow-up is required to know whether these changes reverse completely or not.

Brain MRI characteristics in neuromyelitis optica spectrum disorders: A large multi-center retrospective study in China

PURPOSE

To investigate the brain MRI features in neuromyelitis optica spectrum disorders (NMOSD) and its clinical relevance in a large multi-center cohort in China.

METHODS

270 NMOSD patients were recruited from seven centers. The brain MRI were classified as normal, NMOSD-specific lesions, multiple sclerosis-like, nonspecific white matter changes. Brain volumes including whole brain, white, gray matter, cortex and subcortex gray matter volume were measured. The relationship between MRI measures, clinical disability and cognitive impairment were investigated.

RESULTS

98 patients (36.3%) had normal brain MRI; 48 patients (17.7%) had NMOSD-specific lesions located in dorsal brainstem, corticospinal tract corpus, callosum and periependymal lesions surrounding the ventricular system; 16 patients (6%) had multiple sclerosis-like lesions; and 108 patients (40%) had nonspecific white matter changes. NMOSD patients with brain lesions had a trend of lower subcortex gray matter volume compared to patients without lesions. 52.5% patients with normal brain MRI and 50.8% patients with abnormal brain MRI showed cognitive impairment. No significant differences were identified in brain volume between cognitive impairment and cognitive preserved groups.

CONCLUSION

In this large multicenter NMOSD cohort, nonspecific white matter changes were the most common findings (40%). NMOSD patients with brain lesions demonstrated a trend of having lower brain volume than patients without lesions. Approximately 50% NMOSD patients presented cognitive impairment independent of brain lesions.

Association of impaired fasting glucose and Type 2 Diabetes Mellitus with brain volume changes in Alzheimer's Disease patients analyzed by MRI: a retrospective study

Objectives

Alzheimer’s disease (AD), impaired fasting glucose (IFG), and Type 2 diabetes mellitus (T2DM) were reported associated with smaller brain volumes. Nevertheless, the association of hyperglycemia with brain volume changes in AD patients remains unclear. To investigate this issue, structural magnetic resonance imaging was used to compare brain volumes among AD patients with different fasting glucose levels.

Methods

Eighty-five AD patients were divided into three groups based on their fasting glucose level as suggested by the American Diabetes Association: normal fasting glucose group (AD_NFG, n = 45), AD_IFG group (n = 15), and AD_T2DM group (n = 25). Sagittal 3D T1-weighted images were obtained to calculate the brain volume. Brain parenchyma and 33 brain structures were automatically segmented. Each regional volume was analyzed among groups. For regions with statistical significance, partial correlation analysis was used to evaluate their relationships with fasting glucose level, corrected for Mini-Mental State Examination score, age, education level, cholesterol, triglyceride, and blood pressure.

Results

Compared with the AD_IFG and AD_NFG groups, the volume of pons in AD_T2DM group was significantly smaller. Fasting glucose was negatively correlated with pontine volume.

Conclusions

T2DM may exacerbate pontine atrophy in AD patients, and fasting glucose level is associated with pontine volume.

Associations of Blood Pressure and Carotid Flow Velocity with Brain Volume and Cerebral Small Vessel Disease in a Community-Based Population

Cerebral small vessel disease (CSVD) is a common finding on brain magnetic resonance imaging (MRI). We previously demonstrated that high blood pressure (BP) and low carotid flow velocity were associated with cerebrovascular disease. However, their associations with brain volume and CSVD remain to be determined. A total of 721 adults (≥ 50 years) from the community-based I-Lan Longitudinal Aging Study were included. Flow velocities at the common (CCA) and internal carotid artery (ICA), including peak systolic velocity (PSV) and end-diastolic velocity (EDV), were measured with Doppler ultrasound. We further detected the presence of CSVD including lacune, microbleed, and white matter hyperintensity (WMH) on brain MRI, which were used to construct a combined CSVD score. General linear regression and logistic regression analysis were exploited to evaluate the association between carotid flow velocity, BP, brain volume, and CSVD. The mean of white matter, gray matter, and WMH volume were 422.2 cm³, 546.9 cm³, and 2.61 cm³, respectively. The proportion of lacune and microbleed were 11.1% and 14.2%, respectively. The CSVD score were negatively associated with gray (r = - 0.121, p < .01) and white matter volume (r = 0.058, p = 0.12), but positively associated with systolic BP (beta = 1.02, p = 0.0017). EDV at common carotid artery associated positively with white matter volume (beta = 1.013, p = 0.0064) and negatively predicted the presence CSVD (odds ratio [OR] = 0.93, p = 0.0023). In the ordinal logistic regression analysis adjusting for age, sex, total intracranial volume education, low-density lipoprotein cholesterol, and fasting glucose, compared with hypertensive subjects with low EDV, normotensive subjects with low, middle, and high EDV had an odds ratio of 0.656 (0.327-1.318), 0.429 (0.261-0.705), and 0.272 (0.147-0.502) for CSVD score, respectively. High SBP and low carotid flow velocities were independently associated with brain volume and CSVD. These associations may be involved in the pathophysiology of cognitive function decline.

A longitudinal study of brain volume changes in rhesus macaque model infected with SIV

Given the current lack of understanding of brain volume changes caused by HIV infection, this study aimed to longitudinally assess the changes in regional brain tissue volume following HIV infection and to explore its relationship with peripheral blood absolute CD4+ lymphocyte count (CD4+), the percentage of monocytes in plasma(MON%) and cerebrospinal fluid viral load (CFVL).Four adult male rhesus monkeys were examined in healthy status and following infection with simian immunodeficiency virus using high-resolution 3D T1-weighted sagittal whole brain magnetic resonance imaging. DPABI and SPM were used to process and record changes in brain tissue volume. Correlation analyses were then used to explore the above relationships. Compared with brain tissue volume during the healthy stage, there was no change at 12 and 24 weeks postinoculation (12 wpi, 24 wpi). At 36 wpi, 48 wpi, and 60 wpi, basal ganglia, left inferior temporal gyrus, left occipital gyrus, and left superior frontal gyrus exhibited varying degrees of atrophy. There was no association found between CD4+, MON%, CFVL, and brain volume loss in any brain region. Our research demonstrated that in the early stage of HIV infection, local brain tissue atrophy can be demonstrated by MRI technique; furthermore, MRI can identify the earliest site of atrophy as well as the most severely affected site. Although there was no significant correlation between brain tissue volume loss and CD4+, MON%, and CFVL, our findings provided some evidence in the application of volumetric MR imaging in the early diagnosis and treatment follow-up of patients with HIV infection.

Midlife alcohol consumption and longitudinal brain atrophy: the PREVENT-Dementia study

Background and aims

Consensus is lacking on whether light to moderate consumption of alcohol compared to abstinence is neuroprotective. In this study, we investigated the relationship between self-reported alcohol use and brain volume change over 2 years in middle-aged subjects.

Methods

A sample of 162 subjects (aged 40–59 at baseline) from the PREVENT-Dementia programme underwent MRI scans on two separate occasions (mean interval 734 days; SD 42 days). We measured longitudinal rates of brain atrophy using the FSL Siena toolbox, and change in hippocampal volume from segmentation in SPM.

Results

Controlling for age and sex, there were no significant associations of either total brain, ventricular, or hippocampal volume change with alcohol consumption. Adjusting for lifestyle, demographic and vascular risk factors did not alter this.

Conclusions

We did not find any evidence of influence of alcohol consumption on changes in brain volume over a 2-year period in 40–60-year-olds.

Evidence against the "normalization" prediction of the early brain overgrowth hypothesis of autism

BACKGROUND

The frequently cited Early Overgrowth Hypothesis of autism spectrum disorder (ASD) postulates that there is overgrowth of the brain in the first 2 years of life, which is followed by a period of arrested growth leading to normalized brain volume in late childhood and beyond. While there is consistent evidence for early brain overgrowth, there is mixed evidence for normalization of brain volume by middle childhood. The outcome of this debate is important to understanding the etiology and neurodevelopmental trajectories of ASD.

METHODS

Brain volume was examined in two very large single-site samples of children, adolescents, and adults. The primary sample comprised 456 6-25-year-olds (ASD n = 240, typically developing controls (TDC) n = 216), including a large number of females (n = 102) and spanning a wide IQ range (47-158). The replication sample included 175 males. High-resolution T1-weighted anatomical MRI images were examined for group differences in total brain, cerebellar, ventricular, gray, and white matter volumes.

RESULTS

The ASD group had significantly larger total brain, cerebellar, gray matter, white matter, and lateral ventricular volumes in both samples, indicating that brain volume remains enlarged through young adulthood, rather than normalizing. There were no significant age or sex interactions with diagnosis in these measures. However, a significant diagnosis-by-IQ interaction was detected in the larger sample, such that increased brain volume was related to higher IQ in the TDCs, but not in the ASD group. Regions-of-significance analysis indicated that total brain volume was larger in ASD than TDC for individuals with IQ less than 115, providing a potential explanation for prior inconsistent brain size results. No relationships were found between brain volume and measures of autism symptom severity within the ASD group.

LIMITATIONS

Our cross-sectional sample may not reflect individual changes over time in brain volume and cannot quantify potential changes in volume prior to age 6.

CONCLUSIONS

These findings challenge the "normalization" prediction of the brain overgrowth hypothesis by demonstrating that brain enlargement persists across childhood into early adulthood. The findings raise questions about the clinical implications of brain enlargement, since we find that it neither confers cognitive benefits nor predicts increased symptom severity in ASD.

Developmental outcomes of very low birthweight infants with non-hemorrhagic ventricular dilatations and the relationships thereof with absolute brain volumes measured via two-dimensional ultrasonography

PURPOSE

We calculated the brain volumes of preterm infants using two-dimensional cranial ultrasonography and explored the relationships thereof with neurodevelopment.

METHODS

Cranial measurements were derived using routine ultrasonographic scanning. The brain was considered to be an ellipsoid and estimated absolute brain volumes (EABVs) were calculated by substracting the volumes of the two lateral ventricles from the total brain volumes.

RESULTS

We enrolled preterm infants of mean gestational age 28 ± 2 weeks and mean birthweight 973 ± 187 g. Twenty-one exhibited dilated ventricles; their EABVs were lower than normal (206 ± 11 cm³ vs. 275 ± 17 cm³, p < 0.001). The mental development indices were similar (74 ± 5 vs. 78 ± 14, p = 0.069), but the psychomotor development indices (PDIs) differed significantly (77 ± 7 vs. 86 ± 17, p = 0.001). We found a slight positive correlation between the PDI and EABV (r = + 0.258, p = 0.012).

CONCLUSION

The EABV can be calculated using two-dimensional measurements and low EABV found to be associated with poor neurological outcomes.

TRIAL REGISTRATION

NCT02848755.

Concentrated ambient fine particulate matter (PM2.5) exposure induce brain damage in pre and postnatal exposed mice

Air pollution is a public health concern that has been associated with adverse effects on the development and functions of the central nervous system (CNS). However, studies on the effects of exposure to pollutants on the CNS across the entire developmental period still remain scarce. In this study, we investigated the impacts of prenatal and/or postnatal exposure to fine particulate matter (PM_2.5) from São Paulo city, on the brain structure and behavior of juvenile male mice. BALB/c mice were exposed to PM_2.5 concentrated ambient particles (CAP) at a daily concentration of 600 μg/m³ during the gestational [gestational day (GD) 1.5-18.5] and the postnatal periods [postnatal day (PND) 22-90] to filtered air (FA) in both periods (FA/FA), to CAP only in the postnatal period (FA/CAP), to CAP only in the gestational period (CAP/FA), and to CAP in both periods (CAP/CAP). Behavioral tests were performed when animals were at PND 30 and PND 90. Glial activation, brain volume, cortical neuron number, serotonergic and GABAergic receptors, as well as oxidative stress, were measured. Mice at PND 90 presented greater behavioral changes in the form of greater locomotor activity in the FA-CAP and CAP-CAP groups. In general, these same groups explored objects longer and the CAP-FA group presented anxiolytic behavior. There was no difference in total brain volume among groups, but a lower corpus callosum (CC) volume was observed in the CAP-FA group. Also, the CAP-CAP group presented an increase in microglia in the cortex and an increased in astrocytes in the cortex, CC, and C1A and dentate gyrus of hippocampus regions. Gene expression analysis showed a decrease in BDNF in the hippocampus of CAP-CAP group. Treatment of immortalized glial cells with non-cytotoxic doses of ambient PM_2.5 increased micronuclei frequencies, indicating genomic instability. These findings highlight the potential for negative neurodevelopmental outcomes induced by exposure to moderate levels of PM_2.5 in Sao Paulo city.

Cross-sectional and longitudinal associations of family income-to-needs ratio with cortical and subcortical brain volume in adolescent boys and girls

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Sex-specific associations of SES with neurodevelopment may emerge in adolescence.

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We used a whole-brain approach to examine gray and white matter volume.

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Sex interacted with SES to explain variation in volume across adolescence.

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Sex is an important variable to consider in analyses of SES and brain volume.

Deviations in neurodevelopment may underlie the association between lower childhood socioeconomic status and difficulties in cognitive and socioemotional domains. Most previous investigations of the association between childhood socioeconomic status and brain morphology have used cross-sectional designs with samples that span wide age ranges, occluding effects specific to adolescence. Sex differences in the association between socioeconomic status and neurodevelopment may emerge or intensify during adolescence. In a sample representative of the San Francisco Bay Area, we used whole-brain tensor-based morphometry to examine sex differences in the cross-sectional association between variation in family income-to-needs ratio (INR) and cortical and subcortical gray and white matter volume during early adolescence (ages 9–13 years; N = 147), as well as in the longitudinal association between INR and change in volume from early to later adolescence (ages 11–16 years, N = 109). Biological sex interacted with INR to explain variation in volume in several areas cross-sectionally and longitudinally. Effects were primarily in cortical gray matter areas, including regions of the association cortex and sensorimotor processing areas. Effect sizes tended to be larger in boys than in girls. Biological sex may be an important variable to consider in analyses of the effects of family income on structural neurodevelopment during adolescence.

Impact of brain volume and intracranial cerebrospinal fluid volume on the clinical outcome in endovascularly treated stroke patients

PURPOSE

Previously, brain volume (BV) and intracranial cerebrospinal fluid volume (CSFV) have been investigated regarding clinical outcomes of subgroups of ischemic stroke patients. This study aimed to examine if the preexisting, preischemic BV and CSFV have an impact on good functional outcome and mortality in acute ischemic stroke (AIS) patients treated with mechanical thrombectomy (MT).

METHODS

Preischemic BV, CSFV, and CSFV/Total intracranial volume (TICV)-ratio were calculated with a fully automated segmentation platform. Univariate and multivariate analyses were used to study associations.

RESULTS

In this retrospective study 107 subsequent AIS patients of a prospective database were included. The segmentation results of the fully automated algorithm based on non-contrast computerized tomography scans (NCCT) correlated significantly with the segmentation results obtained from 3D T1 weighted magnetic resonance images (P < 0.001). In the univariate analysis a preexisting BV (P < 0.001), preexisting CSFV (P = 0.009), and the ratio CSFV/total intracranial volume (P < 0.001) each significantly correlated with good functional outcome and mortality. However, in the multivariate regression analysis, also correcting for patient age, none of these volumes remained to correlate with these outcome parameters.

CONCLUSION

In summary, an association of BV, CSFV, and the CSFV/TICV-ratio with good functional outcome and mortality in AIS treated with MT could not be established. A fully automated segmentation algorithm based on NCCT was successfully developed in-house for calculating the volumes of interest.

Planar single plane area determination is a viable substitute for total volumetry of CSF and brain in childhood hydrocephalus

BACKGROUND

In the treatment of childhood hydrocephalus, 3D volumetry seems to have many advantages over classical planar index measurements for dedicated monitoring of changes in cerebrospinal fluid and brain volume. Nevertheless, this method requires extensive technical effort and access to the complete three-dimensional data set. Against this background, we evaluated the possibility of planar area determination in a single plane and the correlation to volumetry.

METHODS

138 routinely performed true FISP MRI sequences (1 mm isovoxel) were analyzed retrospectively in 68 patients with pediatric hydrocephalus. After preprocessing, the 3D-data sets were skull stripped to estimate the inner skull volume. A 2-class segmentation into different tissue types (brain matter and CSF) was performed, and the volumes of CSF (VCSF) and brain matter (VBrain) were calculated. A plane at the level of the foramina of Monro was manually identified in the ac-pc oriented data. In this plane, the areas of brain (ABrain) and CSF (ACSF) in cm² were calculated and used for further correlation analysis.

RESULTS

Mean VCSF was 340 ± 145 cm³ and VBrain 1173 ± 254 cm³. In the selected plane, ACSF was 26 ± 14 cm², and ABrain was 107 ± 25 cm². There was a very strong positive correlation between both ACSF and VCSF (r = 0.895) and between ABrain and VBrain (r = 0.846). The prediction equations for VBrain and VCSF were highly significant.

CONCLUSION

Planar area determination of brain and CSF correlates excellently with both VCSF and VBrain. Thus, areas can serve as a surrogate marker for total brain and CSF volumes for a quantitated objective tracking of changes during treatment of childhood hydrocephalus.

Brain volumes and dual-task performance correlates among individuals with cognitive impairment: a retrospective analysis

Cognitive impairment (CI) is a prevalent condition characterized by loss of brain volume and changes in cognition, motor function, and dual-tasking ability. To examine associations between brain volumes, dual-task performance, and gait and balance in those with CI to elucidate the mechanisms underlying loss of function. We performed a retrospective analysis of medical records of patients with CI and compared brain volumes, dual-task performance, and measures of gait and balance. Greater cognitive and combined dual-task effects (DTE) are associated with smaller brain volumes. In contrast, motor DTE is not associated with distinct pattern of brain volumes. As brain volumes decrease, dual-task performance becomes more motor prioritized. Cognitive DTE is more strongly associated with decreased performance on measures of gait and balance than motor DTE. Decreased gait and balance performance are also associated with increased motor task prioritization. Cognitive DTE appears to be more strongly associated with decreased automaticity and gait and balance ability than motor DTE and should be utilized as a clinical and research outcome measure in this population. The increased motor task prioritization associated with decreased brain volume and function indicates a potential for accommodative strategies to maximize function in those with CI. Counterintuitive correlations between motor brain volumes and motor DTE in our study suggest a complicated interaction between brain pathology and function.

Altered neurotransmission and neuroimaging biomarkers of chronic arsenic poisoning in wild muskrats (Ondatra zibethicus) and red squirrels (Tamiasciurus hudsonicus) breeding near the City of Yellowknife, Northwest Territories (Canada)

Chronic arsenic poisoning has been shown to be a risk factor for the development of intellectual disability. Numerous human and animal studies have also confirmed that low-level arsenic exposure has deleterious effects on neurotransmission and brain structures which have been further linked to neurobehavioral disorders. The aim of this present work was to comparatively assess structural brain volume changes and alteration of two (2) neurotransmitters, specifically dopamine (DA) and serotonin (5-HT) in the brains of wild muskrats and squirrels breeding in arsenic endemic areas, near the vicinity of the abandoned Giant mine site in Yellowknife and in reference locations between 52 and 105 km from the city of Yellowknife. The levels of DA and 5-HT were measured in the brain tissues, and Magnetic Resonance Imaging (MRI) was used to attempt brain volume measurements. The results revealed that the concentrations of DA and 5-HT were slightly increased in the brains of squirrels from the arsenic endemic areas compared to the reference site. Further, DA and 5-HT were slightly reduced in the brains of muskrats from the arsenic endemic areas compared to the reference location. In general, no statistically significant neurotransmission changes and differences were observed in the brain tissues of muskrats and squirrels from both arsenic endemic areas and non-endemic sites. Although MRI results showed that the brain volumes of squirrels and muskrats were not statistically different between sites after multiple comparison correction; it was noted that core brain regions were substantially affected in muskrats, in particular the hippocampal memory circuit, striatum and thalamus. Squirrel brains showed more extensive neuroanatomical changes, likely due to their relatively smaller body mass, with extensive shrinkage of the core brain structures, and the cortex, even after accounting for differences in overall brain size. The results of this present study constitute the first observation of neuroanatomical changes in wild small mammal species breeding in arsenic endemic areas of Canada.

Vitamin E Intake Is Associated with Lower Brain Volume in Haptoglobin 1-1 Elderly with Type 2 Diabetes

BACKGROUNDS

The efficacy of vitamin E in prevention of diabetes-related complications differs by Haptoglobin (Hp) genotype.

OBJECTIVE

To examine the role of Hp genotype in the relationship of vitamin E intake with brain volume in cognitively normal elderly patients with type 2 diabetes.

METHODS

Brain volumes for the superior, middle, and inferior frontal gyri and for the middle temporal gyrus were generated from structural T1 MRI in 181 study participants (Hp 1-1: n = 24, Hp 2-1: n = 77, Hp 2-2: n = 80). Daily vitamin E intake was assessed using the Food Frequency Questionnaire. Analyses of covariance, controlling for demographic and cardiovascular variables was used to evaluate whether the association of daily vitamin E intake with brain volume was modified by Hp genotype.

RESULTS

Average age was 70.8 (SD = 4.2) with 40% females, and mean Mini-Mental State Examination score of 28.17 (SD = 1.90). A significant interaction was found between vitamin E intake and Hp genotype in inferior frontal gyrus' volume; p = 0.0108. For every 1 microgram increase in vitamin E intake, the volume of the inferior frontal gyrus decreased by 0.955% for Hp 1-1 (p = 0.0348), increased by 0.429% for Hp 2-1 (p = 0.0457), and by 0.077% for Hp 2-2 (p = 0.6318). There were no significant interactions between vitamin E intake and Hp genotype for the middle (p = 0.6011) and superior (p = 0.2025) frontal gyri or for the middle temporal gyrus (p = 0.503).

CONCLUSIONS

The effect of dietary vitamin E on the brain may differ by Hp genotype. Studies examining the impact of vitamin E on brain-related outcomes should consider Hp genotype.

Chronic oral treatment with risperidone impairs recognition memory and alters brain-derived neurotrophic factor and related signaling molecules in rats

Antipsychotic drugs (APDs) are essential for the treatment of schizophrenia and other neuropsychiatric illnesses such as bipolar disease. However, they are also extensively prescribed off-label for many other conditions, a practice that is controversial given their potential for long-term side effects. There is clinical and preclinical evidence that chronic treatment with some APDs may lead to impairments in cognition and decreases in brain volume, although the molecular mechanisms of these effects are unknown. The purpose of the rodent studies described here was to evaluate a commonly prescribed APD, risperidone, for chronic effects on recognition memory, brain-derived neurotrophic factor (BDNF), its precursor proBDNF, as well as relevant downstream signaling molecules that are known to influence neuronal plasticity and cognition. Multiple cohorts of adult rats were treated with risperidone (2.5 mg/kg/day) or vehicle (dilute acetic acid solution) in their drinking water for 30 or 90 days. Subjects were then evaluated for drug effects on recognition memory in a spontaneous novel object recognition task and protein levels of BDNF-related signaling molecules in the hippocampus and prefrontal cortex. The results indicated that depending on the treatment period, a therapeutically relevant daily dose of risperidone impaired recognition memory and increased the proBDNF/BDNF ratio in the hippocampus and prefrontal cortex. Risperidone treatment also led to a decrease in Akt and CREB phosphorylation in the prefrontal cortex. These results indicate that chronic treatment with a commonly prescribed APD, risperidone, has the potential to adversely affect recognition memory and neurotrophin-related signaling molecules that support synaptic plasticity and cognitive function.

Automatic volumetry of cerebrospinal fluid and brain volume in severe paediatric hydrocephalus, implementation and clinical course after intervention

BACKGROUND

In childhood hydrocephalus, both the amount of cerebrospinal fluid and the brain volume are relevant for the prognosis of the development and for therapy monitoring. Since classical planar measurements of ventricular size are subject to strong limitations, imprecise and neglect brain volume, 3D volumetry is most desirable. We used and evaluated the robust segmentation algorithms of the freely available FSL-toolbox in paediatric hydrocephalus patients before and after specific therapy.

METHODS

Retrospectively 76 pre- and postoperative high-resolution T2-weighted MRI sequences (true FISP, 1 mm isovoxel) were analyzed in 38 patients with paediatric hydrocephalus (mean 4.4 ± 5.1 years) who underwent surgical treatment (ventriculo-peritoneal (VP) shunt n = 22, endoscopic third ventriculostomy (ETV) n = 16). After preprocessing, the 3D-datasets were skull stripped to estimate the inner skull surface. Following, a 2 class segmentation into different tissue types (brain matter and CSF) was performed. The volumes of CSF and brain were calculated.

RESULTS

The method could be implemented in an automated fashion in all 76 MRIs. In the VP shunt cohort, the amount of CSF (p < 0.001) decreased. Consecutively brain volume increased significantly (p < 0.001). Following ETV, CSF volume (p = 0.019) decreased significantly (p = 0.012) although the reduction was less pronounced than after shunt implantation. Brain volume expanded (p = 0.02).

CONCLUSION

A reliable automated segmentation of CSF and brain could be performed with the implemented algorithm. The method was able to track changes after therapy and detected significant differences in CSF and brain volumes after shunting and after ETV.

Individual and social factors affecting the ability of American crows to solve and master a string pulling task

Crows and other birds in the family Corvidae regularly share information to learn the identity and whereabouts of dangerous predators, but can they use social learning to solve a novel task for a food reward? Here we examined the factors affecting the ability of 27 wild-caught American crows to solve a common string-pulling task in a laboratory setting. We split crows into two groups; one group was given the task after repeatedly observing a conspecific model the solution, the other solved in the absence of conspecific models. We recorded the crows' estimated age, sex, size, body condition, level of nervousness, and brain volume using DICOM images from a CT scan. Although none of these variables were statistically significant, crows without a conspecific model and large brain volumes consistently mastered the task in the minimum number of days, whereas those with conspecific models and smaller brain volumes required varying and sometimes a substantial number of days to master the task. We found indirect evidence that body condition might also be important for motivating crows to solve the task. Crows with conspecific models were no more likely to initially solve the task than those working the puzzle without social information, but those that mastered the task usually copied the method most frequently demonstrated by their knowledgeable neighbors. These findings suggest that brain volume and possibly body condition may be factors in learning new tasks, and that crows can use social learning to refine their ability to obtain a novel food source, although they must initially learn to access it themselves.

Untargeted metabolomic analysis of plasma from relapsing-remitting multiple sclerosis patients reveals changes in metabolites associated with structural changes in brain

BACKGROUND

Changes in peripheral blood amino acids have been noted in Relapse Remitting Multiple Sclerosis (RRMS), suggesting their potential diagnostic value in anticipating disease progression.

OBJECTIVE

The present study sought to comprehensively assess the plasma metabolome, including amino acids, of RRMS patient and unaffected controls, to identify potential biomarkers of RRMS disease pathogenesis.

METHODS

Untargeted NMR metabolomics was performed on plasma from 28 RRMS patients and 18 unaffected controls to test the hypothesis that metabolomic markers are altered in RRMS patients in association with lesion load, brain atrophy and cognitive performance.

RESULTS

There were no significant differences between RRMS and controls in age, sex and total brain volume. Brain fractional volumes of gray matter, white matter, thalamus and parenchyma as well as multiple neurocognitive scores were significantly lower in RRMS patients compared to unaffected controls. Concentrations of nine plasma metabolites (arginine, isoleucine, citrate, serine, phenylalanine, methionine, asparagine, histidine, myo-inositol) were significantly lower in RRMS patients compared to controls. Plasma arginine concentrations were positively correlated with T1 holes and white matter lesions, and plasma methionine concentrations were positively correlated with T1 holes, but not white matter lesions. Serine was negatively correlated with performance on the Brief Visuospatial Memory Test in controls but not RRMS patients.

CONCLUSIONS

The identified disturbances in metabolite concentrations might be developed as new markers of neuroanatomical vulnerability in RRMS, should the findings be reproduced in larger cohort studies.

The Clock Is Ticking - Brain Atrophy in Case of Acute Trauma?

Objective

Brain atrophy and brain herniation are gaining a lot of attention separately, but a limited amount of studies connected them together, and because of this, we are going to review and examine the subject in the current meta-analysis.

Methods

The authors collected data reporting brain atrophy of alcoholic and schizophrenic cause, as well as data on control patients, all of which was published on MEDLINE between 1996 and 2018. The included 11 articles were processed with a statistical program.

Results

We found that the pericerebral space is unequal among the groups, while the intracranial volume is strongly correlated to the biggest foramen of the body. The effect of this inequality, however, is expressed in emergency cases, where the patients with brain atrophy will have more time before the final stage of brain herniation.

Conclusion

The current study raises a controversial issue that requires careful investigation and high attention from the health care personnel.