Lobe Of Brain Research Articles

Astrocyte expression of aging-associated markers positively correlates with neurodegeneration in the frontal lobe of the rhesus macaque brain.

As the population over the age of 65 increases, rates of neurodegenerative disorders and dementias will rise - necessitating further research into the cellular and molecular mechanisms that contribute to brain aging. With the critical importance of astrocytes to neuronal health and functioning, we hypothesized that alterations in astrocyte expression of aging-associated markers p16INK4a (p16) and sirtuin 1 (SIRT1) with age would correlate with increased rates of neurodegeneration, as measured by FluoroJade C (FJC) staining. To test this hypothesis, 19 rhesus macaques at the Tulane National Primate Research Center were selected based on the following criteria: archival FFPE CNS tissue available to use, no noted neuropathology, and an age range of 5-30 years. Tissues were cut at 5 μm and stained for GFAP, p16, SIRT1, and FJC, followed by whole-slide imaging and HALO® image analysis for percentage of marker-positive cells and relative intensity of each stain. We found the percentage of p16+ cells increases with age in total cells and astrocytes of the frontal (p = 0.0021, p = 0.0012 respectively) and temporal (p = 0.0226, p = 0.0203 respectively) lobes, as well as the relative intensity of p16 staining (frontal lobe: p = 0.0060; temporal lobe: p = 0.0269). For SIRT1, we found no correlation with age except for an increase in the relative intensity of SIRT1 in the temporal lobe (p = 0.0033). There was an increase in neurodegeneration, as measured by the percentage of FJC+ cells in the frontal lobe with age (p = 0.0057), as well as in the relative intensity of FJC staining in the frontal (p = 0.0030) and parietal (p = 0.0481) lobes. Importantly, increased p16 and SIRT1 expression in astrocytes correlated with increasing neurodegeneration in the frontal lobe (p = 0.0009, p = 0.0095 respectively). Together, these data suggest that age-associated alterations in astrocytes contribute to neurodegeneration and provide a target for mechanistic studies in the future.

Automatic detection of obsessive-compulsive disorder from EEG signals based on Hilbert-Huang transform and sparse coding classification

Obsessive-compulsive disorder (OCD) is a chronic disease and psychosocial disorder that significantly reduces the quality of life of patients and affects their personal and social relationships. Therefore, early diagnosis of this disorder is of particular importance and has attracted the attention of researchers. In this research, new statistical differential features are used, which are suitable for EEG signals and have little computational load. Hilbert-Huang transform was applied to EEGs recorded from 26 OCD patients and 30 healthy subjects to extract instant amplitude and phase. Then, modified mean, variance, median, kurtosis and skewness were calculated from amplitude and phase data. Next, the difference of these statistical features between various pairs of EEG channels was calculated. Finally, different scenarios of feature classification were examined using the sparse nonnegative least squares classifier. The results showed that the modified mean feature calculated from the amplitude and phase of the interhemispheric channel pairs produces a high accuracy of 95.37%. The frontal lobe of the brain also created the most distinction between the two groups among other brain lobes by producing 90.52% accuracy. In addition, the features extracted from the frontal-parietal network produced the best classification accuracy (93.42%) compared to the other brain networks examined. The method proposed in this paper dramatically improves the accuracy of EEG classification of OCD patients from healthy individuals and produces much better results compared to previous machine learning techniques.

Assessing the in vivo toxicity of titanium dioxide nanoparticles in Schmidtea mediterranea: uptake pathways and (neuro)developmental outcomes

Titanium dioxide nanoparticles (TiO2-NPs) in aquatic environments, originating from urban run-off, product use and post-consumer degradation, interact with aquatic organisms through water and sediments. Thorough toxicity assessment requires comprehensive data across all ecosystem compartments especially the benthic zone, which is currently lacking. Moreover, a proper physicochemical characterization of the particles is needed before and during toxicity assessment. In the present work, we used the planarian Schmidtea mediterranea to investigate the effects of TiO2-NPs (5 mg/L and 50 mg/L). Planarians are benthic organisms that play an important role in the food chain as predators. Our study integrated particle characterization with toxicokinetic and toxicodynamic parameters and showed that the uptake of TiO2-NPs of 21 nm occurred through the epidermis and intestine. Epidermal irritation and mucus production occurred immediately after exposure, and TiO2-NPs induced stronger effects in regenerating organisms. More specifically, TiO2-NPs interfered with neuroregeneration, inducing behavioral effects. A delay in the formation of the anterior commissure between the two brain lobes after seven and nine days of exposure to 50 mg/L was observed, probably as a result of a decrease in stem cell proliferation. Our findings underscore the need to incorporate multiple exposure routes in toxicity screenings. Additionally, we highlight the vulnerability of developing organisms and recommend their inclusion in future risk assessment strategies.

MAPT Mutations V337M and N297K Alter Organelle Trafficking in Frontotemporal Dementia Patient-Specific Motor Neurons.

Frontotemporal dementia (FTD) is a neurodegenerative disease characterized by the progressive loss of neurons mainly in the frontal and temporal lobes of the brain. Mutations (e.g., V337M, N297K) in the microtubule-associated protein TAU (MAPT) are responsible 5-20% of familial FTD cases and have been associated with defects in organelle trafficking that plays a critical role in the proper function of cells, including transport of essential molecules and degradation of waste products. Due to the critical role of TAU mutations in microtubule stabilization and organelle transportation, it is of great interest to study these molecular mechanisms to develop effective therapeutic strategies. Therefore, herein, we analyzed mitochondrial and lysosomal trafficking in disease-specific spinal motor neurons by using live cell imaging in undirected (uncompartmentalized) and directed (compartmentalized) cell culture systems. While V337M neurons only expressed 3R TAU, the N297K mutant neurons expressed both 3R and 4R TAU. Axonal trafficking was affected differentially in V337M and N297 MAPT mutated neurons. These findings suggest that the MAPT mutations V337M and N297K impaired axon physiology differentially, which highlights the need for mutation- and/or 3R/4R TAU-specific therapeutic approaches.

Intracerebral Dynamics of Sleep Arousals: A Combined Scalp-Intracranial EEG Study.

As an intrinsic component of sleep architecture, sleep arousals represent an intermediate state between sleep and wakefulness and are important for sleep-wake regulation. They are defined in an all-or-none manner, whereas they actually present a wide range of scalp-electroencephalography (EEG) activity patterns. It is poorly understood how these arousals differ in their mechanisms. Stereo-EEG (SEEG) provides the unique opportunity to record intracranial activities in superficial and deep structures in humans. Using combined polysomnography and SEEG, we quantitatively categorized arousals during nonrapid eye movement sleep into slow wave (SW) and non-SW arousals based on whether they co-occurred with a scalp-EEG SW event. We then investigated their intracranial correlates in up to 26 brain regions from 26 patients (12 females). Across both arousal types, intracranial theta, alpha, sigma, and beta activities increased in up to 25 regions (p < 0.05; d = 0.06-0.63), while gamma and high-frequency (HF) activities decreased in up to 18 regions across the five brain lobes (p < 0.05; d = 0.06-0.44). Intracranial delta power widely increased across five lobes during SW arousals (p < 0.05 in 22 regions; d = 0.10-0.39), while it widely decreased during non-SW arousals (p < 0.05 in 19 regions; d = 0.10-0.30). Despite these main patterns, unique activities were observed locally in some regions such as the hippocampus and middle cingulate cortex, indicating spatial heterogeneity of arousal responses. Our results suggest that non-SW arousals correspond to a higher level of brain activation than SW arousals. The decrease in HF activities could potentially explain the absence of awareness and recollection during arousals.

Hypergraph of Functional Connectivity Based on Event-Related Coherence: Magnetoencephalography Data Analysis

We construct hypergraphs to analyze functional brain connectivity, leveraging event-related coherence in magnetoencephalography (MEG) data during the visual perception of a flickering image. Principal network characteristics are computed for the delta, theta, alpha, beta, and gamma frequency ranges. Employing a coherence measure, a statistical estimate of correlation between signal pairs across frequencies, we generate an edge time series, depicting how an edge evolves over time. This forms the basis for constructing an edge-to-edge functional connectivity network. We emphasize hyperedges as connected components in an absolute-valued functional connectivity network. Our coherence-based hypergraph construction specifically addresses functional connectivity among four brain lobes in both hemispheres: frontal, parietal, temporal, and occipital. This approach enables a nuanced exploration of individual differences within diverse frequency bands, providing insights into the dynamic nature of brain connectivity during visual perception tasks. The results furnish compelling evidence supporting the hypothesis of cortico–cortical interactions occurring across varying scales. The derived hypergraph illustrates robust activation patterns in specific brain regions, indicative of their engagement across diverse cognitive contexts and different frequency bands. Our findings suggest potential integration or multifunctionality within the examined lobes, contributing valuable perspectives to our understanding of brain dynamics during visual perception.

Cortical incisions and transcortical approaches for intra-axial and intraventricular lesions: A scoping review.

Transcortical approaches, encompassing various surgical corridors, have been employed to treat an array of intraparenchymal or intraventricular brain pathologies, including tumors, vascular malformations, infections, intracerebral hematomas, and epileptic surgery. Designing cortical incisions relies on the lesion location and characteristics, knowledge of eloquent functional anatomy, and advanced imaging such as tractography. Despite their widespread use in neurosurgery, there is a noticeable lack of systematic studies examining their common lobe access points, associated complications, and prevalent pathologies. This scoping review assesses current evidence to guide the selection of transcortical approaches for treating a variety of intracranial pathologies. A scoping review was conducted using the PRISMA-ScR guidelines, searching PubMed, EMBASE, Scopus, and Web of Science. Studies were included if ≥5 patients operated on using transcortical approaches, with reported data on clinical features, treatments, and outcomes. Data analysis and synthesis were performed. A total of 50 articles encompassing 2604 patients were included in the study. The most common primary pathology was brain tumors (60.6%), particularly gliomas (87.4%). The transcortical-transtemporal approach was the most frequently identified cortical approach (70.48%), and the temporal lobe was the most accessed brain lobe (55.68%). The postoperative course outcomes were reported as good (55.52%), poor (28.38%), and death (14.62%). Transcortical approaches are crucial techniques for managing a wide range of intracranial lesions, with the transcortical-transtemporal approach being the most common. According to the current literature, the selective choice of cortical incision and surgical corridor based on the lesion's pathology and anatomic-functional location correlates with acceptable functional outcomes.

Effect of 24-form simplified Tai Chi on executive inhibitory control of college students: a randomized controlled trial of EEG.

College students, undergoing crucial cognitive development, face challenges during the COVID-19 pandemic that impact their executive functions. While existing research indicates positive effects of Tai Chi (TC) on college students' cognitive abilities, there is a scarcity of studies investigating its impact on executive functions and frontal brain activity. This study aimed to compare the effects of 24-form simplified TC training on college students' executive functions and frontal brain electrical activity. The hypothesis posited that the TC group would exhibit superior performance compared to the control group during COVID-19 pandemic. Seventy college students were randomly assigned to either TC group or control group, engaging in 36 sessions (3 sessions per week, 45 min each) over 12 weeks. Executive inhibitory control was assessed using the Stroop Color and Word Test, and resting brain electrical activity in the frontal area was recorded through Electroencephalography. ACC was influenced by group, group-time interaction, and Stroop task-time interaction. RT was affected by time, task condition, task condition-time interaction, and task condition-group interaction. Notably, the TC group showed improved ACC (from 96.54 ± 3.27% to 98.90 ± 1.32%) and decreased RT (from 0.73 ± 0.12 to 0.66 ± 0.07 s), particularly in the inconsistent task. Regarding EEG band power, significant Group and Time interaction effects were found in F3-θ, F3-α, F3-β, F4-θ, and F4-α. Moreover, within the TC group, significant increases in F3-θ band power (from 4.66 ± 3.55 to 7.71 ± 8.44) and F4-θ band power (from 4.41 ± 2.82 to 8.61 ± 9.51) (10-3·μV·Hz) were noted pre-and post-tests. In the control group, significant decreases were observed in F3-α band power (from 5.18 ± 4.61 to 2.79 ± 2.11) and F4-α band power (from 5.57 ± 6.58 to 2.48 ± 1.95) (10-3·μV·Hz). The pandemic-induced panic may impact frontal lobe brain activity in college students. TC training not only improves executive inhibitory control but may also enhance localized brain activity, suggesting its potential as a holistic intervention for cognitive and neurological well-being during stressful periods.

Differing patterns of cortical grey matter pathology identified by multifractal analysis in UMN-predominant ALS patients with and without corticospinal tract hyperintensity

The pathological hallmarks of amyotrophic lateral sclerosis (ALS) are degeneration of the primary motor cortex grey matter (GM) and corticospinal tract (CST) resulting in upper motor neuron (UMN) dysfunction. Conventional brain magnetic resonance imaging (MRI) shows abnormal CST hyperintensity in some UMN-predominant ALS patients (ALS-CST+) but not in others (ALS-CST–). In addition to the CST differences, we aimed to determine whether GM degeneration differs between ALS-CST+ and ALS-CST– patients by cortical thickness (CT), voxel-based morphometry (VBM) and fractal dimension analyses. We hypothesized that MRI multifractal (MF) measures could differentiate between neurologic controls (n = 14) and UMN-predominant ALS patients as well as between patient subgroups (ALS-CST+, n = 21 vs ALS-CST–, n = 27). No significant differences were observed in CT or GM VBM in any brain regions between patients and controls or between ALS subgroups. MF analyses were performed separately on GM of the whole brain, of frontal, parietal, occipital, and temporal lobes as well as of cerebellum. Estimating MF measures D (Q = 0), D (Q = 1), D (Q = 2), Δf, Δα of frontal lobe GM classified neurologic controls, ALS-CST+ and ALS-CST– groups with 98% accuracy and > 95% in F1, recall, precision and specificity scores. Classification accuracy was only 74% when using whole brain MF measures and < 70% for other brain lobes. We demonstrate that MF analysis can distinguish UMN-predominant ALS subgroups based on GM changes, which the more commonly used quantitative approaches of CT and VBM cannot.

Angong niuhuang pill improves the neurological function of younger patients with basal ganglia and cerebral lobe intracerebral hemorrhage: A randomized controlled trial

Background &amp; Objective: Spontaneous intracerebral hemorrhage (SICH) is one of the stroke forms with the highest disability and mortality rates and significant differences in prognosis among patients with different locations of SICH. Angong Niuhuang Pill (ANP) 安宫牛黄丸 is one of the most well-known traditional Chinese patent medicines used in the clinical emergency treatment of cardio-cerebrovascular diseases. This prospective study was performed to determine the therapeutic effect of ANP in different locations of SICH. Methods: Patients with basal ganglia(n=81) and cerebral lobe (n=67) hemorrhage were randomly assigned into two groups: the standard medical management (SMM) group and the combined ANP as well as medical management group (ANP group). Fisher exact test and Mann- Whitney U test were used for comparing the differences between two groups. Primary and secondary outcomes were the 6-month modified Rankin Scale (mRS) scores and the 2-week Brunnstrom stage ratings. Results: For patients with basal ganglia hemorrhage and cerebral lobe hemorrhage, there were no significant differences observed between the ANP group and the SMM group in terms of patient age (53.1±5.3 vs 52.7±6.4; 54.7±4.8 vs 52.7±5.9), sex (male:64.3% vs 53.8%; 63.6% vs 58.8%), body mass index (25.1±2.1 vs 24.2±2.6; 25.6±2.0 vs 25.0±2.4), mean hematoma volume (17.1±6.6 vs 18.6±5.7; 18.4±7.4 vs 18.9±6.0), as well as the proportions of hypertension (88.1%vs71.8%; 90.9% vs 76.5%), alcoholism (40.5% vs 51.3%; 54.6% vs 41.2%), smoking (40.5% vs 38.5%; 36.4% vs 38.2%), and diabetes mellitus (21.4% vs 18%; 12.1% vs 17.7%). The proportion of basal ganglia hemorrhage patients with a 6-month mRS score of 0-2 in the ANP group was significantly higher than that in the SMM group (26.2% vs. 2.6%, P=0.004), but it was not significantly improved in patients with cerebral lobe hemorrhage (57.6% vs 38.2%, P=0.145). The 2-week Brunnstrom stage ratings of patients with basal ganglia hemorrhage were significant difference (P=0.048). But for patients with cerebral lobe hemorrhage, there was no significant difference (P=0.164). The incidence of liver dysfunction, renal dysfunction, gastrointestinal dysfunction, hypothermia and allergy in the two groups of patients was not significantly different. Conclusions: ANP has different therapeutic effects on different locations of SICH, and has the most obvious effect on improving the long-term neurological function of patients with basal ganglia hemorrhage.

Autism Classification and Identification of Significant Brain Lobe Using Cepstral Coefficients

Autism Classification and Identification of Significant Brain Lobe Using Cepstral Coefficients

Multiparametric Quantitative MRI Evaluation of Changes in Brain Myelin Content after the First Course of Chemotherapy

Objective. Quantitative assessment of changes in brain myelin content after the first course of chemotherapyMaterials and Methods. T1 and T2 maps as well as myelin water fraction (MWF) and macromolecular proton fraction (MPF) maps, reflecting myelin content, were acquired in 6 patients (mean age — 13.7 ± 2.4 years) before and after the first course of chemotherapy. The study was carried out using on 3T MRI scanner. Statistical data processing was carried out using the GraphPad Prism.Results. MPF and T2 values showed an increase in the thalamus and white matter of the occipital lobes of the brain, while MWF values showed an increase in the cerebellum and a decline in the white matter of the frontal lobes. Significant changes were not found for T1 values.Discussion. According to MWF the structures of the brain which are primarily affected by treatment with toxic drugs — the white matter of the frontal lobes and the cerebellum, were revealed. MWF values decreasing in the white matter of the frontal lobes may indicate the process of demyelination in this area, while increased MWF values in the cerebellum could be caused either by remyelination processes or by incomplete cleansing of myelin residues accumulation by macrophages at the site of degeneration. Conclusion. The results obtained demonstrated high potential of MWF values serve as early changes biomarker of neurotoxicity after the chemotherapy treatment. Along with this, the MPF index, which is more sensitive to cerebral edema, may be a predictor of demyelination.

TractGeoNet: A geometric deep learning framework for pointwise analysis of tract microstructure to predict language assessment performance

We propose a geometric deep-learning-based framework, TractGeoNet, for performing regression using diffusion magnetic resonance imaging (dMRI) tractography and associated pointwise tissue microstructure measurements. By employing a point cloud representation, TractGeoNet can directly utilize tissue microstructure and positional information from all points within a fiber tract without the need to average or bin data along the streamline as traditionally required by dMRI tractometry methods. To improve regression performance, we propose a novel loss function, the Paired-Siamese Regression loss, which encourages the model to focus on accurately predicting the relative differences between regression label scores rather than just their absolute values. In addition, to gain insight into the brain regions that contribute most strongly to the prediction results, we propose a Critical Region Localization algorithm. This algorithm identifies highly predictive anatomical regions within the white matter fiber tracts for the regression task. We evaluate the effectiveness of the proposed method by predicting individual performance on two neuropsychological assessments of language using a dataset of 20 association white matter fiber tracts from 806 subjects from the Human Connectome Project Young Adult dataset. The results demonstrate superior prediction performance of TractGeoNet compared to several popular regression models that have been applied to predict individual cognitive performance based on neuroimaging features. Of the twenty tracts studied, we find that the left arcuate fasciculus tract is the most highly predictive of the two studied language performance assessments. Within each tract, we localize critical regions whose microstructure and point information are highly and consistently predictive of language performance across different subjects and across multiple independently trained models. These critical regions are widespread and distributed across both hemispheres and all cerebral lobes, including areas of the brain considered important for language function such as superior and anterior temporal regions, pars opercularis, and precentral gyrus. Overall, TractGeoNet demonstrates the potential of geometric deep learning to enhance the study of the brain's white matter fiber tracts and to relate their structure to human traits such as language performance.

The Relationship of Cortisol Levels and Sleep Quality in Acute Ischemic Stroke Patients: A Literature Review

Hormonal factors are one of several elements that contribute to the process by which patients with acute ischemic stroke experience poor sleep quality. The hypothalamic-pituitary-adrenal (HPA) axis is responsible for producing the hormone cortisol. When the hypothalamus is activated, it releases vasopressin and Corticotropin Releasing Hormone (CRH), both of which influence Adrenocorticotropic Hormone (ACTH). This hormone triggers release of cortisol and other glucocorticoids by the adrenal glands. The HPA axis becomes engaged during an acute disease. Cortisol levels will rise as a result of HPA axis activation. Specifically, injury to the frontal or medial temporal lobes of the brain, as well as inflammation, or a lack of regulation of the HPA axis, can lead to this medical condition. Cortisol levels might remain elevated for up to seven days following the start of a stroke. An increase in cortisol levels is connected to an highly risk of stroke severity, length of hospital stay, and mortality in stroke patients. It is also an early warning sign of deteriorating sleep quality in patients with acute ischemic stroke.

Lower region-specific gray matter volume in females with atypical anorexia nervosa and anorexia nervosa.

Few studies have focused on brain structure in atypical anorexia nervosa (atypical AN). This study investigates differences in gray matter volume (GMV) between females with anorexia nervosa (AN) and atypical AN, and healthy controls (HC). Structural magnetic resonance imaging data were acquired for 37 AN, 23 atypical AN, and 41 HC female participants. Freesurfer was used to extract GMV, cortical thickness, and surface area for six brain lobes and associated cortical regions of interest (ROI). Primary analyses employed linear mixed-effects models to compare group differences in lobar GMV, followed by secondary analyses on ROIs within significant lobes. We also explored relationships between cortical gray matter and both body mass index (BMI) and symptom severity. Our primary analyses revealed significant lower GMV in frontal, temporal and parietal areas (FDR < .05) in AN and atypical AN when compared to HC. Lobar GMV comparisons were non-significant between atypical AN and AN. The parietal lobe exhibited the greatest proportion of affected cortical ROIs in both AN versus HC and atypical AN versus HC. BMI, but not symptom severity, was found to be associated with cortical GMV in the parietal, frontal, temporal, and cingulate lobes. No significant differences were observed in cortical thickness or surface area. We observed lower GMV in frontal, temporal, and parietal areas, when compared to HC, but no differences between AN and atypical AN. This indicates potentially overlapping structural phenotypes between these disorders and evidence of brain changes among those who are not below the clinical underweight threshold. Despite individuals with atypical anorexia nervosa presenting above the clinical weight threshold, lower cortical gray matter volume was observed in partial, temporal, and frontal cortices, compared to healthy individuals. No significant differences were found in cortical gray matter volume between anorexia nervosa and atypical anorexia nervosa. This underscores the importance of continuing to assess and target weight gain in clinical care, even for those who are presenting above the low-weight clinical criteria.

FEATURES OF DISORDERS IN MNESTIC ACTIVITY OF PATIENTS WITH CEREBRAL INFARCTION WITH LESION LOCALISATION IN THE LEFT AND RIGHT HEMISPHERES

The article presents a study of memory impairment in patients with different lesion localisation during an acute cerebrovascular event in the left and right hemispheres. The condition of 72 patients (average age of the sample 46.11±0.9 years) who were found to have damage to the temporal, parietal and occipital lobes of the brain was studied. The characteristics of the mnestic function were assessed using standard neuropsychological techniques. Damage to the left hemisphere led to significant difficulties in memorising texts, a decrease in verbal and auditory memory, the ability to build associative connections and use various mnemonic devices. The deficit in the functioning of the right hemisphere was distinguished by a large defect in memorising visual material. The identified “weaknesses” and “strengths” of patients are extremely important for the development of personalised rehabilitation programmes and future prediction of the recovery process after a cerebral infarction.

BrainAGE: Revisited and reframed machine learning workflow.

Since the introduction of the BrainAGE method, novel machine learning methods for brain age prediction have continued to emerge. The idea of estimating the chronological age from magnetic resonance images proved to be an interesting field of research due to the relative simplicity of its interpretation and its potential use as a biomarker of brain health. We revised our previous BrainAGE approach, originally utilising relevance vector regression (RVR), and substituted it with Gaussian process regression (GPR), which enables more stable processing of larger datasets, such as the UK Biobank (UKB). In addition, we extended the global BrainAGE approach to regional BrainAGE, providing spatially specific scores for five brain lobes per hemisphere. We tested the performance of the new algorithms under several different conditions and investigated their validity on the ADNI and schizophrenia samples, as well as on a synthetic dataset of neocortical thinning. The results show an improved performance of the reframed global model on the UKB sample with a mean absolute error (MAE) of less than 2 years and a significant difference in BrainAGE between healthy participants and patients with Alzheimer's disease and schizophrenia. Moreover, the workings of the algorithm show meaningful effects for a simulated neocortical atrophy dataset. The regional BrainAGE model performed well on two clinical samples, showing disease-specific patterns for different levels of impairment. The results demonstrate that the new improved algorithms provide reliable and valid brain age estimations.

Frontotemporal Dementia: A Clinical Review

Frontotemporal dementia is a disease in which atrophic changes occur in the frontal lobes and frontal temporal lobes of the brain. Frontotemporal dementias are a clinically, neuroanatomically and pathologically diverse group of diseases that collectively constitute an important cause of young-onset dementia. The most common form of frontotemporal dementia is the so-called behavioral variant of frontotemporal dementia. Underlying these pathological changes is the degeneration of nerve cells (i.e. neurons), which occurs through the accumulation of abnormal proteins inside them. Therefore, the review of current studies in the subject of Frontotemporal dementia was conducted in order to access possible risk factors and new ways of management and treatment of this complex disease.

Agent Orange Herbicidal Toxin-Initiation of Alzheimer-Type Neurodegeneration.

Agent Orange (AO) is a Vietnam War-era herbicide that contains a 1 : 1 ratio of 2,4-dichlorophenoxyacetic acid (2,4-D) and 2,4,5-trichlorophenoxyacetic acid (2,4,5-T). Emerging evidence suggests that AO exposures cause toxic and degenerative pathologies that may increase the risk for Alzheimer's disease (AD). This study investigates the effects of the two main AO constituents on key molecular and biochemical indices of AD-type neurodegeneration. Long Evans rat frontal lobe slice cultures treated with 250μg/ml of 2,4-D, 2,4,5-T, or both (D + T) were evaluated for cytotoxicity, oxidative injury, mitochondrial function, and AD biomarker expression. Treatment with the AO constituents caused histopathological changes corresponding to neuronal, white matter, and endothelial cell degeneration, and molecular/biochemical abnormalities indicative of cytotoxic injury, lipid peroxidation, DNA damage, and increased immunoreactivity to activated Caspase 3, glial fibrillary acidic protein, ubiquitin, tau, paired-helical filament phosphorylated tau, AβPP, Aβ, and choline acetyltransferase. Nearly all indices of cellular injury and degeneration were more pronounced in the D + T compared with 2,4-D or 2,4,5-T treated cultures. Exposures to AO herbicidal chemicals damage frontal lobe brain tissue with molecular and biochemical abnormalities that mimic pathologies associated with early-stage AD-type neurodegeneration. Additional research is needed to evaluate the long-term effects of AO exposures in relation to aging and progressive neurodegeneration in Vietnam War Veterans.

Swiss trial of decompressive craniectomy versus best medical treatment of spontaneous supratentorial intracerebral haemorrhage (SWITCH): an international, multicentre, randomised-controlled, two-arm, assessor-blinded trial.

Decompressive craniectomy (DC) is beneficial in people with malignant middle cerebral artery infarction. Whether DC improves outcome in spontaneous intracerebral haemorrhage (ICH) is unknown. To determine whether DC without haematoma evacuation plus best medical treatment (BMT) in people with ICH decreases the risk of death or dependence at 6 months compared to BMT alone. SWITCH is an international, multicentre, randomised (1:1), two-arm, open-label, assessor-blinded trial. Key inclusion criteria are age ⩽75 years, stroke due to basal ganglia or thalamic ICH that may extend into cerebral lobes, ventricles or subarachnoid space, Glasgow coma scale of 8-13, NIHSS score of 10-30 and ICH volume of 30-100 mL. Randomisation must be performed <66 h after onset and DC <6 h after randomisation. Both groups will receive BMT. Participants randomised to the treatment group will receive DC of at least 12 cm in diameter according to institutional standards. A sample of 300 participants randomised 1:1 to DC plus BMT versus BMT alone provides over 85% power at a two-sided alpha-level of 0.05 to detect a relative risk reduction of 33% using a chi-squared test. The primary outcome is the composite of death or dependence, defined as modified Rankin scale score 5-6 at 6 months. Secondary outcomes include death, functional status, quality of life and complications at 180 days and 12 months. SWITCH will inform physicians about the outcomes of DC plus BMT in people with spontaneous deep ICH, compared to BMT alone. ClinicalTrials.gov Identifier: NCT02258919.