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Perivascular cerebrospinal fluid (pCSF) flow is a key component of the glymphatic system. Arterial pulsation has been proposed as the main driving force of pCSF influx along the superficial and penetrating arteries; however, evidence of this mechanism in humans is limited. We proposed an experimental framework of dynamic diffusion tensor imaging with low b-values and ultra-long echo time (dynDTI low-b ) to capture pCSF flow properties during the cardiac cycle in human brains. Healthy adult volunteers (aged 17-28 years; seven men, one woman) underwent dynDTI low-b using a 3T scanner (MAGNETOM Prisma, Siemens Healthcare, Erlangen, Germany) with simultaneously recorded cardiac output. The results showed that diffusion tensors reconstructed from pCSF were mainly oriented in the direction of the neighboring arterial flow. When switching from vasoconstriction to vasodilation, the axial and radial diffusivities of the pCSF increased by 5.7 % and 4.94 %, respectively, suggesting that arterial pulsation alters the pCSF flow both parallel and perpendicular to the arterial wall. DynDTI low-b signal intensity at b=0 s/mm 2 (i.e., T2-weighted, [S(b=0 s/mm 2 )]) decreased in systole, but this change was ∼7.5 % of a cardiac cycle slower than the changes in apparent diffusivity, suggesting that changes in S(b=0 s/mm 2 ) and apparent diffusivity arise from distinct physiological processes and potential biomarkers associated with perivascular space volume and pCSF flow, respectively. Additionally, the mean diffusivities of white matter showed cardiac-cycle dependencies similar to pCSF, although a delay relative to the peak time of apparent diffusivity in pCSF was present, suggesting that dynDTI low-b could potentially reveal the dynamics of magnetic resonance imaging-invisible pCSF surrounding small arteries and arterioles in white matter; this delay may result from pulse wave propagation along penetrating arteries. In conclusion, the vasodilation-induced increases in axial and radial diffusivities of pCSF and mean diffusivities of white matter are consistent with the notion that arterial pulsation can accelerate pCSF flow in human brain. Furthermore, the proposed dynDTI low-b technique can capture various pCSF dynamics in artery pulsation., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024. Published by Elsevier Inc.)

This study sought to define the transit of cefepime between plasma and cerebral spinal fluid (CSF) in a rat model. Male Sprague-Dawley rats received cefepime intravenously. A total daily dose of 150 mg/kg of body weight/day was administered as a single injection every 24 h for 4 days. Plasma samples were obtained via a second dedicated intravenous catheter. CSF sampling occurred via an intracisternal catheter. Cefepime levels in plasma and CSF were quantified via liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pharmacokinetic (PK) analyses were conducted using Pmetrics for R. PK parameters and exposures during the first 24 h (i.e., area under the concentration-time curve from 0 to 24 h [AUC 0-24 ] and maximum concentration of drug in serum from 0 to 24 h [ C max 0-24 ]) were calculated from Bayesian posteriors. CSF penetration was estimated by comparing the exposure profiles between plasma and the CSF. Eleven rats contributed PK data. A four-compartmental model with a lag compartment for CSF fit the data well for both plasma (Bayesian [ R 2 = 0.956]) and CSF (Bayesian [ R 2 = 0.565]). Median parameter values (with the coefficient of variation percentage [CV%] in parentheses) for the rate constants to CSF from the lag compartment ( K 34 ), to the central compartment from the CSF compartment ( K 41 ), and to the lag compartment from the central compartment ( K 13 ) were 2.96 h -1 (116.27%), 0.47 h -1 (54.86%), and 0.13 h -1 (23.42%), respectively. The elimination rate constant ( k This study defines the transit of cefepime between plasma and cerebral spinal fluid (CSF) in a rat model. Male Sprague-Dawley rats received cefepime intravenously. Plasma samples were obtained via a second dedicated intravenous catheter. CSF sampling occurred via an intracisternal catheter. Drug exposures and transfer from the plasma to the CSF during the first 24 h were calculated. The median CSF/blood percentage of penetration was 19%. Cefepime transit to the CSF is rapid and predictable in the rat model. This model will be highly useful for understanding the therapeutic window for cefepime and neurotoxicity.el ) was 3.15 h -1 (7.5%). Exposure estimation revealed a plasma median (with interquartile range [IQR] in parentheses) half-life, AUC 0-24 , and C max 0-24 , of 1.7 (1.5 to 1.9) h, 111.3 (95.7 to 136.5) mg · 24 h/liter, and 177.8 (169.7 to 236.4) μg/ml, from the first dose, respectively. Exposure estimation of CSF demonstrated a median (with IQR in parentheses) AUC 0-24 and C max 0-24 of 26.3 (16.6 to 43.1) mg · 24 h/liter and 6.8 (5.2 to 9.4) μg/ml, respectively. The median CSF/blood percentage of penetration was 19%. Cefepime transit to the CSF is rapid and predictable in the rat model. This model will be highly useful for understanding the therapeutic window for cefepime and neurotoxicity. IMPORTANCE This study defines the transit of cefepime between plasma and cerebral spinal fluid (CSF) in a rat model. Male Sprague-Dawley rats received cefepime intravenously. Plasma samples were obtained via a second dedicated intravenous catheter. CSF sampling occurred via an intracisternal catheter. Drug exposures and transfer from the plasma to the CSF during the first 24 h were calculated. The median CSF/blood percentage of penetration was 19%. Cefepime transit to the CSF is rapid and predictable in the rat model. This model will be highly useful for understanding the therapeutic window for cefepime and neurotoxicity., (Copyright © 2019 Avedissian et al.)

Primary Objective: Closed brain injuries are a common danger in contact sports and motorized vehicular collisions. Mild closed brain injuries, such as concussions, are not easily visualized by computed imaging or scans. Having a comprehensive head/brain model and using fluid-structure interaction (FSI) simulations enable us to see the exact movement of the cerebrospinal fluid (CSF) under such conditions and to identify the areas of brain most affected., Research Design: The presented work is based on the first FSI model capable of simulating the interaction between the CSF flow and brain., Methods and Procedures: FSI analysis combining smoothed-particle hydrodynamics and high-order finite-element method is used., Main Outcomes and Results: The interaction between the CSF and brain under rapid acceleration and deceleration is demonstrated. The cushioning effect of the fluid and its effect on brain are shown., Conclusions: The capability to locate areas (down to the exact gyri and sulci) of the brain the most affected under given loading conditions, and therefore assess the possible damage to the brain and consequently predict the symptoms, is shown.

Purpose: A gravitational valve (GV) may be used to treat hydrocephalus, offering possible advantages that include avoidance of over drainage and long-term complications. Because a GV is made from metal, there are potential safety and other problems related to the use of MRI. The objective of this investigation was to evaluate MRI-related issues (i.e., magnetic field interactions, heating, and artifacts) for a newly developed, metallic GV., Methods: Tests were performed on the GV (GAV 2.0) using well-accepted techniques to assess magnetic field interactions (translational attraction and torque, 3-Tesla), MRI-related heating (1.5-T/64-MH and 3-T/128-MHz, whole body averaged SAR, 2.7-W/kg and 2.9-W/kg, respectively), artifacts (3-Tesla; gradient echo and T1-weighted, spin echo sequences), and possible functional changes related to exposures to different MRI conditions (exposing six samples each to eight different pulse sequences at 1.5-T/64-MHz and 3-T/128-MHz)., Results: Magnetic field interactions were not substantial (deflection angle 2°, no torque) and heating was minor (highest temperature rise, ≥1.9°C, highest background temperature rise, ≥1.7°C). Artifacts on the gradient echo pulse sequence extended approximately 10mm from the size and shape of the GV. The different exposures to 1.5-T/64-MHz and 3-T/128-MHz conditions did not alter or damage the operational aspects of the GV samples., Conclusions: The findings demonstrated that MRI can be safely used in patients with this GV and, thus, this metallic implant is deemed acceptable or "MR Conditional" (i.e., using current labeling terminology), according to the conditions used in this study., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Purpose: To quantify the change in cerebral spinal fluid (CSF) production rate and maximum systolic velocity in astronauts before and after exposure to microgravity and identify any physiologic trend and/or risk factor related to intracranial hypertension., Materials and Methods: Following Institutional Review Board (IRB) approval, with waiver of informed consent, a retrospective review of 27 astronauts imaged at 3T was done. Qualitative analysis was performed on T2 -weighted axial images through the orbits for degree of flattening of the posterior globe according to the following grades: 0 = none, 1 = mild, 2 = moderate, and 3 = severe. One grade level change postflight was considered significant for exposure to intracranial hypertension. CSF production rate and maximum systolic velocity was calculated from cine phase-contrast magnetic resonance imaging and compared to seven healthy controls., Results: Fourteen astronauts were studied. The preflight CSF production rate in astronauts was similar to controls (P = 0.83). Six astronauts with significant posterior globe flattening demonstrated a 70% increase in CSF production rate postflight compared to baseline (P = 0.01). There was a significant increase in CSF maximum systolic velocity in the subgroup without posterior globe flattening (P = 0.01)., Conclusion: The increased postflight CSF production rate in astronauts with positive flattening is compatible with the hypothesis of microgravity-induced intracranial hypertension inferring downregulation in CSF production in microgravity that is upregulated upon return to normal gravity. Increased postflight CSF maximum systolic velocity in astronauts with negative flattening suggests increased craniospinal compliance and a potential negative risk factor to microgravity-induced intracranial hypertension., (© 2015 Wiley Periodicals, Inc.)

Introduction Nosocomial ventriculitis is a severe infection that habitually plagues neurological intensive care units. It is usually associated with external ventricular drains. Unfortunately, classic cerebral spinal fluid parameters are less specific and sensitive compared to community acquired meningitis. This is in part secondary to indolent bacteria commonly infecting external ventricular drains leading to ventriculitis. Case report Herein, a rare case of Sphingomonas paucimobilis ventriculitis in an immunocompetent host is reported. The patient had classic symptoms of ventriculitis, but her cerebral spinal fluid parameters were benign and initial cultures were negative. Consequently, treatment was tailored to an assumed respiratory infection only to have recurrence of her symptoms. Repeat analysis of her cerebral spinal fluid was again benign, but her cerebral spinal fluid culture grew S. paucimobilis. Subsequently, the patient was treated with cefepime, which resolved her symptoms. She completed a two-week course and has had no recurrence of her infection. Conclusions This case reinforces the need for clinicians to have heightened awareness of this emerging pathogen, its antibiotic resistance patterns, and the unique composition of this bacterium's cell wall which has ramifications on disease presentation. [ABSTRACT FROM AUTHOR]

Aims: Alzheimer's disease (AD) is a neurodegenerative disease with challenging early diagnosis and effective treatments due to its complex pathogenesis. AD patients are often diagnosed after the appearance of the typical symptoms, thereby delaying the best opportunity for effective measures. Biomarkers could be the key to resolving the challenge. This review aims to provide an overview of application and potential value of AD biomarkers in fluids, including cerebrospinal fluid, blood, and saliva, in diagnosis and treatment. Methods: A comprehensive search of the relevant literature was conducted to summarize potential biomarkers for AD in fluids. The paper further explored the biomarkers' utility in disease diagnosis and drug target development. Results: Research on biomarkers mainly focused on amyloid‐β (Aβ) plaques, Tau protein abnormal phosphorylation, axon damage, synaptic dysfunction, inflammation, and related hypotheses associated with AD mechanisms. Aβ42, total Tau (t‐Tau), and phosphorylated Tau (p‐Tau), have been endorsed for their diagnostic and predictive capability. However, other biomarkers remain controversial. Drugs targeting Aβ have shown some efficacy and those that target BACE1 and Tau are still undergoing development. Conclusion: Fluid biomarkers hold considerable potential in the diagnosis and drug development of AD. However, improvements in sensitivity and specificity, and approaches for managing sample impurities, need to be addressed for better diagnosis. [ABSTRACT FROM AUTHOR]

• Conventional ventriculitis diagnostics lack sensitivity and specificity. • Alpha-defensins are a novel diagnostic that can aid in diagnosing ventriculitis. • Significantly higher levels of α-defensins were present in the ventriculitis cohort. • Levels of α-defensins were not affected by blood or species of bacteria. Nosocomial ventriculitis is a difficult infectious condition to diagnose given that typical cerebral spinal fluid (CSF) parameters, commonly used in the diagnosis of meningitis, lack sensitivity and specificity in nosocomial ventriculitis. Consequently, novel diagnostics are needed to aid in diagnosing this condition. Herein a pilot study using alpha-defensins (α-defensins) to diagnose ventriculitis is discussed. From May 01, 2022, to December 30, 2022, ten patients with culture-proven external ventricular drain (EVD)-associated ventriculitis and ten patients without EVD-associated ventriculitis had CSF preserved. Levels of α-defensins were compared between the two cohorts with enzyme-linked immunosorbent assay. There was a statistically significant (P ˂0.0001) higher level of CSF α-defensins in the ventriculitis cohort compared to the non-ventriculitis cohort. The levels of α-defensins were not affected by blood in CSF or bacterial virulence. Patients with other infectious conditions had increased levels of α-defensins but these levels were still statistically significantly (P ˂0.001) less than those seen in the ventriculitis cohort. This pilot study shows that α-defensins have promise as a biomarker to aid in the diagnosis of ventriculitis. If larger studies support the findings here, this biomarker can help improve diagnostic accuracy and decrease unwarranted empirical broad-spectrum antibiotic use in suspected EVD-associated ventriculitis. [ABSTRACT FROM AUTHOR]

Traditionally, medicine has held that some human body sites are sterile and that the introduction of microbes to these sites results in infections. This paradigm shifted significantly with the discovery of the human microbiome and acceptance of these commensal microbes living across the body. However, the central nervous system (CNS) is still believed by many to be sterile in healthy people. Using culture-independent methods, we examined the virome of cerebrospinal fluid (CSF) from a cohort of mostly healthy human subjects. We identified a community of DNA viruses, most of which were identified as bacteriophages. Compared to other human specimen types, CSF viromes were not ecologically distinct. There was a high alpha diversity cluster that included feces, saliva, and urine, and a low alpha diversity cluster that included CSF, body fluids, plasma, and breast milk. The high diversity cluster included specimens known to have many bacteria, while other specimens traditionally assumed to be sterile formed the low diversity cluster. There was an abundance of viruses shared among CSF, breast milk, plasma, and body fluids, while each generally shared less with urine, feces, and saliva. These shared viruses ranged across different virus families, indicating that similarities between these viromes represent more than just a single shared virus family. By identifying a virome in the CSF of mostly healthy individuals, it is now less likely that any human body site is devoid of microbes, which further highlights the need to decipher the role that viral communities may play in human health.

The IFN‐γ/STAT1 immune signaling pathway impacts many homeostatic and pathological aspects of neurons, beyond its canonical role in controlling intracellular pathogens. Well known for its potent pro‐inflammatory and anti‐viral functions in the periphery, the IFN‐γ/STAT1 pathway is rapidly activated then deactivated to prevent excessive inflammation; however, neurons utilize unique IFN‐γ/STAT1 activation patterns, which may contribute to the non‐canonical neuron‐specific downstream effects. Though it is now well‐established that the immune system interacts and supports the CNS in health and disease, many aspects regarding IFN‐γ production in the CNS and how neurons respond to IFN‐γ are unclear. Additionally, it is not well understood how the diversity of the IFN‐γ/STAT1 pathway is regulated in neurons to control homeostatic functions, support immune surveillance, and prevent pathologies. In this review, we discuss the neuron‐specific mechanisms and kinetics of IFN‐γ/STAT1 activation, the potential sources and entry sites of IFN‐γ in the CNS, and the diverse set of homeostatic and pathological effects IFN‐γ/STAT1 signaling in neurons has on CNS health and disease. We will also highlight the different contexts and conditions under which IFN‐γ‐induced STAT1 activation has been studied in neurons, and how various factors might contribute to the vast array of downstream effects observed. [ABSTRACT FROM AUTHOR]

Background: Meningitis is a severe infection affecting the central nervous system requiring early management to prevent debilitating consequences and death. Detection of meningitis can be done by the analysis of cerebrospinal fluid cellularity and biochemistry (glucose and protein concentration). Urine reagent strips can be used to assess these variables and reach to the diagnosis of meningitis early, thereby, reducing the delay in the initiation of its treatment. Aims and Objectives: The current study aimed to determine the efficacy of urine reagent strips for the analysis of CSF. Materials and Methods: The current prospective study was done in a tertiary care center in Rewa, M.P., on 100 cerebral spinal fluid (CSF) samples obtained from the children suspected of meningitis, which were, then, analyzed by both the conventional methods of CSF analysis (including routine biochemical and microscopic analysis) the index test, utilizing the Combur-10 urine reagent strips for the estimation of CSF cell, protein, and glucose. These results were, then, correlated to calculate the diagnostic utility of urine reagent strips for the rapid diagnosis of meningitis. Results: The sensitivity, specificity, and diagnostic accuracy of urine reagent strips for the detection of cell count >10/cumm were 81.81%, 98.21%, and 91%, respectively, and 78.57%, 81.25%, and 79% for detection of protein >30 mg/dL. Reagent strips showed a sensitivity and specificity of 96.85% and 79.41% for the detection of glucose levels <50 mg/dL. The two methods showed an almost perfect degree of agreement for the detection of leucocytes with Cohen's kappa value of 0.86. Conclusion: Reagent strips can be a helpful bedside screening test for the detection of meningitis and also in resource-limited settings. [ABSTRACT FROM AUTHOR]

External ventricular drains (EVDs) provide a temporary egress for cerebrospinal fluid (CSF) in patients with symptomatic hydrocephalus following aneurysmal subarachnoid hemorrhage. Before EVD removal, a wean trial, which involves clamping the EVD, is typically attempted to ensure that CSF self-regulation is achieved. Automated infrared pupillometry (AIP) has been shown to detect early neurologic decline. We sought to explore the use of AIP to detect early EVD clamping trial failure. This prospective observational pilot study enrolled aneurysmal subarachnoid hemorrhage patients before an EVD clamp trial. On initiating the clamp trial, nurses included hourly AIP assessment in documentation. Clamp trial outcome was based on neurologic examination and neuroimaging. Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) models were constructed to explore computed tomography (CT) versus AIP as predictors of clamp trial outcome. Among the 30 subjects enrolled, there were 38 clamping trials and 22 successful EVD removals. CT scan as a predictor of clamp trial was found to have a sensitivity of 68.8% and specificity of 89.5% (PPV = 84.6%, NPV = 77.3%). AIP assessment as a predictor of wean trial outcome was found to have a sensitivity of 58.3% and specificity of 100% (PPV = 100%, NPV = 63.2%). The pilot study data support that Neurological Pupil index <3 is a potential indicator of early clamp trial failure, but a CT scan has a higher sensitivity and NPV for predicting successful EVD removal. This finding suggests the benefits of including AIP assessments during clamping trials. [ABSTRACT FROM AUTHOR]

Medulloblastoma (MB) is the most common pediatric malignant central nervous system tumor. Overall survival in MB depends on treatment tuning. There is aneed for biomarkers of residual disease and recurrence. We analyzed the proteome of waste cerebrospinal fluid (CSF) from extraventricular drainage (EVD) from six children bearing various subtypes of MB and six controls needing EVD insertion for unrelated causes. Samples included total CSF, microvesicles, exosomes, and proteins captured by combinatorial peptide ligand library (CPLL). Liquid chromatography-coupled tandem mass spectrometry proteomics identified 3560 proteins in CSF from control and MB patients, 2412 (67.7%) of which were overlapping, and 346 (9.7%) and 805 (22.6%) were exclusive. Multidimensional scaling analysis discriminated samples. The weighted gene co-expression network analysis (WGCNA) identified those modules functionally associated with the samples. A ranked core of 192 proteins allowed distinguishing between control and MB samples. Machine learning highlighted long-chain fatty acid transport protein 4 (SLC27A4) and laminin B-type (LMNB1) as proteins that maximized the discrimination between control and MB samples. Machine learning WGCNA and support vector machine learning were able to distinguish between MB versus non-tumor/hemorrhagic controls. The two potential protein biomarkers for the discrimination between control and MB may guide therapy and predict recurrences, improving the MB patients' quality of life. [ABSTRACT FROM AUTHOR]

Droplet microfluidics with push-pull and microdialysis sampling from brain slices, cultured cells and engineered tissues produce low volume mass limited samples containing analytes sampled from the extracellular space. This sampling approach coupled to mass spectrometry (MS) detection allows evaluation of time-dependent chemical changes. Our goal is an approach for continuous sampling and segregation of extracellular samples into picoliter droplets followed by the characterization of the droplets using nanoelectrospray ionization (nESI) MS. The main focus here is the optimization of the carrier oil for the microfluidic device that neither affects the stability of picoliter droplets nor compatibility with MS detection of a range of analytes. We developed and characterized a 1-octanol-assisted ultra-small volume droplet microfluidic nESI MS system for the analysis of neurotransmitters in distinct samples including cerebrospinal fluid (CSF). The use of a 1-octanol oil phase was effective for generation of aqueous droplets as small as 65 pL and enabled detection of acetylcholine (ACh) and gamma-aminobutyric acid (GABA) in water and artificial CSF. Continuous MS analysis of droplets for extended periods up to 220 min validated the long-term stability of droplet generation and analyte detection by nESI-MS. As an example, ACh response demonstrated a linear working range (R2 = 0.99) between 0.4 μM and 25 μM with a limit of detection of 370 nM (24 amol), enabling its quantitation in rodent CSF. The established droplet microfluidics – nESI MS approach allows the analysis of microenvironments at high spatiotemporal resolution. The approach may allow microsampling and monitoring of spatiotemporal dynamics of neurochemicals and drugs in the brain and spinal cord of live animals. [Display omitted] • A pL droplet microfluidic-nESI MS system optimized for neurotransmitter detection. • The 1-octanol oil phase effectively generates aqueous droplets as small as 65 pL. • Long-term stability for droplet generation and analyte detection by MS. • Acetylcholine quantified from rat cerebral spinal fluid samples. • Characteristics of the system designed for in vivo monitoring of neurotransmitters. [ABSTRACT FROM AUTHOR]

Background Human chorionic gonadotropin (hCG) detection in cerebrospinal fluid (CSF) can provide additional value in the diagnosis of germinoma. However, matrix effects can influence the results when alternative sample types are used. Therefore, modified-cleared/approved methods, which are standard methods used outside their intended scope, are of interest. The aim of the present studywas to establish a model to validate modified-approved methods in agreement with the College of American Pathologists (CAP) accreditation requirements. Methods Concentrations of hCG in CSF were determined by means of electrochemiluminescence immunoassay using a Roche Cobas e 602 immunoassay analyzer. Based on the intended use, the following performance characteristics were evaluated: precision, the limit of quantitation (LoQ), and the analytical measurement range (AMR). The reference interval (RI) was also established. For the clinical application study, CSF and serum hCG were measured in 10 patients diagnosed with germinoma. Results The intra- and inter-assay precisions at two levels (10, 250 IU/L) were 0.64 and 0.57% and 4.26 and 3.54%, respectively. The LoQ for hCG was determined to be 0.25 IU/L. The AMR was set from0.2 to 1,200 IU/L. The RI for hCG in CSF was below 0.40 IU/L. The CSF hCG levels of 10 patients were all above 0.4 IU/L before therapy. Conclusion Modified-approved methods were validated and showed that the quality specifications of the medical laboratory have a positive value in the clinical context. The illustration of quantification of hCG in CSF resulted in compliance with the CAP accreditation requirements. [ABSTRACT FROM AUTHOR]

The improvement of cognitive function following bariatric surgery has been highlighted, yet its underlying mechanisms remain elusive. Finding the improved brain glucose uptake of patients after Roux-en-Y gastric bypass (RYGB), duodenum-jejunum bypass (DJB), and sham surgery (Sham) were performed on obese and diabetic Wistar rats, and intracerebroventricular (ICV) injection of glucagon-like peptide-1 (GLP-1) analog liraglutide (Lira), antagonist exendin-(9-39) (Exe-9), and the viral-mediated GLP-1 receptor (Glp-1r) knockdown (KD) were applied on both groups to elucidate the role of GLP-1 in mediating cognitive function and brain glucose uptake assessed with the Morris water maze (MWM) and positron emission tomography (PET). Insulin and GLP-1 in serum and cerebral spinal fluid (CSF) were measured, and the expression of glucose uptake-related proteins including glucose transporter 1 (GLUT-1), GLUT-4, phospho-Akt substrate of 160kDa (pAS160), AS160, Rab10, Myosin-Va as well as the c-fos marker in the brain were examined. Along with augmented glucose homeostasis following DJB, central GLP-1 was correlated with the improved cognitive function and ameliorated brain glucose uptake, which was further confirmed by the enhancive role of Lira on both groups whereas the Exe-9 and Glp-1r KD were opposite. Known to activate insulin-signaling pathways, central GLP-1 contributes to improved cognitive function and brain glucose uptake after DJB [ABSTRACT FROM AUTHOR]

Stroke is the destruction of brain function and structure, and is caused by either cerebrovascular obstruction or rupture. It is a disease associated with high mortality and disability worldwide. Brain edema after stroke is an important factor affecting neurologic function recovery. The glymphatic system is a recently discovered cerebrospinal fluid (CSF) transport system. Through the perivascular space and aquaporin 4 (AQP4) on astrocytes, it promotes the exchange of CSF and interstitial fluid (ISF), clears brain metabolic waste, and maintains the stability of the internal environment within the brain. Excessive accumulation of fluid in the brain tissue causes cerebral edema, but the glymphatic system plays an important role in the process of both intake and removal of fluid within the brain. The changes in the glymphatic system after stroke may be an important contributor to brain edema. Understanding and targeting the molecular mechanisms and the role of the glymphatic system in the formation and regression of brain edema after stroke could promote the exclusion of fluids in the brain tissue and promote the recovery of neurological function in stroke patients. In this review, we will discuss the physiology of the glymphatic system, as well as the related mechanisms and therapeutic targets involved in the formation of brain edema after stroke, which could provide a new direction for research against brain edema after stroke. [ABSTRACT FROM AUTHOR]

Despite numerous studies in human patients and animal models for phenylketonuria (PKU; OMIM# 261600), the pathophysiology of PKU and the underlying causes of brain dysfunction and cognitive problems in PKU patients are not well understood. In this study, lumbar cerebral spinal fluid (CSF) was obtained immediately after blood sampling from early-treated adult PKU patients who had fasted overnight. Metabolite and amino acid concentrations in the CSF of PKU patients were compared with those of non-PKU controls. The CSF concentrations and CSF/plasma ratios for glucose and lactate were found to be below normal, similar to what has been reported for glucose transporter1 (GLUT1) deficiency patients who exhibit many of the same clinical symptoms as untreated PKU patients. CSF glucose and lactate levels were negatively correlated with CSF phenylalanine (Phe), while CSF glutamine and glutamate levels were positively correlated with CSF Phe levels. Plasma glucose levels were negatively correlated with plasma Phe concentrations in PKU subjects, which partly explains the reduced CSF glucose concentrations. Although brain glucose concentrations are unlikely to be low enough to impair brain glucose utilization, it is possible that the metabolism of Phe in the brain to produce phenyllactate, which can be transported across the blood-brain barrier to the blood, may consume glucose and/or lactate to generate the carbon backbone for glutamate. This glutamate is then converted to glutamine and carries the Phe-derived ammonia from the brain to the blood. While this mechanism remains to be tested, it may explain the correlations of CSF glutamine, glucose, and lactate concentrations with CSF Phe. • Adult phenylketonurics have low CSF, but normal plasma, glucose and lactate levels. • Similar findings occur in glucose transporter1 deficiency syndrome patients. • CSF glucose and lactate are negatively correlated with CSF phenylalanine level. • CSF glutamine level is positively correlated with CSF phenylalanine level. • Brain phenylalanine metabolism can consume glucose/lactate and generate glutamine. [ABSTRACT FROM AUTHOR]

Background Subarachnoid neurocysticercosis (SANCC) represents the most severe and difficult to treat form of neurocysticercosis. The inflammatory response contributes significantly to the morbidity and mortality of the disease. This study sought to understand the nature and evolution of the inflammation associated with SANCC, and evaluate for predictors of time to cure. Methods There were 16 subjects with SANCC (basilar cistern, sylvian fissure, and/or spinal involvement) during active infection who had cerebrospinal fluid (CSF) cytokine and chemokine profiling, of whom 9 had a second CSF sample at (or following) the time of cure. The relationships between clinical parameters and cytokine/chemokine results were assessed. Results Compared to pools of healthy donor CSF, those with active SANCC showed a significant (P <.05) increase in chemokines and cytokines associated with Type 1 immunity (interferon [IFN] γ, interleukin [IL] 12p70, C-X-C Motif Ligand 10 CXCL-10); Type 2 immunity (IL-10, IL-13); IFNα2; and the chemokines Macrophage inflammatory protein MIP-1α/CCL3, MIP-1ß/CCL4, and Vascular Endothelial Growth Factor VEGF that appears to be locally (central nervous system [CNS]) produced. Compared to those with active disease, those with CSF taken at the time of cure showed a significant decrease in most of these chemokines and cytokines. Despite this, CSF from cured SANCC patients had levels of IL-10 (P =.039), CXCL-10 (P =.039), and IL-12p70 (P =.044) above those seen in CSF from uninfected subjects. High ratios of IL-12p70/IL-10 early in infections were associated with a shorter time to cure (r = −0.559; P =.027), and a high Taenia solium burden (by quantitative polymerase chain reaction) was associated with longer times to cure (r = 0.84; P =.003). Conclusions SANCC is associated with a marked, CNS-localized cytokine-/chemokine-driven inflammatory response that largely decreases with curative therapy, though some analytes persisted above the normal range. The relative balance between proinflammatory and regulatory cytokines may be an important determinant for a cure in SANCC. [ABSTRACT FROM AUTHOR]

Background: Disability from migraine has a profound impact on the world's economy. Research has been ongoing to identify biomarkers to aid in diagnosis and treatment.Objective: The aim of this study was to highlight the purported diagnostic and therapeutic migraine biomarkers and their role in precision medicine.Methods: A comprehensive literature search was conducted using PubMed, Google Scholar, and clinicaltrials.gov using keywords: "migraine" OR "headache" combined with "biomarkers" OR "marker." Other keywords included "serum," "cerebral spinal fluid," "inflammatory," and "neuroimaging."Results: After a review of 88 papers, we find the literature supports numerous biomarkers in the diagnosis of migraine. Therapeutic biomarkers, while not as extensively published, highlight calcitonin gene-related peptide (CGRP) and pituitary adenylate cyclase-activating peptide-38 (PACAP-38) as biomarkers with the most substantiated clinical relevance. Genetic markers mainly focusing on gene mutations with resultant biochemical alterations continue to be studied and show promise.Conclusion: Although there are several proposed biomarkers for migraine, continued research is needed to substantiate their role in clinical practice. [ABSTRACT FROM AUTHOR]

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Many previous studies have investigated the use of post-mortem biochemistry to estimate the post-mortem interval (PMI). Vitreous humour (VH) potassium and sodium/chloride levels are well recognized to increase and decrease, respectively, in the post-mortem period but have limited ability in estimating PMI. Cerebrospinal fluid (CSF) is described to have different post-mortem biochemical properties than VH, but is not well studied in relation to estimating PMI. This exploratory study examined 20 paired cases of VH and CSF to investigate their use in estimating PMI. Linear univariate analysis showed Na+, Cl− and K+ in VH and CSF share similar trends, but only K+ in VH and CSF collected via lumbar puncture (LP) showed a significant regression coefficient (p < 0.01). In subsequent linear multivariate analysis, the coefficient for K+ in VH remained positive and significant but not for K+ in CSF. Only minor improvement was observed in the multivariate analysis. Our study showed changes in analytes in VH and CSF follow similar trends. K+ in VH is most accurate in estimating the PMI, with no significant improvement in accuracy when K+ in CSF is combined. Thus, the role of CSF electrolytes in estimating PMI may be very limited. [ABSTRACT FROM AUTHOR]

Listeria rhombencephalitis (L. rhombencephalitis) is an uncommon form of central nervous system infection caused by Listeria monocytogenes (LM). It often occurs to immunocompetent individuals. Here, we described the case of a 45-year-old female patient without medical histories, who presented for high-grade fever, headache, and focal neurological manifestations. She was initially empirically diagnosed with acute disseminated encephalomyelitis (ADEM) because of clinical symptoms, acute clinical course, and neuroimaging. However, the biochemical analysis of cerebral spinal fluid (CSF) questioned the diagnosis of ADEM. The final diagnosis of L. rhombencephalitis was based on CSF culture for LM. Thus, L. rhombencephalitis should be preferentially and empirically considered for a patient with significantly elevated lactic acid and moderately increased red cells in CSF at early time, accompanied with rapidly progressive neurological dysfunctions involved in the brain stem. [ABSTRACT FROM AUTHOR]

Cerebrospinal fluid (CSF) and vitreous humour (VH) can be biochemically analysed post-mortem. CSF can be aspirated from the ventricular system (VA) and from lumbar puncture (LP), whereas, VH is aspirated from the orbits. This study compared the biochemical constituents between CSF and VH in 20 post-mortem subjects as well as the effect post-mortem interval and subject age have on these variables. VH samples had significantly higher sodium (Na) and chloride (Cl) and lower magnesium (Mg), potassium (K), urea (Ur) and creatinine (Cr) compared with CSF samples. No statistically significant difference was demonstrated with beta-hydroxybutyrate (BHB) and glucose levels in both VH and both CSF samples. Interestingly, some of the differences in the biochemical analysis correlated with age, but none with post-mortem interval. In addition to sampling and pre-analytical sample processing differences, there may also be ante- and post-mortem factors explaining these observations. This study suggests that post-mortem CSF and VH are biochemically different and reference ranges for VH are not recommended for use in CSF samples. [ABSTRACT FROM AUTHOR]

Summary: Central nervous system (CNS) relapse is a common cause of treatment failure in patients with acute lymphoblastic leukaemia (ALL) despite current CNS‐directed therapies that are also associated with significant short‐ and long‐term toxicities. Herein, we showed that leukaemia cells exhibit decreased proliferation, elevated reactive oxygen species (ROS) and increased cell death in cerebral spinal fluid (CSF) both in vitro and in vivo. However, interactions between leukaemia and meningeal cells mitigated these adverse effects. This work expands our understanding of the pathophysiology of CNS leukaemia and suggests novel therapeutic approaches for more effectively targeting leukaemia cells in the CNS. [ABSTRACT FROM AUTHOR]

The complex interfacial condition between the human brain and the skull has been difficult to emulate in a surrogate system. Surrogate head models have typically been built using a homogeneous viscoelastic material to represent the brain, but the effect of different interfacial conditions between the brain and the skull on pressure transduction into the brain during blast has not been studied. In the present work, three interfacial conditions were generated in physical surrogate human head models. The first surrogate consisted of a gel brain separated from the skull by a layer of saline solution similar in thickness to the cerebrospinal fluid (CSF) layer in the human head: the fluid interface head model. The second surrogate head had the entire cranial cavity filled with the gel: the fixed interface head model. The third surrogate head contained a space-filling gel brain wrapped in a thin plastic film: the stick-slip interface head model. The human head surrogates were evaluated in a series of frontal blast tests to characterize the effect of skull-brain interfacial conditions on overpressure propagation into the gel brains. The fixed and the stick-slip interface head models showed nearly equal peak brain overpressures. In contrast, the fluid interface head model had much higher in-brain peak overpressures than the other two models, thus representing the largest transmission of forces into the gel brain. Given that the elevated peak overpressures occurred only in the fluid interface head model, the presence of the saline layer is likely responsible for this increase. This phenomenon is hypothesized to be attributed to the incompressibility of the saline and/or the impedance differences between the materials. The fixed interface head model showed pronounced high frequency energy content relative to the other two models, implying that the fluid and the stick-slip conditions provided better dampening. The cumulative impulse energy entering the three brain models were similar, suggesting that the interface conditions do not affect the total energy transmission over the positive phase duration of a blast event. This study shows that the fidelity of the surrogate human head models would improve with a CSF-emulating liquid layer. [ABSTRACT FROM AUTHOR]

Dravet syndrome (DS) is a neurodevelopmental genetic disorder caused by mutations in the SCN1A gene encoding the α subunit of the NaV1.1 voltage-gated sodium channel that controls neuronal action potential firing. The high density of this mutated channel in GABAergic interneurons results in impaired inhibitory neurotransmission and subsequent excessive activation of excitatory neurons. The syndrome is associated with severe childhood epilepsy, autistic behaviors, and sudden unexpected death in epilepsy. Here, we compared the rescue effects of an adeno-associated viral (AAV) vector coding for the multifunctional β1 sodium channel auxiliary subunit (AAV-NaVβ1) with a control vector lacking a transgene. We hypothesized that overexpression of NaVβ1 would facilitate the function of residual voltage-gated channels and improve the DS phenotype in the Scn1a+/− mouse model of DS. AAV-NaVβ1 was injected into the cerebral spinal fluid of neonatal Scn1a+/− mice. In untreated control Scn1a+/− mice, females showed a higher degree of mortality than males. Compared with Scn1a+/− control mice, AAV-NaVβ1-treated Scn1a+/− mice displayed increased survival, an outcome that was more pronounced in females than males. In contrast, behavioral analysis revealed that male, but not female, Scn1a+/− mice displayed motor hyperactivity, and abnormal performance on tests of fear and anxiety and learning and memory. Male Scn1a+/− mice treated with AAV-NaVβ1 showed reduced spontaneous seizures and normalization of motor activity and performance on the elevated plus maze test. These findings demonstrate sex differences in mortality in untreated Scn1a+/− mice, an effect that may be related to a lower level of intrinsic inhibitory tone in female mice, and a normalization of aberrant behaviors in males after central nervous system administration of AAV-NaVβ1. The therapeutic efficacy of AAV-NaVβ1 in a mouse model of DS suggests a potential new long-lasting biological therapeutic avenue for the treatment of this catastrophic epilepsy. [ABSTRACT FROM AUTHOR]

Gilles de la Tourette syndrome (GTS) is a neuropsychiatric disorder characterized by motor and vocal tics. There are several hypotheses as to the cause of the disease. One of which suggests that the immune system is involved in the pathophysiology of GTS. Here, we present a 40-year-old female patient with a typical history and clinical presentation of GTS with tics and psychiatric comorbidities, in whom positive oligoclonal bands (OCBs) type 2 in cerebral spinal fluid (CSF) were detected in an earlier study. At that time point, all other investigations were unremarkable (including neurological examination and cMRI), but 2 years later, she presented with further neurological symptoms including tetraparesis mostly affecting the left limbs, distal hypesthesia and paresthesia, and dyspnea. Since further examinations (including EMG, MRI, CSF, virological, and bacteriological tests, as well as autoimmune-encephalitis antibodies) revealed normal results, based on clinical presentation, the diagnosis of Guillain-Barré-like immune-mediated neuropathy was made and treatment with intravenous immunoglobulins (IVIg) (30 g/day for 5 days) was initiated resulting in complete remission of immune-mediated neuropathy. Based on the "immune hypothesis" of GTS, we were interested in whether in this patient positive CSF OCBs might serve as a biomarker for treatment response of tics and additional GTS-related psychiatric symptoms to IVIg, and therefore assessed tics, premonitory urges, and psychiatric comorbidities before and several times after the IVIg treatment. However, even though immune-mediated neuropathy resolved after treatment, tics, premonitory urges, and comorbidities remained unchanged. Thus, this case study suggests that treatment with IVIg is not effective in the treatment of GTS—even in a patient with intrathecal antibody synthesis as expressed by CSF isolated OCBs. [ABSTRACT FROM AUTHOR]

Quantitative volumes of cerebrospinal fluid (CSF) and brain tissue were measured on magnetic resonance images (MRIs) of 287 individuals from 5 diagnostic groups: Alzheimer's disease (AD), chronic alcoholics (ALC), individuals positive for human immunodeficiency virus (HIV), schizophrenia subjects (SZ), and normal comparison subjects (NC) older than 50 years of age. Within each group, mean volumes were calculated for ventricular CSF, cortical (sulcal) CSF, cortical gray matter, total white matter, basal ganglia gray matter, and thalamic gray matter. Correlations of CSF measures with brain tissue measures were determined, and multiple regression analyses were performed to try and predict volume of gray matter or white matter region from volume of CSF compartment. Results indicated the following: 1. Enlarged cortical fluid volume significantly predicts cortical gray matter deficits for subjects with AD and those who are ALC and SZ but not for subjects with HIV or NC. 2. Enlarged cortical fluid volume also significantly predicts white matter deficits in all five groups. 3. Enlarged ventricular fluid volume significantly predicts basal ganglia deficits in AD, HIV, and NC but not in SZ or ALC. 4. Enlarged ventricular volume has no predictive value for thalamic volume for any of the groups. This study supports the clinical practice of predicting brain tissue volume loss from CSF enlargement but not for all brain regions in all diagnoses.

Aim: The apathetic syndrome is a common clinical feature in patients with Alzheimer diseases (AD), from preclinical phases to late stages of dementia, and it is strongly related to major disease outcomes. Unfortunately, no specific pharmacological treatments for apathy have been accomplished so far. Translational evidences have previously shown that a link between apathy and hallmarks of AD-related pathophysiology, that is, β-amyloid (Aβ) plaques and neurofibrillary tangles, exists. However, only few studies investigated the association between core biomarkers of AD and apathy scores, finding conflicting results.Methods: Thirty-seven patients were identified as having AD dementia according to National Institute on Aging-Alzheimer Association 2011 criteria. All participants underwent an extensive diagnostic workup including cerebrospinal fluid (CSF) assessment to measure the concentrations of Aβ42, t-tau, and pTau181. To follow, they were stratified as: apathy absence, apathy mild, and apathy severe according to the Neuro Psychiatric Inventory-apathy item scores. We investigated for potential associations between apathy scores and CSF biomarkers concentrations as well as for differences in terms of clinical and CSF biomarkers data across the 3 apathy groups.Results: The CSF Aβ42 concentrations were negatively correlated with apathy scores. In addition, patients with severe apathy had significantly lower Aβ42 levels compared to nonapathetic ones.Conclusion: Based on our results, we encourage further studies to untangle the potential association between the complex pathophysiological dynamics of AD and apathy which may represent an innovative reliable clinical outcome measure to use in clinical trials, investigating treatments with either a symptomatic or a disease-modifying effect. [ABSTRACT FROM AUTHOR]

Background: For definitive diagnosis of cryptococcal meningitis, Cryptococcus neoformans and/or C. gattii must be identified within cerebral spinal fluid from the patients. The traditional methods for detecting Cryptococcus spp. such as India ink staining and culture are not ideal. Although sensitive and specific enough, detection of cryptococcal antigen polysaccharide has a high dose hook effect. Therefore, the aim of this study was to introduce a new rapid and simple detection method of Cryptococcus neoformans and C. gattii in cerebral spinal fluid.Methods: The lateral flow strips combined with recombinase polymerase amplification (LF-RPA) assay was constructed to detect the specific DNA sequences of C. neoformans and C. gattii. The detection limit was evaluated using serial dilutions of C. neoformans and C. gattii genomic DNA. The specificity was assessed by excessive amount of other pathogens genomic DNA. The optimal detection time and amplification temperature were also analyzed. The diagnostic parameters were first calculated using 114 clinical specimens and then compared with that of other diagnostic method. A brief analysis and comparison of different DNA extraction methods was discussed, too.Results: The LF-RPA assay could detect 0.64 pg of genomic DNA of C. neoformans per reaction within 10 min and was highly specific for Cryptococcus spp.. The system could work well at a wide range of temperature from 25 to 45 °C. The overall sensitivity and specificity were 95.2 and 95.8% respectively. As amplification template for LF-RPA assay, both cell lysates and genomic DNA produce similar experimental results.Conclusions: The LF-RPA system described here is shown to be a sensitive and specific method for the visible, rapid, and accurate detection of Cryptococcus spp. in cerebral spinal fluid and might be useful for clinical preliminary screening of cryptococcal meningitis. [ABSTRACT FROM AUTHOR]

Ghrelin is physiologically important for maintaining sleep rhythm. Cigarette smoking has been demonstrated to significantly increase the risk of insufficient sleep by regulating ghrelin at the central and peripheral levels. No research has been published to study the relationship between active smoking and sleep via ghrelin level in cerebrospinal fluid (CSF). A total of 139 Chinese males were recruited and divided into active smokers (n = 77) and non-smokers (n = 62). The levels of CSF and plasma ghrelin were measured. The Pittsburgh Sleep Quality Index (PSQI) was used to evaluate sleep. Non-smokers had lower PSQI scores (1.71 ± 1.93) than active smokers (3.70 ± 1.78). Non-smokers have significantly lower plasma ghrelin levels and lower plasma/CSF ghrelin ratio but higher CSF ghrelin than active smokers. Among non-smokers, plasma ghrelin levels were not correlated with PSQI scores (all p > 0.05), CSF ghrelin levels were positively correlated with PSQI scores (r = 0.309, p = 0.019), and the plasma/CSF ghrelin ratio was negatively correlated with PSQI scores (r = −0.346, p = 0.008). This study is the first to reveal the relationship between cigarette smoking, high CSF ghrelin levels and insufficient sleep, suggesting that maintaining a normal plasma/CSF ghrelin ratio may be the physiological mechanism of healthy sleep, and the insufficient sleep population must quit smoking. • This is the first case-control study to probe the relationship of smoking with sleep and ghrelin both in CSF and plasma • A normal plasma/CSF ghrelin ratio may contribute to healthy sleep • Smoking may disturb the association between sleep and CSF ghrelin, as shown by the high plasma/CSF and PSQI scores in smokers [ABSTRACT FROM AUTHOR]

Traumatic brain injury (TBI) is a public health problem that causes high mortality and disability worldwide. Secondary brain damage from this type of injury may cause brain edema, blood–brain barrier destruction, and neurological dysfunction. MicroRNAs (miRNAs) are a class of small non-coding RNAs that regulate gene expression at the post-transcriptional level and play vital roles in maintaining and regulating physiological function. Notably, studies suggest that miRNA levels are altered in the cerebral cortex and hippocampus of rats and mice after TBI. These miRNAs exhibit promoting or inhibiting effects on the formation of secondary brain damage, such as promotion of neuron regeneration and apoptosis, alleviation of leakage across the blood–brain barrier (BBB), disruption of intracellular transport, and decreasing the inflammatory response. miRNA levels are also altered in the blood and cerebral spinal fluid (CSF) of humans with TBI. Some special miRNAs in blood were used in clinical trials for TBI diagnosis and prognosis prediction. Treatment with miRNA agomirs or antagomirs alleviated the lesion volume and improved neurological deficits post-injury. We review the current progress of miRNA studies in TBI patients and animal models and identify the prospects and difficulties involved in the clinical applications of miRNAs. [ABSTRACT FROM AUTHOR]

Mucopolysaccharidosis III type A (MPS IIIA; Sanfilippo syndrome), a genetic lysosomal disorder causing a deficiency of heparan N-sulfatase (HNS), leads to progressive cognitive decline from an early age. An effective enzyme replacement therapy (ERT) for MPS IIIA requires central nervous system (CNS) biodistribution. Recombinant human heparan N-sulfatase (rhHNS), an investigatory ERT for MPS IIIA, has been formulated for intrathecal (IT) administration since intravenous (IV) administration cannot cross the blood brain barrier (BBB) in sufficient amounts to have a therapeutic effect. In this study, systemic and CNS distribution of rhHNS in cynomolgus monkeys following IV and IT administration was evaluated by quantitation of rhHNS in serum, cerebral spinal fluid (CSF) and various tissues, and positron emission tomography (PET) imaging of live animals. Following IV administration, rhHNS levels were low to non-detectable in the CSF, and systemic clearance was rapid (≤2 h). With IT administration, rhHNS was observable in CNS tissues in ≤1 h, with varying Tmax (1-24 h). Appreciable systemic distribution was observed up to 7 days. This provides evidence that in this animal model, intrathecal administration of rhHNS delivers the replacement enzyme to therapeutically relevant tissues for the treatment of Sanfilippo Syndrome type A. Penetration into grey matter and cortex was 3-4 times greater than concentrations in white matter and deeper parenchymal regions, suggesting some limitations of this ERT strategy. [ABSTRACT FROM AUTHOR]

Background: Although the most serious consequence of neuronal ischemia is acute neuronal death, mounting evidence suggests similarities between stroke and neurodegenerative disease. Brain atrophy visualized on structural MRI and pathological cerebrospinal fluid (CSF) concentrations of microtubule-associated protein tau (T-tau) and phosphorylated microtubule-associated protein tau indicate neurofibrillary degeneration. We aimed to explore the association between CSF T-tau and brain atrophy 1 year post-stroke.Methods: We included 210 patients with first-ever ischemic stroke or transitory ischemic attack without pre-existing cognitive impairment. After 12 months, subjects underwent MRI, and CSF biomarkers were assessed. Using SIENAX (part of FSL), ventricular CSF volume and total brain volume were estimated and normalized for subject head size. The association between T-tau as explanatory variable and ventricular and total brain volume as outcome variables were studied using linear regression.Results: One hundred eighty-two patients completed the follow-up. Forty-four had a lumbar puncture. Of these, 31 had their MRI with identical scan parameters. Mean age was 70.2 years (SD 11.7). Ventricular volume on MRI was significantly associated with age, but not with gender. In the multiple regression model, there was a significant association between T-tau and both ventricular (beta 0.44, 95% CI 376.3, 394.9, p = 0.021) and global brain volume (beta -0.50, 95% CI -565.9, -78.3, p = 0.011). There was no significant association between CSF T-tau 1 year post-stroke and baseline volumes.Conclusion: T-tau measured 1 year post-stroke is associated with measures of brain atrophy. The findings indicate that acute stroke may enhance or trigger tau-linked neurodegeneration with loss of neurons.Trial Registration: Clinicaltrials.gov NCT00506818 , July 23, 2007. Inclusion from February 2007, randomization and intervention from May 2007 and trial registration in July 2007. [ABSTRACT FROM AUTHOR]

Diffuse Optical Tomography commonly neglects or assumes as insignificant the presence of optically clear regions in biological tissues, estimating their contribution as a small perturbation to light transport. The inaccuracy introduced by this practice is examined in detail in the context of a complete, based on realistic geometry, virtual fluorescence Diffuse Optical Tomography experiment where a mouse head is imaged in the presence of cerebral spinal fluid. Despite the small thickness of such layer, we point out that an error is introduced when neglecting it from the model with possibly reduction in the accuracy of the reconstruction and localization of the fluorescence distribution within the brain. The results obtained in the extensive study presented here suggest that fluorescence diffuse neuroimaging studies can be improved in terms of quantitative and qualitative reconstruction by accurately taking into account optically transparent regions especially in the cases where the reconstruction is aided by the prior knowledge of the structural geometry of the specimen. Thus, this has only recently become an affordable choice, thanks to novel computation paradigms that allow to run Monte Carlo photon propagation on a simple graphic card, hence speeding up the process a thousand folds compared to CPU-based solutions. [ABSTRACT FROM PUBLISHER]

Advances in medicine mean there are more women with complex medical histories giving birth. This may include women with conditions such as hydrocephalus requiring a cerebrospinal fluid shunt. Midwives should understand the principles of care for such women and work with the multidisciplinary team to provide indiviulaised care throughout the pregnancy and intrapartum period. [ABSTRACT FROM AUTHOR]

In the present paper a one-dimensional mathematical model of a cerebral aneurysm is considered. The model combines the interaction between the arterial wall structure, blood pressure and the cerebral spinal fluid (CSF) that is around the aneurysm. CSF is considered electrically conducting in the presence of a uniform magnetic field. Therefore, it may be possible to control pressure and its flow behavior by using an appropriate magnetic field. Hence, such studies have potential for the treatment of Cerebral aneurysms, diseases of heart and blood vessels. The modeled mathematical equations are solved algebraically and the displacement of the arterial wall is plotted to visualize the wall movement. It is evident from the graphs the inclusion of magnetic field reduce the movement of the arterial wall and in turn prevent the rupture of the cerebral aneurysm. The solution is also investigated using computational tools for various other parameters involve in the model. [ABSTRACT FROM AUTHOR]

Leptomeningeal Carcinomatosis (LC) is the dissemination of cancer, commonly breast, lung, melanoma, acute lymphoblastic leukaemia and Non-Hodgkin lymphoma occurring through either direct extension from surrounding tumours or metastasis of a preexisting, parenchymal central nervous system tumour. A rise in the diagnosis of leptomeningeal disease has been seen with increased survival rates of cancer due to improved medical treatment, with 5-8% of patients with cancer going on to develop LC. Leptomeningeal Carcinomatosis spreads to the meninges, the outer covering of the brain and spinal cord, directly migrating into the cerebral spinal fluid (CSF), arachnoid and pia mater. This migration of tumour cells occurs throughout the arachnoid vessels or choroid plexus into the surrounding outer layers extending into the CSF. On entry into the CSF, tumour cells are infiltrated in a diffuse or multifocal manner where the leptomeninges cover the surface of the brain and spinal cord. This covering causes the meninges to become irritated causing patients to exhibit signs of photophobia, neck stiffness, neurological decline and cranial nerve defects. LC has a significant morbidity and mortality rate with a median survival of 4-6 weeks if untreated and 2-3 months if treated. Diagnosis is based on analysis of the cerebral spinal fluid, through detection of positive cytology of LC tumour cells, elevated protein and CSF pressures. Magnetic resonance imaging findings identify areas of meningeal enhancement indicative of meningeal irritation. The neuroscience nurse role in the patient care includes providing a supportive environment and thorough assessment of vital and neurological signs. Treatment aims to improve or maintain a patient's neurological status while prolonging survival and palliation. The literature review will highlight the diagnosis, progression and treatment for LC to further increase awareness and inform neuroscience nurses of increasing trends in management. [ABSTRACT FROM AUTHOR]

Background: Postoperative intracranial hypotension-associated venous congestion (PIHV) is an uncommon cause of clinical deterioration after a neurosurgical procedure that is often unrecognized until late in its course. Functional outcomes range from remarkable neurological recovery to death. Little is understood about the reason for deterioration in certain patients compared with improvement in others. A 68-year-old man with a progressive cervical myelopathy underwent an uncomplicated cervical decompression and alignment restoration at our hospital and suffered violent generalized tonic-clonic seizures intraoperatively and postoperatively. A postoperative head CT showed a right parietal hematoma, but no other cranial findings. A subsequent MRI demonstrated what we describe as early PIHV with symmetric T2 signal changes in the bilateral deep gray structures. No diffusion restriction corresponded to these areas. A CT myelogram revealed a considerable CSF collection within the operative bed. Upon returning to the operating room to localize the source of the leak, a large dural tear was identified off of midline with a bone chip alongside the defect. The defect was repaired, and the patient remained comatose for over a week postoperatively. He made a remarkable gradual recovery, and after a month in the hospital and rehabilitation, he returned home with relatively minimal neurological deficits.Conclusions: We postulate that if caught early and treated aggressively, neurologic injury resulting from PIHV may be reversible despite initially ominous imaging. Neurosurgeons and neurointensivists should therefore be compelled to search for dural defects and return to the operating room for immediate repair. [ABSTRACT FROM AUTHOR]

Postoperative continuous bloody cerebral spinal fluid drainage with external ventricular drainage catheter could decrease the incidence of inflammation. But the drainage catheter left in place will interrupt the watertight dura matter closure. To prevent the related cerebrospinal fluid leakage and subgaleal pseudomeningocele after the catheter removal, we developed a patched closure method to seal the dural outlet of the drainage catheter with a favorable clinical outcome. [ABSTRACT FROM AUTHOR]