Ventricular Cerebrospinal Fluid Research Articles

Cerebrospinal fluid:serum glucose ratio in the ventricular and lumbar compartments: implications for clinical practice.

Calculation of the cerebrospinal fluid:serum glucose (CSF:SGlu ) ratio is part of the routine cerebrospinal fluid (CSF) work-up. Reference values have been defined for lumbar CSF, but are lacking for ventricular CSF. The objective of this study was to investigate whether the CSF:SGlu ratio is similar in lumbar and ventricular compartments, and to determine cut-off values for CSF:SGlu ratio in ventricular CSF. We included CSF samples that were collected by either lumbar puncture or ventricular drainage, with a red blood cell count <500/μL, normal white blood cell count and age-related normal total protein content, with simultaneously withdrawn serum sample and time to laboratory processing of ≤2 h. This resulted in 1808 sample pairs. Glucose concentrations in CSF and serum were measured by enzymatic spectrophotometry. The CSF:SGlu ratio was similar in ventricular and lumbar compartments after controlling for age, sex, time between sample withdrawal and laboratory processing, CSF white blood cell and red blood cell count, CSF total protein and serum glucose concentration using a multiple linear regression model. Lower limits for CSF:SGlu ratio in the ventricular compartment, defined as 5th percentile, were 0.51 for patients with serum glucose concentration < 100 mg/dL, 0.45 for those with serum glucose concentration ≥ 100 mg/dL and <150 mg/dL, and 0.36 for those with serum glucose concentration ≥150 mg/dL. The CSF:SGlu ratio was similar in the ventricular and lumbar compartments, and depended mainly on time to laboratory processing and absolute serum glucose levels. Previously established lower limits for CSF:SGlu ratio in lumbar CSF can be also applied for ventricular CSF.

T2 mapping of cerebrospinal fluid: 3\xa0T versus 7\xa0T

ObjectCerebrospinal fluid (CSF) T2 mapping can potentially be used to investigate CSF composition. A previously proposed CSF T2–mapping method reported a T2 difference between peripheral and ventricular CSF, and suggested that this reflected different CSF compositions. We studied the performance of this method at 7 T and evaluated the influence of partial volume and B1 and B0 inhomogeneity.Materials and methodsT2-preparation-based CSF T2-mapping was performed in seven healthy volunteers at 7 and 3 T, and was compared with a single echo spin-echo sequence with various echo times. The influence of partial volume was assessed by our analyzing the longest echo times only. B1 and B0 maps were acquired. B1 and B0 dependency of the sequences was tested with a phantom.ResultsT2,CSF was shorter at 7 T compared with 3 T. At 3 T, but not at 7 T, peripheral T2,CSF was significantly shorter than ventricular T2,CSF. Partial volume contributed to this T2 difference, but could not fully explain it. B1 and B0 inhomogeneity had only a very limited effect. T2,CSF did not depend on the voxel size, probably because of the used method to select of the regions of interest.ConclusionCSF T2 mapping is feasible at 7 T. The shorter peripheral T2,CSF is likely a combined effect of partial volume and CSF composition.

Chapter 2 - The cerebrospinal fluid and barriers – anatomic and physiologic considerations

The cerebrospinal fluid (CSF) space consists of the intracerebral ventricles, subarachnoid spaces of the spine and brain (e.g., cisterns and sulci), and the central spinal cord canal. The CSF protects the central nervous system (CNS) in different ways involving metabolic homeostasis, supply of nutrients, functioning as lymphatic system, and regulation of intracranial pressure. CSF is produced by the choroid plexus, brain interstitium, and meninges, and it circulates in a craniocaudal direction from ventricles to spinal subarachnoid space from where it is removed via craniocaudal lymphatic routes and the venous system. The CSF is renewed 3-5 times daily and its molecular constituents are mainly blood-derived (80%), while the remainder consists of brain-derived and intrathecally produced molecules (20%). The CSF space is separated from the vascular system by the blood-CSF barrier (BCB), whereas the blood-brain barrier (BBB), responsible for maintaining the homeostasis of the brain, is located between brain parenchyma and vascular system. Although both barriers have similar functions, they differ with regard to their morphologic and functional properties. Both barrier systems are permeable not only for small molecules, but also for macromolecules and circulating cells. The transport of molecules across the BBB and BCB is regulated by passive diffusion (e.g., albumin, immunoglobulins) and facilitated or active transport (e.g., glucose). The extracellular space volume, potassium buffering, CSF circulation, and interstitial fluid absorption are mainly regulated by aquaporin-4 channels, which are abundantly located at the blood-brain and brain-CSF interfaces. The composition of CSF shows a high dynamic range, and the levels of distinct proteins vary due to several influencing factors, such as site of production (brain or blood-derived), site of sampling (ventricular or lumbar), CSF flow rate (BCB function), diurnal fluctuations of CSF production rate, and finally, molecular size of blood-derived proteins (IgM vs. albumin) and circadian rhythm (glucose, prostaglandin D synthase). Alterations of lumbar CSF are mainly influenced by processes of the CNS located adjacent to the ventricular and spinal CSF space and less by pathologies in cortical areas remote from the ventricles.

Spaceflight-induced changes in white matter hyperintensity burden in astronauts.

To assess the effect of weightlessness and the respective roles of CSF and vascular fluid on changes in white matter hyperintensity (WMH) burden in astronauts. We analyzed prespaceflight and postspaceflight brain MRI scans from 17 astronauts, 10 who flew a long-duration mission on the International Space Station (ISS) and 7 who flew a short-duration mission on the Space Shuttle. Automated analysis methods were used to determine preflight to postflight changes in periventricular and deep WMH, CSF, and brain tissue volumes in fluid-attenuated inversion recovery and high-resolution 3-dimensional T1-weighted imaging. Differences between cohorts and associations between individual measures were assessed. The short-term reversibility of the identified preflight to postflight changes was tested in a subcohort of 5 long-duration astronauts who had a second postflight MRI scan 1 month after the first postflight scan. Significant preflight to postflight changes were measured only in the long-duration cohort and included only the periventricular WMH and ventricular CSF volumes. Changes in deep WMH and brain tissue volumes were not significant in either cohort. The increase in periventricular WMH volume was significantly associated with an increase in ventricular CSF volume (ρ = 0.63, p = 0.008). A partial reversal of these increases was observed in the long-duration subcohort with a 1-month follow-up scan. Long-duration exposure to microgravity is associated with an increase in periventricular WMH in astronauts. This increase was linked to an increase in ventricular CSF volume documented in ISS astronauts. There was no associated change in or abnormal levels of WMH volumes in deep white matter as reported in U-2 high-altitude pilots.

Postnatal polyunsaturated fatty acids associated with larger preterm brain tissue volumes and better outcomes.

BackgroundHuman studies investigating the link between postnatal polyunsaturated fatty acids and preterm brain growth are limited, despite emerging evidence of potential effects on outcomes.MethodsSixty preterm neonates <32 weeks gestational age with magnetic resonance imaging (MRI) scanning at near-birth and near-term age were assessed for brain tissue volumes, including cortical gray matter, white matter, deep gray matter, cerebellum, brainstem, and ventricular cerebrospinal fluid. Red blood cell fatty acid content was evaluated within 1 week of each MRI scan. Neurodevelopmental outcome at 30-36 months corrected age was assessed.ResultsAdjusting for potential confounders, higher near-birth docosahexaenoic acid levels are associated with larger cortical gray matter, deep gray matter, and brainstem volumes and higher near-term levels with larger deep gray matter, cerebellar, and brainstem volumes at near-term age; lower near-birth linoleic acid levels are correlated with larger white matter volume at near-term age. By 30-36 months corrected age, larger cortical and deep gray matter, cerebellar, and brainstem volumes by term age are associated with improved language scores and larger cerebellar and brainstem volumes with improved motor scores.ConclusionSpecific polyunsaturated fatty acid levels have differential and time-dependent associations with brain region growth. Larger brain volumes are associated with improved outcomes at preschool age.

MEDI+0: Morphology enabled dipole inversion with automatic uniform cerebrospinal fluid zero reference for quantitative susceptibility mapping.

To develop a quantitative susceptibility mapping (QSM) method with a consistent zero reference using minimal variation in cerebrospinal fluid (CSF) susceptibility. The ventricular CSF was automatically segmented on the R2* map. An L2 -regularization was used to enforce CSF susceptibility homogeneity within the segmented region, with the averaged CSF susceptibility as the zero reference. This regularization for CSF homogeneity was added to the model used in a prior QSM method (morphology enabled dipole inversion [MEDI]). Therefore, the proposed method was referred to as MEDI+0 and compared with MEDI in a numerical simulation, in multiple sclerosis (MS) lesions, and in a reproducibility study in healthy subjects. In both the numerical simulations and in vivo experiments, MEDI+0 not only decreased the susceptibility variation within the ventricular CSF, but also suppressed the artifact near the lateral ventricles. In the simulation, MEDI+0 also provided more accurate quantification compared to MEDI in the globus pallidus, substantia nigra, corpus callosum, and internal capsule. MEDI+0 measurements of MS lesion susceptibility were in good agreement with those obtained by MEDI. Finally, both MEDI+0 and MEDI showed good and similar intrasubject reproducibility. QSM with a minimal variation in ventricular CSF is viable to provide a consistent zero reference while improving image quality. Magn Reson Med 79:2795-2803, 2018. © 2017 International Society for Magnetic Resonance in Medicine.

Global and regional brain atrophy is associated with low or retrograde facial vein flow in multiple sclerosis

Increased collateral facial vein (FV) flow may be associated with structural damage in patients with multiple sclerosis (MS). The objective was to assess differences in FV flow and magnetic resonance imaging (MRI)-derived outcomes in MS. The study included 136 MS patients who underwent neck and head vascular system examination by echo-color Doppler. Inflammatory MRI markers were assessed on a 3T MRI using a semi-automated edge detection and contouring/ thresholding technique. MRI volumetric outcomes of whole brain (WB), gray matter (GM), white matter (WM), cortex, ventricular cerebrospinal fluid (vCSF), deep gray matter (DGM), thalamus, caudate nucleus (CN), putamen, globus pallidus (GP), and hippocampus were calculated. Independent &lt;em&gt;t&lt;/em&gt;-test and ANCOVA, adjusted for age, were used to compare groups based on FV flow quartiles. Thirty-four MS patients with FV flow ≤327.8 mL/min (lowest quartile) had significantly lower WB (P&amp;lt;0.001), WM (P&amp;lt;0.001), thalamus (P=0.004), cortex (P=0.004), GM (P=0.004), DGM (P=0.008), hippocampus (P=0.005), and GP volumes (P=0.044) compared to 102 patients with FV flow of &amp;gt;327.8 mL/min (higher quartiles). There were no differences in T1-, T2- and gadolinium- enhancing lesion volumes between the quartile groups. The lack of an association between FV blood flow and inflammatory MRI measures in MS patients, but an association with brain atrophy, suggests that the severity of neurodegenerative process may be related to hemodynamic alterations. MS patients with more advanced global and regional brain atrophy showed low or retrograde FV volume flow.

Correlation of CSF flow using phase-contrast MRI with ventriculomegaly and CSF opening pressure in mucopolysaccharidoses

BackgroundVery little is known about the incidence and prevalence of hydrocephalus in patients with mucopolysaccharidoses (MPS). The biggest challenge is to distinguish communicating hydrocephalus from ventricular dilatation secondary to brain atrophy, because both conditions share common clinical and neuroradiological features. The main purpose of this study is to assess the relationship between ventriculomegaly, brain and cerebrospinal fluid (CSF) volumes, aqueductal and cervical CSF flows, and CSF opening pressure in MPS patients, and to provide potential biomarkers for abnormal CSF circulation.MethodsForty-three MPS patients (12 MPS I, 15 MPS II, 5 MPS III, 9 MPS IV A and 2 MPS VI) performed clinical and developmental tests, and T1, T2, FLAIR and phase-contrast magnetic resonance imaging (MRI) followed by a lumbar puncture with the CSF opening pressure assessment. For the analysis of MRI variables, we measured the brain and CSF volumes, white matter (WM) lesion load, Evans’ index, third ventricle width, callosal angle, dilated perivascular spaces (PVS), craniocervical junction stenosis, aqueductal and cervical CSF stroke volumes, and CSF glycosaminoglycans concentration.ResultsAll the scores used to assess the supratentorial ventricles enlargement and the ventricular CSF volume presented a moderate correlation with the aqueductal CSF stroke volume (ACSV). The CSF opening pressure did not correlate either with the three measures of ventriculomegaly, or the ventricular CSF volume, or with the ACSV. Dilated PVS showed a significant association with the ventriculomegaly, ventricular CSF volume and elevated ACSV.ConclusionsIn MPS patients ventriculomegaly is associated with a severe phenotype, increased cognitive decline, WM lesion severity and enlarged PVS. The authors have shown that there are associations between CSF flow measurements and measurements related to CSF volumetrics. There was also an association of volumetric measurements with the degree of dilated PVS.

Neurodegenerative cerebrospinal fluid biomarkers tau and amyloid beta predict functional, quality of life, and neuropsychological outcomes after aneurysmal subarachnoid hemorrhage.

Cerebrospinal fluid (CSF) biomarkers might be useful in predicting outcome after aneurysmal subarachnoid hemorrhage (aSAH). It was the aim to determine whether tau and amyloid beta CSF concentrations predict functional, health-related quality of life (hrQoL), and neuropsychological outcomes after aSAH. Ventricular CSF was obtained from n=24 aSAH patients at admission (D0), day 2 (D2), and day 6 (D6). CSF total (t)Tau, phosphorylated (p)Tau(181P), and amyloid beta(1-40 and 1-42) (Aβ40/Aβ42) levels were compared between patients with favorable and unfavorable functional (modified Rankin Scale (mRS)), hrQoL (Euro-Qol (EQ-5D)), and neuropsychological outcomes at 3 (3m) and 12months (12m). Patients with unfavorable functional (mRS 4-6) and hrQoL outcome (EQ-5D z-score≤-1.0) at 3 and 12m had higher CSF tTau/pTau and lower Aβ40/Aβ42 at D0, D2, and D6 with varying degrees of statistical significance. In terms of predicting neuropsychological outcome, CSF pTau showed a statistically significant correlation with the z-scores of executive function (r=-0.7486, p=0.008), verbal memory (r=-0.8101, p=0.002), attention (r=-0.6498, p=0.030), and visuospatial functioning (r=-0.6944, p=0.017) at 3m. At 12m, CSF pTau had statistically significant correlations with the z-scores of verbal memory (r=-0.7473, p=0.008) and visuospatial functioning (r=-0.6678, p=0.024). In conclusion, higher tTau/pTau and lower Aβ40/Aβ42 CSF levels predict unfavorable long-term functional and hrQoL outcomes. Neuropsychological deficits correlate with increased CSF tTau and pTau concentrations.

The pathophysiology of chronic noncommunicating hydrocephalus: lessons from continuous intracranial pressure monitoring and ventricular infusion testing.

OBJECTIVE The pathophysiology of chronic noncommunicating hydrocephalus (ncHC) is poorly understood. This present study explored whether lessons about the pathophysiology of this clinical entity might be retrieved from results of overnight monitoring of pulsatile and static intracranial pressure (ICP) and ventricular infusion testing. METHODS The study cohort included adult patients (> 20 years of age) with chronic ncHC due to aqueductal stenosis in whom symptoms had lasted a minimum of 6 months. A reference cohort consisted of age- and sex-matched patients managed for communicating HC (cHC). Information about symptoms and clinical improvement following surgery was retrieved from a quality register, and results of overnight ICP recordings and ventricular infusion testing were retrieved from the hospital ICP database. RESULTS The cohort with ncHC consisted of 61 patients of whom 6 (10%) were managed conservatively, 34 (56%) by endoscopic third ventriculostomy (ETV), and 21 (34%) using ETV and subsequent shunt surgery. In patients responding to surgery, pulsatile ICP (mean ICP wave amplitude) was significantly increased to a similar magnitude in patients with ncHC and the reference cohort (cHC). Furthermore, intracranial compliance (ICC) was reduced in clinical responders. The results of ventricular infusion testing provided evidence that patients responding to ETV have impaired ventricular CSF absorption, while those requiring shunt placement after ETV present with impaired CSF absorption both in the intraventricular and extraventricular compartments. CONCLUSIONS The study may provide some lessons about the pathophysiology of chronic ncHC. First, increased pulsatile ICP and impaired ICC characterize patients with chronic ncHC who respond clinically to CSF diversion surgery, even though static ICP is not increased. Second, in patients responding clinically to ETV, impaired ventricular CSF absorption may be a key factor. Patients requiring shunt placement for clinical response appear to have both intraventricular and extraventricular CSF absorption failure. A subgroup of patients with ncHC due to aqueductal stenosis has normal ventricular CSF absorption and normal ICC and may not be in need of surgical CSF diversion.

Cerebral Aβ40 and systemic hypertension

Mid-life hypertension and cerebral hypoperfusion may be preclinical abnormalities in people who later develop Alzheimer’s disease. Although accumulation of amyloid-beta (Aβ) is characteristic of Alzheimer’s disease and is associated with upregulation of the vasoconstrictor peptide endothelin-1 within the brain, it is unclear how this affects systemic arterial pressure. We have investigated whether infusion of Aβ40 into ventricular cerebrospinal fluid modulates blood pressure in the Dahl salt-sensitive rat. The Dahl salt-sensitive rat develops hypertension if given a high-salt diet. Intracerebroventricular infusion of Aβ induced a progressive rise in blood pressure in rats with pre-existing hypertension produced by a high-salt diet (p < 0.0001), but no change in blood pressure in normotensive rats. The elevation in arterial pressure in high-salt rats was associated with an increase in low frequency spectral density in systolic blood pressure, suggesting autonomic imbalance, and reduced cardiac baroreflex gain. Our results demonstrate the potential for intracerebral Aβ to exacerbate hypertension, through modulation of autonomic activity. Present findings raise the possibility that mid-life hypertension in people who subsequently develop Alzheimer’s disease may in some cases be a physiological response to reduced cerebral perfusion complicating the accumulation of Aβ within the brain.

Imaging in cutis laxa syndrome caused by a dominant negative ALDH18A1 mutation, with hypotheses for intracranial vascular tortuosity andwide perivascular spaces.

The autosomal dominant progeroid form of cutis laxa is a recently identified multiple congenital anomaly disorder characterized by thin, wrinkled skin, a progeroid appearance, intra-uterine growth retardation, postnatal growth restriction, psychomotor developmental delay, microcephaly, cataract, hypotonia and contractures. De novo heterozygous mutations in ALDH18A1 have been described in this condition. We present neuroimaging abnormalities in three patients. One patient had intracranial arterial and venous tortuosity, widened ventricular and extra-axial cerebrospinal fluid (CSF) spaces, wide perivascular spaces and increased T2 signal intensity in the cerebral white matter over time. The second patient had vascular tortuosity. The third patient had prominent ventricular and extra-axial cerebrospinal fluid (CSF) spaces on CT. We propose an embryological mechanism for the development of intracranial vascular tortuosity and discuss the anatomical basis of wide perivascular spaces in relation to this syndrome. Although we do not know the clinical implications of these cerebral vascular anomalies, we suggest inclusion of neuroimaging in the baseline evaluation of these patients.

DISPROPORTIONATE INCREASE IN VENTRICULAR RELATIVE TO SULCAL CEREBROSPINAL FLUID VOLUME AND COGNITIVE FUNCTIONING: THE SMART-MR STUDY

Global cerebral volume loss is associated with neurodegenerative diseases but also with normal aging. To understand their etiology studies aim to pinpoint specific brain tissue regions that are affected early in the disease process or investigate disproportionate volume loss of specific brain tissue regions. Here, we take a different perspective by examining the disproportionate increase in ventricular relative to sulcal cerebrospinal fluid (CSF) and the association with age and cognitive functioning. Within the SMART-MR study a 1.5T MRI was performed in 1232 patients with vascular disease (mean age 58±10 years, 80% male). Automated brain segmentation was used to quantify brain tissue volumes, CSF and lesions. The ventricular-sulcal CSF (VS) ratio was calculated by dividing ventricular volume by sulcal CSF volume. Z-scores for the domains memory and executive functioning were calculated. Multiple linear regression analysis was used to estimate the associations of VS ratio with age and with memory performance and executive functioning. The mean ventricular and sulcal CSF volumes were 31±15ml and 276±43ml, respectively. The VS ratio was 0.11±0.05. Pearson correlation coefficients between the natural log-transformed VS ratio and total brain volume, intracranial volume, brain parenchymal fraction, log-deep WMH, log-periventricular WMH, and age were 0.02 (p=0.52), 0.18, -0.40, 0.21, 0.33, and 0.35, respectively (p-values <0.0001). The VS ratio increased with older age (p<0.0001) independent of sex, total WMH, and ICV. It was also significantly associated with poorer memory performance (b of Z-score=-1.29; 95% CI -2.41 to -0.17) and poorer executive functioning (b of Z-score=-1.72; 95% CI -2.78 to -0.67), adjusted for age, sex, log-WMH, and ICV. In this population, a disproportionate increase in ventricular volume relative to sulcal CSF is associated with older age and with poorer memory and executive functioning. Future studies should investigate to what extent this is a biomarker of accelerated cognitive aging.

Association between total-Tau and brain atrophy one year after first-ever stroke

BackgroundAlthough 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.MethodsWe 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.ResultsOne 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.ConclusionT-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 registrationClinicaltrials.gov NCT00506818, July 23, 2007.Inclusion from February 2007, randomization and intervention from May 2007 and trial registration in July 2007.

Cyst Fluid From Cystic, Malignant Brain Tumors: A Reservoir of Nutrients, Including Growth Factor-Like Nutrients, for Tumor Cells

Brain tumors may have cysts, whose content of nutrients could influence tumor cell microenvironment and growth. To measure nutrients in cyst fluid from glioblastoma multiforme (GBM) and metastatic brain tumors. Quantification of nutrients in cyst fluid from 12 to 18 GBMs and 4 to 10 metastatic brain tumors. GBM cysts contained glucose at 2.2 mmol/L (median value; range <0.8-3.5) and glutamine at 1.04 mmol/L (0.17-4.2). Lactate was 7.1 mmol/L (2.4-12.5) and correlated inversely with glucose level (r = -0.77; P < .001). Amino acids, including glutamate, varied greatly, but median values were similar to previously published serum values. Ammonia was 75 μmol/L (11-241). B vitamins were present at previously published serum values, and riboflavin, nicotinamide, pyridoxal 5΄-phosphate, and cobalamin were higher in cyst fluid than in cerebrospinal fluid. Inorganic phosphate was 1.25 mmol/L (0.34-3.44), which was >3 times higher than in ventricular cerebrospinal fluid: 0.35 mmol/L (0.22-0.66; P < .001). Tricarboxylic acid cycle intermediates were in the low micromolar range, except for citrate, which was 240 μmol/L (140-590). In cystic metastatic malignant melanomas and lung tumors values were similar to those in GBMs. Tumor cysts may be a nutrient reservoir for brain tumors, securing tumor energy metabolism and synthesis of cell constituents. Serum is one likely source of cyst fluid nutrients. Nutrient levels in tumor cyst fluid are highly variable, which could differentially stimulate tumor growth. Cyst fluid glutamate, lactate, and phosphate may act as tumor growth factors; these compounds have previously been shown to stimulate tumor growth at concentrations found in tumor cyst fluid.

Shunting outcomes in posthemorrhagic hydrocephalus: results of a Hydrocephalus Clinical Research Network prospective cohort study.

OBJECTIVE Previous Hydrocephalus Clinical Research Network (HCRN) retrospective studies have shown a 15% difference in rates of conversion to permanent shunts with the use of ventriculosubgaleal shunts (VSGSs) versus ventricular reservoirs (VRs) as temporization procedures in the treatment of hydrocephalus due to high-grade intraventricular hemorrhage (IVH) of prematurity. Further research in the same study line revealed a strong influence of center-specific decision-making on shunt outcomes. The primary goal of this prospective study was to standardize decision-making across centers to determine true procedural superiority, if any, of VSGS versus VR as a temporization procedure in high-grade IVH of prematurity. METHODS The HCRN conducted a prospective cohort study across 6 centers with an approximate 1.5- to 3-year accrual period (depending on center) followed by 6 months of follow-up. Infants with premature birth, who weighed less than 1500 g, had Grade 3 or 4 IVH of prematurity, and had more than 72 hours of life expectancy were included in the study. Based on a priori consensus, decisions were standardized regarding the timing of initial surgical treatment, upfront shunt versus temporization procedure (VR or VSGS), and when to convert a VR or VSGS to a permanent shunt. Physical examination assessment and surgical technique were also standardized. The primary outcome was the proportion of infants who underwent conversion to a permanent shunt. The major secondary outcomes of interest included infection and other complication rates. RESULTS One hundred forty-five premature infants were enrolled and met criteria for analysis. Using the standardized decision rubrics, 28 infants never reached the threshold for treatment, 11 initially received permanent shunts, 4 were initially treated with endoscopic third ventriculostomy (ETV), and 102 underwent a temporization procedure (36 with VSGSs and 66 with VRs). The 2 temporization cohorts were similar in terms of sex, race, IVH grade, head (orbitofrontal) circumference, and ventricular size at temporization. There were statistically significant differences noted between groups in gestational age, birth weight, and bilaterality of clot burden that were controlled for in post hoc analysis. By Kaplan-Meier analysis, the 180-day rates of conversion to permanent shunts were 63.5% for VSGS and 74.0% for VR (p = 0.36, log-rank test). The infection rate for VSGS was 14% (5/36) and for VR was 17% (11/66; p = 0.71). The overall compliance rate with the standardized decision rubrics was noted to be 90% for all surgeons. CONCLUSIONS A standardized protocol was instituted across all centers of the HCRN. Compliance was high. Choice of temporization techniques in premature infants with IVH does not appear to influence rates of conversion to permanent ventricular CSF diversion. Once management decisions and surgical techniques are standardized across HCRN sites, thus minimizing center effect, the observed difference in conversion rates between VSGSs and VRs is mitigated.

Elevated ventricular CSF lactate within the first week after aneurysmal subarachnoid hemorrhage is associated with poor outcome (P5.068)

Elevated ventricular CSF lactate within the first week after aneurysmal subarachnoid hemorrhage is associated with poor outcome (P5.068)

Third Ventricular Cerebrospinal Fluid Cysts of Thalamic Origin: Review of Embryologic Origin, Presentation, and Management Strategies with a Case Series.

Third ventricular cerebrospinal fluid (CSF) cysts of thalamic origin are rare. The objective of this study is to review their possible pathogenesis, clinical presentation, and management strategies with a case series describing management via an endoscopic approach with fenestration using a single burr-hole technique. A systematic literature review of reported cases of thalamic cysts was conducted with further meta-analysis of CSF cysts that involve the third ventricle. The mode of presentation, pathologic analysis, surgical management, and outcomes were analyzed. Twenty-two studies reported between 1990 and 2013 described 42 cases of thalamic cyst. Of those cases, 13 were consistent with CSF cyst that originated in the thalamus and involved the third ventricle. Eight cases (61.5%) were treated via endoscopic fenestration, 2 cases (15.4%) were surgically drained, 2 cases (15.4%) were stereotactically aspirated, and 1 case (7.69%) was observed. The most common presenting symptoms were gait disturbance (26.3%) and headaches (26.3%) followed by tremors (15.8%) and weakness (15.8%). In our series, a single burr-hole technique was a successful definitive treatment, with an average period of 23 months. Third ventricular CSF cysts of thalamic origin most commonly present with hydrocephalus. They can be safely definitively treated via endoscopic fenestration to the CSF circulation using a single burr-hole technique. Long-term follow-up shows lasting improvement in symptoms without reaccumulation of the cyst.

Fornix Under Water? Ventricular Enlargement Biases Forniceal Diffusion Magnetic Resonance Imaging Indices in Anorexia Nervosa

BackgroundAcute anorexia nervosa (AN) is characterized by reduced brain mass and corresponding increased sulcal and ventricular cerebrospinal fluid. Recent studies of white matter using diffusion tensor imaging consistently identified alterations in the fornix, such as reduced fractional anisotropy (FA). However, because the fornix penetrates the ventricles, it is prone to cerebrospinal fluid–induced partial volume effects that interfere with a valid assessment of FA. We investigated the hypothesis that in the acute stage of AN, FA of the fornix is markedly affected by ventricular volumes. MethodsFirst, using diffusion tensor imaging data we established the inverse associations between forniceal FA and volumes of the third and lateral ventricles in a prestudy with 32 healthy subjects to demonstrate the strength of ventricular influence on forniceal FA independent of AN. Second, we investigated a sample of 25 acute AN patients and 25 healthy control subjects. ResultsUsing ventricular volumes as covariates markedly reduced the group effect of forniceal FA, even with tract-based spatial statistics focusing only on the center of the fornix. In addition, after correcting for free water on voxel level, the group differences in forniceal FA between AN patients and controls disappeared completely. ConclusionsIt is unlikely that microstructural changes affecting FA occurred in the fornix of AN patients. Previously identified alterations in acute AN may have been biased by partial volume effects and the proposed central role of this structure in the pathophysiology may need to be reconsidered. Future studies on white matter alterations in AN should carefully deal with partial volume effects.

New cerebrospinal fluid biomarkers in Alzheimer’s disease

New cerebrospinal fluid biomarkers in Alzheimer’s disease