Profound changes in cerebrospinal fluid proteome and metabolic profile are associated with congenital hydrocephalus

The aetiology of congenital hydrocephalus (cHC) has yet to be resolved. cHC manifests late in rodent gestation, and by 18–22 weeks in human fetuses, coinciding with the start of the major phase of cerebral cortex development. Previously we found that cerebrospinal fluid (CSF) accumulation is associated with compositional changes, folate metabolic impairment and consequential arrest in cortical development. Here, we report a proteomics study on hydrocephalic and normal rat CSF using LC-MSMS and a metabolic pathway analysis to determine the major changes in metabolic and signalling pathways. Non-targeted analysis revealed a proteome transformation across embryonic days 17–20, with the largest changes between day 19 and 20. This provides evidence for a physiological shift in CSF composition and identifies some of the molecular mechanisms unleashed during the onset of cHC. Top molecular regulators that may control the shift in the CSF metabolic signature are also predicted, with potential key biomarkers proposed for early detection of these changes that might be used to develop targeted early therapies for this condition. This study confirms previous findings of a folate metabolic imbalance as well as providing more in depth metabolic analysis and understanding of cHC CSF.     

Treatment of traumatic acute subdural hematoma in adult hydrocephalus patients with cerebrospinal fluid shunt

Objective

The presence of a cerebrospinal fluid (CSF) shunt is a predisposing factor for the development of subdural hematoma (SDH) in patients with hydrocephalus. However, few reports have addressed how patients with a CSF shunt should be treated in the event of traumatic acute SDH. The purpose of this study was to show how post-traumatic management of CSF shunt affects acute SDH in adult patients with hydrocephalus.

Methods

Twelve patients were studied retrospectively. Pressure settings of shunt valve prior to head injury (HI), severity of HI, treatment on admission, changes in SDH thickness and subsequent hydrocephalus were mainly analyzed.

Results

Ten patients experienced mild HI, with nine showing neurological deterioration until admission. Five patients needed surgical hematoma removal soon after admission. SDH recurred in four cases where shunt pressure levels were kept relatively low. Shunt ligation or raising the pressure level in the programmable valve proved effective for controlling postoperative SDH in such cases. Six of the remaining seven patients underwent only shunt ligation or readjustment of pressure level in the programmable valve on admission. SDH thickness was reduced as ventricles dilated without major neurological complications. Four patients showed delayed development of SDH even though shunts were kept ligated.

Conclusions

Hematoma removal alone may result in hematoma recurrence and require a second treatment comprising shunt management to effectively control hematoma. Using shunt management as the only initial treatment can reduce hematoma volume, but some patients may suffer delayed SDH development and require surgery.     

Non-invasive assessment of cerebrospinal fluid flow dynamics using phase-contrast magnetic resonance imaging in communicating hydrocephalus

This work aims to evaluate the changes in cerebrospinal fluid (CSF) hydrodynamics in patients diagnosed with communicating hydrocephalus. Besides, we establish the relationship between CSF flow dynamic parameters on the midbrain aqueduct and intracranial pressure (ICP). CSF hydrodynamics analysis was performed using Phase-Contrast Magnetic Resonance Imaging (PC‐MRI) techniques on the midbrain aqueduct of 41 patients diagnosed with communicating hydrocephalus and 22 healthy volunteers. The correlation between CSF average flow in the midbrain aqueduct and intracranial pressure measured by Lumbar Puncture (LP) was assessed in patients with hydrocephalus. Pearson correlation coefficient was used to establish the correction between the average CSF flow of midbrain aqueduct and ICP. CSF dynamic parameters of the midbrain aqueduct in hydrocephalus patients, including peak positive velocity (7.348 cm/s), average velocity (0.623 cm/s), average flow (50.799 mm³/s), and regions of interest (ROI) area (9.978 mm²) were significantly higher than in the healthy controls (p < 0.05). This was after adjusting the age, gender, heart rate, systolic blood pressure, diastolic blood pressure, and body mass index. However, only the peak negative velocity of the midbrain aqueduct did not significantly differ between the groups (p = 0.209). A positive correlation was noted between the average flow (AF) of the midbrain aqueducts and ICP in hydrocephalus patients (y (AF) = 0.386× (ICP)−33.738, r = 0.787, p < 0.05). Reference data of CSF flow dynamic parameters was obtained through the PC-MRI in middle-aged healthy volunteers and communicating hydrocephalus patients. Although the sample size was constrained, this study has significant contributions. For instance, a significant correlation was noted between the average CSF flow of the aqueduct and ICP. This therefore provides a reference for clinicians to monitor ICP in patients with hydrocephalus.     

慢性脑低灌注诱导VEGF的表达

目的通过建立慢性脑低灌注动物模型,研究慢性脑低灌注诱导血管内皮细胞生长因子(VEGF)表达的时程变化。方法21只SD大鼠随机分为假手术组、模型组,动物按动静脉分流术后不同时间点分组。采用半定量RT-PCR和Westernblot方法分析VEGF蛋白及其mRNA的表达,免疫组化观察VEGF蛋白表达的细胞来源。结果半定量RT-PCR扩增得到3个片断:713bp、640bp和513bp,分别对应于VEGF188、VEGF164和VEGF120,其中以VEGF164为主,模型组动物于术后24h明显升高,1w达高峰,3w降低,3m恢复到基础水平;Westernblot检测发现单一条带,分子量为45kD,相当于VEGF164,其表达的时程变化与VEGFmRNA相一致;VEGF蛋白表达主要位于血管内皮细胞胞浆。结论慢性脑低灌注可持续性诱导VEGFmRNA及其蛋白表达;VEGF参与了脑动静脉畸形(AVM)的病理发生过程。     

A cerebrospinal fluid shunt: a theoretical concept

An innovative shunt design for the treatment of hydrocephalus is discussed. It is based on a two-tube configuration which restores accumulator function to suppress intracranial pressure fluctuations emanating from the brain and resulting from changes in the subject's postural position. Current shunt problems of overdrainage, occlusion, and infection are addressed and corrections inherent in the proposed design are described. Specific materials and characteristics for the construction of the proposed design are suggested.     

Quantitative evaluation of changes in gait after extended cerebrospinal fluid drainage for normal pressure hydrocephalus

Idiopathic normal pressure hydrocephalus (iNPH) is characterized by gait instability, urinary incontinence and cognitive dysfunction. These symptoms can be relieved by cerebrospinal fluid (CSF) drainage, but the time course and nature of the improvements are poorly characterized. Attempts to prospectively identify iNPH patients responsive to CSF drainage by evaluating presenting gait quality or via extended lumbar cerebrospinal fluid drainage (eLCD) trials are common, but the reliability of such approaches is unclear. Here we combine eLCD trials with computerized quantitative gait measurements to predict shunt responsiveness in patients undergoing evaluation for possible iNPH. In this prospective cohort study, 50 patients presenting with enlarged cerebral ventricles and gait, urinary, and/or cognitive difficulties were evaluated for iNPH using a computerized gait analysis system during a 3 day trial of eLCD. Gait speed, stride length, cadence, and the Timed Up and Go test were quantified before and during eLCD. Qualitative assessments of incontinence and cognition were obtained throughout the eLCD trial. Patients who improved after eLCD underwent ventriculoperitoneal shunt placement, and symptoms were reassessed serially over the next 3 to 15 months. There was no significant difference in presenting gait characteristics between patients who improved after drainage and those who did not. Gait improvement was not observed until 2 or more days of continuous drainage in most cases. Symptoms improved after eLCD in 60% of patients, and all patients who improved after eLCD also improved after shunt placement. The degree of improvement after eLCD correlated closely with that observed after shunt placement.     

延迟性脑脊液漏伴脑积水的治疗

临床上外伤性脑脊液漏多在伤后一周左右自行停止，而部分脑脊液漏出现在伤后数周或数月，其为延迟性脑脊液漏，原因主要与漏口和颅内压有密切关系，多需手术修补。我们诊治6例延迟性脑脊液漏伴脑积水患者，对其治疗方法与手术方式选择进行了探讨。     

急性脑梗死患者血清血管内皮生长因子的测定

目的　探讨急性脑梗死与血管内皮生长因子 (VEGF)的关系。方法　对 3 0例急性脑梗死患者和 40例健康人血清血管内皮生长因子含量进行测定。患者采血时间为病后第 2天或第 3、4天 ,取均数与对照组比较。结果　 3 0例急性脑梗死患者血清 VEGF含量为 (2 95 .0 4± 3 5 .73 ) pg/ ml,对照组为 (13 7.71± 11.5 3 ) pg/ m l,两组比较差异显著。结论　急性脑梗死患者血清 VEGF升高 ,提示 VEGF是脑梗死急性期的自我保护机制之一。     

Effects of vascular endothelial growth factor in ischemic stroke

Vascular endothelial growth factor (VEGF) is a pleiotropic growth factor that is crucially involved in neurovascular remodeling in the ischemic brain. VEGF promotes angiogenesis, protects ischemic neurons from injury, has potent anti‐inflammatory actions, and promotes brain plasticity, in addition to enhancing the recruitment and proliferation of neural precursor cells. These broad actions make VEGF interesting as a model molecule that allows understanding endogenous responses of the brain to injuries. However, several studies indicate that the route and timing of VEGF administration are crucial for the effects of VEGF on ischemic brain tissue. Hence, systemic VEGF delivery in the very acute stroke phase may exacerbate brain damage because of the promotion of blood–brain barrier breakdown that inevitably accompanies vascular growth. Future studies aimed at the promotion of neurovascular remodeling in ischemic stroke should carefully take into consideration pleiotropic actions of angiogenic growth factors beyond vascular growth. © 2012 Wiley Periodicals, Inc.     

Fibroblast growth factor and hydrocephalus

Abstract

The Immunohistochemical localization of basic fibroblast growth factor (bFCF) was studied in ventricular ependyma and choroid plexus of aged-matched normotensive and spontaneously hypertensive rats at different ages using a polyclonal antibody against bFCF. The bFCF-like immunoreactivity was observed in brain ependyma and choroid plexus of young and old normotensive rats. However, a progressive loss of immunoreactivity was observed with age in spontaneously hypertensive rats, that was associated with a progressive cerebroventricuiar dilation. These results show a new neuroendocrine anomaly to be added to the many others previously observed in this rat strain, when they develop hydrocephalus as they age. [Neurol Res 2000; 22: 102-104]     

Elevated leukocyte count in cerebrospinal fluid of patients with chronic inflammatory demyelinating polyneuropathy

Cerebrospinal fluid (CSF) examination is often part of the diagnostic work‐up of a patient suspected of having chronic inflammatory demyelinating polyneuropathy (CIDP). According to the European Federation of Neurological Societies and the Peripheral Nerve Society (EFNS/PNS) criteria, an elevated protein level without pleocytosis (leukocytes <10 cells/µl) is supportive of the diagnosis CIDP. It is unclear how many CSF leukocytes are compatible with the diagnosis CIDP and how extensive the diagnostic work‐up should be in patients with a demyelinating neuropathy and pleocytosis. We performed a retrospective study at two tertiary neuromuscular referral clinics and identified 14 out of 273 (6%) patients with CIDP with elevated CSF leukocytes (≥10 cells/µl). All these patients met the EFNS/PNS criteria for definite or probable CIDP. Eight patients (57%) presented with a subacute onset and four patients with an antecedent infection. Most patients responded well to therapy, and eight patients are currently in remission. In four patients, lumbar puncture was repeated. A spontaneous decrease in leukocytes before start of treatment was found in three patients. Our data indicate that a mild to moderate pleocytosis in CSF does not exclude the diagnosis of CIDP, especially in patients with a subacute onset of disease.     

Hypoxia-induced vascular endothelial growth factor expression in normal rat astrocyte cultures

Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen, which also enhances vascular permeability. Because this angiogenic factor has been suggested to play a role in brain tumor biology, we have begun to investigate the regulation of VEGF expression in cultures of rat type I astrocytes. In this report, we have focused on the influence of hypoxia on VEGF expression. Under standard in vitro conditions (21% O₂) VEGF expression in astrocytes is barely detectable by northern analysis. However, after exposure to 0.2% O₂ for as little as 3 h VEGF mRNA levels are markedly increased reaching a maximum by approximately 8 h of exposure. Treatment of astrocytes with CoCl₂ or desferrioxamine results in a similar induction of VEGF, suggesting that the oxygen sensor regulating VEGF expression in astrocytes is a heme-containing molecule. Although acute treatment with TPA (6 h) induces VEGF expression, chronic exposure to TPA (24 h) to deplete PKC activity does not reduce the hypoxia-induced VEGF expression. These data indicate that VEGF induction in astrocytes can proceed through PKC-dependent and -independent pathways. Furthermore, chronic exposure to TPA or treatment with herbimycin A results in the enhancement of the hypoxia-mediated increase in VEGF mRNA levels. These results suggest that PKC and herbimycin-sensitive tyrosine kinase may serve as negative regulators of the hypoxia-activated signal transduction pathway that leads to the induction of VEGF expression. However, treatment of astrocytes with the nonspecific kinase inhibitors H7 and H8 reduced the level of VEGF induction by hypoxia, indicating that some type of kinase activity is required in this signaling pathway. © 1995 Wiley-Liss, Inc.     

Cerebrospinal fluid vascular endothelial growth factor in patients with amyotrophic lateral sclerosis

Oxidative stress and glutamate-mediated toxicity may play an important role in the etiopathogenesis of amyotrophic lateral sclerosis (ALS). The vascular endothelial growth factor (VEGF) is a neuroprotective cytokine activated by hypoxia. The aim of this study was to measure VEGF levels in the cerebrospinal fluid (CSF) of ALS patients. The study concerned 30 ALS patients and 30 control subjects. The VEGF was measured by the enzyme-linked immunosorbent assay. The results have shown that CSF VEGF levels are significantly increased in patients with long duration of ALS and in patients with limb-onset of the disease compared with controls (P<0.05). Moreover, the type of ALS patients’ subgroup significantly influences CSF VEGF levels (P=0.05). The CSF VEGF levels were significantly increased in patients with limb-onset compared to patients with bulbar-onset of ALS, and in patients with long duration of ALS compared to patients with its short duration (P<0.05). There was a significant correlation between CSF VEGF levels and duration of ALS (P<0.05). It seems that a significant increase in CSF VEGF levels in patients with limb-onset of ALS and in patients with long duration of the disease may have a protective role against glutamate-mediated toxicity and oxidative damage of motor neurons. However, the conclusions are limited due to relatively small subgroups of ALS patients and by lack of a control group consisting of healthy persons. Further investigations could help to confirm the results from this preliminary report.     

Schwann cells upregulate vascular endothelial growth factor secondary to chronic nerve compression injury

To better understand the pathogenesis of chronic nerve compression injuries, we investigated the possibility that Schwann cell production of vascular endothelial growth factor (VEGF) is responsible for the increased vascularity and Schwann cell proliferation associated with chronic nerve injury. In situ hybridization was used to evaluate VEGF mRNA production with immunohistochemistry to further localize the production of VEGF and its receptor proteins in an animal model of chronic nerve compression injury. VEGF mRNA and protein expression increased within Schwann cells as early as 2 weeks after compression and peaked by 1 month with a subsequent marked increase in the number of blood vessels. Thus, chronic nerve compression injury induces Schwann cells to increase VEGF production, which may be responsible for changes in neural vasculature secondary to chronic nerve compression injury. With a better understanding of these nerve injuries, more effective treatments may be developed to help patients with these impairments.     

Intracranial venous pressures,hydrocephalus and effects of cerebrospinal fluid shunts

Data concerning venous anatomy, interstitial fluid pressure and cerebral blood flow indicate that obstruction of cerebral venous outflow (as a whole or involving the deep venous system alone) is the essential cause of hydrocephalus. Choroidal and ventricular veins both belong to the deep system. Choroidal venous pressure determines cerebrospinal fluid pressure; pressure in the ventricular veins determines interstitial fluid pressure in the paraventricular white matter. A decrease in deep cerebral blood flow causes paraventricular atrophy. CSFP is higher than interstitial fluid pressure, normally and in venous obstruction. Thus, CSFP prevents venocongestive edema (but not inflammatory edema) of the brain. Collateral venous pathways are described. Venous obstruction causes hydrocephalus only when it leads to insufficient blood flow. Cerebrospinal fluid shunting causes increased CBF as essential therapeutic effect in hydrocephalus, but also causes venocongestive brain edema, which explains the decrease in ventricle size and the side effects of shunting.Presented at the XVI Annual Meeting of the International Society for Pediatric Neurosurgery, Rome 1988     

Serum levels of vascular endothelial growth factor elevated in patients with muscular dystrophy

In patients with muscular dystrophy, such as Duchenne muscular dystrophy (DMD), microcirculation abnormalities and hypoxic ischemic conditions in muscle tissues are suspected to be induced by non-symptomatic coagulation fibrinolysis abnormalities and vascular dysfunction. Vascular endothelial growth factor (VEGF) is a critical regulating factor in angiogenesis that is known to be induced by hypoxic and/or ischemic conditions. To examine whether VEGF is associated with muscular dystrophy, we measured serum levels of VEGF in 52 patients with DMD, 15 with Becker muscular dystrophy (BMD), 20 with Fukuyama congenital muscular dystrophy (FCMD), eight with myotonic dystrophy (DM), and four with spinal muscular atrophy (SMA), as well as in 15 healthy and eight disease controls. The serum level of VEGF in the DMD patients was 267.7 ± 25.3 pg/ml (10.5–800.0), while it was 358.8 ± 96.3 pg/ml (0.2–1320.0) in the BMD patients, 261.4 ± 45.6 pg/ml (0.1–758.0) in the FCMD patients, 165.0 ± 63.4 pg/ml (2.6–479.0) in the DM patients, 96.0 ± 30.3 pg/ml (41.0–168.0) in the SMA patients, 148.3 ± 20.1 pg/ml (46.5–298.0) in the healthy controls, and 154.1 ± 54.0 pg/ml (7.2–343.0) in the disease controls. The level of VEGF in BMD was significantly elevated, as compared with DM, SMA, and control groups. Further, the level of VEGF in the bedridden sub-group of DMD patients was significantly elevated as compared with chair-bound DMD, DM, SMA, and control groups. We concluded that VEGF may reflect hypoxic and/or ischemic conditions in muscle tissue, and have a relationship with the process of disease progression in DMD and BMD patients.     

血管内皮生长因子基因对大鼠缺血脑组织的保护作用

目的　探讨血管内皮生长因子基因对大鼠缺血脑组织的保护作用 ,为临床治疗脑梗死提供实验依据。方法　用线拴法制成Wistar大鼠大脑中动脉永久性闭塞模型 ,将VEGF1 6 5真核表达质粒 (pUCCAGGS/hVEGF1 6 5)经颅骨注入到缺血区。术后 7d断头取脑 ,2 %红四氮唑 (TTC)染色测梗死体积、HE染色观察组织坏死情况、免疫组织化学检测VEGF1 6 5基因的表达。结果　治疗组VEGF表达高 ,脑组织坏死明显减轻 ,脑梗死体积明显缩小 (P <0 .0 1 )。结论　在质粒载体介导下 ,VEGF基因可转化到缺血脑组织中并表达VEGF ,进而保护神经细胞 ,治疗脑梗死     

Study of tryptophan metabolism via serotonin in cerebrospinal fluid of patients with noncommunicating hydrocephalus using a new endoscopic technique

By a recent minimally invasive neuroendoscopic technique, the cerebral ventricles have been reached in a quick, reliable, and harmless way, making possible the study of cerebrospinal fluid (CSF) of the lateral ventricles and, above all, the CSF adjacent to the walls of the third ventricle. Tryptophan, 5-hydroxytryptophan, serotonin (5-HT), and 5-hydroxyindoleacetic acid (5-HIAA) were measured in CSF by HPLC equipment. Twenty-six patients affected with noncommunicating hydrocephalus were enrolled in the study and, as controls, 28 subjects not suffering from any neurological disease. The concentrations of tryptophan were higher in right ventricular CSF than in lumbar CSF (P < 0.01). 5-HT was detectable in the CSF of the right ventricle of hydrocephalic patients. 5-HIAA was higher in right ventricular CSF than in cisternal and lumbar CSF (P < 0.01), both in controls and in hydrocephalic patients. However, there was a higher concentration of 5-HIAA in right ventricular (P < 0.05) and cisternal (P < 0.01) CSF in hydrocephalic patients in comparison with controls. In the CSF samples withdrawn during neuroendoscopy, 5-HT presented the highest concentrations in the pineal recess. The highest amounts of 5-HIAA were found in the choroid plexus, third and right ventricles, pituitary recess, and aqueduct, and the lowest in pineal recess, subarachnoid space, infundibulum, and interpeduncolar cistern. These results provide new insight into the fate of tryptophan and its metabolites via serotonin in the CSF and suggest the feasibility of the new neuroendoscopic technique for brain metabolic studies.