Associations of Growth-Associated Protein 43 with Cerebral Microbleeds: A Longitudinal Study

Background

Cerebral microbleeds (CMB) play an important role in neurodegenerative pathology.

Objective

The present study aims to test whether cerebrospinal fluid (CSF) growth-associated protein 43 (GAP-43) level is linked to CMBs in elderly people.

Methods

A total of 750 participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI) who had measurements of GAP-43 and CMBs were included in the study. According to the presence and extent of CMBs, participants were stratified into different groups. Regression analyses were used to assess cross-sectional and longitudinal associations between GAP-43 and CMBs.

Results

Participants with CMB were slightly older and had higher concentrations of CSF GAP43. In multivariable adjusted analyses for age, gender, APOEɛ4 status, and cognitive diagnoses, higher CSF GAP-43 concentrations were modestly associated with CMB presence (OR = 1.169, 95% CI = 1.001-1.365) and number (β= 0.020, SE = 0.009, p = 0.027). Similarly, higher CSF GAP43 concentrations were accrual of CMB lesions, associated with higher CMB progression (OR = 1.231, 95% CI = 1.044-1.448) and number (β= 0.017, SE = 0.005, p = 0.001) in the follow up scan. In stratified analyses, slightly stronger associations were noted in male participants, those 65 years and older, carriers of APOEɛ4 alleles, and with more advanced cognitive disorders.

Conclusions

CSF GAP-43 was cross-sectionally associated with the presence and extent of CMBs. GAP-43 might be used as a biomarker to track the dynamic changes of CMBs in elderly persons.

Tract-Specific Relationships Between Cerebrospinal Fluid Biomarkers and Periventricular White Matter in Posthemorrhagic Hydrocephalus of Prematurity

BACKGROUND

Posthemorrhagic hydrocephalus (PHH) is associated with neurological morbidity and complex neurosurgical care. Improved tools are needed to optimize treatments and to investigate the developmental sequelae of PHH.

OBJECTIVE

To examine the relationship between diffusion magnetic resonance imaging (dMRI) and cerebrospinal fluid (CSF) biomarkers of PHH.

METHODS

A total of 14 preterm (PT) infants with PHH and 46 controls were included. PT CSF was collected at temporizing surgery in PHH infants (PHH PT CSF) or lumbar puncture in controls. Term-equivalent age (TEA) CSF was acquired via implanted device or at permanent CSF diversion surgery in PHH (PHH-TEA-CSF) or lumbar puncture in controls. TEA dMRI scans were used to measure fractional anisotropy (FA) and mean diffusivity (MD) in the genu of corpus callosum (gCC), posterior limb of internal capsule (PLIC), and optic radiations (OPRA). Associations between dMRI measures and CSF amyloid precursor protein (APP), neural cell adhesion-1 (NCAM-1), and L1 cell adhesion molecule (L1CAM) were assessed using Pearson correlations.

RESULTS

APP, NCAM-1, and L1CAM were elevated over controls in PHH-PT-CSF and PHH-TEA-CSF. dMRI FA and MD differed between control and PHH infants across all tracts. PHH-PT-CSF APP levels correlated with gCC and OPRA FA and PLIC MD, while L1CAM correlated with gCC and OPRA FA. In PHH-TEA-CSF, only L1CAM correlated with OPRA MD.

CONCLUSION

Tract-specific associations were observed between dMRI and CSF biomarkers at the initiation of PHH treatment. dMRI and CSF biomarker analyses provide innovative complementary methods for examining PHH-related white matter injury and associated developmental sequelae.

Elevated Pro-Inflammatory Cell-Free MicroRNA Levels in Cerebrospinal Fluid of Premature Infants after Intraventricular Hemorrhage

Intraventricular hemorrhage (IVH) represents a high risk of neonatal mortality and later neurodevelopmental impairment in prematurity. IVH is accompanied with inflammation, hemolysis, and extracellular hemoglobin (Hb) oxidation. However, microRNA (miRNA) expression in cerebrospinal fluid (CSF) of preterm infants with IVH has been unknown. Therefore, in the present study, candidate pro-inflammatory cell-free miRNAs were analyzed in CSF samples from 47 preterm infants with grade III or IV IVH vs. clinical controls (n = 14). miRNAs were quantified by RT-qPCR, normalized to “spike-in” cel-miR-39. Oxidized Hb and total heme levels were determined by spectrophotometry as well as IL-8, VCAM-1, ICAM-1, and E-selectin concentrations by ELISA. To reveal the origin of the investigated miRNAs, controlled hemolysis experiments were performed in vitro; in addition, human choroid plexus epithelial cell (HCPEpiC) cultures were treated with metHb, ferrylHb, heme, or TNF-α to replicate IVH-triggered cellular conditions. Levels of miR-223, miR-155, miR-181b, and miR-126 as well as Hb metabolites along with IL-8 were elevated in CSF after the onset of IVH vs. controls. Significant correlations were observed among the miRNAs, oxidized Hb forms, and the soluble adhesion molecules. During the post-IVH follow-up, attenuated expression of miRNAs and protein biomarkers in CSF was observed upon elimination of Hb metabolites. These miRNAs remained unaffected by a series of artificially induced hemolysis, which excluded red blood cells as their origin, while stimulation of HCPEpiCs with oxidized Hb fractions and heme resulted in increased extracellular miRNA levels in the cell culture supernatant. Overall, the hemorrhage-induced CSF miRNAs reflected inflammatory conditions as potential biomarkers in preterm IVH.

Retrieval of germinal zone neural stem cells from the cerebrospinal fluid of premature infants with intraventricular hemorrhage

Intraventricular hemorrhage is a common cause of morbidity and mortality in premature infants. The rupture of the germinal zone into the ventricles entails loss of neural stem cells and disturbs the normal cytoarchitecture of the region, compromising late neurogliogenesis. Here we demonstrate that neural stem cells can be easily and robustly isolated from the hemorrhagic cerebrospinal fluid obtained during therapeutic neuroendoscopic lavage in preterm infants with severe intraventricular hemorrhage. Our analyses demonstrate that these neural stem cells, although similar to human fetal cell lines, display distinctive hallmarks related to their regional and developmental origin in the germinal zone of the ventral forebrain, the ganglionic eminences that give rise to interneurons and oligodendrocytes. These cells can be expanded, cryopreserved, and differentiated in vitro and in vivo in the brain of nude mice and show no sign of tumoral transformation 6 months after transplantation. This novel class of neural stem cells poses no ethical concerns, as the fluid is usually discarded, and could be useful for the development of an autologous therapy for preterm infants, aiming to restore late neurogliogenesis and attenuate neurocognitive deficits. Furthermore, these cells represent a valuable tool for the study of the final stages of human brain development and germinal zone biology.

Astrogliosis inhibition attenuates hydrocephalus by increasing cerebrospinal fluid reabsorption through the glymphatic system after germinal matrix hemorrhage

Germinal matrix hemorrhage (GMH) results from the rupture of the immature thin-walled blood vessels and consequent bleeding into the subependymal germinal matrix and possible lateral ventricles. The purpose of this study is to investigate how astrogliosis impacts the glymphatic-meningeal lymphatic system in cerebrospinal fluid (CSF) reabsorption after GMH and how the anti-scarring agent olomoucine attenuates post-hemorrhagic hydrocephalus. GMH was induced by stereotaxic collagenase infusion into P7 Sprague-Dawley rats of both sexes. Western blot and immunofluorescence were used to assess astrogliosis and how astrogliosis affects glymphatic function by measuring Aquaporin-4 expression. Intracisternal injection of fluorescence tracer was used to measure CSF diffusion throughout the brain, its dispersion in the paravascular area and CSF drainage into the deep cervical lymph nodes at 28 days after GMH. Both short-term and long-term behavioral tests were used to assess the neurological outcomes. Nissl staining was used to assess the morphological changes at 28 days after hemorrhage. GMH elicited astrogliotic scarring and reduced the exchange between CSF and interstitial fluid, as well as CSF reabsorption through the meningeal lymphatic vessels. This might be associated with redistribution of Aquaporin-4. Olomoucine ameliorated scar tissue formation and attenuated post-hemorrhagic hydrocephalus. These findings of this study suggested that the glymphatic system might play a role in CSF reabsorption in neonates following GMH. Scar tissue formation impairs this CSF clearance route, and therefore astrogliosis inhibition might be a potential therapeutic strategy for neonatal post-hemorrhagic hydrocephalus.

Effect of irrigation on fibrinolytic rtPA therapy in a clot model of intracerebral haemorrhage: a systematic in vitro study

OBJECTIVE

Although fibrinolytic therapy is an upcoming treatment for intracerebral haemorrhage (ICH), standard guidelines are lacking, and some clinical issues persist. Here, we used our recently devised clot model of ICH to systematically analyse effects of irrigation and cerebrospinal fluid (CSF) on fibrinolysis.

METHODS

In vitro clots of human blood (25 ml) were generated and a catheter irrigation system was applied to deliver fluid/treatment. Clots were weighed before and after treatment and compared to rtPA treatment alone. First various drainage periods (15, 30 and 60 min; n = 3 each) and irrigation rates (0, 15, 90 and 180 ml/h; n = 3-5 each) were tested, followed by rtPA administration (1 mg, 15 min incubation) at each irrigation rate. Potential fibrinolytic effect of CSF was examined by incubation with 5 ml healthy vs. haemorrhagic CSF (n = 3 each). To assess a washout effect treatment with saline (0.9%), rtPA (1 mg) and high-rate irrigation (180 ml/h) were compared with measuring plasminogen level before and after. Furthermore clots were treated with a combination of plasminogen (150% serum concentration) and rtPA (1 mg).

RESULTS

Relative clot end weights after 60 min irrigation system treatments were 66.3 ± 3.8% (0 ml/h), 46.3 ± 9.5% (15 ml/h), 46.5 ± 7.1% (90 ml/h) and 53.3 ± 4.1% (180 ml/h). At a lower irrigation rate (15 ml/h), relative end weights were lowest (49.5 ± 4.6%) after 60 min (15 min: 62 ± 4.3%, p = 0.016; 30 min: 62.90 ± 1.88%, p = 0.012). The combination of rtPA and irrigation produced following relative end weights: 0 ml/h, 35 ± 3.2%; 15 ml/h, 32.1 ± 5.7%; 90 ml/h, 36.7 ± 6.3% and 180 ml/h, 41.9 ± 7.5%. No irrigation (0 ml/h) versus rtPA alone showed a significant difference (p < 0.0001) in higher clot weight reduction by rtPA. Similar rtPA+15 ml/h irrigation achieved a significant higher weight reduction compared to 15 ml/h irrigation alone (p = 0.0124). No differences were evident at 90 and 180 ml/h irrigation rates with and without rtPA. Healthy (55.1 ± 5%) or haemorrhagic (65.2 ± 6.2%) CSF showed no fibrinolytic activity. Plasminogen levels in clots declined dramatically (> 80% initially to < 10%) after 1 mg single rtPA dosing and high-rate (180 ml/h) irrigation. The fibrinolytic benefit of adding plasminogen to rtPA was marginal.

CONCLUSIONS

In our in vitro clot model, irrigation combined with rtPA (vs. rtPA alone) conferred no added lytic benefit. Likewise, exposure to haemorrhagic CSF did not increase clot lysis.

Is cerebral microbleed prevalence relevant as a biomarker in amnestic mild cognitive impairment and mild Alzheimer's disease?

Introduction The search for a reliable neuroimaging biomarker in Alzheimer's disease is a matter of intense research. The presence of cerebral microbleeds seems to be a potential biomarker. However, it is not clear if the presence of microbleeds has clinical usefulness to differentiate mild Alzheimer's disease and amnestic mild cognitive impairment from normal aging. We aimed to verify if microbleed prevalence differs among three groups: mild Alzheimer's disease, amnestic mild cognitive impairment due to Alzheimer's disease, and normal controls. Moreover, we studied whether microbleeds were associated with apolipoprotein E allele ɛ4 status, cerebrospinal fluid amyloid-beta, total and phosphorylated tau protein levels, vascular factors, and cognition. Methods Twenty-eight mild Alzheimer's disease patients, 34 with amnestic mild cognitive impairment and 36 cognitively normal elderly subjects underwent: magnetic resonance imaging with a susceptibility-weighted imaging sequence on a 3T scanner, apolipoprotein E genotyping and a full neuropsychological evaluation. Only amnestic mild cognitive impairment and mild Alzheimer's disease underwent cerebrospinal fluid analysis. We compared the groups and verified if microbleeds were predicted by all other variables. Results Mild Alzheimer's disease presented a higher prevalence of apolipoprotein E allele ɛ4 in relation to amnestic mild cognitive impairment and control group. No significant differences were found between groups when considering microbleed presence. Logistic regression tests failed to find any relationship between microbleeds and the variables. We performed three different regression models using different independent variables: Model 1 - amyloid-beta, phosphorylated tau protein, total tau, apolipoprotein E allele ɛ4 status, age, and sex; Model 2 - vascular risk factors, age, and sex; Model 3 - cognitive scores sex, age, and education. Conclusion Although microbleeds might be related to the Alzheimer's disease process, their presence is not a good candidate for a neuroimaging biomarker of the disease, especially in its early phases.

Comparison of cerebrospinal fluid profiles in Alzheimer's disease with multiple cerebral microbleeds and cerebral amyloid angiopathy-related inflammation

Brain magnetic resonance imaging (MRI) of patients with Alzheimer's disease (AD) sometimes reveals multiple cerebral microbleeds (CMBs) and confluent white matter hyperintensities (WMHs) similar to those observed in cerebral amyloid angiopathy-related inflammation (CAA-I). To determine whether there might be common pathophysiological mechanisms underlying the MRI findings of multiple CMBs and confluent WMHs, we investigated the cerebrospinal fluid (CSF) profiles of 38 AD, five amnestic mild cognitive impairment (MCI), and six CAA-I patients. The AD and MCI patients were divided into groups of patients with (n = 10) or without (n = 33) multiple CMBs (n ≥ 2) on T2*-gradient echo sequences of brain MRI. We compared the CSF profiles of AD and MCI patients with or without multiple CMBs, and CAA-I patients. The brain MRIs of the patients with multiple CMBs revealed severe degrees of WMHs compared with the patients without multiple CMBs. The levels of CSF anti-amyloid β autoantibody and interleukin 8, and CSF/serum albumin ratios and immunoglobulin G indexes, were significantly higher in CAA-I patients than the other groups. However, there were no significant differences in the CSF profiles of patients with or without multiple CMBs. Our study provides evidence for different pathophysiological mechanisms underlying these differential MRI findings in AD and CAA-I.

[Stroke-induced nosocomial pneumonia in the acute period of cerebral hemorrhage: clinical pathogenic and age-associated aspects]

The article presents the clinical features of stroke-induced nosocomial pneumonia and interleukin-1alpha level monitoring in serum and cerebrospinal fluid of 100 patients with cerebral hemorrhage on the 1st, 3rd and 10th day. The authors show that 66% of patients with cerebral hemorrhage develop nosocomial pneumonia since the end of 2nd up to 5th day of conservative hospital treatment, more frequently in the serious cases with high level of neurological deficiency. The most important risk factors of stroke-induced nosocomial pneumonia are chronic focal infection, diabetes mellitus, cardiac failure, smoking, obesity. Since the first day of stroke the interleukin-1alpha level both in serum and cerebrospinal fluid exceeds 25-30 times its content in healthy people and increases more in the presence of nosocomial pneumonia. Interleukin-1alpha level can serve as an early risk marker of lethal outcome in patients with cerebral hemorrhage.

[Effect of polydatin on dynamic changes of excitatory amino acids in cerebrospinal fluid of cerebral hemorrhage rats]

OBJECTIVE

To observe the effects of polydatin on dynamic changes of excitatory amino acids in cerebrospinal fluid and water content of brain tissue of cerebral hemorrhage rats. And to discuss the therapeutic action and mechanisms of polydatin on brain hemorrhagic injured rats.

METHOD

A quantitative determination method of Asp and Glu was established by microdialysis-HPLC. The cerebral hemorrhage model in rats was induced by local injection of type VII collagenase. The dynamic changes of Asp and Glu in cerebrospinal fluid were observed on 0, 6, 12, 24, 36, 48, 60, 72, 84, 96, 108 h of cerebral hemorrhage rats, and then the water content of brain tissue was detected.

RESULT

The content of Asp and Glu increased rapidly within 24 h after cerebral hemorrhage, and to the highest in 24 h, then decreased gradually. Compared with the cerebral hemorrhage model group, the content of Asp and Glu increased slowly in polydatin group, and there were significant differences in 12-72 h and 6-84 h (P < 0.01, P < 0.05), but there was no significant difference after 84 h and 96 h. Compared with sham group, water content of brain tissue significantly higher in model group, while significantly lower (P < 0.01) in polydatin group.

CONCLUSION

Polydatin can inhibit increasing content of Asp and Glu in cerebrospinal fluid dynamics, and significantly inhibit cerebral edema of cerebral hemorrhage rats. It shows that the mechanisms of anti-cerebral hemorrhage injury of polydatin may be related to increasing of excitatory amino acids after cerebral hemorrhage.

Presence of secretory cellular apoptosis susceptibility protein in cerebrospinal fluids of patients with intracerebral hemorrhage caused by stroke and neurotrauma

OBJECTIVE

The blood-brain barrier (BBB) is a specialized structure that separates blood vessels from the central nervous system (CNS) and restricts the entry of biomolecules and cells into the brain. Matrix metalloproteinase-2 (MMP-2) produced by interferon-gamma-activated microglia (brain macrophages) is essential for disrupting the glia limitans of BBB, which is critical for lymphocytes penetration into brain capillaries in various CNS disorders. The cellular apoptosis susceptibility (CSE1L/CAS) protein has been shown to regulate MMP-2 secretion.

METHODS

We examined if CSE1L played a role in regulating the progression of intracerebral brain hemorrhage disorders.

RESULTS

CSE1L was detected by immunoblotting in cerebrospinal fluids (CSFs) of patients with intracerebral hemorrhage brain disorders, including stroke and neurotrauma. Interferon-gamma treatment induced CSE1L expression and increased the secretions of CSE1L and MMP-2 by U937 macrophages. Moreover, tranfection of U937 macrophages with siRNA that targeted CSE1L inhibited interferon-gamma-induced CSE1L and MMP-2 secretion by U937 macrophages. The numbers of lymphocytes in CSF were correlated with the levels of CSE1L and MMP-2 in patients' CSF.

CONCLUSIONS

Our results suggest that CSE1L plays a role in regulating MMP-2-mediated BBB breakdown and it may be a target for control of BBB permeability in intracerebral brain hemorrhage disorders.

The diagnostic accuracy of CSF analyses in stroke

The ability of routine analyses of cerebrospinal fluid (CSF) to differentiate between haemorrhage and infarction was evaluated in 231 stroke patients, whose diagnoses were based on computed tomography or autopsy. In all diagnostic groups the mean protein level was above normal, the highest values being associated with haemorrhage. Taking a protein level greater than 1 g/l to be characteristic of bleeding, sensitivity was 89% and specificity 92%. Spectrophotometric CSF absorbance was measured at wave lengths of 410, 415, 455 and 630 nm. Validity was equal for the first three. Taking absorbance greater than or equal to 0.040 at 415 nm to be diagnostic for haemorrhage, sensitivity was 72% and specificity 94%. The human eye was almost as sensitive as spectrophotometry in this context. Thus, among 100 patients with stroke, 7-9 out of 10 plausible cases of haemorrhage would be identified by means of routine CSF analyses. At the same time, 5-9 patients with ischaemic lesions would be diagnosed incorrectly as bleedings.

[Intraventricular thrombolysis and liquor filtration in treatment of newborns with severe intraventricular hemorrhages]

The authors have analyzed 32 cases of complex treatment of severe forms of neonatal intraventricular hemorrhages and proved high clinical efficiency of complex treatment. The stage-by-stage application of tissue plasminogen activator and operation of extracorporeal cerebrospinal fluid filtration resulted in decreased mortality, reduced duration of the cerebrospinal fluid sanitation period, reduced number of shunting-dependent children. One year follow-up showed an improvement of the patients' quality of life.

CSF orexin-A/hypocretin-1 concentrations in patients with intracerebral hemorrhage (ICH)

Orexins/hypocretins are neuropeptides that have various physiological effects, including the regulation of both the feeding behavior neuroendocrine functions and sleep-wakefulness cycle. Recent studies have suggested that the orexin system may also be involved in neuronal damage in the clinical setting and animal experiments. The aim of this study was to examine the role of the hypothalamic orexin-A/hypocretin-1 system in patients with intracerebral hemorrhage (ICH). The CSF orexin-A/hypocretin-1 levels were measured in 11 ICH patients. CSF orexin-A/hypocretin-1 levels were low in ICH patients during the 13 days following the ICH event. The mean CSF orexin-A/hypocretin-1 levels were 61.1+/-22.3 (S.D.) pg/ml (range 27.5-106.9 pg/ml). The decreasing in the CSF orexin-A/hypocretin-1 levels was not related to the severity of ICH. The CSF orexin-A/hypocretin-1 levels were lower in the thalamic hemorrhage patients than those in other patients (48.5+/-23.3 pg/ml vs. 65.2+/-21.2 pg/ml; p=0.03.) These data indicate that orexin-A/hypocretin-1 may therefore play an important role in the various physiological responses including sleep, feeding, and the overall metabolism in ICH patients.

High Thrombopoietin Concentrations in The Cerebrospinal Fluid of Neonates with Sepsis And Intraventricular Hemorrhage May Contribute to Brain Damage

Thrombopoietin (TPO) and its receptor (TPOR) are expressed in the central nervous system (CNS). Although TPO shares significant homology with various neurotrophins, recent data indicate a proapoptotic function of TPO in the CNS. In this study, TPO concentrations were analyzed in the cerebrospinal fluid (CSF) of neonates. Human neuroblastoma-derived SH-SY5Y cells were established to elucidate the effects of inflammation and hypoxia on neuronal Tpo expression. TPO was detectable in the CSF of 6 of 15 neonates with bacterial infection/sepsis (median 140, range 2-613 pg/mL), 5 of 9 neonates with posthemorrhagic hydrocephalus (median 31, range 1.4-469 pg/mL), 3 of 4 neonates with posthemorrhagic hydrocephalus plus bacterial infection/sepsis or meningitis (median 97, range 6-397 pg/mL), but not in controls ( n = 3). Neither the presence of detectable TPO nor its level in the CSF significantly correlated with any clinical or laboratory parameter. In SH-SY5Y cells, TPO and TPOR expression was detected by RT-PCR and Western blot analysis. In vitro, interleukin-6 (IL-6) did not significantly change Tpo gene expression. In contrast, Tpo mRNA expression significantly decreased under hypoxia, whereas erythropoietin (EPO) mRNA expression increased. In conclusion, our data provide evidence that in neuronal cells, TPO production is regulated by different mechanisms than in hepatocytes.

Hydrocephalus in a rat model of intraventricular hemorrhage

The aims of the current study were 1) to establish an adult rat model of intraventricular hemorrhage (IVH) and post-hemorrhagic ventricular dilatation, and 2) to examine the role of alterations in cerebrospinal fluid (CSF) drainage and parenchymal injury in that dilatation. Rats underwent infusion of 200 microl of autologous blood over 15 minutes. The rats were used to measure hematoma mass, ventricular dilatation, and cortical mantle volume (with T2 imaging), resistance to CSF absorption, and brain edema (as a marker of brain injury). IVH resulted in ventricular dilatation peaking at day 2 but persisting for at least 8 weeks. Although there was an increased resistance to CSF absorption at 3 days, it returned to normal at day 7. Long-term ventricular dilatation was not associated with an alteration in cortical mantle volume, although there was evidence of cortical damage (edema). It is possible that initial ventricular distension (due to the hematoma and the impaired CSF drainage) in combination with periventricular white matter damage results in structural changes that prevent total recoil once the hematoma has resolved and CSF drainage is normalized, leading to long-term hydrocephalus.

Multiparametric analysis of cerebral substrates and nitric oxide delivery in cerebrospinal fluid in patients with intracerebral haemorrhage: correlation with hemodynamics and outcome

BACKGROUND

There is no information regarding the possible role of cerebral substrates in the pathogenesis of neuronal injury in intracerebral haemorrhages (ICHs). Purposes of this prospective study were to clarify whether changes in substrates are the consequence of the initial brain damage in ICH and to elucidate the relationship among the biochemical mechanisms and clinical course of patients with ICH.

METHOD

During a period of two years, patients (GCS < or =8) who had ICH secondary to an aneurysm (SAH), stroke (sICH), or trauma (tICH) and underwent ventriculostomy with ICP monitoring and/or underwent cranial surgery were randomly enrolled in this study. Extracellular concentrations of glutamate, aspartate, glycine, GABA, lactate, lactate/pyruvate ratio, and glucose in the CSF were measured by use of high-performance liquid chromatography (HPLC). The nitric oxide (NO) concentration in the CSF was analyzed by chemiluminescence.

FINDINGS

There were 75 patients (38 women and 37 men) with ICH included in this study. Twenty-one patients had SAH, 28 sICH, and 26 tICH. In tICH patients, there was a 30-fold increase in glutamate and a 10-fold in aspartate over reference values. The levels of glutamate, aspirate, GABA, lactate, glucose, and NO differed significantly among the three groups (p<0.001). There were no significant differences in glycine and L/P ratio among the groups. The initial GCS, the mean CPP and outcome six months after the insult were all significantly correlated with the concentration of substrates (p<0.01), both within groups and among the total sample. The CSF levels of glutamate lactate, NO and glucose correlated significantly with outcome (p<0.005).

CONCLUSIONS

This study confirms the correlation between the level of EAAs and the outcome of ICHs, suggesting that neurochemical monitoring of these substances may have a role in caring for patients.

Remote cerebellar hemorrhage: A review

Remote cerebellar hemorrhage remains a complication rarely occurring after supratentorial surgery (<5%) and presumably even less frequent after spinal surgery. Although the pathomechanisms leading to RCH with its typical bleeding pattern are still not definitely understood, intra- or even more likely postoperative loss of larger volumes of CSF seem to be related to this complication. Prognosis significantly depends on severity of hemorrhage and patient age. Outcome in more than 50% of all cases is good with only mild remaining neurological symptoms or complete recovery, while death occurs in approximately 10-15%. Close monitoring of patients undergoing surgery that involves the risk of draining large volumes of CSF is mandatory and patients with postoperative drainage of larger amounts of fluid acquire increased attentiveness. Early detection and correct interpretation of the typical bleeding pattern might help to avoid further aggravation of symptoms. This review will address incidence, typical appearance and pathophysiological considerations, as well as risk factors, treatment options, and outcome related with RCH.

Multiple simultaneous intracerebral hemorrhages following accidental massive lumbar cerebrospinal fluid drainage: Case report and literature review

Multiple simultaneous intracerebral hemorrhages (ICH) are uncommon. We report the case of an 80-year-old woman with previous diagnosis of normal pressure hydrocephalus and who was brought to our hospital with altered mental status and urinary incontinence. Medical history of hypertension, hematological disorders or severe head trauma was absent. Platelet count and coagulation profile were unremarkable. An initial head computed tomography (CT) showed sulcal enlargement and ventricular dilatation, but no evidence of ICH. A tap test indicated as a guide to case selection for shunt surgery accidentally resulted in cerebrospinal fluid (CSF) overdrainage. The patient presented sudden neurological deterioration, with sluggishly responsive pupils and generalized tonic-clonic seizures. A new head CT demonstrated multiple supra and infratentorial ICH. The patient became comatose and had a fatal course. Hence, CSF overdrainage may either cause or precipitate multiple simultaneous ICHs, affecting both the infratentorial and supratentorial regions.

Axonal pathology in subarachnoid and intracerebral hemorrhage

Electrically active axons degenerate in the presence of nitric oxide (NO) in vitro. High CSF NO concentrations have been observed in patients with hemorrhagic brain injury such as subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH). This study investigated the evidence for axonal injury in SAH and ICH and related this to CSF NO levels. In this study, neurofilament phosphoforms (NfH(SMI34), NfH(SMI35), NfH(SMI38), NfH(SMI310)), surrogate markers for axonal injury, and NO metabolites (nitrate, nitrite = NOx) were measured by ELISA in cerebrospinal fluid (CSF) from patients with SAH and ICH and from a group of controls. Injury severity was classified using the Glasgow Coma Scale, and survival was used as the outcome measure. Compared to the control group, a higher proportion of patients with SAH and ICH had elevated NfH(SMI34) levels from day 0 to day 6 (p < 0.001), elevated NfH(SMI35) levels from day 1 to 6 (p < 0.001), and elevated NfH(SMI310) levels at day 0, 1, 4, and 6 (p < 0.001). The NOx levels were higher in the SAH and ICH patients than in the controls (p < 0.05) and distinguished the non-survivors from the survivors (p < 0.05). No direct correlation was found for NOx with any of the NfH phosphoforms. This study provides evidence for primary and secondary axonal injury in patients with SAH and ICH, with non-survivors also having higher NOx levels. CSF NfH phosphoforms might emerge as a putative surrogate marker for monitoring the development for secondary axonal degeneration in neurocritical care and guiding targeted neuroprotective strategies.

Why Human Color Vision Cannot Reliably Detect Cerebrospinal Fluid Xanthochromia

Background— Visual assessment of cerebrospinal fluid (CSF) for xanthochromia (yellow color) is practiced by the majority of laboratories worldwide as a means of diagnosing intracranical bleeds.

Methods— Colorimetric and spectrophotometric analysis of CSF samples for recognizing the presence of bilirubin either in low concentrations or in the presence of hemolysed blood.

Results— The experiments provide the physiological and colorimetric basis for abandoning visual assessment of CSF for xanthochromia.

Conclusion— We strongly recommend relying on spectrophotometry as the analytical method of choice.

Cerebellar Hemorrhage Caused by Cerebrospinal Fluid Leak After Spine Surgery

Spine surgery is associated with a wide range of surgical and anesthetic complications. Excessive cerebrospinal fluid leak can be a cause of cerebellar hemorrhage postoperatively. We report a 43-yr-old patient who had lumbar spine reexploration surgery complicated by a cerebrospinal fluid leak which led to cerebellar hemorrhage manifested by postoperative mental status changes. Early detection and proper management resulted in full recovery.

Vascular endothelial growth factor and transforming growth factor-beta1 are highly expressed in the cerebrospinal fluid of premature infants with posthemorrhagic hydrocephalus

The expression of specific growth factors such as vascular endothelial growth factor (VEGF) and transforming growth factor-beta1 (TGF-beta1) is of importance during brain development and in the pathogenesis of neurodegenerative disorders. VEGF and TGF-beta1 was studied in the cerebrospinal fluid (CSF) of neonates with posthemorrhagic hydrocephalus (PHHC) and nonhemorrhagic hydrocephalus. For determining the interference of inflammatory cytokine interaction with the expression of VEGF and TGF-beta1, IL-6 and IL-10 CSF concentrations were measured. Eighteen neonates who had PHHC and underwent serial reservoir puncture and nine neonates who had congenital nonhemorrhagic hydrocephalus (CHC) and underwent first shunt surgery were included in the study. CSF samples of 11 neonates with lumbar puncture for the exclusion of meningitis served as control subjects. VEGF, TGF-beta1, IL-6, and IL-10 concentrations in the CSF were measured by ELISA technique. VEGF concentrations in the CSF of patients with PHHC were significantly higher (median: 377 pg/mL; range: 101-1301 pg/mL) when compared with patients with CHC (median: 66 pg/mL; range: 3-1991; p < 0.001) and control subjects (median: 2 pg/mL; range: 0-12 pg/mL; p < 0.0001). TGF-beta1 CSF concentrations did not differ from control infants in all groups. Median IL-6 and IL-10 concentrations in the CSF were found to be low in all patient groups. Increased release of VEGF in the CSF of neonates with PHHC and nonhemorrhagic hydrocephalus may serve as an indicator of brain injury from progressive ventricular dilation. TGF-beta1 CSF concentrations are not elevated in the phase of acute fibroproliferative reactions in patients with PHHC.

New lumbar method for monitoring cerebrospinal fluid pressure in rats

OBJECTIVE

Monitoring cerebrospinal fluid pressure or intracranial pressure (ICP) is crucial in the study of neurosurgical disorders. In the present study, we report a new lumbar method for monitoring ICP in rats.

METHODS

A PE10 catheter connected to a pressure transducer was placed into the subarachnoid space of L5 through the duramater after laminectomy to record lumbar cerebrospinal fluid pressure (lumbar-ICP). ICP at the cisterna magna (cisterna-ICP) was recorded simultaneously via a catheter in the subarachnoid space at the cisterna magna. Eighteen anesthetized adult male S-D rats were subjected to baseline recording followed by either experimental subarachnoid hemorrhage (SAH) induced by intravascular puncture method or experimental intracerebral hemorrhage (ICH) induced by blood injection with a stereotaxic system.

RESULTS

Baseline lumbar-ICP and cisterna-ICP varied between 6 and 8 mmHg, and respiratory variation could be detected. A similar acute response to SAH was recorded in both the lumbar-ICP and cisterna-ICP in all rats. In rats subjected to SAH, the lumbar catheter continuously and accurately monitored lumbar-ICP, and reliable pressure tracings were obtained for up to 24 h after SAH. However, continued cisterna-ICP monitoring was abandoned in two rats in the cisterna magna method due to obstruction of the catheter by blood clots (hematoma).

CONCLUSION

This new lumbar-ICP method is simple, safe, easy, and reliable in rats. Continued lumbar-ICP measurements provided monitoring for up to 24 h after experimental manipulation.

Kernspintomographischer Nachweis der Subarachnoidalblutung

Computed tomography (CT) is the method of choice to detect acute subarachnoid hemorrhage (SAH). The sensitivity of CT has been reported to range from 85 to 100 %. Magnetic resonance imaging (MRI) using FLAIR sequences shows a comparable sensitivity in acute SAH and in some cases can even be superior to CT. However, additional proton density weighted (PDW) TSE sequences or 3D-FLAIR sequences should be used to avoid false-positive results caused by flow artifacts. Conventional T (1)- or T (2)-weighted SE sequences or susceptibility weighted T (2)* or EPI sequences used for the diagnosis of intracerebral hemorrhage do not detect SAH reliably enough. In subacute SAH, starting from day 5 after the suspected hemorrhage, the sensitivity of MRI is clearly superior to CT. Patients with suspected ischemic stroke scheduled for the initial evaluation by MRI no longer need additional CT studies to rule out subarachnoid hemorrhage as long as the MRI protocols are adequate and the radiologist has the necessary experience.

Posthaemorrhagic ventricular dilatation: new mechanisms and new treatment

Post haemorrhagic ventricular dilatation is associated with a high rate of disability, multiple impairments and adverse effects of shunt surgery for hydrocephalus. Post haemorrhagic ventricular dilatation results initially from multiple small blood clots throughout the cerebrospinal fluid channels impeding circulation and re-absorption. Transforming growth factor beta is released into the cerebrospinal fluid and there is evidence that this cytokine stimulates the laying down of extracellular matrix proteins which produce permanent obstruction to the cerebrospinal fluid pathways. Prolonged raised pressure, pro-inflammatory cytokines and free radical damage from iron may contribute to periventricular white matter damage and subsequent disability. Interventions such as early lumbar punctures, diuretic drugs to reduce cerebrospinal fluid production and intraventricular fibrinolytic therapy have been tested and, not only fail to prevent shunt dependence, death or disability, but have significant adverse effects. Surgical interventions such as subcutaneous reservoir, external drain, choroid plexus coagulation and third ventriculostomy have not been subject to controlled trial. Ventriculoperitoneal shunt is not feasible in the early phase after intraventricular haemorrhage but, despite the problems with blockages and infections, remains the only option for infants with excessive head expansion over periods of weeks. We have piloted drainage, irrigation and fibrinolytic therapy as a way of removing blood early enough to stop the progressive deposition of matrix proteins, permanent hydrocephalus and shunt dependence.

Cytokine response in cerebrospinal fluid from preterm infants with posthaemorrhagic ventricular dilatation

AIM

Posthaemorrhagic ventricular dilatation (PHVD) is closely associated with white matter damage and neurological disability in the preterm infant. Proinflammatory cytokines have been implicated in the pathogenesis of white matter injury and subsequent cerebral palsy. The aim of this study was to determine the levels of proinflammatory cytokines in cerebrospinal fluid (CSF) from preterm infants with PHVD and to correlate the levels to white matter damage and neurodevelopmental outcome.

METHODS

CSF samples were obtained from 24 preterm infants with expanding PHVD and 19 preterm infants with normal ultrasound. Tumour necrosis factor-alphaa (TNF-alpha ), interleukin-1beta (IL-1beta), interleukin-8 (IL-8) and interferon-gamma (IFN-gamma) in CSF were measured by enzyme-linked immunosorbent assay, and IL-6 was measured by bioassay.

RESULTS

The concentrations of TNF-alpha, IL-1beta, IL-6 and IL-8 were significantly elevated in CSF from infants with PHVD. TNF-alpha was detected in 43% of PHVD infants and 11% of controls (p = 0.04). IL-1beta was detected in 67% of PHVD infants and 0% of controls (p < 0.0001). The concentrations of IL-6 were 368 (145-460) pg ml(-1) in the PHVD group and 30 (25-41) pg ml(-1) in the control group (p < 0.0001), and those of IL-8 were 3000 (1620-3400) pg ml(-1) in the PHVD group and 35 (0-230) pg ml(-1) in the control group (p < 0.0001). Cytokine concentrations did not correlate with white matter lesions on ultrasound, shunt dependence or neurological outcome within the PHVD group.

CONCLUSION

There was an intense and prolonged inflammatory reaction in CSF from preterm infants with PHVD and a high risk for subsequent white matter injury and permanent neurological impairment.

Definitive angiographic detection of subarachnoid haemorrhage compared with laboratory assessment of intracranial bleed in CT-negative patients

BACKGROUND

Between 2.5% and 5% of cases of subarachnoid haemorrhage (SAH) give negative results for computed tomography (CT) scanning. Recent UK guidelines make recommendations as to standardization of laboratory methodology for the detection of SAH in individuals with a negative CT scan. We have compared this approach with our routine assessment using first-order derivative spectrophotometry, a recently reported iterative computer prediction model and measurement of cerebrospinal fluid (CSF) ferritin concentration. All methods were judged against cerebral angiography as the definitive means of determining patient outcome.

METHODS

Scanning spectrophotometry of CSF is necessary for both the UK guidelines and our in-house method. Absorbance measurements at 360, 405, 414 and 455 nm are required for the computer model. CSF ferritin concentration was measured using a serum method on a DPC Immulite 2000. This gave a value of <12 microg/L for normal CSF. Ethical approval and informed patient consent to additional investigation were obtained.

RESULTS

The sensitivity and specificity for the UK guidelines method, derivative spectrophotometry (in-house), iterative computer model and CSF ferritin were, respectively: 0.8, 1.0; 0.9, 1.0; 0.9, 0.5; 1.0, 0.78.

CONCLUSION

First-order derivative spectrophotometry had best concordance with angiography. Combination of this with CSF ferritin measurement may improve sensitivity, although the zero-order method recommended in the UK guidelines for the detection of an intracranial bleed is more amenable and has comparable performance.

Metabolic alterations in cerebrospinal fluid from double hemorrhage model of dogs

OBJECTIVE

Even though cerebral vasospasm after subarachnoid hemorrhage (SAH) causes cerebral ischemia or infarction, the metabolic alterations in cerebrospinal fluids (CSF) after SAH have not been studied. This study was undertaken to measure the levels of glucose, lactate, pyruvate and glutamate in CSF from double hemorrhage dog models.

METHOD

Thirty-two mongrel dogs of either sex, weighing 15-30 kg, underwent double hemorrhage by percutaneous needle puncture of the cisterna magna and injection of autologous blood on day 0 and day 2. The dogs were then sacrificed on day 3, 5 and 7, after collecting CSF. In another study, the dogs were treated with mitogen-activated protein kinase (MAPK) inhibitors PD98059 and U0126, and caspase-2 and caspase-3 inhibitors from day 3 to day 6 after initial blood injection. CSF was collected on day 7 before dogs were sacrificed. The concentration of glucose, lactate, pyruvate and glutamate in CSF was measured by photometrical method.

RESULTS

Compared with CSF collected on day 0, glucose was decreased on days 5-7, lactate was increased on days 2-7, pyruvate was increased on days 2-7, and glutamate was increased on days 3-7 (P < 0.05). In the groups treated with MAPK or caspase inhibitors, most of the metabolic alterations remained unchanged as compared with CSF from untreated dogs. Clinically, caspase inhibitors-2 and -3, and MAPK inhibitor U0126 all failed to prevent vasospasm. MAPK inhibitor PD98059 partially prevented vasospasm.

CONCLUSION

Our data demonstrated a metabolic alteration of glucose, glutamate, lactate and pyruvate in CSF during cerebral vasospasm. This metabolic change is consistent with the time course of cerebral vasospasm. This study suggests that brain energy metabolites and excitative amino acids are altered during cerebral vasospasm.

Intracranial pressure and cerebral blood flow velocity in preterm infants with posthaemorrhagic ventricular dilatation

AIM

To determine the volume of cerebrospinal fluid (CSF) that should be tapped in preterm infants with posthaemorrhagic ventricular dilatation as guided by intracranial pressure (ICP) and cerebral blood flow velocity (CBFV).

METHODS

The total number of measurements was 106 in 22 infants. Birth weights ranged from 630 to 2050 g, gestational age from 24.5 to 30.3 weeks, and age at insertion from 12 to 67 days. A subcutaneous ventricular catheter reservoir for repetitive CSF drainage was placed when the diameter of a ventricle was > 4 mm above the 97th centile. A volume of 5 ml/kg body weight was removed twice daily. ICP and CBFV were determined before and after CSF tapping.

RESULTS

If the ICP after tapping exceeded 7 cm H(2)O, tapping did not result in a significant improvement in CBFV. If the ICP before tapping was less than 6 cm H(2)O, tapping also had no effect on CBFV. Longitudinal studies in individual infants showed a slight correlation between ICP and CBFV.

CONCLUSION

Volume of repetitive CSF drainage in preterm infants with posthaemorrhagic ventricular dilatation guided by ICP and CBFV may be a useful technique. An ICP of about 6 cm H(2)O is the cut off point for CSF drainage.

Haemoglobin and ATP levels in CSF from a dog model of vasospasm

Haemoglobin and adenosine 5'-triposphate (ATP) released from lysed erythrocytes have been postulated to be responsible for delayed cerebral vasospasm after subarachnoid haemorrhage (SAH). However, the concentrations of haemoglobin and ATP in cerebrospinal fluid (CSF) in patients or in an animal model of vasospasm have not been reported. In this study, 12 mongrel dogs underwent a double blood injection via the cisterna magna on day 0 and 2, after an initial collection of CSF. On day 3, 5 or 7, the dogs were sacrificed after a second collection of CSF. An angiogram was recorded on day 0 and on the day of sacrifice. Results showed that the diameter of the dog's basilar artery was reduced 20% on day 3 (P > 0.05), 35% on day 5 (P < 0.05) and 45% on day 7 (P < 0.05). The concentrations of OxyHb, deOxyHb and MetHb in CSF were increased (P < 0.05), and all peaked on day 3. OxyHb and MetHb remained significantly higher than control (day 0) from day 3 to day 7, while deOxyHb remained at a high level on day 5 but returned to normal on day 7. In contrast, ATP was decreased (P < 0.05) on days 5 and 7 after SAH compared with day 0. The results indicate that haemoglobin might be involved in the development of cerebral vasospasm. The possible role of ATP in vasospasm remains unclear.

Procollagen I C-propeptide in the cerebrospinal fluid of neonates with posthaemorrhagic hydrocephalus

BACKGROUND

The pathogenesis of posthaemorrhagic hydrocephalus (PHHC) following intraventricular haemorrhage (IVH) in premature infants includes a fibroproliferative reaction leading to arachnoidal fibrosis, ultimately causing malresorption of cerebrospinal fluid (CSF) at the arachnoid villi.

AIMS

To determine whether an increased concentration of the carboxyterminal propeptide of type I procollagen (PICP) in the CSF of neonates after IVH reflects the activation of collagen synthesis preceding the manifestation of PHHC.

METHODS

From 20 neonates with PHHC (median birth weight 740 g, median gestational age 25+1 weeks), 52 CSF samples were collected. CSF samples of four neonates (median birth weight 2170 g, median gestational age 32+4 weeks) with congenital non-haemorrhagic hydrocephalus served as controls. PICP was measured by radioimmunoassay.

RESULTS

PICP in CSF taken at the start of external CSF drainage (median day 21, range 17-25 days postnatal age) was significantly increased (median 851.5, range 153.5-1944 microg/l) compared with controls (median 136.1, range 33.8-169.5 microg/l). CSF concentrations of PICP declined until permanent shunt placement (median day 70, range days 41-113).

CONCLUSION

In neonates who develop PHHC, significant elevation of PICP concentration in the CSF is present 3-4 weeks after IVH. It reflects the increase of local type I collagen turnover, thereby correlating with manifestation of PHHC.

Nitric oxide (NO) metabolism in the cerebrospinal fluid of patients with severe head injury. Inflammation as a possible cause of elevated no metabolites

BACKGROUND

This article investigates nitric oxide (NO) metabolism following severe head injury (SHI). We wished to clarify the alterations of NO metabolism end products that is associated with SHI, and to delineate the role of inflammation in this process.

METHODS

In a prospective study, we simultaneously measured the concentrations of NO metabolites and interleukin-8 (IL-8) in the ventricular cerebrospinal fluid (CSF) of 11 patients who had suffered SHI. The CSF concentrations of nitrite (NO(-)(2)) and nitrate (NO(-)(3)) combined, and of IL-8 were measured during the following four time periods post-trauma: 6 to 10, 20 to 28, 40 to 56, and 64 to 74 hours. Levels were measured using the corresponding kits.

RESULTS

Compared to the ventricular CSF control values, all of our SHI patients had significantly elevated CSF levels of NO(-)(2) plus NO(-)(3) (NO(-)(2) + NO(-)(3)) and IL-8 during all periods tested. CSF NO(-)(2) + NO(-)(3) and IL-8 concentrations reached their maximums simultaneously at 20 to 28 hours following trauma (Spearman's rank correlation = 0.609, p < 0.05), and NO(-)(2) + NO(-)(3) levels were significantly higher than those measured at 6 to 10, 40 to 56, and 64 to 74 hours. [Nitrite-nitrate concentrations: 6-10 hours: 19.22 +/- 6.75, 20-28 hours: 25 +/- 6.2 micromol/l, 40-56 hours: 19.82 +/- 4.47, and 64-74 hours: 19.72 +/- 4.61 micromol/l, (p < 0.05). IL-8 concentrations: 6-10 hours: 3,232 +/- 2,976.2, 20-28 hours: 3,458.45 +/- 3,048 pg/mL, 40-56 hours: 2,616.41 +/- 2,539.21, 64-74 hours: 1,388.88 +/- 1,216.7 pg/mL, (p < 0.001).]. This simultaneous surge in NO(-)(2) + NO(-)(3) and IL-8 in the initial 24 hours post-traumatic indicated that inflammation secondary to SHI increased the rate of NO metabolism, resulting in higher levels of metabolites in the CSF.

CONCLUSION

In patients with SHI, CSF concentrations of the dominant metabolites of NO are elevated in the first 3 days after trauma. A similar concurrent spike in the CSF level of IL-8, a marker of acute inflammatory response, can also be demonstrated. These data indicate that the predominant cause of the higher CSF NO(-)(2) + NO(-)(3) concentrations observed in SHI is most likely inflammation.

Blood clot resolution in human cerebrospinal fluid: evidence of first-order kinetics

OBJECTIVE

To determine the kinetics of blood clot resolution in human cerebrospinal fluid.

METHODS

Computed tomographic scans of 17 adult patients with intraventricular hemorrhages were analyzed. Intraventricular clot volume was determined and analyzed over time to determine both a standardized percentage rate and an absolute rate of clot resolution. Results were analyzed by use of regression for cross sectional time-series data. To determine the kinetics of intraventricular clot resolution, the effect of the clot volume on the percentage rate of clot resolution, clot half-life, and absolute rate of clot resolution was analyzed. The potential effect of age, sex, type of hemorrhage, and treatment with external ventricular drainage on the percentage rate of clot resolution was assessed.

RESULTS

The percentage rate of clot resolution was 10.8% per day (95% confidence interval, 9.05-12.61 %), and it was independent of initial clot volume, age, sex, type of underlying hemorrhage, and use of external ventricular drainage. The absolute rate of clot resolution varied directly with the maximal clot volume (R2 = 0.88; P < 0.001). The percentage clot resolution data are consistent with events during the first 24 to 48 hours that antagonize clot resolution.

CONCLUSION

These findings demonstrate that intraventricular blood clot resolution in patients with intraventricular hemorrhage follows first-order kinetics. The thrombolytic enzyme system responsible for intraventricular clot resolution seems to be saturated at 24 to 48 hours after the initial hemorrhage.

The cerebral hemorrhage-producing cystatin C variant (L68Q) in extracellular fluids

A variant of the normal extracellular cysteine protease inhibitor cystatin C (L68Q-cystatin C), is the amyloid precursor in hereditary cystatin C amyloid angiopathy (HCCAA). It has been suggested that the mutation causes cellular entrapment of L68Q-cystatin C in vivo and that the variant protein is not secreted to extracellular fluids. In order to test this hypothesis, we used matrix-assisted laser desorption ionization time-of-flight mass spectrometry in an effort to demonstrate the presence of L68Q- along with wildtype cystatin C in plasma and cerebrospinal fluid (CSF) of HCCAA-patients. Plasma from all five investigated HCCAA-patients contained both L68Q- and wildtype cystatin C. The presence of approximately equal amounts of cystatin C dimers and monomers was demonstrated in plasma from HCCAA-patients, whereas only monomers could be found in normal plasma. L68Q-wildtype-cystatin C heterodimers seem to be present in the dimeric cystatin C population. CSF from six HCCAA-patients also contained cystatin C-dimers and monomers, but the dimeric fraction was minute. CSF from control patients did not contain dimeric cystatin C. These results suggest that the milieu of L68Q-cystatin C is important for its stability and dimerization status and that certain milieus might hinder its further development into oligomers, amyloid fibrils and other precipitating aggregates.

Brain specific proteins in posthaemorrhagic ventricular dilatation

Median neurofilament and glial fibrillary acidic protein concentrations in the cerebrospinal fluid of 18 infants with posthaemorrhagic ventricular dilatation were 20-200 times higher than control values. S-100 protein in cerebrospinal fluid was four times higher than control values. Glial fibrillary acidic protein concentrations correlated with death or disability and with parenchymal lesions but not with shunt dependence.

Non-protein-bound iron is elevated in cerebrospinal fluid from preterm infants with posthemorrhagic ventricular dilatation

Posthemorrhagic ventricular dilatation (PHVD) is closely associated with white matter injury and neurologic disability in the preterm infant. An important factor in periventricular white matter damage may be the specific vulnerability of iron-rich immature oligodendroglia to reactive oxygen species toxicity. Non-protein-bound iron (NPBI) is a potent catalyst in the generation of hydroxyl radicals (Fenton reaction). Our objective was to determine whether NPBI is increased in cerebrospinal fluid (CSF) from preterm infants with PHVD compared with preterm control infants. Samples of CSF were obtained from 20 infants with PHVD and 10 control subjects. The level of NPBI was determined by a new spectrophotometric method using bathophenanthroline as a chelator. To evaluate the effect of hemolysis, CSF and blood were mixed in different proportions, spun, frozen and thawed, and then analyzed for NPBI. NPBI was found in 75% (15 of 20) of infants with PHVD and in 0% (0 of 10) of control infants (p = 0.0002). Hemolysis induced in vitro did not result in any significant levels of NPBI. Within the group with PHVD, NPBI concentrations in CSF did not correlate with disability, parenchymal brain lesions, or the need for shunt surgery. NPBI was increased in CSF from preterm infants with PHVD, and the increase could not be explained by hemolysis alone. Free iron may help to explain the association between intraventricular hemorrhage and white matter damage.

Spontaneous brain hemorrhage associated with Lyme neuroborreliosis

We present the case of a patient with late neuroborreliosis and a spontaneous temporal lobe hemorrhage. Although ischemic stroke and subarachnoid hemorrhage have been reported in association with Lyme disease, intraparenchymal brain hemorrhage has not been previously described in the course of this disease. The patient is a 48-year old male with a progressive spastic paraparesis of months' duration who presented acute headache, confusion, severe left hemiparesis with sensory deficit and homonymous hemianopsia. A cranial computed tomography scan showed an extensive right temporal lobe hemorrhage with subarachnoid invasion. Brain angiographic and angio-magnetic resonance imaging studies excluded hemorrhage-predisposing vascular abnormalities. Cerebrospinal fluid (CSF) studies disclosed mononuclear pleocytosis with elevated protein levels. Both serum and CSF anti-Borrelia titers were significantly increased, and serum Western Blot showed bands to protein 34 (ops B), 57, 59 and 62. The patient was treated with ceftriaxone for 4 weeks, with a favorable outcome. It is suspected that cause of the hemorrhage was parenchymatous Lyme-associated vascular damage and/or microaneurysmatic rupture.

[The role of biochemical processes in the pathogenesis of complicated hydrocephalus in children]

Spinal fluid radical formation levels, malonic dialdehyde concentrations, and intrinsic antioxidative activity were studied in 84 patients with hydrocephalus. The findings suggest that there is a considerable activation of free radical reactions and lipid peroxidation, as well as a reduction in antioxidative activity. These changes were most drastically profound in children with inflammation-complicated hydrocephalus with spinal fluid hemorrhagic changes in particular. Timely correction of impaired energy exchange in children by using antioxidants and nootropics promotes the arrest of inflammation and prevents a number of postoperative complications.

The continuous measurement of cerebrospinal fluid gas tensions in critically ill neurosurgical patients: a prospective observational study

OBJECTIVE

To determine the feasibility and usefulness of continuous cerebrospinal fluid pH and gas tension monitoring in critically ill neurosurgical patients.

DESIGN

Prospective, observational study.

SETTING

Neurosurgical intensive care unit in a teaching hospital.

PATIENTS

Five critically ill neurosurgical patients (GCS < 8) requiring intensive care intracranial pressure monitoring and intermittent positive pressure ventilation.

INTERVENTIONS

Placement of a Paratrend 7 sensor into the external ventricular drain.

MEASUREMENTS AND MAIN RESULTS

The cerebrospinal fluid (CSF) pH, PCO2 and PO2 were recorded at 1-min intervals. Intracranial pressure (ICP) and cerebral perfusion pressure (CPP) were recorded at 15-min intervals. The mean baseline CSF pH, O2 and PO2 values were 7.28 +/- 0.08 pH units, 44 +/- 6 torr and 43 +/- 27 torr, respectively. The ranges of CSF pH, PCO2 and PO2 observed during the study were 6.3-7.8 pH units, 37-150 torr and 4-150 torr, respectively. A statistically significant correlation between ICP, CPP and CSF gas tensions occurred in patient 3. Significant changes in CSF PO2 and pH were observed with augmentation of CPP and preceded clinical improvement in patient 4. There were no complications attributable to sensor placement. CSF gas tensions and pH values obtained from patients 3 and 4 suggest that these measurements may be an indicator of cerebral perfusion.

CONCLUSIONS

Continuous CSF gas tension measurements in critically ill patients are possible and may be an indicator of adequacy of cerebral perfusion. The relative merits and limitations of the technique are discussed.

Intraventricular streptokinase infusion in acute post-haemorrhagic hydrocephalus

Neonatal post-haemorrhagic hydrocephalus is a clinical condition with a high mortality and long-term morbidity. Its clinical management is difficult and not well standardized. We describe the case of a term baby suffering from acute intracranial hypertension caused by an intraventricular and thalamic haemorrhage. In this case, the external ventricular drain inserted to control intracranial pressure was ineffective because of repeated obstructions due to blood clots. Continuous intraventricular infusion of streptokinase of 20,000 U/day allowed quick lysis of the clots, drainage of the cerebrospinal fluid and relief from the coma. Although it did not prevent a permanent ventriculoperitoneal shunt, we obtained reabsorption of the intraventricular haemorrhage without rebleeding complications. We suggest the use of low-dose fibrinolytic infusion through an external drain for the treatment of acute intracranial hypertension following intraventricular haemorrhage in term infants.

[The morphological bases of the pathology of the cerebrospinal fluid circulatory system in gunshot wounds of the head]

Pathomorphology of structural elements of the liquor circulation system and its three components (liquor production, circulation, and outflow) in gunshot wounds of the head is discussed. Their role in the development of traumatic diseases of the brain and its complications is analyzed. Classification and characteristics of the main pathomorphological variants of liquor circulation disorders in gunshot wounds of the skull and brain are presented.

Cerebrospinal fluid plasminogen activator inhibitor-1: a prognostic factor in posthaemorrhagic hydrocephalus

Intraventricular fibrinolytic enhancement with plasminogen activators is an experimental treatment for posthaemorrhagic hydrocephalus, but some infants do not respond. The objectives of this study were to investigate whether plasminogen activator inhibitor-1 is detectable in normal or posthaemorrhagic neonatal cerebrospinal fluid and whether higher neonatal cerebrospinal fluid concentrations of plasminogen activator inhibitor-1 are associated with failure of fibrinolytic therapy. Cerebrospinal fluid samples from 7 controls and 16 infants with posthaemorrhagic hydrocephalus (15 treated with exogenous fibrinolytic agents) were analysed for plasminogen activator inhibitor-1. Plasminogen activator inhibitor-1 was not detectable in any of the control samples but was detectable in all but one of the posthaemorrhagic samples, and at significantly higher levels in the treatment failures (median 94 ng ml(-1)) than in the treatment successes (median 25 ng ml(-1)). High levels of plasminogen activator inhibitor-1 in the cerebrospinal fluid are predictive of, and provide a plausible biological explanation for, failure of intraventricular fibrinolytic therapy.

Rapid analysis of endogenous LVV-hemorphin-7 in cerebrospinal fluid by size-exclusion chromatography and electrospray ionization mass spectrometry

LVV-hemorphin-7 is a peptide with opioid-like activity which is recognized by mu and sigma receptors. The sequence, derived from beta-, gamma-, delta- or epsilon- chains of human hemoglobin has been found in cerebrospinal fluid (CSF) of patients suffering from cerebrovascular bleedings, but not in CSF from healthy individuals. Procedures for isolation and identification of neuropeptides in body fluids and tissue extracts are often laborious and time-consuming. Additionally, extraction yield tends to be low after several chromatographic steps. In this study, we developed a rapid technique to analyze LVV-hemorphin-7 in CSF fluid from a patient with cerebrovascular bleedings using a combination of size-exclusion chromatography and electrospray ionization mass spectrometry. The methodology described utilizes small quantities of CSF (0.3-0.5 ml) and can be completed within a few hours. The proposed strategy opens possibilities for direct measurement of endogenous peptides in small volumes of body fluids.

Role of lysophosphatidic acid in endothelin-1- and hematoma-induced alteration of cerebral microcirculation

Cerebral hematoma increases cerebrospinal fluid (CSF) endothelin-1 (ET-1). Inhibitors of ET-1 synthesis prevent this increment and hematoma-induced modification of cerebral arteriolar reactivity. We hypothesized that intrathecal ET-1 injection could 1) modify pial arteriolar reactivity similarly to hematoma; 2) increase CSF lysophosphatidic acid (LPA), a potential contributor to altered cerebrovascular reactivity; and 3) reduce the level of adenosine 3',5'-cyclic monophosphate (cAMP) in the CSF. Either ET-1 (10(-7) M) or artificial CSF was injected over the left parietal cortex of newborn pigs. Four days later, cranial windows were implanted. CSF ET was increased from a basal level of 11 fmol/ml to 18 fmol/ml 4 days after ET-1 injection, whereas CSF cAMP was reduced from 2,700 to 950 fmol/ml. The mean diameter of pial arterioles was reduced 31%. In control animals, 10(-12) M ET caused dilation, and higher concentrations induced vasoconstriction. Four days after ET-1 injection topical ET-1 caused constriction instead of dilation at 10(-12) M, and constrictions at higher doses were enhanced. Norepinephrine-induced constrictions were potentiated in the ET-1-injected group. Dilations to cAMP-dependent (but not independent) vasodilators were attenuated after ET-1. The concentration of the vasoconstrictor lipid mediator LPA increased approximately fourfold. Thus intrathecal injection of ET-1 mimics hematoma-induced modification of cerebral vascular reactivity and increase in LPA production. The mechanism(s) of ET-1- and hematoma-induced modifications may involve LPA, which is known to contribute to the loss of dilator responses by inhibition of cAMP product on. The present study further suggests that ET-1 together with LPA could be causing changes in cerebrovascular reactivity following cerebral hemorrhage. ET-1 stimulates the release of LPA from brain parenchyma independent of serum so that LPA could serve as a secondary mediator.

Ventricular dilatation in experimental intraventricular hemorrhage in pigs. Characterization of cerebrospinal fluid dynamics and the effects of fibrinolytic treatment

BACKGROUND AND PURPOSE

Hemorrhagic ventricular dilatation (HVD) is a prominent feature of human intraventricular hemorrhage (IVH) and a strong indicator for poor outcome. We developed an IVH model to define the mechanisms responsible for HVD and to test the efficacy of intraventricular administration of tissue plasminogen activator (TPA) in the treatment of HVD.

METHODS

Isolated IVH was produced in pigs by injecting 10 mL of blood simultaneously with thrombin into the right lateral ventricle. The treatment group received 1.5 mg of TPA after induction of IVH. Intraventricular blood volume and the volume of the lateral ventricles were assessed by CT after 90 minutes, 7 days, and 42 days. Intracranial pressure, the pressure-volume index, and the resistance to outflow of cerebrospinal fluid (R(out)) were measured 30 minutes and 7 days after IVH.

RESULTS

After IVH, the volume of the lateral ventricles increased from 1.98 +/- 0.69 to 6.43 +/- 1.23 mL (P < .001). There was a linear relationship between ventricular and clot volume (P = .014). Initially, R(out) increased from 24.34 +/- 7.13 to 63.56 +/- 64.91 mm Hg/mL per minute (P < .001). After 7 days, restoration of normal cerebrospinal fluid circulation occurred, but the ventricles were still significantly enlarged (5.24 +/- 1.76 mL, P < .001) and filled with blood. Within 6 weeks, ventricular volume had returned to normal values, paralleled by complete clot resolution. Intraventricular administration of TPA significantly accelerated clot clearance and restoration of normal ventricle volume.

CONCLUSIONS

These results suggest that intraventricular bleeding may cause impairment of cerebrospinal fluid circulation but that the mass effect of clots distending the ventricle walls is the most important mechanism responsible for HVD. This model closely imitates several prominent features of human IVH and may therefore be a useful tool for preclinical assessment of the efficacy and safety of treatment with TPA.