Detection of soluble intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 in both cerebrospinal fluid and serum of patients after aneurysmal subarachnoid hemorrhage

Regulatory T Cell- and Natural Killer Cell-Mediated Inflammation, Cerebral Vasospasm, and Delayed Cerebral Ischemia in Aneurysmal Subarachnoid Hemorrhage-A Systematic Review and Meta-Analysis Approach

Aneurysmal subarachnoid hemorrhage (SAH) involves a significant influx of blood into the cerebrospinal fluid, representing a severe form of stroke. Despite advancements in aneurysm closure and neuro-intensive care, outcomes remain impaired due to cerebral vasospasm and delayed cerebral ischemia (DCI). Previous pharmacological therapies have not successfully reduced DCI while improving overall outcomes. As a result, significant efforts are underway to better understand the cellular and molecular mechanisms involved. This review focuses on the activation and effects of immune cells after SAH and their interactions with neurotoxic and vasoactive substances as well as inflammatory mediators. Particular attention is given to clinical studies highlighting the roles of natural killer (NK) cells and regulatory T cells (Treg) cells. Alongside microglia, astrocytes, and oligodendrocytes, NK cells and Treg cells are key contributors to the inflammatory cascade following SAH. Their involvement in modulating the neuro-inflammatory response, vasospasm, and DCI underscores their potential as therapeutic targets and prognostic markers in the post-SAH recovery process. We conducted a systematic review on T cell- and natural killer cell-mediated inflammation and their roles in cerebral vasospasm and delayed cerebral ischemia. We conducted a meta-analysis to evaluate outcomes and mortality in studies focused on NK cell- and T cell-mediated mechanisms.

The choroid plexus synergizes with immune cells during neuroinflammation

The choroid plexus (ChP) is a vital brain barrier and source of cerebrospinal fluid (CSF). Here, we use longitudinal two-photon imaging in awake mice and single-cell transcriptomics to elucidate the mechanisms of ChP regulation of brain inflammation. We used intracerebroventricular injections of lipopolysaccharides (LPS) to model meningitis in mice and observed that neutrophils and monocytes accumulated in the ChP stroma and surged across the epithelial barrier into the CSF. Bi-directional recruitment of monocytes from the periphery and, unexpectedly, macrophages from the CSF to the ChP helped eliminate neutrophils and repair the barrier. Transcriptomic analyses detailed the molecular steps accompanying this process and revealed that ChP epithelial cells transiently specialize to nurture immune cells, coordinating their recruitment, survival, and differentiation as well as regulation of the tight junctions that control the permeability of the ChP brain barrier. Collectively, we provide a mechanistic understanding and a comprehensive roadmap of neuroinflammation at the ChP brain barrier.

Compartmental Cerebrospinal Fluid Events Occurring after Subarachnoid Hemorrhage: An "Heparin Oriented" Systematic Review

Subarachnoid hemorrhage (SAH) represents a severe acute event with high morbidity and mortality due to the development of early brain injury (EBI), secondary delayed cerebral ischemia (DCI), and shunt-related hydrocephalus. Secondary events (SSE) such as neuroinflammation, vasospasm, excitotoxicity, blood-brain barrier disruption, oxidative cascade, and neuronal apoptosis are related to DCI. Despite improvement in management strategies and therapeutic protocols, surviving patients frequently present neurological deficits with neurocognitive impairment. The aim of this paper is to offer to clinicians a practical review of the actually documented pathophysiological events following subarachnoid hemorrhage. To reach our goal we performed a literature review analyzing reported studies regarding the mediators involved in the pathophysiological events following SAH occurring in the cerebrospinal fluid (CSF) (hemoglobin degradation products, platelets, complement, cytokines, chemokines, leucocytes, endothelin-1, NO-synthase, osteopontin, matricellular proteins, blood-brain barrier disruption, microglia polarization). The cascade of pathophysiological events secondary to SAH is very complex and involves several interconnected, but also distinct pathways. The identification of single therapeutical targets or specific pharmacological agents may be a limited strategy able to block only selective pathophysiological paths, but not the global evolution of SAH-related events. We report furthermore on the role of heparin in SAH management and discuss the rationale for use of intrathecal heparin as a pleiotropic therapeutical agent. The combination of the anticoagulant effect and the ability to interfere with SSE theoretically make heparin a very interesting molecule for SAH management.

Inflammatory Response in Patients with Spontaneous Intracranial Hemorrhages

Mortality and disability rates in spontaneous intracranial hemorrhages remain high despite medical advances. In recent decades, much attention has been paid to neuroinflammation as a typical response to brain damage. Inflammation plays an important role in the acute and chronic phases of the disease. The relationship between plasma and cerebrospinal fluid cytokines, as well as the factors affecting their ratios, is currently not completely clear.

The objective was to study the inflammatory response to spontaneous intracranial hemorrhage.

Subjects and Methods. 59 patients aged 18 to 72 years (48 ± 6) were enrolled in the study. Patients were admitted to the intensive care unit after an episode of spontaneous intracranial hemorrhage. The levels of interleukins in blood plasma were studied: 6, 8, 10, TNF-α, C-reactive protein,

blood leukocytes, and procalcitonin (by a semi-quantitative method). In the cerebrospinal fluid, the following parameters were evaluated: cytosis, protein, glucose, lactate, cytokines (6, 8, 10, TNF-α). Blood samples were collected on days 1, 2, 3, 5, 7, 9, 14, 21, 28, 35, and 45.

Results. Systemic inflammatory response developed in all patients from the first day of acute brain injury. The most significant response was formed by glial brain cells which was confirmed by high levels of cytokines in the cerebrospinal fluid, hundreds and thousands of times higher than blood levels of cytokines.

Conclusion. Levels of pro-inflammatory cytokines are predictors of an unfavorable outcome.

Glymphatic dysfunction correlates with severity of small vessel disease and cognitive impairment in cerebral amyloid angiopathy

BACKGROUND

Cerebral amyloid angiopathy (CAA) is characterized by β-amyloid deposition in cortical and leptomeningeal arterioles, which might result from glymphatic dysfunction. We aimed to explore glymphatic function in CAA using the non-invasive diffusion tensor image analysis along the perivascular space (DTI-ALPS) method.

METHODS

We prospectively recruited 63 patients with CAA, and 70 age- and sex-matched normal controls. We applied Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) to screen global cognitive status. We conducted MRI scans to calculate the index for diffusivity along the perivascular space (ALPS-index), and linear regression models to assess its relationships with cerebral small vessel disease (CSVD) markers, cognitive status, and blood biomarkers. We applied Cox proportional hazard models to explore the role of baseline ALPS-index in disease recurrence.

RESULTS

Patients with CAA exhibited a lower ALPS-index than controls globally (p < 0.001). Besides, the lower ALPS-index was related to more enlarged perivascular space in basal ganglia (p = 0.026), more lacunes (p < 0.001), higher white matter hyperintensities Fazekas score (p = 0.049), elevated total MRI burden of CSVD (p = 0.034), and lower MMSE (p = 0.001) as well as MoCA (p < 0.001) in CAA. During a median follow-up of 4.1 years, higher ALPS-index was associated with lower disease recurrence (p=0.022). ALPS-index was also negatively correlated with serum soluble intercellular adhesion molecule-1, neurofilament light and chitinase-3-like protein 1 in CAA.

CONCLUSIONS

Patients with CAA showed impaired glymphatic function. ALPS-index was significantly related to CSVD severity, cognitive impairment, and disease recurrence in CAA.

Pathophysiology of Delayed Cerebral Ischemia After Subarachnoid Hemorrhage: A Review

Delayed cerebral ischemia is a major predictor of poor outcomes in patients who suffer subarachnoid hemorrhage. Treatment options are limited and often ineffective despite many years of investigation and clinical trials. Modern advances in basic science have produced a much more complex, multifactorial framework in which delayed cerebral ischemia is better understood and novel treatments can be developed. Leveraging this knowledge to improve outcomes, however, depends on a holistic understanding of the disease process. We conducted a review of the literature to analyze the current state of investigation into delayed cerebral ischemia with emphasis on the major themes that have emerged over the past decades. Specifically, we discuss microcirculatory dysfunction, glymphatic impairment, inflammation, and neuroelectric disruption as pathological factors in addition to the canonical focus on cerebral vasospasm. This review intends to give clinicians and researchers a summary of the foundations of delayed cerebral ischemia pathophysiology while also underscoring the interactions and interdependencies between pathological factors. Through this overview, we also highlight the advances in translational studies and potential future therapeutic opportunities.

MSK1 downregulation is involved in inflammatory responses following subarachnoid hemorrhage in rats

Subarachnoid hemorrhage (SAH) is a life-threatening neurological disease. Recently, inflammatory factors have been confirmed to be responsible for the brain damage associated with SAH. Therefore, studying the post-SAH inflammatory reaction may clarify the mechanism of SAH. Mitogen and stress-activated protein kinase 1 (MSK1) causes the phosphorylation of NF-κB and regulates the activity of pro-inflammatory transcription factors. The present study aimed to identify the potential role of MSK1 in inflammation and brain damage development following SAH. A cisterna magna blood injection model was established in Sprague-Dawley rats. Hematoxylin and eosin staining, reverse transcription-quantitative polymerase chain reaction assays and double immunofluorescence staining were used to analyze the role of MSK1, IL-1β and TNF-α in the inflammatory process after SAH. In a model of lipopolysaccharide-induced astrocyte inflammation, the effect of overexpressing MSK1 overexpression was analyzed by western blot analysis. The results demonstrated that MSK1 expression were negatively correlated with TNF-α and IL-1β expression levels, and reached peak levels 2 days after TNF-α and IL-1β. The double immunofluorescence staining results showed that the expression of MSK1 was in the same plane of view as TNF-α and IL-1β in the brain cortex. Furthermore, the in vitro studies indicated that the overexpression of MSK1 inhibited the expression of TNF-α and IL-1β following LPS challenge. These results imply that MSK1 may be involved in the inflammatory reaction following SAH, and may potentially serve as a negative regulator of inflammation.

Preliminary results in the analysis of the immune response after aneurysmal subarachnoid hemorrhage

Cerebral vasospasm (VSP) is a common phenomenon after aneurysmal subarachnoid hemorrhage (aSAH) and contributes to neurocognitive decline. The natural history of the pro-inflammatory immune response after aSAH has not been prospectively studied in human cerebrospinal fluid (CSF). In this pilot study, we aimed to identify specific immune mediators of VSP after aSAH. Peripheral blood (PB) and CSF samples from patients with aSAH were prospectively collected at different time-points after hemorrhage: days 0–1 (acute); days 2–4 (pre-VSP); days 5–9 (VSP) and days 10 + (post-VSP peak). Presence and severity of VSP was assessed with computed tomography angiography/perfusion imaging and clinical examination. Cytokine and immune mediators’ levels were quantified using ELISA. Innate and adaptive immune cells were characterized by flow cytometry, and cell counts at different time-points were compared with ANOVA. Confocal immunostaining was used to determine the presence of specific immune cell populations detected in flow cytometry. Thirteen patients/aneurysms were included. Five (38.5%) patients developed VSP after a mean of 6.8 days from hemorrhage. Flow cytometry demonstrated decreased numbers of CD45+ cells during the acute phase in PB of aSAH patients compared with healthy controls. In CSF of VSP patients, NK cells (CD3-CD161 +) were increased during the acute phase and progressively declined, whereas CD8+CD161+ lymphocytes significantly increased at days 5–9. Microglia cells (CD45dimCD11b +) increased over time after SAH. This increase was particularly significant in patients with VSP. Levels of VEGF and MMP-9 were consistently higher in VSP patients, with the highest difference occurring at the acute phase. Confocal immunostaining demonstrated the presence of CD8+CD161+ lymphocytes in the arterial wall of two unruptured intracranial aneurysms. In this preliminary study, human CSF showed active presence of innate and adaptive immune cells after aSAH. CD8+CD161+ lymphocytes may have an important role in the inflammatory response after aneurysmal rupture and were identified in the aneurysmal wall of unruptured brain aneurysms. Microglia activation occurs 6 + days after aSAH.

Mfsd2a Attenuates Blood-Brain Barrier Disruption After Sub-arachnoid Hemorrhage by Inhibiting Caveolae-Mediated Transcellular Transport in Rats

Blood-brain barrier (BBB) disruption is one of the critical mechanisms of brain injury induced by subarachnoid hemorrhage (SAH). Past studies have often focused on the tight junctions of endothelial cells. However, low transcellular transport levels also play an important role in the normal functioning of the BBB. Major facilitator superfamily domain-containing 2a (Mfsd2a) has been demonstrated to be essential for the maintenance of the normal BBB. Our present study aimed to explore the roles and mechanisms of Mfsd2a in BBB disruption after SAH. In this study, a prechiasmatic cistern single-injection model was used to produce experimental SAH in Sprague-Dawley rats. Specific small-interfering RNA and plasmids were used to downregulate and upregulate the expression of Mfsd2a prior to assessments in our SAH model. Omega-3 fatty acid deficiency diet was used to reduce DHA in rat brain. The expression level of Mfsd2a decreased significantly after SAH and reached its lowest level at 72 h post-SAH, which then gradually recovered. At 72 h after SAH, BBB function was disrupted; upregulation of Mfsd2a reversed this damage, whereas downregulation of Mfsd2a exacerbated this damage. These effects were primarily mediated through transcellular transport, especially for changes in caveolae compared to those of tight junctions. After stopping the supply of omega-3 fatty acids, the effect of Mfsd2a on inhibition of caveolae and protection of the blood-brain barrier was eliminated. Taken together, Mfsd2a inhibits caveolae-based transcellular transport by transporting omega-3 fatty acids to protect the BBB after SAH.

Neuroinflammation and Microvascular Dysfunction After Experimental Subarachnoid Hemorrhage: Emerging Components of Early Brain Injury Related to Outcome

Aneurysmal subarachnoid hemorrhage has a high mortality rate and, for those who survive this devastating injury, can lead to lifelong impairment. Clinical trials have demonstrated that cerebral vasospasm of larger extraparenchymal vessels is not the sole contributor to neurological outcome. Recently, the focus of intense investigation has turned to mechanisms of early brain injury that may play a larger role in outcome, including neuroinflammation and microvascular dysfunction. Extravasated blood after aneurysm rupture results in a robust inflammatory response characterized by activation of microglia, upregulation of cellular adhesion molecules, recruitment of peripheral immune cells, as well as impaired neurovascular coupling, disruption of the blood-brain barrier, and imbalances in endogenous vasodilators and vasoconstrictors. Each of these phenomena is either directly or indirectly associated with neuronal death and brain injury. Here, we review recent studies investigating these various mechanisms in experimental models of subarachnoid hemorrhage with special emphasis on neuroinflammation and its effect on microvascular dysfunction. We discuss the various therapeutic targets that have risen from these mechanistic studies and suggest the utility of a multi-targeted approach to preventing delayed injury and improving outcome after subarachnoid hemorrhage.

The role of inflammation and potential use of sex steroids in intracranial aneurysms and subarachnoid hemorrhage

Background

Aneurysmal subarachnoid hemorrhage (aSAH) continues to be a devastating neurological condition with a high risk of associated morbidity and mortality. Inflammation has been shown to increase the risk of complications associated with aSAH such as vasospasm and brain injury in animal models and humans. The goal of this review is to discuss the inflammatory mechanisms of aneurysm formation, rupture and vasospasm and explore the role of sex hormones in the inflammatory response to aSAH.

Methods

A literature review was performed using PubMed using the following search terms: "intracranial aneurysm," "cerebral aneurysm," "dihydroepiandrosterone sulfate" "estrogen," "hormone replacement therapy," "inflammation," "oral contraceptive," "progesterone," "sex steroids," "sex hormones" "subarachnoid hemorrhage," "testosterone." Only studies published in English language were included in the review.

Results

Studies have shown that administration of sex hormones such as progesterone and estrogen at early stages in the inflammatory cascade can lower the risk and magnitude of subsequent complications. The exact mechanism by which these hormones act on the brain, as well as their role in the inflammatory cascade is not fully understood. Moreover, conflicting results have been published on the effect of hormone replacement therapy in humans. This review will scrutinize the variations in these studies to provide a more detailed understanding of sex hormones as potential therapeutic agents for intracranial aneurysms and aSAH.

Conclusion

Inflammation may play a role in the pathogenesis of intracranial aneurysm formation and subarachnoid hemorrhage, and administration of sex hormones as anti-inflammatory agents has been associated with improved functional outcome in experimental models. Further studies are needed to determine the therapeutic role of these hormones in the intracranial aneurysms and aSAH.

Roflumilast Reduces Cerebral Inflammation in a Rat Model of Experimental Subarachnoid Hemorrhage

Roflumilast, a selective inhibitor for PDE4, is approved by FDA as an anti-inflammation drug for treatment of chronic obstructive pulmonary disease (COPD). This study investigates the effects of roflumilast on cerebral inflammation in the rat SAH model. Here, we show that subcutaneous administration of roflumilast (3 mg/kg) significantly improved the neurological deficits. Measurement of evans blue extravasation and brain water content revealed a significant reduction of blood-brain barrier permeability and brain edema. Importantly, roflumilast treatment remarkably decreased levels of IL-1β, IL-6, and TNF-α and the number of apoptotic neurons in the brain after SAH. These results indicate that roflumilast is effective in treating cerebral inflammation following SAH.

Vascular diseases and bleedings

Diseases of the central nervous system that are caused by an underlying vascular pathology typically result in either hemorrhage or ischemia. Most prominent entities include spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. For anatomic reasons, cerebrospinal fluid (CSF) qualifies as body fluid for the exploration of biomarkers in these disorders. Even though in subarachnoid hemorrhage a few CSF parameters have been established for routine diagnostic purposes, there is still an unmet need and broad interest in the identification of molecules that would allow further insight into disease mechanisms and supplement patients' medical care. This chapter provides an overview on what is presently known about CSF biomarkers in spontaneous subarachnoid hemorrhage, spontaneous intracerebral hemorrhage, and ischemic stroke. We recapitulate current evidence on established diagnostic tests, discuss the role of various CSF molecules in the pathophysiology of these diseases, and illuminate their potential use in future clinical practice. Furthermore, we address methodologic aspects as well as shortcomings of research in this field.

Time Courses of Inflammatory Markers after Aneurysmal Subarachnoid Hemorrhage and Their Possible Relevance for Future Studies

Object

Aneurysmal subarachnoid hemorrhage triggers an intense inflammatory response, which is suspected to increase the risk for secondary complications such as delayed cerebral ischemia (DCI). However, to date, the monitoring of the inflammatory response to detect secondary complications such as DCI has not become part of the clinical routine diagnostic. Here, we aim to illustrate the time courses of inflammatory parameters after aneurysmal subarachnoid hemorrhage (aSAH) and discuss the problems of inflammatory parameters as biomarkers but also their possible relevance for deeper understanding of the pathophysiology after aSAH and sophisticated planning of future studies.

Materials and methods

In this prospective cohort study, 109 patients with aSAH were initially included, n = 28 patients had to be excluded. Serum and—if possible—cerebral spinal fluid samples (n = 48) were retrieved at days 1, 4, 7, 10, and 14 after aSAH. Samples were analyzed for leukocyte count and C-reactive protein (CRP) (serum samples only) as well as matrix metallopeptidase 9 (MMP9), intercellular adhesion molecule 1 (ICAM1), and leukemia inhibitory factor (LIF) [both serum and cerebrospinal fluid (CSF) samples]. Time courses of the inflammatory parameters were displayed and related to the occurrence of DCI.

Results

We illustrate the time courses of leukocyte count, CRP, MMP9, ICAM1, and LIF in patients’ serum samples from the first until the 14th day after aSAH. Time courses of MMP9, ICAM1, and LIF in CSF samples are demonstrated. Furthermore, no significant difference was shown relating the time courses to the occurrence of DCI.

Conclusion

We estimate that the wide range of the measured values hampers their interpretation and usage as a biomarker. However, understanding the inflammatory response after aSAH and generating a multicenter database may facilitate further studies: realistic sample size calculations on the basis of a multicenter database will increase the quality and clinical relevance of the acquired results.

Cytochrome P450 eicosanoids in cerebrovascular function and disease

Cytochrome P450 eicosanoids play important roles in brain function and disease through their complementary actions on cell-cell communications within the neurovascular unit (NVU) and mechanisms of brain injury. Epoxy- and hydroxyeicosanoids, respectively formed by cytochrome P450 epoxygenases and ω-hydroxylases, play opposing roles in cerebrovascular function and in pathological processes underlying neural injury, including ischemia, neuroinflammation and oxidative injury. P450 eicosanoids also contribute to cerebrovascular disease risk factors, including hypertension and diabetes. We summarize studies investigating the roles P450 eicosanoids in cerebrovascular physiology and disease to highlight the existing balance between these important lipid signaling molecules, as well as their roles in maintaining neurovascular homeostasis and in acute and chronic neurovascular and neurodegenerative disorders.

Neuroinflammation responses after subarachnoid hemorrhage: A review

Subarachnoid hemorrhage (SAH) is an important cause of stroke mortality and morbidity, especially in the young stroke population. Recent evidences indicate that neuroinflammation plays a critical role in both early brain injury and the delayed brain deterioration after SAH, including cellular and molecular components. Cerebral vasospasm (CV) can lead to death after SAH and independently correlated with poor outcome. Neuroinflammation is evidenced to contribute to the etiology of vasospasm. Besides, systemic inflammatory response syndrome (SIRS) commonly occurs in the SAH patients, with the presence of non-infectious fever and systematic complications. In this review, we summarize the evidences that indicate the prominent role of inflammation in the pathophysiology of SAH. That may provide the potential implications on diagnostic and therapeutic strategies.

An introduction to the pathophysiology of aneurysmal subarachnoid hemorrhage

Pathophysiological processes following subarachnoid hemorrhage (SAH) present survivors of the initial bleeding with a high risk of morbidity and mortality during the course of the disease. As angiographic vasospasm is strongly associated with delayed cerebral ischemia (DCI) and clinical outcome, clinical trials in the last few decades focused on prevention of these angiographic spasms. Despite all efforts, no new pharmacological agents have shown to improve patient outcome. As such, it has become clear that our understanding of the pathophysiology of SAH is incomplete and we need to reevaluate our concepts on the complex pathophysiological process following SAH. Angiographic vasospasm is probably important. However, a unifying theory for the pathophysiological changes following SAH has yet not been described. Some of these changes may be causally connected or present themselves as an epiphenomenon of an associated process. A causal connection between DCI and early brain injury (EBI) would mean that future therapies should address EBI more specifically. If the mechanisms following SAH display no causal pathophysiological connection but are rather evoked by the subarachnoid blood and its degradation production, multiple treatment strategies addressing the different pathophysiological mechanisms are required. The discrepancy between experimental and clinical SAH could be one reason for unsuccessful translational results.

Protective effect 3,4-dihydroxyphenylethanol in subarachnoid hemorrhage provoked oxidative neuropathy

Clinical studies have indicated that early brain injury (EBI) following subarachnoid hemorrhage (SAH) is associated with fatal outcomes. Oxidative stress and brain edema are the characteristic pathological events in occurrence EBI following SAH. The present study aimed to examine the effect of 3,4-dihydroxyphenylethanol (DOPET) against SAH-induced EBI, and to demonstrate whether the effect is associated with its potent free radical scavenging property. SAH was induced in rats using an endovascular perforation technique, and 24 h later the rats displayed diminished neurological scores and brain edema. Furthermore, elevated malondialdehyde (an index of lipid peroxidation) and depleted levels of antioxidants were observed in the rat cerebral cortex tissue. Quantitative polymerase chain reaction analysis indicated the upregulated mRNA expression of the apoptotic markers caspase-3 and -9 in the cerebral cortex. Furthermore, the protein expression levels of the proinflammatory cytokines tumor necrosis factor-α, interleukin (IL)-1β and IL-6 were significantly upregulated in SAH-induced rats. By constrast, treatment with DOPET significantly attenuated EBI by reducing brain edema, elevation of antioxidant status, inhibition of apoptosis and inflammation. In this context, DOPET may be a potent agent in the treatment of EBI following SAH, as a result of its free radical scavenging capacity.

The Role of Clinical Proteomics, Lipidomics, and Genomics in the Diagnosis of Alzheimer's Disease

The early diagnosis of Alzheimer’s disease (AD) has become important to the reversal and treatment of neurodegeneration, which may be relevant to premature brain aging that is associated with chronic disease progression. Clinical proteomics allows the detection of various proteins in fluids such as the urine, plasma, and cerebrospinal fluid for the diagnosis of AD. Interest in lipidomics has accelerated with plasma testing for various lipid biomarkers that may with clinical proteomics provide a more reproducible diagnosis for early brain aging that is connected to other chronic diseases. The combination of proteomics with lipidomics may decrease the biological variability between studies and provide reproducible results that detect a community’s susceptibility to AD. The diagnosis of chronic disease associated with AD that now involves genomics may provide increased sensitivity to avoid inadvertent errors related to plasma versus cerebrospinal fluid testing by proteomics and lipidomics that identify new disease biomarkers in body fluids, cells, and tissues. The diagnosis of AD by various plasma biomarkers with clinical proteomics may now require the involvement of lipidomics and genomics to provide interpretation of proteomic results from various laboratories around the world.

Impact of Early Leukocytosis and Elevated High-Sensitivity C-Reactive Protein on Delayed Cerebral Ischemia and Neurologic Outcome After Subarachnoid Hemorrhage

BACKGROUND

The role of inflammatory response in the pathophysiology of subarachnoid hemorrhage (SAH) is being increasingly recognized. This study analyzed the impact of cellular and biochemical markers of early inflammatory response to ictus on outcome after SAH.

METHODS

Patients with SAH were prospectively studied for markers of early cellular, biochemical, and cytotoxic inflammatory response, including total leukocyte count (TLC), high-sensitivity C-reactive protein (hs-CRP), and lactate dehydrogenase. The relationship of these markers to delayed cerebral ischemia (DCI), new infarct, and Glasgow Outcome Scale (GOS) score at 3 months was studied.

RESULTS

The study comprised 246 patients. Of patients, 94 who developed DCI had a significantly higher TLC [± SD] (11.2 × 10(3)/mm(3) [± 4.0] vs. 9.4 × 10(3)/mm(3) [± 2.9], P = 0.001) and 62 with new infarct had significantly higher TLC (11.0 × 10(3)/mm(3) [± 3.6] vs. 9.8 × 10(3)/mm(3) [± 3.4], P = 0.05). GOS score had a significant inverse relationship to TLC at admission. The mean TLC [± SD] was 12.7 × 10(3)/mm(3) [± 4.2], 11.7 × 10(3)/mm(3) [± 3.1], 10.2 × 10(3)/mm(3) [± 3.4], and 9.3 × 10(3)/mm(3) [± 2.8] among patients with GOS scores of 1, 3, 4, and 5 (P < 0.001). hs-CRP showed a trend of an inverse relationship to GOS score in univariate analysis. Lactate dehydrogenase had no relationship with any outcome parameter. In multivariate analysis, higher admission TLC had a significant association with DCI (P = 0.01) and poorer GOS score (P < 0.001), and higher hs-CRP had a significant association with poorer GOS score (P = 0.05).

CONCLUSIONS

A leukocytosis response to ictus seems to have a significant independent association with both DCI and poor GOS score, and hs-CRP level had a significant independent association with poor GOS score, indicating preeminence of early cellular response in SAH pathophysiology.

Association of early inflammatory parameters after subarachnoid hemorrhage with functional outcome: A prospective cohort study

OBJECTIVE

Early brain injury after aneurysmal subarachnoid hemorrhage (aSAH) comprises a pronounced neuroinflammatory reaction. Nevertheless, its relevance for functional outcome and its role as outcome predictor remains uncertain. We evaluated the relationship of various early inflammatory parameters regarding functional outcome according to the modified Rankin Scale score (mRS) at discharge (primary objective) and six months after aSAH.

PATIENTS

A total of 81 patients (63% female) with a mean age of 53.8 ± 13.2 years were included.

METHODS

At admission clinical data and various inflammatory parameters in serum and - wherever applicable - cerebrospinal fluid (CSF) of patients after aSAH were assessed. Outcome was evaluated according to dichotomized mRS at discharge and six months after aSAH (unfavorable outcome: mRS 3-6). Univariate and thereafter multivariate logistic regression analyses were performed using SAS 9.2.

RESULTS

Elevated levels of interleukin 6 (IL-6) and leukemia inhibitory factor (LIF) in serum and CSF were related to unfavorable outcome at discharge (p<0.05; univariate analyses). IL-6 remains the only parameter relevant for outcome applying a multivariate model including the relevant baseline characteristics. Six months after aSAH no significant correlation was found regarding the outcome, most likely due to the high drop-out rate (27%). A pronounced rise of LIF serum and CSF levels after aSAH was observed.

CONCLUSION

Higher early IL-6 serum levels after aSAH are associated with poor outcome at discharge. In addition, involvement of LIF in the early inflammatory reaction after aSAH has been demonstrated.

Soluble Epoxide Hydrolase in Hydrocephalus, Cerebral Edema, and Vascular Inflammation After Subarachnoid Hemorrhage

BACKGROUND AND PURPOSE

Acute communicating hydrocephalus and cerebral edema are common and serious complications of subarachnoid hemorrhage (SAH), whose causes are poorly understood. Using a mouse model of SAH, we determined whether soluble epoxide hydrolase (sEH) gene deletion protects against SAH-induced hydrocephalus and edema by increasing levels of vasoprotective eicosanoids and suppressing vascular inflammation.

METHODS

SAH was induced via endovascular puncture in wild-type and sEH knockout mice. Hydrocephalus and tissue edema were assessed by T2-weighted magnetic resonance imaging. Endothelial activation was assessed in vivo using T2*-weighted magnetic resonance imaging after intravenous administration of iron oxide particles linked to anti-vascular cell adhesion molecule-1 antibody 24 hours after SAH. Behavioral outcome was assessed at 96 hours after SAH with the open field and accelerated rotarod tests.

RESULTS

SAH induced an acute sustained communicating hydrocephalus within 6 hours of endovascular puncture in both wild-type and sEH knockout mice. This was followed by tissue edema, which peaked at 24 hours after SAH and was limited to white matter fiber tracts. sEH knockout mice had reduced edema, less vascular cell adhesion molecule-1 uptake, and improved outcome compared with wild-type mice.

CONCLUSIONS

Genetic deletion of sEH reduces vascular inflammation and edema and improves outcome after SAH. sEH inhibition may serve as a novel therapy for SAH.

Early events after aneurysmal subarachnoid hemorrhage

The first 72 h after aneurysmal subarachnoid hemorrhage (SAH) is a critical period for the patient. Most of the deaths in the SAH patient population occur during this time, and a number of key events activate and trigger mechanisms that not only contribute to early brain injury but evolve over time and participate in the delayed complications. This review highlights the contribution of key events to the early brain injury and to overall outcome after SAH.

Inflammation, vasospasm, and brain injury after subarachnoid hemorrhage

Subarachnoid hemorrhage (SAH) can lead to devastating neurological outcomes, and there are few pharmacologic treatments available for treating this condition. Both animal and human studies provide evidence of inflammation being a driving force behind the pathology of SAH, leading to both direct brain injury and vasospasm, which in turn leads to ischemic brain injury. Several inflammatory mediators that are elevated after SAH have been studied in detail. While there is promising data indicating that blocking these factors might benefit patients after SAH, there has been little success in clinical trials. One of the key factors that complicates clinical trials of SAH is the variability of the initial injury and subsequent inflammatory response. It is likely that both genetic and environmental factors contribute to the variability of patients' post-SAH inflammatory response and that this confounds trials of anti-inflammatory therapies. Additionally, systemic inflammation from other conditions that affect patients with SAH could contribute to brain injury and vasospasm after SAH. Continuing work on biomarkers of inflammation after SAH may lead to development of patient-specific anti-inflammatory therapies to improve outcome after SAH.

To look beyond vasospasm in aneurysmal subarachnoid haemorrhage

Delayed cerebral vasospasm has classically been considered the most important and treatable cause of mortality and morbidity in patients with aneurysmal subarachnoid hemorrhage (aSAH). Secondary ischemia (or delayed ischemic neurological deficit, DIND) has been shown to be the leading determinant of poor clinical outcome in patients with aSAH surviving the early phase and cerebral vasospasm has been attributed to being primarily responsible. Recently, various clinical trials aimed at treating vasospasm have produced disappointing results. DIND seems to have a multifactorial etiology and vasospasm may simply represent one contributing factor and not the major determinant. Increasing evidence shows that a series of early secondary cerebral insults may occur following aneurysm rupture (the so-called early brain injury). This further aggravates the initial insult and actually determines the functional outcome. A better understanding of these mechanisms and their prevention in the very early phase is needed to improve the prognosis. The aim of this review is to summarize the existing literature on this topic and so to illustrate how the presence of cerebral vasospasm may not necessarily be a prerequisite for DIND development. The various factors determining DIND that worsen functional outcome and prognosis are then discussed.

Biomarkers and acute brain injuries: interest and limits

For patients presenting with acute brain injury (such as traumatic brain injury, subarachnoid haemorrhage and stroke), the diagnosis and identification of intracerebral lesions and evaluation of the severity, prognosis and treatment efficacy can be challenging. The complexity and heterogeneity of lesions after brain injury are most probably responsible for this difficulty. Patients with apparently comparable brain lesions on imaging may have different neurological outcomes or responses to therapy. In recent years, plasmatic and cerebrospinal fluid biomarkers have emerged as possible tools to distinguish between the different pathophysiological processes. This review aims to summarise the plasmatic and cerebrospinal fluid biomarkers evaluated in subarachnoid haemorrhage, traumatic brain injury and stroke, and to clarify their related interests and limits for diagnosis and prognosis. For subarachnoid haemorrhage, particular interest has been focused on the biomarkers used to predict vasospasm and cerebral ischaemia. The efficacy of biomarkers in predicting the severity and outcome of traumatic brain injury has been stressed. The very early diagnostic performance of biomarkers and their ability to discriminate ischaemic from haemorrhagic stroke were studied.

Biomarkers as outcome predictors in subarachnoid hemorrhage--a systematic review

CONTEXT

Subarachnoid hemorrhage (SAH) has a high fatality rate and many suffer from delayed neurological deficits. Biomarkers may aid in the identification of high-risk patients, guide treatment/management and improve outcome.

OBJECTIVE

The aim of this review was to summarize biomarkers of SAH associated with outcome.

METHODS

An electronic database query was completed, including an additional review of reference lists to include all potential human studies.

RESULTS

A total of 298 articles were identified; 112 were reviewed; 55 studies were included.

CONCLUSION

This review details biomarkers of SAH that correlate with outcome. It provides the basis for research investigating their possible translation into the management of SAH patients.

The importance of early brain injury after subarachnoid hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is a medical emergency that accounts for 5% of all stroke cases. Individuals affected are typically in the prime of their lives (mean age 50 years). Approximately 12% of patients die before receiving medical attention, 33% within 48 h and 50% within 30 days of aSAH. Of the survivors 50% suffer from permanent disability with an estimated lifetime cost more than double that of an ischemic stroke. Traditionally, spasm that develops in large cerebral arteries 3-7 days after aneurysm rupture is considered the most important determinant of brain injury and outcome after aSAH. However, recent studies show that prevention of delayed vasospasm does not improve outcome in aSAH patients. This finding has finally brought in focus the influence of early brain injury on outcome of aSAH. A substantial amount of evidence indicates that brain injury begins at the aneurysm rupture, evolves with time and plays an important role in patients' outcome. In this manuscript we review early brain injury after aSAH. Due to the early nature, most of the information on this injury comes from animals and few only from autopsy of patients who died within days after aSAH. Consequently, we began with a review of animal models of early brain injury, next we review the mechanisms of brain injury according to the sequence of their temporal appearance and finally we discuss the failure of clinical translation of therapies successful in animal models of aSAH.

Cerebrospinal fluid catecholamine levels as predictors of outcome in subarachnoid hemorrhage

OBJECTIVE

Subarachnoid hemorrhage (SAH) is associated with marked sympathetic activation at the time of ictus. The purpose of this study is to determine whether early central catecholamine levels measured from cerebrospinal fluid (CSF) relate to outcome in patients with SAH.

METHODS

Observational study of consecutive SAH grade 3-5 patients who underwent ventriculostomy placement, but did not undergo open craniotomy for aneurysm obliteration. CSF samples were obtained during the first 48 h following symptom onset and assayed for catecholamine levels. Statistical analyses were performed to determine whether the levels predicted mortality by day 15 or mortality/disability by day 30.

RESULTS

For the 102 patients included, mean age was 58, and 73% were female - 21% experienced day-15 mortality, and 32% experienced mortality/disability by day 30. Early mortality was related to Hunt-Hess (H/H) grade (p < 0.001), neurogenic cardiomyopathy (NC) (p = 0.003), cerebral infarction (p = 0.001), elevated intracranial pressure (ICP) (p = 0.029), epinephrine (EPI) level (p = 0.002) and norepinephrine/3,4-dihydroxyphenylglycol (NE/DHPG) ratio (p = 0.003). Mortality/disability was related to H/H grade (p < 0.001), NC (p = 0.018), infarction (p < 0.001), elevated ICP (p = 0.002), EPI (p = 0.004) and NE/DHPG (p = 0.014). Logistic regression identified age [OR 1.09 (95% CI 1.01-1.17)], H/H grade [9.52 (1.19-77)], infarction [10.87 (1.22-100)], ICP elevation [32.26 (2-500)], EPI [1.06 (1.01-1.10)], and (inversely) DHPG [0.99 (0.99-1.00)] as independent predictors of early mortality. For mortality/disability, H/H grade [OR 21.74 (95% CI 5.62-83)], ICP elevation [18.52 (1.93-166)], and EPI [1.05 (1.02-1.09)] emerged as independent predictors. Proportional-hazards analysis revealed age [HR 1.041 (95% CI 1.003-1.08)], H/H grade [6.9 (1.54-31.25)], NC [4.31 (1.5-12.35)], and EPI [1.032 (1.009-1.054)] independently predicted early mortality.

CONCLUSIONS

CSF catecholamine levels are elevated in SAH patients who experience early mortality or disability. EPI may potentially serve as useful index of outcome in this population of patients with SAH.

The association between serum adhesion molecules and outcome in acute spontaneous intracerebral hemorrhage

Introduction

Serum concentrations of adhesion molecules may be connected to the pathogenesis of secondary brain injury after spontaneous intracerebral hemorrhage (ICH). This study posits the hypothesis that levels of adhesion molecules substantially increase after ICH and are decreased thereafter, and that they can predict treatment outcomes.

Methods

Two hundred and thirty-nine blood samples were collected from 60 consecutive patients admitted within 24 hours after onset of spontaneous ICH and 60 blood samples were collected from 60 volunteers. Additional samples were obtained on Days 4, 7, 10, and 14 after onset of ICH regardless of clinical deterioration.

Results

Upon discharge, the therapeutic outcomes of the 60 spontaneous ICH cases based on the modified Rankin Disability Scale (mMRS) showed that 17 had no disability while 8.3% developed delayed cerebral infarction (DCI). Statistical analysis of adhesion molecules between patient groups with good outcome (mMRS = 0 or 1) and poor outcome (mMRS ≥2) revealed significant differences in diabetes mellitus (P=0.049), hyperlipidemia (P=0.012), mentality change (P=0.043), ICH volume and intraventricular hemorrhage on admission (P=0.036 and 0.006, respectively), Glasgow Coma Scale (GCS) on admission (P≤0.001), neuro-surgical intervention (P=0.003), and sE-selectin and soluble intercellular cell adhesion-molecule-1 (sICAM-1) levels on admission (P=0.036 and 0.019, respectively). Multiple logistic regression analysis of these significant variables showed that GCS on admission, hyperlipidemia, and sICAM-1 (P=0.039, 0.042, and 0.022, respectively) were independently associated with outcome of acute spontaneous ICH.

Conclusion

Increased sICAM-1 and sE-selectin levels may imply poor therapeutic outcomes for the treatment of spontaneous ICH during hospitalization. These early inflammatory responses may cause whole-brain injury immediately after spontaneous ICH and offer a potential therapeutic target for such patients. The importance of these findings is that they offer a potential therapeutic target for patients with spontaneous ICH.

Monitoring of the inflammatory response after aneurysmal subarachnoid haemorrhage in the clinical setting: review of literature and report of preliminary clinical experience

BACKGROUND

Clinical and experimental studies showed a marked inflammatory response in aneurysmal subarachnoid haemorrhage (SAH), and it has been proposed to play a key role in the development of cerebral vasospasm (CVS). Inflammatory response and occurrence of CVS may represent a common pathogenic pathway allowing point of care diagnostics of CVS. Therefore, monitoring of the inflammatory response might be useful in the daily clinical setting of an ICU. The aim of the current report is to give a summary about factors contributing to the complex pathophysiology of inflammatory response in SAH and to discuss possible monitoring modalities.

METHODS

Review and analysis of the existing literature and definition of own study protocols.

RESULTS

In cerebrospinal fluid, interleukin (IL)-6 has been found to be significantly higher in patients with CVS during the peri-vasospasm period. While systemic inflammatory response syndrome, high C-reactive protein levels and leukocyte counts has been linked with the occurrence of CVS, less has been reported about cytokines levels in the jugular bulb of the internal jugular vein and in the peripheral blood. Preliminary evaluation of own data suggests, that IL-6 values in the peripheral blood and the arterio-jugular differences of IL-6 are increased with the inflammatory response after SAH.

CONCLUSION

Monitoring of the inflammatory response, in particular IL-6, might be a useful tool for the daily clinical management of patients with SAH and CVS.

Gardenia jasminoides inhibits tumor necrosis factor-alpha-induced vascular inflammation in endothelial cells

Inflammatory mediators such as tumor necrosis factor-alpha (TNF-alpha) enhance binding of low-density lipoprotein to endothelium and upregulate the expression of endothelial leukocyte adhesion molecules during atherogenesis. The present study examined the effect of ethanol extract of Gardenia jasminoides (EGJ) on vascular inflammation in primary cultured human umbilical vein endothelial cells (HUVEC). TNF-alpha-induced the expression of vascular cell adhesion molecule-1 (VCAM-1) and endothelial cell-selectin (E-selectin) expression was inhibited in HUVEC pretreated with EGJ. In a functional study, EGJ dose-dependently attenuated adhesion of HL-60 monocytes to endothelial monolayers. A further analysis indicated that EGJ attenuated TNF-alpha-induced nuclear p65 nuclear factor-kappa B (NF-kappaB) translocation, suggesting that EGJ primarily affects the TNF-alpha-induced NF-kappaB signaling pathway. Taken together, we provided here the first evidence showing that EGJ is able to inhibit TNF-alpha-induced NF-kappaB activation, adhesion molecule expression, and monocyte-endothelial interaction, suggesting an anti-inflammatory role of EGJ, which may be useful in preventing vascular diseases, such as atherosclerosis.

Proteomic biomarker discovery in cerebrospinal fluid for cerebral vasospasm following subarachnoid hemorrhage

Currently, there are no established biomarkers for diagnosing preclinical vasospasm or monitoring its progression. Two areas of extensive biomarker research are neuroimaging and biochemical markers in body fluids, such as cerebrospinal fluid (CSF). We performed a review of studies conducted over the past 2 decades summarizing the science to date and the evolution of CSF biomarkers in subarachnoid hemorrhage (SAH). A Medline search performed using the search terms "subarachnoid hemorrhage marker AND cerebrospinal fluid," limited to the period January 1, 1990 to June 1, 2009, returned 62 references. Abstracts that did not deal primarily with SAH and potential markers in the CSF of humans were excluded, resulting in 27 abstracts. Only articles providing sufficient information for a substantiated analysis were selected. In addition, articles identified in reference lists of individual articles were selected if considered appropriate. Evidence was classified as class I-IV and recommendations were classified as category A-C according to European Federation of Neurological Societies guidelines. We evaluated CSF markers in SAH patients and divided them into 3 categories: A, markers with auspicious value; B, candidate markers; and C, noncandidate markers. Category A markers included tumor necrosis factor (TNF)-α, soluble tumor necrosis factor receptor I (sTNFR-I), and interleukin (IL)-1 receptor antagonist (IL-1ra), as well as the neurofilament proteins NFL and NfH. Category B markers included apolipoprotein E (ApoE), F2-isoprostane (F2-IsoP), NOx, and the indicators for thrombin activity membrane-bound tissue factor (mTF) and thrombin-antithrombin III complex (TAT) for neurologic outcome prediction, as well as E-selectin, lactate, alpha-II spectrin breakdown products (SBDPs), asymmetric dimethyl-L-arginine (ADMA), and monocyte chemoattractant protein-1 (MCP-1) for vasospasm prognostication. Category C markers included S100B, platelet-derived growth factor (PDGF), YKL-40, chitotriosidase, intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and IL-8. Cytokines and their receptors, as well as neuronal intracellular proteins, seem to be potential markers for outcome determination in patients after SAH.

Controlled delivery of nitric oxide inhibits leukocyte migration and prevents vasospasm in haptoglobin 2-2 mice after subarachnoid hemorrhage

OBJECTIVE

Cerebral vasospasm is the leading cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (SAH) occurs. The haptoglobin 2-2 genotype likely increases the risk for developing posthemorrhagic vasospasm, but potential treatments for vasospasm have never been tested in an animal model of this genotype. We used the nitric oxide (NO) donor diethylenetriamine (DETA)/NO incorporated into ethylene/vinyl acetate (EVAc) polymers to evaluate the efficacy of controlled NO repletion in a haptoglobin 2-2 mouse basilar artery SAH model.

METHODS

Mice were randomized to 3 groups: autologous blood injection and empty polymer implantation into the subarachnoid space (n = 16); blood injection and 30% DETA/NO-EVAc implantation (n = 20); and sham operation (n = 19). At 24 hours after surgery, activity level was assessed on a 3-point scale, and basilar arteries were processed for morphometric measurements. Leukocyte extravasation was assessed by immunohistochemistry (n = 12).

RESULTS

Treatment with controlled release of NO from DETA/NO-EVAc polymers after SAH resulted in a significant increase in basilar artery lumen patency (73.3% +/- 4.3% versus 96.5% +/- 4.3%, mean +/- standard error of the mean; P = 0.01), a significant improvement in activity after experimental SAH (2.14 +/- 0.14 versus 2.56 +/- 0.10 points; P = 0.025), and a significant decrease in extravasated leukocytes (21 +/- 4.55 versus 6.75 +/- 3.77 leukocytes per high-power field, untreated versus treated mice; P = 0.001).

CONCLUSION

Treatment with controlled release of NO prevented posthemorrhagic vasospasm in haptoglobin 2-2 mice, and mitigated neurological deficits, suggesting that DETA/NO-EVAc would be an effective therapy in patients with a genotype that confers higher risk for vasospasm after SAH. In addition to smooth muscle relaxation, inhibition of leukocyte migration may contribute to the therapeutic mechanism of NO.

Role of inflammation (leukocyte-endothelial cell interactions) in vasospasm after subarachnoid hemorrhage

BACKGROUND

Delayed vasospasm is the leading cause of morbidity and mortality after aneurysmal subarachnoid hemorrhage (aSAH). This phenomenon was first described more than 50 years ago, but only recently has the role of inflammation in this condition become better understood.

METHODS

The literature was reviewed for studies on delayed vasospasm and inflammation.

RESULTS

There is increasing evidence that inflammation and, more specifically, leukocyte-endothelial cell interactions play a critical role in the pathogenesis of vasospasm after aSAH, as well as in other conditions including meningitis and traumatic brain injury. Although earlier clinical observations and indirect experimental evidence suggested an association between inflammation and chronic vasospasm, recently direct molecular evidence demonstrates the central role of leukocyte-endothelial cell interactions in the development of chronic vasospasm. This evidence shows in both clinical and experimental studies that cell adhesion molecules (CAMs) are up-regulated in the perivasospasm period. Moreover, the use of monoclonal antibodies against these CAMs, as well as drugs that decrease the expression of CAMs, decreases vasospasm in experimental studies. It also appears that certain individuals are genetically predisposed to a severe inflammatory response after aSAH based on their haptoglobin genotype, which in turn predisposes them to develop clinically symptomatic vasospasm.

CONCLUSION

Based on this evidence, leukocyte-endothelial cell interactions appear to be the root cause of chronic vasospasm. This hypothesis predicts many surprising features of vasospasm and explains apparently unrelated phenomena observed in aSAH patients. Therapies aimed at preventing inflammation may prevent and/or reverse arterial narrowing in patients with aSAH and result in improved outcomes.

Serum and cerebrospinal fluid C-reactive protein levels as predictors of vasospasm in aneurysmal subarachnoid hemorrhage. Clinical article

OBJECT

Cerebral vasospasm is a common and potentially devastating complication of aneurysmal subarachnoid hemorrhage (aSAH). Inflammatory processes seem to play a major role in the pathogenesis of vasospasm. The C-reactive protein (CRP) constitutes a highly sensitive inflammatory marker. The association of elevated systemic CRP and coronary vasospasm has been well established. Additionally, elevation of the serum CRP levels has been demonstrated in patients with aSAH. The purpose of the current study was to evaluate the possible relationship between elevated CRP levels in the serum and CSF and the development of vasospasm in patients with aSAH.

METHODS

A total of 41 adult patients in whom aSAH was diagnosed were included in the study. Their demographics, the admitting Glasgow Coma Scale (GCS) score, Hunt and Hess grade, Fisher grade, CT scans, digital subtraction angiography studies, and daily neurological examinations were recorded. Serial serum and CSF CRP measurements were obtained on Days 0, 1, 2, 3, 5, 7, and 9. All patients underwent either surgical or endovascular treatment within 48 hours of their admission. The outcome was evaluated using the Glasgow Outcome Scale and the modified Rankin Scale.

RESULTS

The CRP levels in serum and CSF peaked on the 3rd postadmission day, and the CRP levels in CSF were always higher than the serum levels. Patients with lower admission GCS scores and higher Hunt and Hess and Fisher grades had statistically significantly higher levels of CRP in serum and CSF. Patients with angiographic vasospasm had higher CRP measurements in serum and CSF, in a statistically significant fashion (p < 0.0001). Additionally, patients with higher CRP levels in serum and CSF had less favorable outcome in this cohort.

CONCLUSIONS

Patients with aSAH who had high Hunt and Hess and Fisher grades and low GCS scores showed elevated CRP levels in their CSF and serum. Furthermore, patients developing angiographically proven vasospasm demonstrated significantly elevated CRP levels in serum and CSF, and increased CRP measurements were strongly associated with poor clinical outcome in this cohort.

A review of medical treatments of cerebral vasospasm

We review the literature on the established perioperative therapies for cerebral vasospasm (CV) following aneurysmal subarachnoid hemorrhage (aSAH). Despite aSAH treatment advances, CV continues to be a significant source of post-SAH morbidity and mortality. In fact, CV has been correlated with a 7.5- to three-fold increase in mortality in the first 2 weeks after SAH. As new treatment modalities show promise in animal models and early clinical trials, greater efforts are needed to test these new approaches. Few evidence-based indications for the treatment of vasospasm currently exist. Large-scale randomized clinical trials are needed to determine whether therapies such as magnesium, statins, nitric oxide modulators, endothelin antagonists and others will become standard of care in the prevention and/or treatment of CV.

Cytosolic Ca2+ oscillations in human cerebrovascular endothelial cells after subarachnoid hemorrhage

Molecular mechanisms of cerebral vasospasm after subarachnoid hemorrhage (SAH) include specific modes of cell signaling like activation of nuclear factor (NF)-kappaB and vascular cell adhesion molecules (VCAM)-1 expression. The study's hypothesis is that cisternal cerebral spinal fluid (CSF) from patients after SAH may cause Ca(2+) oscillations which induce these modes of vascular inflammation in an in vitro model of human cerebral endothelial cells (HCECs). HCECs were incubated with cisternal CSF from 10 SAH patients with confirmed cerebral vasospasm. The CSF was collected on days 5 and 6 after hemorrhage. Cytosolic Ca(2+) concentrations and cell contraction as an indicator of endothelial barrier function were examined by fura-2 microflurometry. Activation of NF-kappaB and VCAM-1 expression were measured by immunocytochemistry. Incubation of HCEC with SAH-CSF provoked cytosolic Ca(2+) oscillations (0.31+/-0.09 per min), cell contraction, NF-kappaB activation, and VCAM-1 expression, whereas exposure to native CSF had no significant effect. When endoplasmic reticulum (ER) Ca(2+)-ATPase and ER inositol trisphosphate (IP3)-sensitive Ca(2+) channels were blocked by thapsigargin or xestospongin, the frequency of the Ca(2+) oscillations was reduced significantly. In analogy to the reduction of Ca(2+) oscillation frequency, the blockers impaired HCEC contraction, NF-kappaB activation, and VCAM-1 expression. Cisternal SAH-CSF induces cytosolic Ca(2+) oscillations in HCEC that results in cellular constriction, NF-kappaB activation, and VCAM-1 expression. The Ca(2+) oscillations depend on the function of ER Ca(2+)-ATPase and IP3-sensitive Ca(2+) channels.

Serum inflammatory adhesion molecules and high-sensitivity C-reactive protein correlates with delayed ischemic neurologic deficits after subarachnoid hemorrhage

BACKGROUND

The purpose of the present study was to investigate the relationship between serum concentrations of the immunoglobulin-like superfamily, selectins, hsCRP, and the development of DIND in patients with aneurysmal SAH.

METHODS

Serum ICAM-1, VCAM-1, E-selectin, P-selectin, L-selectin, and hsCRP were measured in 33 patients with SAH who underwent aneurysmal clipping within 48 hours of the onset of symptoms. Serum samples were obtained during the early period (day 0) and the late period (day 7).

RESULTS

The serum concentrations of ICAM-1 (P = .009), VCAM-1 (P = .0383) and hsCRP (P = .0014) during the early period were significantly higher in patients with SAH than in control patients. Further, serum hsCRP concentration during the late period was significantly higher in patients with SAH than in control patients (P = 0033). Finally, serum concentrations of ICAM-1, VCAM-1, and hsCRP during the early (P = .0055, P = .0266, and P = .0266) and late (P = .0423, P = .0041, and P = .0004) period were significantly higher in patients with DIND than in patients without DIND.

CONCLUSIONS

Serum levels of ICAM-1, VCAM-1 and hsCRP during the early and late period following SAH correlate with DIND.

Elevated cerebrospinal fluid and serum YKL-40 levels are not associated with symptomatic vasospasm in patients with aneurysmal subarachnoid haemorrhage

YKL-40 is a newly discovered matrix protein that is thought to be released during the acute stages of inflammation. It has recently been speculated that YKL-40 may serve as a specific serological marker of neutrophil function at the site of tissue inflammation. Our aim was to determine whether the levels of YKL-40 in both the cerebrospinal fluid and sera of 22 patients with aneurysmal subarachnoid haemorrhage were associated with either vasospasm or outcome. The levels were also compared with those of 16 control patients with hydrocephalus. We found that patients with aneurysmal subarachnoid haemorrhage had significantly higher YKL-40 levels in both cerebrospinal fluid and serum than controls. However, elevated YKL-40 levels were not associated with symptomatic vasospasm or 6-month outcome. We show that elevated YKL-40 levels are not correlated with the severity of subarachnoid haemorrhage and cannot be used as a serological marker of inflammation in patients with an aneurysm rupture.

Time course of VCAM-1 and ICAM-1 in CSF in patients with basal ganglia haemorrhage

OBJECTIVES

In a pilot study we found a correlation of the clinical outcome with adhesion molecule (AM) concentrations in ventricular cerebrospinal fluid (CSF) but not in serum in patients with intracerebral haemorrhage. We now determined the time course of AM concentration in CSF and serum after basal ganglia haemorrhage (BGH) in order to further uncover pathogenetic mechanisms.

MATERIALS AND METHODS

We included 11 patients with acute BGH and ventricular tamponade in which an extraventricular drainage had been applied to treat ventricular ballonade. Paired CSF and serum samples were obtained within 8 h after onset of BGH, as well as on the consecutive days 2, 4, 6, and 8, respectively. The concentrations of soluble ICAM-1 (sICAM-1) and VCAM-1 (sVCAM-1) in CSF and serum were measured by enzyme-linked immunosorbent assay. Moreover, we determined blood volume and perifocal oedema by a semi-automated planimetry technique from initial cranial computed tomography scans.

RESULTS

sICAM-1 and sVCAM-1 levels in CSF were highest within the first hours after onset of BGH, then decreased significantly (P < 0.005 and <0.05, respectively) on day 2 and slightly increased thereafter. Furthermore, BGH volume was significantly correlated with the concentrations of sICAM-1 (r = 0.63, P < 0.05) and sVCAM-1 (r = 0.66, P < 0.05) in ventricular CSF but not in serum.

CONCLUSIONS

Our results might indicate that the local inflammatory reaction is pronounced early after onset of BGH and appears to be restricted to the central nervous system. Moreover, AM concentrations measured early after BGH onset correlated stronger with radiological and clinical data than follow-up measurements.

Detection of caspase-3, neuron specific enolase, and high-sensitivity C-reactive protein levels in both cerebrospinal fluid and serum of patients after aneurysmal subarachnoid hemorrhage

OBJECTIVE

The purpose of this study is to explore whether or not the levels of caspase-3 (Casp3), neuron-specific enolase (NSE), and high-sensitivity C-reactive protein (hsCRP) were elevated in cerebrospinal fluid (CSF) and serum of patients after aneurysmal subarachnoid hemorrhage (SAH).

METHODS

This prospective clinical study consisted of 20 patients who experienced recent aneurysmal SAH and 15 control patients who experienced hydrocephalus without any other central nervous system disease. CSF and serum samples obtained within the first 3 days, and on the fifth and seventh days of SAH were assayed for Casp3, NSE, and hsCRP by using enzyme-linked immunosorbent assay.

RESULTS

Levels of Casp3, NSE, and hsCRP in the CSF (P = 0.00001, P = 0.00001, and P <0.003, respectively) and in the serum (P = 0.00001, P <0.01, and P = 0.00001, respectively) of SAH patients were found to be elevated when compared with controls with normal pressure hydrocephalus.

CONCLUSION

The authors have demonstrated the synchronized elevation of Casp3, NSE, and hsCRP in both CSF and serum of patients with aneurysmal SAH. Further studies with a large number of patients are recommended to more accurately determine the roles of these molecules in aneurysmal SAH.

Leukocyte-endothelial cell interactions in chronic vasospasm after subarachnoid hemorrhage

Leukocyte-endothelial cell interactions appear to be the root cause of chronic vasospasm after aneurysmal subarachnoid hemorrhage (aSAH). Early clinical observations and indirect experimental evidence suggested an association between inflammation and chronic vasospasm. Early clinical observations in patients with post-hemorrhagic vasospasm included pyrexia, leukocytosis and the presence of circulating immune complexes. Inflammatory infiltrates and increased levels of immunoglobulins and complement fractions within spastic cerebral arteries also provided early evidence for an inflammatory mechanism underlying chronic vasospasm. Early indirect experimental evidence included the ability to reproduce chronic vasospasm with the introduction of inflammatory agents into the subarachnoid space and the inhibition of vasospasm with anti-inflammatory agents. Currently, however, there is an increasing body of direct molecular evidence that demonstrates the pivotal role of leukocyte-endothelial cell interactions in the development of chronic vasospasm. Cell adhesion molecules such as intercellular adhesion molecule-1 (ICAM-1), lymphocyte function-associated antigen-1 (LFA-1), macrophage antigen-1 (Mac-1) and endothelial (E)-selectin mediate interactions between circulating leukocytes and cerebral endothelium. Following aSAH, ICAM-1 is up-regulated in cerebral endothelial cells and along with other cell adhesion molecules, can be detected in the serum and cerebrospinal fluid (CSF) of patients with post-hemorrhagic vasospasm. Monoclonal antibody blocking experiments have demonstrated that the prevention of leukocyte extravasation into the subarachnoid space prevents chronic vasospasm. Similarly, drugs like ibuprofen, which prevent ICAM-1 up-regulation and transendothelial cell migration of leukocytes, prevent vasospasm. In this review, we highlight early observations that suggested an association between inflammation and post-hemorrhagic vasospasm, detail the role of leukocyte-endothelial cell interactions in the development of chronic vasospasm and discuss therapeutic implications of an inflammatory etiology of post-hemorrhagic cerebral vasospasm.

Thromboembolism and delayed cerebral ischemia after subarachnoid hemorrhage: an autopsy study

OBJECTIVE

Recent findings have cast doubt on vasospasm as the sole cause of delayed cerebral ischemia after subarachnoid hemorrhage.

METHODS

We reviewed the medical records of 29 patients who died after subarachnoid hemorrhage. Brain sections were taken from the insula, cingulate gyrus, and hippocampus. Adjacent sections were stained with hematoxylin-eosin and immunostained for thromboemboli. The density (burden) of the latter was calculated blindly and correlated with evidence for ischemia and with the amount of subarachnoid blood.

RESULTS

There is a strong correlation between microclot burden and delayed cerebral ischemia. Patients with clinical or radiological evidence of delayed ischemia had mean microclot burdens of 10.0/cm2 (standard deviation [SD], +/-6.6); those without had mean burdens of 2.8 (SD, +/-2.6), a highly significant difference (P = 0.002). There is also significant association (P = 0.001) between microclot burden and histological evidence of ischemia, with the mean burdens being 10.9 in sections exhibiting severe ischemia and 4.1 in those in which ischemia was absent. Microclot burden is high in patients who died within 2 days of hemorrhage, decreasing on Days 3 and 4. In delayed ischemia, the numbers rise again late in the first week and remain high until after the second week. In contrast, the average clot burden is low in patients dying without developing delayed ischemia. The amount of blood on an individual slide influenced the microclot burden on that slide to a highly significant extent (P < 0.001).

CONCLUSION

Thromboembolism after subarachnoid hemorrhage may contribute to delayed cerebral ischemia, which parallels that caused by vasospasm. The pathogenesis of thromboembolism is discussed.

Vasospasm as the sole cause of cerebral ischemia: how strong is the evidence?

✓ The authors review literature that challenges the view that vasospasm involving large arteries is the exclusive cause of delayed ischemic neurological deficits (DINDs) following subarachnoid hemorrhage. They discuss alternative mechanisms and review the evidence supporting a potential role for thromboembolism. They conclude that vasospasm and thromboembolism play interrelated and additive roles in the development of DINDs, and that this interaction provides opportunities for novel therapeutic approaches.

A review of current and future medical therapies for cerebral vasospasm following aneurysmal subarachnoid hemorrhage

✓In an effort to help clarify the current state of medical therapy for cerebral vasospasm, the authors reviewed the relevant literature on the established medical therapies used for cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH), and they discuss burgeoning areas of investigation. Despite advances in the treatment of aneurysmal SAH, cerebral vasospasm remains a common complication and has been correlated with a 1.5- to threefold increase in death during the first 2 weeks after hemorrhage. A number of medical, pharmacological, and surgical therapies are currently in use or being investigated in an attempt to reverse cerebral vasospasm, but only a few have proven to be useful. Although much has been elucidated regarding its pathophysiology, the treatment of cerebral vasospasm remains a dilemma. Although a poor understanding of SAH-induced cerebral vasospasm pathophysiology has, to date, hampered the development of therapeutic interventions, current research efforts promise the eventual production of new medical therapies.