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

Systemic Inflammation after Aneurysmal Subarachnoid Hemorrhage

Aneurysmal subarachnoid hemorrhage (aSAH) is one of the most severe neurological disorders, with a high mortality rate and severe disabling functional sequelae. Systemic inflammation following hemorrhagic stroke may play an important role in mediating intracranial and extracranial tissue damage. Previous studies showed that various systemic inflammatory biomarkers might be useful in predicting clinical outcomes. Anti-inflammatory treatment might be a promising therapeutic approach for improving the prognosis of patients with aSAH. This review summarizes the complicated interactions between the nervous system and the immune system.

A Comparison of LASSO Regression and Tree-Based Models for Delayed Cerebral Ischemia in Elderly Patients With Subarachnoid Hemorrhage

Backgrounds

As a most widely used machine learning method, tree-based algorithms have not been applied to predict delayed cerebral ischemia (DCI) in elderly patients with aneurysmal subarachnoid hemorrhage (aSAH). Hence, this study aims to develop the conventional regression and tree-based models and determine which model has better prediction performance for DCI development in hospitalized elderly patients after aSAH.

Methods

This was a multicenter, retrospective, observational cohort study analyzing elderly patients with aSAH aged 60 years and older. We randomly divided the multicentral data into model training and validation cohort in a ratio of 70–30%. One conventional regression and tree-based model, such as least absolute shrinkage and selection operator (LASSO), decision tree (DT), random forest (RF), and eXtreme Gradient Boosting (XGBoost), was developed. Accuracy, sensitivity, specificity, area under the precision-recall curve (AUC-PR), and area under the receiver operating characteristic curve (AUC-ROC) with 95% CI were employed to evaluate the model prediction performance. A DeLong test was conducted to calculate the statistical differences among models. Finally, we figured the importance weight of each feature to visualize the contribution on DCI.

Results

There were 111 and 42 patients in the model training and validation cohorts, and 53 cases developed DCI. According to AUC-ROC value in the model internal validation, DT of 0.836 (95% CI: 0.747–0.926, p = 0.15), RF of 1 (95% CI: 1–1, p < 0.05), and XGBoost of 0.931 (95% CI: 0.885–0.978, p = 0.01) outperformed LASSO of 0.793 (95% CI: 0.692–0.893). However, the LASSO scored a highest AUC-ROC value of 0.894 (95% CI: 0.8–0.989) than DT of 0.764 (95% CI: 0.6–0.928, p = 0.05), RF of 0.821 (95% CI: 0.683–0.959, p = 0.27), and XGBoost of 0.865 (95% CI: 0.751–0.979, p = 0.69) in independent external validation. Moreover, the LASSO had a highest AUC-PR value of 0.681 than DT of 0.615, RF of 0.667, and XGBoost of 0.622 in external validation. In addition, we found that CT values of subarachnoid clots, aneurysm therapy, and white blood cell counts were the most important features for DCI in elderly patients with aSAH.

Conclusions

The LASSO had a superior prediction power than tree-based models in external validation. As a result, we recommend the conventional LASSO regression model to predict DCI in elderly patients with aSAH.

Development and external validation of a dynamic nomogram for delayed cerebral ischaemia after aneurysmal subarachnoid hemorrhage: a study protocol for a multicentre retrospective cohort study

INTRODUCTION

Delayed cerebral ischaemia (DCI) caused by aneurysmal subarachnoid haemorrhage (aSAH) is the most frequent complication and typically contributes to poor neurological outcome or deterioration of patients' condition. Therefore, early accurate and effective prediction of DCI is urgently needed. This study aims to construct a dynamic nomogram for precisely calculating the risk of DCI in patients with aSAH. Internal validation of this tool is conducted using the training cohort, and independent external validation is completed by using other medical centre datasets.

METHODS AND ANALYSIS

This study is a multicentre, retrospective, observational cohort study using data from patients with aSAH. The participants include all adult patients who received surgical treatment in neurosurgery of multiple medical centres from 1 September 2019 to 1 April 2021, including Renmin Hospital of Wuhan University, Huzhou Central Hospital, First Affiliated Hospital of Harbin Medical University, General Hospital of Northern Theatre Command and Affiliated Hospital of Panzhihua University. Clinical information is collected via the electronic medical record system, including demographic data, clinical state on admission and serum laboratory tests. Modified Fisher grade at admission, admission subarachnoid clot and cerebral oedema density, and residual postoperative subarachnoid clot density are determined using the electronic imagine record software. The primary outcome is DCI.

ETHICS AND DISSEMINATION

This study protocol was reviewed and approved by the Medical Ethics Committee of Renmin Hospital of Wuhan University, which is the principal affiliation of this study (approval number: WDRM2021-K022). The other Ethics Committees, including Huzhou Central Hospital (approval number: 202108005-01), First Affiliated Hospital of Harbin Medical University (approval number: H202156), General Hospital of Northern Theater Command (approval number: Y2021060) and Affiliated Hospital of Panzhihua University (approval number: 202105002), also approved the protocol. The results of this research will be published in a peer-reviewed medical journal.

TRIAL REGISTRATION NUMBER

ChiCTR2100044448.

Predictive effects of admission white blood cell counts and hounsfield unit values on delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Neuroinflammatory response is deemed the primary pathogenesis of delayed cerebral ischemia (DCI) caused by aneurysmal subarachnoid hemorrhage (aSAH). Both white blood cell (WBC) count and Hounsfield Unit (HU) are gradually considered can reflect inflammation in DCI. This study aims to identify the relationship between WBC count and HU value and investigate the effects of both indicators in predicting DCI after aSAH.

METHODS

We enrolled 109 patients with aSAH admitted within 24 h of onset in our study. A multivariate logistic regression analysis was used to evaluate the admission WBC count, HU value, and combined WBC-HU associated with DCI. The receiver operating characteristic curve and area under the curve (AUC) were used to determine thresholds and detect the predictive ability of these predictors. These indicators were also compared with the established inflammation markers.

RESULTS

Thirty-six (33%) patients developed DCI. Both WBC count and HU value were strongly associated with the admission glucose level (ρ = .303, p = .001; ρ = .273, p = .004), World Federation of Neurosurgical Societies grade (ρ = .452, p < .001; ρ = .578; p < .001), Hunt-Hess grade (ρ = .450, p < .001; ρ = .510, p < .001), and modified Fisher scale score (ρ = .357, p < .001; ρ = .330, p < .001). After controlling these public variables, WBC count (ρ = .300, p = .002) positively correlated with HU value. An early elevated WBC (odds ratio [OR] 1.449, 95% confidence interval [CI]: 1.183-1.774, p < .001) count and HU value (OR 1.304, 95%CI: 1.149-1.479, p < .001) could independently predict the occurrence of DCI. However, only these patients with both WBC count and HU value exceeding the cut-off points (OR 36.89, 95%CI: 5.606-242.78, p < .001) were strongly correlated with DCI. Compared with a single WBC count (AUC 0.811, 95%CI: 0.729-0.892, p < .001) or HU value (AUC 0.869, 95%CI: 0.803-0.936, p < .001), the combined WBC-HU (AUC 0.898, 95%CI: 0.839-0.957, p < .001) demonstrated a better ability to predict the occurrence of DCI. Inspiringly, the prediction performance of these indicators outperformed the established inflammatory markers.

CONCLUSION

An early elevated WBC count and HU value could independently predict DCI occurrence between 4 and 30 days after aSAH. Furthermore, WBC count was positively correlated with HU value, and the combined WBC-HU demonstrated a superior prediction ability for DCI development compared with the individual indicator.

Plasma Levels of IL-6, IL-8, IL-10, ICAM-1, VCAM-1, IFNγ, and TNFα are not Associated with Delayed Cerebral Ischemia, Cerebral Vasospasm, or Clinical Outcome in Patients with Subarachnoid Hemorrhage

BACKGROUND

Delayed cerebral ischemia (DCI) is a serious and frequent complication following subarachnoid hemorrhage (SAH). The pathophysiology behind DCI remains poorly understood, but inflammation has been proposed to play a significant role. This study investigated the relationship between plasma levels of some of the most important inflammatory markers and DCI, cerebral vasospasm, and functional outcome in patients with SAH.

METHODS

In 90 patients with SAH, interleukin-6, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, high sensitivity C-reactive protein (HsCRP), interleukin-8, interleukin-10, interferon gamma, and tumor necrosis factor alpha were measured in peripheral blood day 3 and day 8 after SAH. Any occurrence of DCI or infection was recorded, and computed tomography angiography was performed on day 8. Clinical outcome was assessed after 3 months.

RESULTS

HsCRP on day 3 was higher in patients with angiographic vasospasm (P = 0.003), and HsCRP on day 8 was higher in patients with poor outcome (P = 0.014). No association with DCI, vasospasm, or outcome was found for any of the remaining analyzed substances.

CONCLUSIONS

High plasma levels of HsCRP were significantly associated with angiographic vasospasm and clinical outcome. Plasma levels of interleukin-6, vascular cell adhesion molecule-1, intercellular adhesion molecule-1, interleukin-8, interleukin-10, interferon gamma, and tumor necrosis factor alpha were not associated with DCI, angiographic vasospasm, or clinical outcome at 3 months.

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.

Neurocognitive outcomes after aneurysmal subarachnoid hemorrhage: Identifying inflammatory biomarkers

Aneurysmal subarachnoid hemorrhage (aSAH) is a severe type of stroke which carries a high case-fatality rate. Those who survive the ictus of aneurysm rupture harbor substantial risks of neurological morbidity, functional disability, and cognitive dysfunction. Although the pervasiveness of cognitive impairment is widely acknowledged as a long-term sequela of aSAH, the mechanisms underlying its development are poorly understood. The onset of aSAH elicits activation of the inflammatory cascade, and ongoing neuroinflammation is suspected to contribute to secondary complications, such as vasospasm and delayed cerebral ischemia. In this review, we analyze the extant literature regarding the relationship between neuroinflammation and cognitive dysfunction after aSAH. Pro-inflammatory cytokines appear to play a role in maintaining normal cognitive function in adults unaffected by aSAH. However, in the setting of aSAH, elevated cytokine levels may correlate with worse neuropsychological outcomes. This seemingly dichotomous relationship between neuroinflammation and cognition suggests that the action of cytokines varies, depending on their physiologic environment. Experimental therapies which suppress the immune response to aSAH appear to have a beneficial effect on cognitive outcomes. However, further studies are necessary to determine the utility of inflammatory mediators as biomarkers of neurocognitive outcomes, as well as their role in the management of aSAH.

Inhibition of myeloid differentiation primary response protein 88 provides neuroprotection in early brain injury following experimental subarachnoid hemorrhage

Accumulating of evidence suggests that activation of nuclear factor-kappa B (NF-κB) and mitogen-activated protein kinases (MAPKs) exacerbates early brain injury (EBI) following subarachnoid hemorrhage (SAH) by provoking pro-inflammatory and pro-apoptotic signaling. Myeloid differentiation primary response protein 88 (MyD88) is an endogenous adaptor protein in the toll-like receptors (TLRs) and interleukin (IL) -1β family signaling pathways and acts as a bottle neck in the NF-κB and MAPK pathways. Here, we used ST2825, a selective inhibitor of MyD88, to clarify whether inhibiting MyD88 could provide neuroprotection in EBI following SAH. Our results showed that the expression of MyD88 was markedly increased at 24 h post SAH. Intracerebroventricular injection of ST2825 significantly reduced the expression of MyD88 at 24 h post SAH. Involvement of MAPKs and NF-κB signaling pathways was revealed that ST2825 inhibited SAH-induced phosphorylation of TAK1, p38 and JNK, the nuclear translocation of NF-κB p65, and degradation of IκBα. Further, ST2825 administration diminished the SAH-induced inflammatory response and apoptosis. As a result, SAH-induced EBI was alleviated and neurological deficits caused by SAH were reversed. Our findings suggest that MyD88 inhibition confers marked neuroprotection against EBI following SAH. Therefore, MyD88 might be a promising new molecular target for the treatment of SAH.

The Role of Thromboinflammation in Delayed Cerebral Ischemia after Subarachnoid Hemorrhage

Delayed cerebral ischemia (DCI) is a major determinant of patient outcome following aneurysmal subarachnoid hemorrhage. Although the exact mechanisms leading to DCI are not fully known, inflammation, cerebral vasospasm, and microthrombi may all function together to mediate the onset of DCI. Indeed, inflammation is tightly linked with activation of coagulation and microthrombi formation. Thromboinflammation is the intersection at which inflammation and thrombosis regulate one another in a feedforward manner, potentiating the formation of thrombi and pro-inflammatory signaling. In this review, we will explore the role(s) of inflammation and microthrombi in subarachnoid hemorrhage (SAH) pathophysiology and DCI, and discuss the potential of targeting thromboinflammation to prevent DCI after SAH.

The role of nitric oxide in stroke

Stroke is considered to be an acute cerebrovascular disease, including ischemic stroke and hemorrhagic stroke. The high incidence and poor prognosis of stroke suggest that it is a highly disabling and highly lethal disease which can pose a serious threat to human health. Nitric oxide (NO), a common gas in nature, which is often thought as a toxic gas, because of its intimate relationship with the pathological processes of many diseases, especially in the regulation of blood flow and cell inflammation. However, recent years have witnessed an increased interest that NO plays a significant and positive role in stroke as an essential gas signal molecule. In view of the fact that the neuroprotective effect of NO is closely related to its concentration, cell type and time, only in the appropriate circumstances can NO play a protective effect. The purpose of this review is to summarize the roles of NO in ischemic stroke and hemorrhagic stroke.

Early Diagnosis of Delayed Cerebral Ischemia: Possible Relevance for Inflammatory Biomarkers in Routine Clinical Practice?

BACKGROUND

Delayed cerebral ischemia (DCI) after subarachnoid hemorrhage (SAH) is one of the main causes of neurologic deterioration. However, it frequently evades timely detection. Early identification and effective reversal may improve the clinical outcome. In this prospective study, we evaluate several serum inflammatory markers after aneurysmal SAH with regard to the occurrence of DCI.

METHODS

On days 1, 4, 7, 10, and 14 after SAH, leucocyte count, C-reactive protein, interleukin 6, E-selectin, matrix metallopeptidase 9, intercellular adhesion molecule 1, and leukemia inhibitory factor were assessed in patients' serum samples. Using a Cox regression model (SPSS 21.0), associations of baseline parameters, maximum and delta (maximum minus baseline) values with occurrence of DCI were evaluated.

RESULTS

Considering the assessed parameters, leucocyte count (high baseline and delta values) matches most closely with occurrence of DCI. Although baseline levels of C-reactive protein are also associated with occurrence of DCI, neither maximum (only on a borderline level) nor delta levels do so.

CONCLUSIONS

Our data analysis identified leucocyte count as the parameter most likely associated with occurrence of DCI. However, because of its lack of specificity leucocyte count, it cannot be used as a biomarker. As hypothesized earlier, the results indicate a possible involvement of the inflammatory reaction after aneurysmal SAH in the pathomechanism of DCI.

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.

Soluble intercellular adhesion molecule-1: a potential biomarker for pain intensity in chronic pain patients

AIM

Pain therapy is strongly guided by patients' self-reporting. However, when self-reporting is not an option, pain assessment becomes a challenge and may lead to undertreatment of painful conditions. Pain is a complex and multifactorial phenomenon. Recent work has connected pain pathophysiology also with the inflammatory system. We therefore hypothesized that pain intensity could be predicted by cytokine-levels.

PATIENTS & METHODS

In this observational, single-center study, we investigated 30 serum cytokines to predict pain intensity in a screening/follow-up set of 95 chronic pain patients and controls. We then prospectively validated soluble intercellular adhesion molecule-1 (sICAM-1)'s discriminatory capability (n = 21).

RESULTS & CONCLUSION

sICAM-1 was significantly associated with patient-reported pain intensity and yielded differential serum levels in patients of varying degrees of pain intensity. Changes in pain ratings over time correlated with changes in sICAM-1 levels. Our findings suggest the possibility of a clinical use of sICAM-1 as a potential biomarker for pain intensity.

Heart Rate Variability for the Early Detection of Delayed Cerebral Ischemia

Delayed cerebral ischemia is considered the leading cause of death or major disability in subarachnoid hemorrhage after the impact of the initial event and rebleeding. Waiting to treat patients until they exhibit clinical symptoms of ischemia is too late to prevent cerebral infarction for more than 60% of patients, and transcranial Doppler ultrasonography has not proven to be a reliable screening tool to identify high-risk patients. Continuous heart rate variability monitoring may provide an alternative screening strategy to identify patients at high risk for delayed cerebral ischemia. Heart rate variability is a composite reflection of autonomic outflow, neuroendocrine influences, and autonomic responsiveness. Most importantly, heart rate variability is responsive to changes in systemic inflammation, which evidence suggests is important to the causal pathway of delayed cerebral ischemia. The clinical application of continuous heart rate variability monitoring in critical care is relatively recent despite its existence for more than 50 years. Initial studies suggest promise for heart rate variability monitoring as a delayed cerebral ischemia screening tool, but significant research is still required before this approach may achieve clinical applicability and bring benefit to patients.

The Potential Therapeutic Effects of Artesunate on Stroke and Other Central Nervous System Diseases

Artesunate is an important agent for cerebral malaria and all kinds of other severe malaria because it is highly efficient, lowly toxic, and well-tolerated. Loads of research pointed out that it had widespread pharmacological activities such as antiparasites, antitumor, anti-inflammation, antimicrobes activities. As we know, the occurrence and development of neurological disorders usually refer to intricate pathophysiologic mechanisms and multiple etiopathogenesis. Recent progress has also demonstrated that drugs with single mechanism and serious side-effects are not likely the candidates for treatment of the neurological disorders. Therefore, the pluripotent action of artesunate may result in it playing an important role in the prevention and treatment of these neurological disorders. This review provides an overview of primary pharmacological mechanism of artesunate and its potential therapeutic effects on neurological disorders. Meanwhile, we also briefly summarize the primary mechanisms of artemisinin and its derivatives. We hope that, with the evidence presented in this review, the effect of artesunate in prevention and curing for neurological disorders can be further explored and studied in the foreseeable future.

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.

Valproic acid attenuates intercellular adhesion molecule-1 and E-selectin through a chemokine ligand 5 dependent mechanism and subarachnoid hemorrhage induced vasospasm in a rat model

BACKGROUND

Up-regulation of regulated upon activation, normal T-cell expressed and secreted (RANTES/CCL5) and adhesion molecules is observed in the serum of animals following experimental subarachnoid hemorrhage (SAH). The present study was to examine the effect of valproic acid (VPA) on RANTES and alternation of adhesion molecules in this model.

METHODS

A rodent SAH model was employed. Animals were randomly assigned into six groups. Basilar artery (BA) was harvested for intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and E-selectin evaluation (western blotting) and RANTES (rt-PCR). 1 ng CCL5 recombinant protein intrathecal injection was performed in the VPA + SAH groups. (N = 5).

RESULTS

Convoluted internal elastic lamina, distorted endothelial wall, and smooth muscle micro-necrosis was prominently observed in the SAH groups, which is absent in the VPA treatment and the healthy controls. Treatment with VPA dose-dependently reduced the ICAM-1, E-selectin and RANTES level, compared with the SAH group (p <0.01). The administration of CCL5 significantly increased CD45(+) glia and ICAM-1 level in the VPA treatment groups.

CONCLUSION

VPA exerts its anti-vasospastic effect through the dual effect of inhibiting RANTES expression and reduced adhesion molecules. Besides, VPA also decreased CD45(+) cells transmigrated to the vascular wall. The administration of CCL5 significantly reversed the inhibitory effect of this compound on CD45(+) monocytes, E-selectin, and ICAM-1 level. This study also lends credence to support this compound could attenuate SAH induced adhesion molecules and neuro-inflammation in a CCL5 dependent mechanism.

Curcumin, encapsulated in nano-sized PLGA, down-regulates nuclear factor κB (p65) and subarachnoid hemorrhage induced early brain injury in a rat model

BACKGROUND

More and more evidence revealed early brain injury (EBI) may determine the final outcome in aneurismal subarachnoid hemorrhage (SAH) patients. This study is of interest to examine the efficacy of nano-particle curcumin (nanocurcumin), a diarylheptanoid, on a SAH-induced EBI model.

METHODS

A rodent double hemorrhage model was employed. Nanocurcumin (75/150/300μg/kg/day) was administered via osmotic mini-pump post-SAH. CSF samples were collected to examine IL-1β, IL-6, IL-8 and TNF-α (rt-PCR). Cerebral cortex was harvested for NF-κB (p50/p65) (western blot), caspases (rt-PCR) measurement.

RESULTS

Nanocurcumin significantly reduced the bio-expression of NF-κB (p65), when compared with the SAH groups. The levels of IL-1β and IL-6 were increased in animals subjected to SAH, compared with the healthy controls, but absent in the high dose nanocurcumin+SAH group. Moreover, the levels of TNF-α in the SAH groups were significantly elevated. Treatment with nanocurcumin (300μg/kg) reduced the level to the healthy control. The cleaved caspase-3 and -9a was significantly reduced in 300μg/kg nanocurcumin treatment groups (P<0.05).

CONCLUSION

Treatment with nanocurcumin exerts its neuroprotective effect through the upward regulation of NF-κB (p65) and also reduced mitochondrion related caspase-9a expression. Besides, nanocurcumin decreased CSF levels of TNF-α and IL-1β, which may contribute to the extrinsic antiapoptotic effect. This study shows promise to support curcuminin, in a nano-particle, could attenuate SAH induced EBI.

Heart rate variability for preclinical detection of secondary complications after subarachnoid hemorrhage

BACKGROUND

We sought to determine if monitoring heart rate variability (HRV) would enable preclinical detection of secondary complications after subarachnoid hemorrhage (SAH).

METHODS

We studied 236 SAH patients admitted within the first 48 h of bleed onset, discharged after SAH day 5, and had continuous electrocardiogram records available. The diagnosis and date of onset of infections and DCI events were prospectively adjudicated and documented by the clinical team. Continuous ECG was collected at 240 Hz using a high-resolution data acquisition system. The Tompkins-Hamilton algorithm was used to identify R-R intervals excluding ectopic and abnormal beats. Time, frequency, and regularity domain calculations of HRV were generated over the first 48 h of ICU admission and 24 h prior to the onset of each patient's first complication, or SAH day 6 for control patients. Clinical prediction rules to identify infection and DCI events were developed using bootstrap aggregation and cost-sensitive meta-classifiers.

RESULTS

The combined infection and DCI model predicted events 24 h prior to clinical onset with high sensitivity (87 %) and moderate specificity (66 %), and was more sensitive than models that predicted either infection or DCI. Models including clinical and HRV variables together substantially improved diagnostic accuracy (AUC 0.83) compared to models with only HRV variables (AUC 0.61).

CONCLUSIONS

Changes in HRV after SAH reflect both delayed ischemic and infectious complications. Incorporation of concurrent disease severity measures substantially improves prediction compared to using HRV alone. Further research is needed to refine and prospectively evaluate real-time bedside HRV monitoring 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.

Controversies and evolving new mechanisms in subarachnoid hemorrhage

Despite decades of study, subarachnoid hemorrhage (SAH) continues to be a serious and significant health problem in the United States and worldwide. The mechanisms contributing to brain injury after SAH remain unclear. Traditionally, most in vivo research has heavily emphasized the basic mechanisms of SAH over the pathophysiological or morphological changes of delayed cerebral vasospasm after SAH. Unfortunately, the results of clinical trials based on this premise have mostly been disappointing, implicating some other pathophysiological factors, independent of vasospasm, as contributors to poor clinical outcomes. Delayed cerebral vasospasm is no longer the only culprit. In this review, we summarize recent data from both experimental and clinical studies of SAH and discuss the vast array of physiological dysfunctions following SAH that ultimately lead to cell death. Based on the progress in neurobiological understanding of SAH, the terms "early brain injury" and "delayed brain injury" are used according to the temporal progression of SAH-induced brain injury. Additionally, a new concept of the vasculo-neuronal-glia triad model for SAH study is highlighted and presents the challenges and opportunities of this model for future SAH applications.

The endothelium, a protagonist in the pathophysiology of critical illness: focus on cellular markers

The endotheliumis key in the pathophysiology of numerous diseases as a result of its precarious function in the regulation of tissue homeostasis. Therefore, its clinical evaluation providing diagnostic and prognostic markers, as well as its role as a therapeutic target, is the focus of intense research in patientswith severe illnesses. In the critically ill with sepsis and acute brain injury, the endothelium has a cardinal function in the development of organ failure and secondary ischemia, respectively. Cellular markers of endothelial function such as endothelial progenitor cells (EPC) and endothelialmicroparticles (EMP) are gaining interest as biomarkers due to their accessibility, although the lack of standardization of EPC and EMP detection remains a drawback for their routine clinical use. In this paper we will review data available on EPC, as a general marker of endothelial repair, and EMP as an equivalent of damage in critical illnesses, in particular sepsis and acute brain injury. Their determination has resulted in new insights into endothelial dysfunction in the critically ill. It remains speculative whether their determination might guide therapy in these devastating acute disorders in the near future.

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.

Current management of delayed cerebral ischemia: update from results of recent clinical trials

Subarachnoid hemorrhage (SAH) accounts for 5-7% of all strokes worldwide and is associated with high mortality and morbidity. Even after surgical intervention, approximately 30% of patients develop long-term cognitive and neurological deficits that significantly affect their capacity to return to work or daily life unassisted. Much of this stems from a secondary ischemic phenomenon referred to as delayed cerebral ischemia (DCI). While DCI has been historically attributed to the narrowing of the large basal cerebral arteries, it is now recognized that numerous pathways contribute to its pathogenesis, including microcirculatory dysfunction, microthrombosis, cortical spreading depression, and early brain injury. This paper seeks to summarize some of the key pathophysiological events that are associated with poor outcome after SAH, provide a general overview of current methods of treating SAH patients, and review the results of recent clinical trials directed at improving outcome after SAH. The scientific basis of these studies will be discussed, in addition to the available results and recommendations for effective patient management. Therapeutic methods under current clinical investigation will also be addressed. In particular, the mechanisms by which they are expected to elicit improved outcome will be investigated, as well as the specific study designs and anticipated time lines for completion.

Significance of C-reactive protein and transcranial Doppler in cerebral vasospasm following aneurysmal subarachnoid hemorrhage

Objective

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. C-reactive protein (CRP) constitutes a highly sensitive inflammatory marker. Elevation of serum CRP levels has been demonstrated in patients with aSAH. The purpose of the current study was to evaluate the possible relationship between CRP levels in the serum and transcranial Doppler (TCD) and the development of vasospasm in patients with aSAH.

Methods

A total of 61 adult patients in whom aSAH was diagnosed were included in the study from November 2008 to May 2011. The patients' demographics, Hunt and Hess grade, Fisher grade, CT scans, digital subtraction angiography studies, and daily neurological examinations were recorded. Serial serum CRP measurements were obtained on days 1, 3, 5, 7, 9, 11 and 13 and TCD was measured on days 3, 5, 7, 9, 11 and 13. All patients underwent either surgical or endovascular treatment within 24 hours of their hemorrhagic attacks.

Results

Serum CRP levels peaked on the 3rd postoperative day. There were significant differences between the vasospasm group and the non-vasospasm group on the 1st, 3rd and 5th day. There were significant differences between the vasospasm group and the non-vasospasm group on the 3rd day in the mean middle cerebral artery velocities on TCD.

Conclusion

Patients with high levels of CRP on the 1st postoperative day and high velocity of mean TCD on the 3rd postoperative day may require closer observation to monitor for the development of vasospasm.

Statins and anti-inflammatory therapies for subarachnoid hemorrhage

OPINION STATEMENT

Aneurysmal subarachnoid hemorrhage (SAH) induces a potent inflammatory cascade that contributes to endothelial dysfunction, imbalance of vasoactive substances (excess endothelin, depletion of nitric oxide), and arterial vasospasm. This process results in delayed cerebral ischemia, a major cause of neurologic disability in those surviving the initial hemorrhage. The only therapy shown to be effective in improving neurologic outcomes after SAH is a calcium-channel antagonist, nimodipine (although it achieved this result without reducing vasospasm). A number of novel therapies have been explored to inhibit the development of vasospasm and reduce the burden of ischemia and cerebral infarction. Statins are promising candidates, as they block multiple aspects of the inflammatory pathway that contributes to ischemic brain injury. Early clinical trials have produced conflicting results, however, and the adoption of statins in clinical practice should await the results of larger, more definitive studies. Though endothelin-receptor antagonists showed promise in significantly reducing vasospasm in preliminary trials, their failure to improve clinical outcomes in phase 3 studies has been disappointing, highlighting the complex link between vasospasm and ischemia. Future directions in the quest to improve outcomes of patients with SAH may need to approach ischemia as a multifactorial process with inflammatory, vasoactive, and ionic/metabolic components.

Purine anti-metabolite attenuates nuclear factor κB and related pro-inflammatory cytokines in experimental vasospasm

BACKGROUND

Increased nuclear factor κB (NF-κB) bioexpression, as well as TNF-α, IL-1β and IL-6 levels, were observed after aneurysmal subarachnoid hemorrhage (SAH). It is of interest to investigate the effect of 6-mercaptopurine (6-mp) on cytokines/NF-κB in this SAH model.

MATERIALS AND METHODS

A rodent double-hemorrhage SAH model was employed. Serum and cerebrospinal fluid (CSF) samples were collected to examine IL-1, IL-6 and TNF-α levels. NF-κB subunit p65 and its inhibitor of nuclear factor κB (IκB) were examined (by Western blot). TNF-α was used to induce the phosphorylation of IκB in the presence or absence of 6-mp.

RESULTS

Nuclear NF-κB subunit p65/IκB kinase in the basilar artery was over-expressed, and cytokines was notably increased in the SAH groups, compared with the controls (P < 0.01). In the 6-mp SAH group, obvious reduction was observed in NF-κB subunit p65 (nuclei) (P < 0.01). Treatment with 6-mp significantly reduced IL-1β and TNF-α levels to those of the healthy control. 6-Mercaptopurine also significantly increased the level of IκB in the TNF-α-stimulated SAH rats.

CONCLUSIONS

Through inhibiting IκB bioexpression, 6-mp decreases NF-κB-related IL-1β, IL-6, and TNF-α in the presence of SAH. The study suggests 6-mp exerts vascular anti-inflammatory properties through inhibiting IκB kinase and subsequently blocks bio-activation of NF-κB and related cytokines, which may contribute to its antivasospastic effect in animals subjected to SAH.

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.

C-reactive protein as predictor for poor outcome after aneurysmal subarachnoid haemorrhage

BACKGROUND

Aneurysmal subarachnoid haemorrhage (SAH) is a severe disease with high case-fatality and morbidity rates. After SAH, the value of C-reactive protein (CRP)--an acute phase sensitive inflammatory marker--as a prognostic factor has been poorly studied, with conflicting results. In this prospective study, we tested whether increased CRP levels increase independently the risk for cerebral infarct and poor outcome.

METHODS

Previous diseases as well as clinical, laboratory and radiological variables were recorded for 178 patients with SAH admitted within 48 h and with aneurysms occluded within 60 h after bleeding. Plasma CRP was measured, as well as computed tomography (CT) scans routinely obtained on admission, in the morning after aneurysm occlusion, and at discharge during second week after SAH. Factors predicting occurrence of cerebral infarct and poor outcome at 3 months after SAH were tested with multiple logistic regression.

RESULTS

CRP levels increased significantly (p < 0.001) between hospital admission (mean ± SD, 11.4 ± 21.3 mg/l) and the postoperative morning (27.0 ± 31.0 mg/l) and then decreased (p < 0.001) during the the second week (19.8 ± 25.0 mg/l). Admission (18.0 ± 35.7 vs 8.5 ± 8.4 mg/l) and postoperative (41.0 ± 40.2 vs 21.1 ± 24.1 mg/l) CRP levels were higher (p < 0.001) in those with a poor outcome than in those with a favourable outcome, but CRP values did not predict delayed cerebral ischaemia or cerebral infarction. CRP levels did not independently predict outcome, since these correlated with admission clinical grade and occurrence of intraventricular haemorrhage. Higher increase in CRP level between admission and postoperative morning, however, independently predicted poor outcome (p = 0.004). Part of this increased risk was likely due to an appearance of early postoperative cerebral infarction.

CONCLUSIONS

CRP levels correlate with outcome but do not seem to predict delayed cerebral ischaemia or infarction after SAH.

The association between symptomatic delayed cerebral infarction and serum adhesion molecules in aneurysmal subarachnoid hemorrhage

BACKGROUND

Serum concentrations of adhesion molecules may be connected to the pathogenesis of delayed cerebral infarction (DCI) after aneurysmal subarachnoid hemorrhage (SAH).

OBJECTIVE

To test the hypothesis that levels of adhesion molecules are substantially increased after DCI and decreased thereafter and that these levels can predict treatment outcomes.

METHODS

Serial circulating markers of adhesion molecules were examined in 21 consecutive SAH patients and 2 risk control subjects. All underwent cerebral angiography and magnetic resonance imaging to confirm the DCI. The timing of magnetic resonance imaging was fixed in the acute phase and before hospital discharge.

RESULTS

Symptomatic DCI developed in 33% of the patients (7 of 21). Statistical analysis of levels of adhesion molecules between patients with and those without DCI revealed that soluble (s) L-selectin, sP-selectin, and sE-selectin concentrations significantly increased after symptomatic DCI (P=.003, .013, and .043, respectively). Only higher sL-selectin level on presentation (cutoff value > 636 ng/mL) was significantly associated with poor outcome after 6 months of follow-up.

CONCLUSION

Increased sL-selectin, sP-selectin, and sE-selectin levels imply risks of symptomatic DCI after aneurysmal SAH. The high frequency of symptomatic DCI and higher sL-selectin level on presentation may be associated with worse outcomes.

Relationship between C-reactive protein, systemic oxygen consumption, and delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage

BACKGROUND AND PURPOSE

Subarachnoid hemorrhage (SAH) is known to result in elevated systemic oxygen consumption (Vo(2)) and increases in high-sensitivity C-reactive protein (hsCRP), although the relationship among hsCRP, Vo(2), and delayed cerebral ischemia (DCI) after SAH remains unknown. We hypothesized that hsCRP is directly associated with Vo(2) and that elevated Vo(2) is a predictor of DCI after SAH.

METHODS

Prospective serial assessments of Vo(2) and hsCRP over 4 prespecified time periods during the first 14 days after bleed in consecutive SAH patients admitted to a single academic medical center for a 2-year period.

RESULTS

One hundred ten SAH patients met study criteria (mean age, 55±16 years; 62% women), with a median admission Hunt Hess grade of 3 (interquartile range, 2-4). In multivariate generalized estimating equation model of the first 14 days after bleed, Vo(2) was associated with younger age (P=0.01), male gender (P=0.01), and hsCRP levels (P=0.03). Twenty-four (22%) patients had DCI develop, with a median onset on day 7 after bleed (interquartile range, 5-11). The mean Vo(2) (291±65 mL/min versus 226±55 mL/min; P=0.003) was higher in DCI patients. In a multivariable Cox proportional hazards model, younger age (hazard ratio, 1.2 per 5 years; 95% CI, 1.1-1.3), a higher modified Fisher scale score (hazard ratio, 3.4 per 1-point increase; 95% CI, 1.7-6.9), and higher Vo(2) (HR, 1.2 per 50-mL/min increase; 95% CI, 1.1-1.3) were predictive of DCI.

CONCLUSIONS

Systemic oxygen consumption is associated with hsCRP levels in the first 14 days after SAH and is an independent predictor of DCI.

6-Mercaptopurine reverses experimental vasospasm and alleviates the production of endothelins in NO-independent mechanism-a laboratory study

INTRODUCTION

Increased endothelin-1 (ET-1) production and diminished nitric oxide synthase (NOS) bioavailability has been observed in aneurysmal subarachnoid hemorrhage (SAH). The authors previously found that 6-mercaptopurine (6-mp) is effective in preventing and reversing arterial narrowing in a rodent SAH model. This present study is of interest to examine the effect of 6-mp on ET-1/endothelial nitric oxide synthase (eNOS) in this animal model.

METHODS

A rodent double hemorrhage SAH model was employed. Animals were randomly assigned to six groups (sham, SAH only, vehicle, 0.5, 1.0 and 2 mg kg(-1) day(-1) 6-mp treatment). Monoclonal CD45 immunostaining was utilized to evaluate monocytes and microglia. The level of pro-inflammatory cytokines, such as IL-1, IL-6 and TNF-α(RT-PCR), and ET-1 (ELISA) was measured. The basilar arteries (BAs) were harvested and sliced, and their cross-sectional areas were determined. Radiolabeled NOS assay kit was applied to detect eNOS.

RESULTS

Morphologically, convolution of internal elastic lamina, endothelial cells distortion, and necrotic smooth muscle were prevalently present in the basilar artery of SAH groups, which was absent in the 1 and 2 mg kg(-1) day(-1) 6-mp plus SAH group or the healthy controls. Significant vasospasm was noted in the vehicle group (lumen patency, 54.6%, p ≤ 0.01 compared with the sham group), but it was less prominent in the 2 mg kg(-1) day(-1) 6-mp treatment group (lumen patency, 87.6%, p < 0.05). In addition, administration with 2 mg kg(-1) day(-1) 6-mp reduced cytokine levels by 11%, 47%, and 34% for IL-1, IL-6, and TNF-α, respectively, and increased ET-1 levels were found in all the animals subject to SAH (SAH only, SAH plus vehicle, SAH plus 0.5 and 1.0 mg kg(-1) day(-1) 6-mp) except in the 2 mg kg(-1) day(-1) 6-mp SAH group, when compared with the healthy controls (no SAH). Meanwhile, treatment with 6-mp did not induce the levels of expressed eNOS in BAs in the 6-mp groups (0.5, 1.0, and 2 mg kg(-1) day(-1) 6-mp plus SAH) when compared with that in the SAH groups (p > 0.1).

CONCLUSION

In summary, treatment with 6-mp decreased the release of pro-inflammatory cytokines and diminished experimental vasospasm. This study offered first evidence that 6-mp dose-dependently reduces the level of ET-1 in a NO-independent mechanism, which corresponds to its antivasospastic effect in the condition of chronic vasospasm.

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.

Metamorphosis of subarachnoid hemorrhage research: from delayed vasospasm to early brain injury

Delayed vasospasm that develops 3–7 days after aneurysmal subarachnoid hemorrhage (SAH) has traditionally been considered the most important determinant of delayed ischemic injury and poor outcome. Consequently, most therapies against delayed ischemic injury are directed towards reducing the incidence of vasospasm. The clinical trials based on this strategy, however, have so far claimed limited success; the incidence of vasospasm is reduced without reduction in delayed ischemic injury or improvement in the long-term outcome. This fact has shifted research interest to the early brain injury (first 72 h) evoked by SAH. In recent years, several pathological mechanisms that activate within minutes after the initial bleed and lead to early brain injury are identified. In addition, it is found that many of these mechanisms evolve with time and participate in the pathogenesis of delayed ischemic injury and poor outcome. Therefore, a therapy or therapies focused on these early mechanisms may not only prevent the early brain injury but may also help reduce the intensity of later developing neurological complications. This manuscript reviews the pathological mechanisms of early brain injury after SAH and summarizes the status of current therapies.

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.