Increased blood coagulation is associated with poor neurological outcome in aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Patients with aneurysmal subarachnoid hemorrhage (aSAH) have demonstrated increased blood coagulation which is thought to contribute to delayed cerebral ischemia (DCI) and to a worse outcome. Therefore, we sought to determine whether this increased blood coagulation, detectable with rotational thromboelastometry (ROTEM), was associated with DCI and neurological outcome. METHODS: We conducted a prospective observational study of 60 consecutive adult aSAH patients. ROTEM's EXTEM and FIBTEM assays and D-dimer were analyzed at admission and post-bleed days (PBDs) 2-3, 4-5, 7-8, and 11-12. ROTEM's clot formation time (CFT) represents the stabilization of the clot, and the maximum clot firmness (MCF) the maximum clot strength. Glasgow Outcome Scale extended (GOSe) at three months determined the neurological outcome. RESULTS: DCI incidence was 41.7%. EXTEM-CFT was significantly shorter in patients with unfavorable neurological outcome (GOSe 1-4) on PBDs 4-5 and 7-8, p < 0.05, respectively. FIBTEM-MCF was significantly higher in patients with unfavorable neurological outcomes on PBD 4-5 (p < 0.05), PBD 7-8 (p < 0.05), and PBD 11-12 (p < 0.05). EXTEM-CFT decreased, and FIBTEM-MCF rose during the study period in all patients. Patients with unfavorable neurological outcome had a higher D-dimer at all studied time points, p < 0.05. No difference was found in the ROTEM parameters or D-dimer when assessing patients with and without DCI. CONCLUSIONS: Patients were in a state of increased blood coagulation after aSAH, with those with unfavorable neurological outcome being more coagulable than those with favorable outcome. However, increased blood coagulation was not associated with DCI. CLINICALTRIALS: gov, NCT03985176.

Platelet count is not associated with delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage as defined by the 2010 consensus definition.

BACKGROUND: Although delayed cerebral ischemia (DCI) commonly complicates recovery in survivors of aneurysmal subarachnoid hemorrhage (aSAH), its pathophysiology is incompletely understood. Previous studies examining the association of DCI and platelet count have demonstrated contradictory results. This study aimed to investigate this association in a cohort of aSAH patients using the 2010 consensus definition of DCI. METHODS: We conducted a retrospective single-center observational study of consecutive adult aSAH patients admitted to the intensive care unit from January 2010 to December 2014. Platelet count and DCI evaluations were performed daily in the first 14 days after admission. DCI was defined according to the 2010 consensus criteria. RESULTS: A total of 340 patients were included for analysis. DCI incidence was 37.1%. Platelet count was not significantly associated with occurrence of DCI on any day. Mean platelet count was lowest on day 3 after aSAH and then increased to exceed the count at admission on day 6. Treatment modality and use of dual antiplatelet therapy were not associated with DCI. CONCLUSIONS: Platelet count was not associated with DCI as defined by the 2010 consensus criteria. Future studies adhering to the 2010 consensus definition of DCI are needed to clarify the role of platelets and platelet function in DCI pathophysiology.

A kainic acid-induced seizure model in human pluripotent stem cell-derived cortical neurons for studying the role of IL-6 in the functional activity.

Human pluripotent stem cell (hPSC)-derived neural cultures have attracted interest for modeling epilepsy and seizure-like activity in vitro. Clinical and experimental evidence have shown that the multifunctional inflammatory cytokine interleukin (IL)-6 plays a significant role in epilepsy. However, the role of IL-6 in neuronal networks remains unclear. In this study, we modelled seizure-like activity in hPSC-derived cortical neurons using kainic acid (KA) and explored the effects of IL-6 and its counterpart, hyper-IL-6 (H-IL-6), a fusion protein consisting of IL-6 and its soluble receptor, IL-6R. In the seizure-like model, functionally mature neuronal networks responded to KA induction with an increased bursting phenotype at the single electrode level, while network level bursts decreased. The IL-6 receptors, IL6R and gp130, were expressed in hPSC-derived cortical neurons, and the gene expression of IL6R increased during maturation. Furthermore, the expression of IL-6R increased not only after IL-6 and H-IL-6 treatment but also after KA treatment. Stimulation with IL-6 or H-IL-6 was not toxic to the neurons and cytokine pretreatment did not independently modulate neuronal network activity or KA-induced seizures. Furthermore, the increased expression of IL-6R in response to IL-6, H-IL-6 and KA implies that neurons can respond through both classical and trans-signaling pathways. Acute treatment with IL-6 and H-IL-6 did not alter functional activity, suggesting that IL-6 does not affect the induction or modulation of newly induced seizures in healthy cultures. Overall, we propose this model as a useful tool to study seizure-like activity in neuronal networks in vitro.

Prognostic value of the 2010 consensus definition of delayed cerebral ischemia after aneurysmal subarachnoid hemorrhage.

BACKGROUND AND PURPOSE: Delayed cerebral ischemia (DCI) complicates the recovery of approximately 30% of patients with aneurysmal subarachnoid hemorrhage (aSAH). The definition of DCI widely varies, even though a consensus definition has been recommended since 2010. This study aimed to evaluate the prognostic value of the 2010 consensus definition of DCI in a cohort of patients with aSAH. METHODS: We conducted a single-center, retrospective, observational study that included consecutive adult patients with aSAH who were admitted to the intensive care unit from January 2010 to December 2014. DCI was evaluated 48 h to 14 days after onset of aSAH symptoms using the 2010 consensus criteria and outcome was assessed by the Glasgow Outcome Scale (GOS) at discharge from hospital. RESULTS: A total of 340 patients were analyzed and the incidence of DCI was 37.1%. The median time from primary hemorrhage to the occurrence of DCI was 97 h. Neurological deterioration was observed in most (89.7%) of the patients who fulfilled the DCI criteria. The occurrence of DCI was strongly associated with an unfavorable outcome (GOS 1-3) at hospital discharge (OR 2.65, 95% CI 1.69-4.22, p < 0.001). CONCLUSIONS: The incidence of DCI after aSAH is high and its occurrence is strongly associated with an unfavorable neurological outcome. This finding adds to the previous literature, which has shown that DCI appears to be a major contributor affecting the functional ability of survivors of aSAH. To further advance reliable knowledge of DCI, future studies should adhere to the consensus definition of DCI.

S100B, NSE and MMP-9 fail to predict neurologic outcome while elevated S100B associates with milder initial clinical presentation after aneurysmal subarachnoid hemorrhage.

OBJECTIVE: Despite advances in the treatment of aneurysmal subarachnoid hemorrhage (aSAH) one-year mortality remains approximately 50%. Making an accurate prognosis at the early phase of the disease is notoriously difficult. A clinically reliable biomarker that could be used for better prediction of prognosis and/or as a surrogate for developing complications after aSAH is still lacking. In this study, we evaluated the prognostic values of three promising biomarkers, i.e. S100B, NSE, and MMP-9 in aSAH. METHODS: In this prospective population-based study, S100B, NSE, and MMP-9 levels were measured in 47 aSAH patients for up to five days. Blood samples were taken at 0, 12 and 24 h after the admission to the intensive care unit (ICU) and daily after that until the patient was transferred from the ICU. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at six months after aSAH. RESULTS: Biomarker-levels measured during the first 24 h were not associated with neurological outcome. S100B levels during the first 24 h were elevated in patients with a non-severe initial clinical presentation. Otherwise, there was no association between selected clinical variables and the early biomarker levels. In 22 patients, whose ICU follow-up lasted for up to five days, the total release of biomarkers was not associated with the neurological outcome. CONCLUSIONS: None of the measured biomarkers were associated with the neurological outcome evaluated at six months after aSAH. Elevated levels of S100B in patients with non-severe initial presentation suggest an adaptive role of this biomarker in aSAH. Based on our findings it is not advisable to use these biomarkers to guide clinical decision-making in patients with aSAH.

Time-courses of plasma IL-6 and HMGB-1 reflect initial severity of clinical presentation but do not predict poor neurologic outcome following subarachnoid hemorrhage.

OBJECTIVE: Patients with aneurysmal subarachnoid hemorrhage (aSAH) experience high mortality and morbidity. Neuroinflammation causes brain damage expansion after aSAH. Due to the complexity of the inflammatory response multiple biomarkers are needed to evaluate its' progression. We studied inflammatory process after aSAH by measuring two inflammatory biomarkers, interleukin-6 (IL-6) and high-mobility group box 1 (HMGB1) at simultaneous time-points after aSAH. METHODS: In this prospective population-based study, IL-6 and HMGB1 were measured in aSAH patients (n = 47) for up to five days. Plasma concentrations of IL-6 and HMGB1 were measured at 0, 12 and 24 h after hospital admission, and thereafter daily for up to five days or until the patient was transferred from the intensive care unit (ICU). The patients' neurological outcomes were evaluated with the modified Rankin Scale at six months after aSAH. RESULTS: A high IL-6 level during the first day after aSAH was associated with a severe initial clinical presentation (p = 0.002) and infection during follow-up (p = 0.031). The HMGB1 level did not associate with these parameters. There was no correlation between IL-6 and HMGB1 levels at any time point during the follow-up. The concentrations of IL-6 and HMGB1 were not associated with neurological outcome. CONCLUSIONS: High initial IL-6 values seem to reflect the intensity of the inflammatory response but not the brain damage per se. An early inflammatory response might even be beneficial since although elevated IL-6 levels were observed in patients with a more severe initial clinical presentation, they were not associated with neurological outcome. The lack of correlation between IL-6 and HMGB1 questions the role of macrophages in the process of the secretion of these inflammatory markers after aSAH, instead pointing to the activation of alternative pro-inflammatory pathways.

Plasma Soluble Urokinase-Type Plasminogen Activator Receptor Is Not Associated with Neurological Outcome in Patients with Aneurysmal Subarachnoid Hemorrhage.

OBJECT: Aneurysmal subarachnoid hemorrhage (aSAH) is a common cause of death or long-term disability. Despite advances in neurocritical care, there is still only a very limited ability to monitor the development of secondary brain injury or to predict neurological outcome after aSAH. Soluble urokinase-type plasminogen activator receptor (suPAR) has shown potential as a prognostic and as an inflammatory biomarker in a wide range of critical illnesses since it displays an association with overall immune system activation. This is the first time that suPAR has been evaluated as a prognostic biomarker in aSAH. METHODS: In this prospective population-based study, plasma suPAR levels were measured in aSAH patients (n = 47) for up to 5 days. suPAR was measured at 0, 12, and 24 h after patient admission to the intensive care unit (ICU) and daily thereafter until he/she was transferred from the ICU. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at 6 months after aSAH. RESULTS: suPAR levels (n = 47) during the first 24 h after aSAH were comparable in groups with a favorable (mRS 0-2) or an unfavorable (mRS 3-6) outcome. suPAR levels during the first 24 h were not associated with the findings in the primary brain CT, with acute hydrocephalus, or with antimicrobial medication use during 5-days' follow-up. suPAR levels were associated with generally accepted inflammatory biomarkers (C-reactive protein, leukocyte count). CONCLUSION: Plasma suPAR level was not associated with either neurological outcome or selected clinical conditions. While suPAR is a promising biomarker for prognostication in several conditions requiring intensive care, it did not reveal any value as a prognostic biomarker after aSAH.

Increased plasma UCH-L1 after aneurysmal subarachnoid hemorrhage is associated with unfavorable neurological outcome.

OBJECTIVE: Aneurysmal subarachnoid hemorrhage (aSAH) is a common cause of long-term disability and death. After primary hemorrhage, secondary brain injury is the main cause of mortality and morbidity. Despite extensive research, reliable prognostic biomarkers are lacking. We measured ubiquitin carboxy-terminal hydrolase L1 (UCH-L1) levels in aSAH patients to evaluate its prognostic potential. This is the first time that plasma UCH-L1 has been studied as a potential prognostic biomarker in patients with aSAH. METHODS: In this prospective population-based study, UCH-L1 levels were measured in aSAH patients (n=47) for up to five days. UCH-L1 was measured at 0, 12 and 24h after the admission to the intensive care unit (ICU) and daily thereafter until the patient was transferred from the ICU. Only patients whose UCH-L1 was measured within 24h from aSAH were included in the study. The patients' neurological outcome was evaluated with the modified Rankin Scale (mRS) at six months after aSAH. RESULTS: UCH-L1 levels during the first 24h after aSAH were not significantly different between the groups with favorable (mRS 0-2) and unfavorable (mRS 3-6) neurological outcome. In 22 patients, UCH-L1 levels were obtained for up to five days. In this subgroup, UCH-L1 measured at day five showed significant elevation from baseline levels in patients with unfavorable outcome (p=0.026). Elevated UCH-L1 levels at day five were higher in patients with unfavorable outcome than in patients with favorable outcome (p=0.001). CONCLUSIONS: Elevated UCH-L1 levels during the five-day follow-up were associated with unfavorable neurological outcome. Repetitive measurements of UCH-L1 concentrations with an emphasis on change relative to the individual baseline could be the optimal approach for future clinical studies.

Healthy human CSF promotes glial differentiation of hESC-derived neural cells while retaining spontaneous activity in existing neuronal networks.

The possibilities of human pluripotent stem cell-derived neural cells from the basic research tool to a treatment option in regenerative medicine have been well recognized. These cells also offer an interesting tool for in vitro models of neuronal networks to be used for drug screening and neurotoxicological studies and for patient/disease specific in vitro models. Here, as aiming to develop a reductionistic in vitro human neuronal network model, we tested whether human embryonic stem cell (hESC)-derived neural cells could be cultured in human cerebrospinal fluid (CSF) in order to better mimic the in vivo conditions. Our results showed that CSF altered the differentiation of hESC-derived neural cells towards glial cells at the expense of neuronal differentiation. The proliferation rate was reduced in CSF cultures. However, even though the use of CSF as the culture medium altered the glial vs. neuronal differentiation rate, the pre-existing spontaneous activity of the neuronal networks persisted throughout the study. These results suggest that it is possible to develop fully human cell and culture-based environments that can further be modified for various in vitro modeling purposes.