Early prediction of ventricular peritoneal shunt dependency in aneurysmal subarachnoid haemorrhage patients by recurrent neural network-based machine learning using routine intensive care unit data.

Aneurysmal subarachnoid haemorrhage (aSAH) can lead to complications such as acute hydrocephalic congestion. Treatment of this acute condition often includes establishing an external ventricular drainage (EVD). However, chronic hydrocephalus develops in some patients, who then require placement of a permanent ventriculoperitoneal (VP) shunt. The aim of this study was to employ recurrent neural network (RNN)-based machine learning techniques to identify patients who require VP shunt placement at an early stage. This retrospective single-centre study included all patients who were diagnosed with aSAH and treated in the intensive care unit (ICU) between November 2010 and May 2020 (n = 602). More than 120 parameters were analysed, including routine neurocritical care data, vital signs and blood gas analyses. Various machine learning techniques, including RNNs and gradient boosting machines, were evaluated for their ability to predict VP shunt dependency. VP-shunt dependency could be predicted using an RNN after just one day of ICU stay, with an AUC-ROC of 0.77 (CI: 0.75-0.79). The accuracy of the prediction improved after four days of observation (Day 4: AUC-ROC 0.81, CI: 0.79-0.84). At that point, the accuracy of the prediction was 76% (CI: 75.98-83.09%), with a sensitivity of 85% (CI: 83-88%) and a specificity of 74% (CI: 71-78%). RNN-based machine learning has the potential to predict VP shunt dependency on Day 4 after ictus in aSAH patients using routine data collected in the ICU. The use of machine learning may allow early identification of patients with specific therapeutic needs and accelerate the execution of required procedures.

A recurrent machine learning model predicts intracranial hypertension in neurointensive care patients.

The evolution of intracranial pressure (ICP) of critically ill patients admitted to a neurointensive care unit (ICU) is difficult to predict. Besides the underlying disease and compromised intracranial space, ICP is affected by a multitude of factors, many of which are monitored on the ICU, but the complexity of the resulting patterns limits their clinical use. This paves the way for new machine learning techniques to assist clinical management of patients undergoing invasive ICP monitoring independent of the underlying disease. An institutional cohort (ICP-ICU) of patients with invasive ICP monitoring (n = 1346) was used to train recurrent machine learning models to predict the occurrence of ICP increases of ≥22 mmHg over a long (>2 h) time period in the upcoming hours. External validation was performed on patients undergoing invasive ICP measurement in two publicly available datasets [Medical Information Mart for Intensive Care (MIMIC, n = 998) and eICU Collaborative Research Database (n = 1634)]. Different distances (1-24 h) between prediction time point and upcoming critical phase were evaluated, demonstrating a decrease in performance but still robust AUC-ROC with larger distances (24 h AUC-ROC: ICP-ICU 0.826 ± 0.0071, MIMIC 0.836 ± 0.0063, eICU 0.779 ± 0.0046, 1 h AUC-ROC: ICP-ICU 0.982 ± 0.0008, MIMIC 0.965 ± 0.0010, eICU 0.941 ± 0.0025). The model operates on sparse hourly data and is stable in handling variable input lengths and missingness through its nature of recurrence and internal memory. Calculation of gradient-based feature importance revealed individual underlying decisions for our long short time memory-based model and thereby provided improved clinical interpretability. Recurrent machine learning models have the potential to be an effective tool for the prediction of ICP increases with high translational potential.

Diffusion tensor imaging changes in patients with glioma-associated seizures.

INTRODUCTION: Structural white matter changes associated with certain epilepsy subtypes have been demonstrated using diffusion tensor imaging (DTI). This observational study aims to identify potential water diffusion abnormalities in glioma patients with associated seizures. METHODS: Two cohorts from two centers were analyzed independently: (A) Prospectively recruited patients diagnosed with glioma who received preoperative DTI to measure mean diffusivity (MD) and fractional anisotropy (FA) in regions-of-interest (ROIs) including the marginal tumor zone (TU), adjacent peritumoral white matter as well as distant ipsilateral and contralateral white matter and cortex. Data were compared between patients with and without seizures and tested for statistical significance. (B) A retrospective cohort using an alternative technical approach sampling ROIs in contrast enhancement, necrosis, non-enhancing tumor, marginal non-enhancing tumor zone, peritumoral tissue, edema and non-tumorous tissue. RESULTS: (A) The prospective study cohort consisted of 23 patients with 12 (52.2%) presenting with a history of seizures. There were no significant seizure-associated differences in MD or FA for non-tumor white matter or cortical areas. MD-TU was significantly lower in patients with seizures (p = 0.005). (B) In the retrospective cohort consisting of 46 patients with a seizure incidence of 50.0%, significantly decreased normalized values of MD were observed for non-enhancing tumor regions of non-glioblastoma multiforme (GBM) cases in patients with seizures (p = 0.022). CONCLUSION: DTI analyses in glioma patients demonstrated seizure-associated diffusion restrictions in certain tumor-related areas. No other structural abnormalities in adjacent or distant white matter or cortical regions were detected.

Hyperoxia is Dose-Dependently Associated with an Increase of Unfavorable Outcomes in Ventilated Patients with Aneurysmal Subarachnoid Hemorrhage: A Retrospective Cohort Study.

BACKGROUND: Adequate oxygenation in patients with aneurysmal subarachnoid hemorrhage (SAH) is imperative. However, hyperoxia increases formation of reactive oxygen species and may be associated with a dose-dependent toxicity. We postulated a threshold for arterial partial pressure of oxygen (paO2) above which toxicity effects precipitate and sought to study the effects on 30-day mortality, favorable outcome at discharge and at 3 months, and delayed cerebral ischemia. METHODS: In this retrospective single-center cohort study, patients with SAH and mechanical ventilation > 72 h were included. Oxygen integrals were calculated above the following thresholds: 80, 100, 120, and 150 mm Hg and time-weighted mean paO2. All calculations were done from admission to end of day 1, day 3, and day 14. We conducted multivariable logistic regression analyses adjusted for age, sex, duration of ventilation, and Hunt and Hess grade. Time-weighted mean paO2 was categorized by quartiles. Favorable outcome was defined as Glasgow Outcome Scale scores of 4 and 5. RESULTS: From November 2010 to February 2021, 282 of 549 patients fulfilled the inclusion criteria. Odds ratios for 30-day mortality increased dose dependently and were as follows: 1.07 (95% confidence interval [CI] 1.03-1.11; p = 0.001) for each 1 mm Hg per day above 80 mm Hg; 1.16 (95% CI 1.07-1.27), above 100 mm Hg; 1.36 (95% CI 1.15-1.61), above 120 mm Hg; and 1.59 (95% CI 1.22-2.08), above 150 mm Hg (all p < 0.001) at day 14. For favorable outcome at 3 months, odds ratios were 0.96 (95% CI 0.92-0.99) for each 1 mm Hg per day above 80 mm Hg; 0.90 (95% CI 0.84-0.98), above 100 mm Hg; 0.83 (95% CI 0.72-0.97), above 120 mm Hg; and 0.77 (95% CI 0.61-0.97), above 150 mm Hg (all p < 0.05). For time-weighted mean paO2, lowest 30-day mortality and highest favorable outcome at 3 months were found in the second quartile (78-85 mm Hg). Thirty-day mortality increased above 93 mm Hg (fourth quartile), with an odds ratio of 3.4 (95% CI 1.4-8.4, p = 0.007). Odds ratios for favorable outcome at 3 months were 0.28 (95% CI 0.12-0.69), 0.27 (95% CI 0.11-0.67), and 0.24 (95% CI 0.10-0.59) for the first, third, and fourth quartiles, respectively (all p < 0.01). No significant association was found at day 1 and day 3, for favorable outcome at discharge, or for delayed cerebral ischemia. CONCLUSIONS: Integrals above the defined paO2 thresholds were dose-dependently associated with an increase in mortality in ventilated patients with SAH. When we considered time-weighted mean paO2, unfavorable outcomes and 30-day mortality were more frequent both below and above a certain range. Unfavorable outcomes increased in paO2 ranges usually defined as normoxia. This emphasizes the necessity to further characterize oxygenation thresholds in ventilated patients with SAH in prospective clinical studies.

The faster the better? Time to first CT scan after admission in moderate-to-severe traumatic brain injury and its association with mortality.

Fast acquisition of a first computed tomography (CT) scan after traumatic brain injury (TBI) is recommended. This study is aimed at investigating whether the length of the period preceding initial CT scan influences mortality in patients with leading TBI. A retrospective cohort analysis of patients registered in the TraumaRegister DGU® was conducted including adult patients with TBI, defined as Abbreviated Injury ScaleHead ≥ 3 and GCS ≤ 13 who had been treated in level 1 or 2 trauma centers from 2007-2016. Patients were grouped according to time intervals either from trauma or from admission to CT. A total of 6904 patients met the inclusion criteria. Mean time period from trauma to hospital admission was 68.8 min. From admission to first CT, a mean of 19.0 min elapsed. Trauma severity was higher in groups with a longer duration from trauma to CT as represented by a mean (± standard deviation) Injury Severity Score (ISS) of 19.8 ± 9.0, 20.7 ± 9.3, and 21.4 ± 7.5 and similar distribution of mortality of 24.9%, 29.9%, and 36.3% in the ≤ 60-min, 61-120-min, and ≥ 121-min groups, respectively. An adjusted multivariable logistic regression model showed a significant influence of the level of the trauma center (p = 0.037) but not for interval from admission to CT (p = 0.528). TBI patients with a longer time span from trauma to first CT were more severely injured and demonstrated a worse prognosis, but received a CT scan faster when duration from admission is observed. The duration until the CT scan was obtained showed no significant impact on the mortality.

Operative versus non-operative treatment of traumatic brain injuries in patients 80 years of age or older.

Traumatic brain injury (TBI) in older adults is an increasing issue in modern medicine. Nevertheless, it remains unclear which patients presenting with TBI and 80 years of age or older benefit from an operative treatment. The aim of this study was to explore the effect of an operative treatment in isolated TBI patients ≥ 80 years of age. Data were derived from the TraumaRegister DGU® from 2002 to 2016. Inclusion criteria were ≥ 80 years of age, an Abbreviated Injury ScaleHead (AIS) ≥ 3, and an AISNon-Head ≤ 1. The cohort was split in operatively and non-operatively treated patients, and outcome was assessed at discharge using the Glasgow Outcome Scale (GOS). A favorable outcome was defined as a GOS of 4 or 5. A total of 1.693 patients (431 operatively and 1.262 non-operatively treated patients) were analyzed. Mortality rate was 54.4% (687 patients) in the non-operative group and 49.4% in the operative group. Simultaneously, there were more patients discharged with a GOS 2 (persistent vegetative state) in the operative group (7.9%, 34 patients) than in the non-operative group (1.0%, 13 patients). An analysis of the operatively treated patients showed an association between a higher mortality risk and brainstem hemorrhage (p = 0.04), fixed pupils (p = 0.001), initial intubation (p = 0.03), and an AISHead of 5/6 (p = 0.03). Patients 80 years of age or older seem to benefit from an operative treatment regarding mortality rate. However, there has been a higher rate of a poor neurological outcome particularly with regard to persistent vegetative state in the operative treatment group at discharge.

The role of frameless stereotactic biopsy in contemporary neuro-oncology: molecular specifications and diagnostic yield in biopsied glioma patients.

INTRODUCTION: With the 2016 World Health Organization Classification of Tumors of the Central Nervous System (2016 CNS WHO), diagnosis of glioma is based on molecular parameters in addition to histology potentially leading to additional demands on quality of tissue samples. This may challenge the role of minimally invasive biopsy procedures. This study aims to evaluate the diagnostic yield of glioma samples from frameless stereotactic biopsies with focus on molecular information and explore the neuromolecular profile of a glioma biopsy cohort. METHODS: In a case series analysis, 180 consecutive frameless stereotactic biopsies with the Brainlab® Varioguide system from January 2011 to October 2017 were reviewed and patients with suspected or verified glioma were identified. Neuropathological samples were reprocessed in accordance with 2016 CNS WHO standards. RESULTS: One hundred nineteen glioma patients were identified. Analysis of IDH status could be performed in 95.8% resulting in a cumulative mutation rate of 9.6%. A complete diagnosis according to 2016 CNS WHO including grading and molecular features was achieved in 110 cases (92.4%). Entities were revised in four cases. Most common diagnosis was IDH-wildtype glioblastoma (66.4%) followed by IDH-wildtype anaplastic astrocytoma (21.8%). CONCLUSIONS: A formally complete diagnosis according to 2016 CNS WHO was achieved in the majority of cases. The biopsy cohort showed a prognostically unfavorable distribution of diagnoses and molecular features. Frameless stereotactic biopsy seems to be confirmed as a useful diagnostic tool in contemporary neuro-oncology-however, certain potential limitations should be considered.

Early clinical course after aneurysmal subarachnoid hemorrhage: comparison of patients treated with Woven EndoBridge, microsurgical clipping, or endovascular coiling.

BACKGROUND: The Woven EndoBridge (WEB) device has been increasingly used for the treatment of intracranial aneurysms after aneurysmal subarachnoid hemorrhage (SAH). Still, recent major clinical trials on patient management after SAH have defined WEB embolization as an exclusion criterion. In an analysis of an unselected patient cohort, we evaluate the early clinical course of SAH patients after WEB treatment compared to those treated with endovascular coiling or surgical clipping. METHODS: Data of all patients with proven SAH who were either treated with a WEB device, coil embolization, or neurosurgical clipping between March 2015 and August 2018 was systematically reviewed. Clinical parameters on intensive care unit (ICU), medical history and mortality rates were evaluated and compared between the different treatment approaches. RESULTS: Of all 201 patients included, 107 patients received endovascular coil embolization, 56 patients were treated with clipping and in 38 cases a WEB device was placed. The overall mortality was 17.9%. Thirteen patients (34.2%) in the WEB group had a Hunt and Hess grade > 3. Essential medical factors showed no clinically relevant differences between the treatment groups, and the analyzed blood parameters were predominantly within physiological limits without any relevant outliers. The Hunt and Hess grade but not the treatment modality was identified as independent risk-factor associated with ICU-mortality in the overall cohort (p < 0.001). CONCLUSION: In this study, there was no difference in the early clinical course between those treated with WEB embolization, coil embolization, or neurosurgical clipping. Since WEB embolization is a valuable treatment alternative to coiling, it seems not justified to exclude this procedure from upcoming clinical SAH trials, yet the clinical long-term outcome, aneurysm occlusion, and retreatment rates have to be analyzed in further studies. CLINICAL TRIAL REGISTRATION NUMBER: not applicable.

Rate and impact of multidrug-resistant organisms in patients with aneurysmal subarachnoid hemorrhage.

BACKGROUND: Multidrug-resistant organisms (MDRO) are an increasing problem in critical care medicine. This study describes for the first time the rate and impact of MDRO in patients suffering from aneurysmal subarachnoid hemorrhage (SAH). METHODS: Anonymized data of SAH patients admitted to our institution from November 2010 to August 2017 were retrospectively reviewed. Patients with microbiological tests positive for MDRO were identified. Screening of MDRO was in consensus with national recommendations. RESULTS: 449 SAH patients were reviewed with 18 patients (prevalence: four MDRO-positive patients per 100 SAH patients) having positive tests for MDRO during their hospital stay. The prevalence upon admission was 1.3 MDRO-positive patients per 100 patients. The acquisition rate was 1.1 MDRO-positive patients per 1000 hospital days. Patients positive for an MDRO had a significantly extended length of stay in intensive care (mean ± SD 26.7 ± 13.0 versus 18.4 ± 11.7 days, p = 0.004) and in hospital (mean ± SD 33.9 ± 12.4 versus 24.4 ± 12.6 days, p = 0.002). MDRO detection was associated with a significant prolonged duration of mechanical ventilation (median (IQR) 254.0 (14.9-632.8) versus 37.5 (3.3-277.0) hours, p = 0.02). There was no statistically significant effect on the Glasgow Outcome Scale (GOS) at discharge and at follow-up after 164.4 ± 113.0 days. CONCLUSIONS: MDRO positivity is present in 4% of aneurysmal SAH patients. It seems to be associated with a prolonged length of stay and prolonged duration of mechanical ventilation. The importance of infection control standards in neurointensive care units is emphasized.

Intrathecal penetration of meropenem and vancomycin administered by continuous infusion in patients suffering from ventriculitis-a retrospective analysis.

BACKGROUND: Vancomycin and meropenem are frequently used as empiric treatment for ventriculitis. Penetration into the cerebrospinal fluid (CSF) depends on various factors with a high inter-individual variability. Because attaining and maintaining adequate concentrations of meropenem and vancomycin in the CSF is crucial for their bactericidal effect, we introduced a routine therapeutic drug monitoring (TDM) from CSF and serum for both antibiotics. We studied the antibiotic penetration into the CSF. METHODS: Patient data including serum and CSF concentrations for meropenem and vancomycin were collected in a retrospective fashion. Antibiotic CSF penetration ratio was calculated for each patient. Antibiotics were administered by continuous infusion aiming for serum target concentrations of 20-30 mg/L for vancomycin and 16-32 mg/L for meropenem. RESULTS: Twenty-two patients with 36 CSF/serum pairs for meropenem and 43 pairs for vancomycin were studied. No patient suffered from renal or liver insufficiency. Mean vancomycin serum concentration was 22 ± 8 mg/L and the mean CSF concentration 4.5 ± 2.6 mg/L. CSF penetration was 20 ± 11% (coefficient of determination (R2) 0.02). For meropenem, the mean serum concentration was 30.7 ± 14.9 mg/L, mean CSF concentration 5.5 ± 5.2 mg/L, and a penetration of 18 ± 12%, R2 = 0.42. CONCLUSION: Penetration of meropenem and vancomycin into the CSF is low while showing a high interindividual variability. Various patients in our study cohort were at risk for insufficient target attainment in CSF. Continuous administration of antibiotics under routine TDM appears to be a feasible and reasonable approach for optimization of intrathecal drug levels in patients suffering from ventriculitis. TDM might guide individual dosing adaptation and efforts to predict the CSF penetration of meropenem and vancomycin in cases of ventriculitis.

Patient perception and satisfaction in awake burr hole trepanation under local anesthesia for evacuation of chronic subdural hematoma.

Evacuation of chronic subdural hematoma (CSDH) will be one of the most common neurosurgical procedures in the future in the increasingly aging societies. Performing cranial surgery on awake patients may place a psychological burden on them. Aim of this study was to evaluate the psychological distress of patients during awake CSDH relief. Patients with awake evacuation of CSDH via burr hole trepanation were included in our monocentric prospective study. Patient perception and satisfaction were measured using standardized surveys 3-5 days and 6 months after surgery. Among other questionnaires, the Hospital Anxiety and Depression and the Impact of Event Scale, were used to quantify patients' stress. A total of 50 patients (mean age 72.9 years (range 51 - 92)) were included. During surgery, 28 patients reported pain (mean 4.1 (SD 3.3)). Postoperatively, 26 patients experienced pain (mean 2.7 (SD 2.6)). Patients' satisfaction with intraoperative communication was reported with a mean of 8.3 (SD 2.1). There was a significant negative correlation between intraoperatively perceived pain and satisfaction with intraoperative communication (p = 0.023). Good intraoperative communication during evacuation of CSDH in awake patients is associated with positive patient perception and correlates with pain reduction.

Myeloid cell replacement is neuroprotective in chronic experimental autoimmune encephalomyelitis.

Multiple sclerosis (MS) is an autoimmune disease characterized by demyelination of the central nervous system (CNS). Autologous hematopoietic cell transplantation (HCT) shows promising benefits for relapsing-remitting MS in open-label clinical studies, but the cellular mechanisms underlying its therapeutic effects remain unclear. Using single-nucleus RNA sequencing, we identify a reactive myeloid cell state in chronic experimental autoimmune encephalitis (EAE) associated with neuroprotection and immune suppression. HCT in EAE mice results in an increase of the neuroprotective myeloid state, improvement of neurological deficits, reduced number of demyelinated lesions, decreased number of effector T cells and amelioration of reactive astrogliosis. Enhancing myeloid cell incorporation after a modified HCT further improved these neuroprotective effects. These data suggest that myeloid cell manipulation or replacement may be an effective therapeutic strategy for chronic inflammatory conditions of the CNS.

A cell therapy approach to restore microglial Trem2 function in a mouse model of Alzheimer's disease.

Alzheimer's disease (AD) remains one of the grand challenges facing human society. Much controversy exists around the complex and multifaceted pathogenesis of this prevalent disease. Given strong human genetic evidence, there is little doubt, however, that microglia play an important role in preventing degeneration of neurons. For example, loss of function of the microglial gene Trem2 renders microglia dysfunctional and causes an early-onset neurodegenerative syndrome, and Trem2 variants are among the strongest genetic risk factors for AD. Thus, restoring microglial function represents a rational therapeutic approach. Here, we show that systemic hematopoietic cell transplantation followed by enhancement of microglia replacement restores microglial function in a Trem2 mutant mouse model of AD.

Extracorporeal membrane oxygenation in traumatic brain injury - A retrospective, multicenter cohort study.

INTRODUCTION: Patients with traumatic brain injury (TBI) regularly require intensive care with prolonged invasive ventilation. Consequently, these patients are at increased risk of pulmonary failure, potentially requiring extracorporeal membrane oxygenation (ECMO). The aim of this work was to provide an overview of ECMO treatment in TBI patients based upon data captured into the TraumaRegister DGU® (TR-DGU). METHODS: A retrospective multi-center cohort analysis of patients registered in the TR-DGU was conducted. Adult patients with relevant TBI (AISHead ≥3) who had been treated in German, Austrian, or Swiss level I or II trauma centers using ECMO therapy between 2015 and 2019 were included. A multivariable logistic regression analysis was used to identify risk factors for the need for ECMO treatment. RESULTS: 12,247 patients fulfilled the inclusion criteria. The overall rate of ECMO treatment was 1.1% (134 patients). Patients on ECMO had an overall hospital mortality rate of 38% (51/134 patients) while 13% (1523/12,113 patients) of TBI patients without ECMO therapy died. Male gender (p = 0.014), AISChest 3+ (p<0.001), higher Injury Severity Score (p<0.001) and packed red blood cell (pRBC) transfusion (p<0.001) were associated with ECMO treatment. CONCLUSION: ECMO therapy is a potentially lifesaving modality for the treatment of moderate-to-severe TBI when combined with severe chest trauma and pulmonary failure. The in-hospital mortality is increased in this high-risk population, but the majority of patients is surviving.

Impact of pre-hospital handling and initial time to cranial computed tomography on outcome in aneurysmal subarachnoid hemorrhage patients with out-of-hospital sudden cardiac arrest-a retrospective bi-centric study.

Background: Aneurysmal subarachnoid hemorrhage (SAH) presents occasionally with cardiac arrest (CA). The impact of pre-hospital and emergency room (ER) treatment on outcome remains unclear. Therefore, we investigated the impact of pre-hospital treatment, focusing on lay cardiopulmonary resuscitation (CPR), and ER handling on the outcome of SAH patients with out-of-hospital CA (OHCA). Methods: In this bi-centric retrospective analysis, we reviewed SAH databases for OHCA and CPR from January 2011 to June 2021. Patients were analyzed for general clinical and epidemiological parameters. CPR data were obtained from ambulance reports and information on ER handling from the medical records. Data were correlated with patient survival at hospital discharge as a predefined outcome parameter. Results: Of 1,120 patients with SAH, 45 (4.0%) were identified with OHCA and CPR, 38 of whom provided all required information and were included in this study. Time to resuscitation was significantly shorter with lay resuscitation (5.3 ± 5.2 min vs. 0.3 ± 1.2 min, p = 0.003). Nineteen patients were not initially scheduled for cranial computed tomography (CCT), resulting in a significantly longer time interval to first CCT (mean ± SD: 154 ± 217 min vs. 40 ± 23 min; p < 0.001). Overall survival to discharge was 31.6%. Pre-hospital lay CPR was not associated with higher survival (p = 0.632). However, we observed a shorter time to first CCT in surviving patients (p = 0.065). Conclusions: OHCA in SAH patients is not uncommon. Besides high-quality CPR, time to diagnosis of SAH appears to play an important role. We therefore recommend considering CCT diagnostics as part of the diagnostic algorithm in patients with OHCA.

Augmentation of a neuroprotective myeloid state by hematopoietic cell transplantation.

Multiple sclerosis (MS) is an autoimmune disease associated with inflammatory demyelination in the central nervous system (CNS). Autologous hematopoietic cell transplantation (HCT) is under investigation as a promising therapy for treatment-refractory MS. Here we identify a reactive myeloid state in chronic experimental autoimmune encephalitis (EAE) mice and MS patients that is surprisingly associated with neuroprotection and immune suppression. HCT in EAE mice leads to an enhancement of this myeloid state, as well as clinical improvement, reduction of demyelinated lesions, suppression of cytotoxic T cells, and amelioration of reactive astrogliosis reflected in reduced expression of EAE-associated gene signatures in oligodendrocytes and astrocytes. Further enhancement of myeloid cell incorporation into the CNS following a modified HCT protocol results in an even more consistent therapeutic effect corroborated by additional amplification of HCT-induced transcriptional changes, underlining myeloid-derived beneficial effects in the chronic phase of EAE. Replacement or manipulation of CNS myeloid cells thus represents an intriguing therapeutic direction for inflammatory demyelinating disease.

Corticosteroid-Dependent Leukocytosis Masks the Predictive Potential of White Blood Cells for Delayed Cerebral Ischemia and Ventriculoperitoneal Shunt Dependency in Aneurysmatic Subarachnoid Hemorrhage.

A multitude of pathological and inflammatory processes determine the clinical course after aneurysmal subarachnoid hemorrhage (aSAH). However, our understanding of predictive factors and therapeutic consequences is limited. We evaluated the predictive value of clinically relevant factors readily available in the ICU setting, such as white blood cell (WBC) count and CRP, for two of the leading comorbidities, delayed cerebral ischemia (DCI) and ventriculoperitoneal (VP) shunt dependency in aSAH patients with and without corticosteroid treatment. We conducted a retrospective analysis of 484 aSAH patients admitted to our institution over an eight-year period. Relevant clinical factors affecting the risk of DCI and VP shunt dependency were identified and included in a multivariate logistic regression model. Overall, 233/484 (48.1%) patients were treated with corticosteroids. Intriguingly, predictive factors associated with the occurrence of DCI differed significantly depending on the corticosteroid treatment status (dexamethasone group: Hunt and Hess grade (p = 0.002), endovascular treatment (p = 0.016); no-dexamethasone group: acute hydrocephalus (p = 0.018), peripheral leukocyte count 7 days post SAH (WBC at day 7) (p = 0.009)). Similar disparities were found for VP shunt dependency (dexamethasone group: acute hydrocephalus (p = 0.002); no-dexamethasone group: WBC d7 (p = 0.036), CRP peak within 72 h (p = 0.015)). Our study shows that corticosteroid-induced leukocytosis negates the predictive prognostic potential of systemic inflammatory markers for DCI and VP shunt dependency, which has previously been neglected and should be accounted for in future studies.

The role of L-arginine metabolism in neurocritical care patients.

Nitric oxide is an important mediator of vascular autoregulation and is involved in pathophysiological changes after acute neurological disorders. Nitric oxide is generated by nitric oxide synthases from the amino acid L-arginine. L-arginine can also serve as a substrate for arginases or lead to the generation of dimethylarginines, asymmetric dimethylarginine, and symmetric dimethylarginine, by methylation. Asymmetric dimethylarginine is an endogenous inhibitor of nitric oxide synthase and can lead to endothelial dysfunction. This review discusses the role of L-arginine metabolism in patients suffering from acute and critical neurological disorders often requiring neuro-intensive care treatment. Conditions addressed in this review include intracerebral hemorrhage, aneurysmal subarachnoid hemorrhage, and traumatic brain injury. Recent therapeutic advances in the field are described including current randomized controlled trials for traumatic brain injuries and hemorrhagic stroke.

Traumatic brain injury with concomitant injury to the spleen: characteristics and mortality of a high-risk trauma cohort from the TraumaRegister DGU®.

PURPOSE: Based on the hypothesis that systemic inflammation contributes to secondary injury after initial traumatic brain injury (TBI), this study aims to describe the effect of splenectomy on mortality in trauma patients with TBI and splenic injury. METHODS: A retrospective cohort analysis of patients prospectively registered into the TraumaRegister DGU® (TR-DGU) with TBI (AISHead ≥ 3) combined with injury to the spleen (AISSpleen ≥ 1) was conducted. Multivariable logistic regression modeling was performed to adjust for confounding factors and to assess the independent effect of splenectomy on in-hospital mortality. RESULTS: The cohort consisted of 1114 patients out of which 328 (29.4%) had undergone early splenectomy. Patients with splenectomy demonstrated a higher Injury Severity Score (median: 34 vs. 44, p < 0.001) and lower Glasgow Coma Scale (median: 9 vs. 7, p = 0.014) upon admission. Splenectomized patients were more frequently hypotensive upon admission (19.8% vs. 38.0%, p < 0.001) and in need for blood transfusion (30.3% vs. 61.0%, p < 0.001). The mortality was 20.7% in the splenectomy group and 10.3% in the remaining cohort. After adjustment for confounding factors, early splenectomy was not found to exert a significant effect on in-hospital mortality (OR 1.29 (0.67-2.50), p = 0.45). CONCLUSION: Trauma patients with TBI and spleen injury undergoing splenectomy demonstrate a more severe injury pattern, more compromised hemodynamic status and higher in-hospital mortality than patients without splenectomy. Adjustment for confounding factors reveals that the splenectomy procedure itself is not independently associated with survival.

Multiparametric Monitoring of Early Pathophysiological Changes in a Porcine Model of Sequential Focal and Global Cerebral Ischemia.

OBJECTIVE: Large animal models of cerebral ischemia have the potential to increase the translational value of stroke research. This study aims to measure early changes of brain tissue oxygen pressure (ptiO2) and cerebral blood flow (CBF) to characterize a porcine model of sequential middle cerebral artery occlusion (MCAO) and common carotid artery occlusion (CCAO). METHODS: Eight juvenile German Landrace pigs received unilateral MCAO via a frontotemporal approach under continuous intraparenchymal multiparametric monitoring. Insufficient reduction (i.e., <50% in both ptiO2 and CBF) was followed by additional bilateral CCAO. Neurodegenerative changes were detected by Fluoro-Jade B (FJB) staining. RESULTS: Only 1 of 8 animals demonstrated a decrease of >50% in both ptiO2 and CBF after MCAO. Additional CCAO in 7 pigs led to a significant reduction of both ipsilateral and contralateral ptiO2 (P < 0.01) but not of CBF. There was no difference in ptiO2 and FJB positive area between hemispheres in this group. Measurement of ptiO2 correlated negatively with the FJB positive area (P < 0.05). CONCLUSIONS: Intraparenchymal multiparametric measurements of acute changes in ptiO2 and CBF were variable after MCAO. Bilateral CCAO led to a consistent decrease in ptiO2 and correlated with early degenerative histologic changes, but CBF did not. Real-time procedural ptiO2 monitoring could provide useful guidance in large animal ischemia models. Feasibility in the context of global cerebral hypoperfusion is demonstrated.