Ischemic stroke is the main cause of death and the most common cause of acquired physical disability worldwide. Recent demographic changes increase the relevance of stroke and its sequelae. The acute treatment for stroke is restricted to causative recanalization and restoration of cerebral blood flow, including both intravenous thrombolysis and mechanical thrombectomy. Still, only a limited number of patients are eligible for these time-sensitive treatments. Hence, new neuroprotective approaches are urgently needed. Neuroprotection is thus defined as an intervention resulting in the preservation, recovery, and/or regeneration of the nervous system by interfering with the ischemic-triggered stroke cascade. Despite numerous preclinical studies generating promising data for several neuroprotective agents, successful bench-to-bedside translations are still lacking. The present study provides an overview of current approaches in the research field of neuroprotective stroke treatment. Aside from “traditional” neuroprotective drugs focusing on inflammation, cell death, and excitotoxicity, stem-cell-based treatment methods are also considered. Furthermore, an overview of a prospective neuroprotective method using extracellular vesicles that are secreted from various stem cell sources, including neural stem cells and bone marrow stem cells, is also given. The review concludes with a short discussion on the microbiota–gut–brain axis that may serve as a potential target for future neuroprotective therapies.

Spontaneous (non-traumatic) intracerebral haemorrhage (ICH) affects ~3.4 million people worldwide each year, causing ~2.8 million deaths. Many randomised controlled trials and high-quality observational studies have added to the evidence base for the management of people with ICH since the last European Stroke Organisation (ESO) guidelines for the management of spontaneous ICH were published in 2014, so we updated the ESO guideline. This guideline update was guided by the European Stroke Organisation (ESO) standard operating procedures for guidelines and the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) framework, in collaboration with the European Association of Neurosurgical Societies (EANS). We identified 37 Population, Intervention, Comparator, Outcome (PICO) questions and prioritised clinical outcomes. We conducted systematic literature searches, tailored to each PICO, seeking randomised controlled trials (RCT) – or observational studies when RCTs were not appropriate, or not available – that investigated interventions to improve clinical outcomes. A group of co-authors allocated to each PICO screened titles, abstracts, and full texts and extracted data from included studies. A methodologist conducted study-level meta-analyses and created summaries of findings tables. The same group of co-authors graded the quality of evidence, and drafted recommendations that were reviewed, revised and approved by the entire group. When there was insufficient evidence to make a recommendation, each group of co-authors drafted an expert consensus statement, which was reviewed, revised and voted on by the entire group. The systematic literature search revealed 115,647 articles. We included 208 studies. We found strong evidence for treatment of people with ICH on organised stroke units, and secondary prevention of stroke with blood pressure lowering. We found weak evidence for scores for predicting macrovascular causes underlying ICH; acute blood pressure lowering; open surgery via craniotomy for supratentorial ICH; minimally invasive surgery for supratentorial ICH; decompressive surgery for deep supratentorial ICH; evacuation of cerebellar ICH > 15 mL; external ventricular drainage with intraventricular thrombolysis for intraventricular extension; minimally invasive surgical evacuation of intraventricular blood; intermittent pneumatic compression to prevent proximal deep vein thrombosis; antiplatelet therapy for a licensed indication for secondary prevention; and applying a care bundle. We found strong evidence against anti-inflammatory drug use outside of clinical trials. We found weak evidence against routine use of rFVIIa, platelet transfusions for antiplatelet-associated ICH, general policies that limit treatment within 24 h of ICH onset, temperature and glucose management as single measures (outside of care bundles), prophylactic anti-seizures medicines, and prophylactic use of temperature-lowering measures, prokinetic anti-emetics, and/or antibiotics. New evidence about the management of ICH has emerged since 2014, enabling this update of the ESO guideline to provide new recommendations and consensus statements. Although we made strong recommendations for and against a few interventions, we were only able to make weak recommendations for and against many others, or produce consensus statements where the evidence was insufficient to guide clinical decisions. Although progress has been made, many interventions still require definitive, high-quality evidence, underpinning the need for embedding clinical trials in routine clinical practice for ICH.

OBJECTIVE: Stroke-associated immunosuppression and inflammation are increasingly recognized as factors triggering infections and thus potentially influencing outcome after stroke. Several studies have demonstrated that elevated neutrophil-to-lymphocyte ratio (NLR) is a significant predictor of adverse outcomes for patients with ischemic stroke or intracerebral hemorrhage. Thus far, in patients with subarachnoid hemorrhage the association between NLR and outcome is insufficiently established. The authors sought to investigate the association between NLR on admission and functional outcome in aneurysmal subarachnoid hemorrhage (aSAH).METHODS: This observational study included all consecutive aSAH patients admitted to a German tertiary center over a 5-year period (2008–2012). Data regarding patient demographics and clinical, laboratory, and in-hospital measures, as well as neuroradiological data, were retrieved from institutional databases. Functional outcome was assessed at 3 and 12 months using the modified Rankin Scale (mRS) score and categorized into favorable (mRS score 0–2) and unfavorable (mRS score 3–6). Patients’ radiological and laboratory characteristics were compared between aSAH patients with favorable and those with unfavorable outcome at 3 months. In addition, multivariate analysis was conducted to investigate parameters independently associated with favorable outcome. Receiver operating characteristic (ROC) curve analysis was undertaken to identify the best cutoff for NLR to discriminate between favorable and unfavorable outcome in these patients. To account for imbalances in baseline characteristics, propensity score matching was carried out to assess the influence of NLR on outcome measures.RESULTS: Overall, 319 patients with aSAH were included. Patients with unfavorable outcome at 3 months were older, had worse clinical status on admission (Glasgow Coma Scale score and Hunt and Hess grade), greater amount of subarachnoidal and intraventricular hemorrhage (modified Fisher Scale grade and Graeb score), and higher rates of infectious complications (pneumonia and sepsis). A significantly higher NLR on admission was observed in patients with unfavorable outcome according to mRS score (median [IQR] NLR 5.8 [3.0–10.0] for mRS score 0–2 vs NLR 8.3 [4.5–12.6] for mRS score 3–6; p < 0.001). After adjustments, NLR on admission remained a significant predictor for unfavorable outcome in SAH patients (OR [95% CI] 1.014 [1.001–1.027]; p = 0.028). In ROC analysis, an NLR of 7.05 was identified as the best cutoff value to discriminate between favorable and unfavorable outcome (area under the curve = 0.614, p < 0.001, Youden’s index = 0.211; mRS score 3–6: 94/153 [61.4%] for NLR ≥ 7.05 vs 67/166 [40.4%] for NLR < 7.05; p < 0.001). Subanalysis of patients with NLR levels ≥ 7.05 vs < 7.05, performed using 2 propensity score–matched cohorts (n = 133 patients in each group), revealed an increased proportion of patients with unfavorable functional outcome at 3 months in patients with NLR ≥ 7.05 (mRS score 3–6 at 3 months: NLR ≥ 7.05 82/133 [61.7%] vs NLR < 7.05 62/133 [46.6%]; p = 0.014), yet without differences in mortality at 3 months (NLR ≥ 7.05 37/133 [27.8%] vs NLR < 7.05 27/133 [20.3%]; p = 0.131).CONCLUSIONS: Among aSAH patients, NLR represents an independent parameter associated with unfavorable functional outcome. Whether the impact of NLR on functional outcome is related to preexisting comorbidities or represents independent causal relationships in the context of stroke-associated immunosuppression should be investigated in future studies.

Introduction: To date only two studies have evaluated anemia status in acute intracerebral hemorrhage (ICH) reporting that on admission anemia (OAA) was associated with larger hematoma volume, and lower hemoglobin levels during hospital stay, which related to poorer outcome. The question remains whether anemia influences outcome through related volume-effects or itself has an independent impact? Methods: This single-center investigation included 435 consecutive patients with spontaneous ICH admitted to the Department of Neurology over five years. Functional short- and long-term outcome (3 months and 1 year) were analyzed for anemia status. Multivariate logistic and graphical regression analyses were calculated for associations of anemia and to determine independent effects on functional outcome. It was decided to perform a separate analysis for patients with ICH-volume <30cm³ (minor-volume-ICH). Results: Overall short-term-outcome was worse in anemic patients (mRS[4-6] OAA = 93.3% vs. non-OAA = 61.2%, P < 0.01), and there was a further shift towards an increased long-term mortality (P = 0.02). The probability of unfavorable long-term-outcome (mRS[4-6]) in OAA was elevated 7-fold (OR:7.5; P < 0.01). Receiver operating characteristics curve (ROC) analysis revealed a positive but poor association of ICH-volume and anemia (AUC = 0.67) suggesting volume-undriven outcome-effects of anemia (AUC = 0.75). Multivariate regression analyses revealed that anemia, besides established parameters, has the strongest relation to unfavorable outcome (OR:3.0; P < 0.01). This is even more pronounced in minor-volume-ICH (OR:5.6; P < 0.01). Conclusions: Anemia seems to be a previously unrecognized significant predictor of unfavorable functional outcome with independent effects beyond its association with larger hemorrhage volumes. The recognition of anemia and its treatment may possibly influence outcome after ICH and as such prospective interventional studies are warranted.

Background and Purpose: It is unestablished whether andexanet alfa, compared with guideline-based usual care including prothrombin complex concentrates, is associated with reduced hematoma expansion (HE) and mortality in patients with factor-Xa inhibitor–related intracerebral hemorrhage (ICH). We compared the occurrence of HE and clinical outcomes in patients treated either with andexanet alfa or with usual care during the acute phase of factor-Xa inhibitor–related ICH. Methods: Data were extracted from the multicenter, prospective, single-arm ANNEXA-4 trial (Andexanet Alfa, a Novel Antidote to the Anticoagulation Effects of Factor Xa Inhibitors) and a multicenter observational cohort study, RETRACE-II (German-Wide Multicenter Analysis of Oral Anticoagulant-Associated Intracerebral Hemorrhage - Part Two). HE was based on computed tomography scans performed within 36 hours from baseline imaging. Inverse probability of treatment weighting was performed to adjust for baseline comorbidities and ICH severity. Patients presenting with atraumatic ICH while receiving apixaban or rivaroxaban within 18 hours of admission were included. Patients with secondary ICH or not fulfilling the inclusion criteria for the ANNEXA-4 trial were excluded. We compared ANNEXA-4 patients, who received andexanet alfa for hemostatic treatment, with RETRACE-II patients who were treated with usual care, primarily administration of prothrombin complex concentrates. Primary outcome was rate of HE defined as relative increase of ≥35%. Secondary outcomes comprised mean absolute change in hematoma volume, as well as in-hospital mortality and functional outcome. Results: Overall, 182 patients with factor-Xa inhibitor–related ICH (85 receiving andexanet alfa versus 97 receiving usual care) were selected for analysis. There were no relevant differences regarding demographic or clinical characteristics between both groups. HE occurred in 11 of 80 (14%) andexanet alfa patients compared with 21 of 67 (36%) usual care patients (adjusted relative risk, 0.40 [95% CI, 0.20–0.78]; P =0.005), with a reduction in mean overall hematoma volume change of 7 mL. There were no statistically significant differences among in-hospital mortality or functional outcomes. Sensitivity analysis including only usual care patients receiving prothrombin complex concentrates demonstrated consistent results. Conclusions: As compared with usual care, andexanet alfa was associated with a lower rate of HE in atraumatic factor-Xa inhibitor–related ICH, however, without translating into significantly improved clinical outcomes. A comparative trial is needed to confirm the benefit on limiting HE and to explore clinical outcomes across patient subgroups and by time to treatment. Registration: URL: https://clinicaltrials.gov ; Unique identifier: NCT02329327 and NCT03093233.

Hypoxia triggers reactive microglial inflammation and lipid droplet (LD) accumulation under stroke conditions, although the mutual interactions between these two processes are insufficiently understood. Hence, the involvement of transforming growth factor (TGF)-β1 in inflammation and LD accumulation in cultured microglia exposed to hypoxia were analyzed herein. Primary microglia were exposed to oxygen-glucose deprivation (OGD) injury and lipopolysaccharide (LPS) stimulation. For analyzing the role of TGF-β1 patterns under such conditions, a TGF-β1 siRNA and an exogenous recombinant TGF-β1 protein were employed. Further studies applied Triacsin C, an inhibitor of LD formation, in order to directly assess the impact of LD formation on the modulation of inflammation. To assess mutual microglia-to-neuron interactions, a co-culture model of these cells was established. Upon OGD exposure, microglial TGF-β1 levels were significantly increased, whereas LPS stimulation yielded decreased levels. Elevating TGF-β1 expression proved highly effective in suppressing inflammation and reducing LD accumulation in microglia exposed to LPS. Conversely, inhibition of TGF-β1 led to the promotion of microglial cell inflammation and an increase in LD accumulation in microglia exposed to OGD. Employing the LD formation inhibitor Triacsin C, in turn, polarized microglia towards an anti-inflammatory phenotype. Such modulation of both microglial TGF-β1 and LD levels significantly affected the resistance of co-cultured neurons. This study provides novel insights by demonstrating that TGF-β1 plays a protective role against microglia-mediated neuroinflammation through the suppression of LD accumulation. These findings offer a fresh perspective on stroke treatment, suggesting the potential of targeting this pathway for therapeutic interventions.