Dynamic Brain Lipid Profiles Modulate Microglial Lipid Droplet Accumulation and Inflammation Under Ischemic Conditions in Mice.

Microglia are critically involved in post-stroke inflammation affecting neurological outcomes. Lipid droplet (LD) accumulation in microglia results in a dysfunctional and pro-inflammatory state in the aged brain and worsens the outcome of neuroinflammatory and neurodegenerative diseases. However, the role of LD-rich microglia (LDRM) under stroke conditions is unknown. Using in vitro and in vivo stroke models, herein accumulation patterns of microglial LD and their corresponding microglial inflammatory signaling cascades are studied. Interactions between temporal and spatial dynamics of lipid profiles and microglial phenotypes in different post-stroke brain regions are found. Hence, microglia display enhanced levels of LD accumulation and elevated perilipin 2 (PLIN2) expression patterns when exposed to hypoxia or stroke. Such LDRM exhibit high levels of TNF-α, IL-6, and IL-1ß as well as a pro-inflammatory phenotype and differentially expressed lipid metabolism-related genes. These post-ischemic alterations result in distinct lipid profiles with spatial and temporal dynamics, especially with regard to cholesteryl ester and triacylglycerol levels, further exacerbating post-ischemic inflammation. The present study sheds new light on the dynamic changes of brain lipid profiles and aggregation patterns of LD in microglia exposed to ischemia, demonstrating a mutual mechanism between microglial phenotype and function, which contributes to progression of brain injury.

FAST4D-A New Score to Reduce Missed Strokes in Emergency Medical Service: A Prospective, Multicentric Observational Proof-of-Concept Trial.

Background: Undoubtedly, overlooking a stroke can result in severe disability or even death. However, identifying stroke patients in the prehospital setting poses a significant challenge. While the Face-Arm-Speech-Time (FAST) score is widely used, its effectiveness has been questioned because of its focus on symptoms primarily associated with anterior circulation strokes. In response to this limitation, we developed the innovative FAST4D score and conducted a comparative analysis of stroke detection rates between the novel FAST4D score and the FAST score. Methods: This prospective, multicenter proof-of-concept study aimed to assess stroke detection rates using both the FAST score and the new FAST4D score, which incorporates additional items such as the acute onset of diplopic images, deficit in the field of vision, dizziness/vertigo, and dysmetria/ataxia. Following their presentation to emergency medical services, all patients suspected of having a stroke and those diagnosed with a stroke upon discharge were included in this study. The diagnostic performance of the novel FAST4D score was evaluated and compared with that of the FAST score. Results: Between May 2019 and June 2021, a total of 1469 patients (749 female) were enrolled, with 1035 patients discharged with the diagnosis of stroke. Notably, 259 patients were identified solely through the FAST4D score. This resulted in a significantly higher rate of correctly identified as having had a stroke (stroke detection rate, sensitivity) with the new FAST4D score (93%) compared with the established FAST score (78%) (p < 0.001). This resulted in a reduction in false negative diagnoses by 65%. Conclusions: The novel FAST4D score demonstrated a 15-percentage increase in the stroke detection rate. This heightened detection rate holds the potential for more accurate patient allocation to stroke units, consequently reducing the time to revascularization.

Individual participant data analysis comparing acute stroke patients with anterior versus posterior circulation dissections.

BACKGROUND: Cervical artery dissection (CAD) is a relevant etiology of transient ischemic attacks and strokes. Several trials explored the significance of specific antithrombotic treatments, i.e. oral anticoagulation (OAC) versus antiplatelet treatment (APT), on recurrent ischemic complications and clinical outcomes. As overall incidence rates of complications were low there is still controversy which antithrombotic treatment should be used. However, up to now there has been no systematic investigation among CAD-patients with ischemic stroke specifically comparing clinical course and outcome of patients with anterior versus posterior CAD. METHODS: We performed an individual participant data analysis of patients with CAD and ischemic stroke. Over a five-year period we pooled data from three sites (i.e. West China Hospital, Chengdu, China as well as Erlangen and Giessen University Hospitals, Germany) and enrolled patients with CAD-associated ischemic stroke. Patient demographics, clinical and in-hospital measures as well as radiological data were retrieved from institutional databases. Clinical follow-up was over 6 months and included data on recurrent ischemic strokes and hemorrhages as well as clinical functional outcome assessed by the modified Rankin Scale dichotomized into favourable (mRS=0-2) and unfavourable. RESULTS: A total of 203 patients with CAD were included of which n=112 had anterior and n=91 had posterior CAD. Patients with posterior CAD were younger (46.0 vs. 41.0 y; p<0.001) than patients with anterior CAD and showed less often arterial hypertension. (42.0 % vs. 28.6 %; p<0.048). Antithrombotic treatment with APT and OAC was similarily distributed among patients with anterior and posterior CAD and not significantly differently related to ischemic or hemorrhagic complications during follow-up (all p=n.s.). Main difference between Chinese and German patients were mode of antithrombotic treatment consisting predominantly of APT in China compared to OAC in Germany. Functional outcome overall was good, yet worse in patients with anterior CAD compared to posterior CAD (80.2 % favorable in anterior CAD vs. 92.2 % in posterior CAD (p=0.014). CONCLUSION: This study provides evidence that anterior and posterior CAD show baseline imbalances regarding age and comorbidity which may affect clinical outcome. There are no signals of superiority or harm of any specific mode of antithrombotic treatment nor relevant discrepancies in clinical outcome among Chinese and German CAD-associated stroke patients.

Efgartigimod as Rescue Medication in a Patient with Therapy-Refractory Myasthenic Crisis.

Myasthenic crises (MC) are potentially life-threatening acute exacerbations of myasthenia gravis (MG) characterized by profound muscle weakness, bulbar symptoms, and potential for respiratory failure. Intravenous immunoglobulins (IVIG) and plasma exchange (PLEX) are conventional treatments for myasthenic exacerbations. Recently, new therapeutic options for generalized acetylcholine-receptor antibody positive (AchR+) MG were approved as an add-on therapy. They mainly consist of complement C5 inhibitors such as eculizumab and ravulizumab and neonatal Fc receptor antagonists such as efgartigimod with the approval of more options pending, e.g., zilucoplan and rozanolixizumab. More therapeutic options are in the pipeline. Although the data show a quick and reliable treatment response, these medications have not been studied for the therapy of myasthenic crisis. We present the case of a 57-year-old male with his first episode of generalized myasthenia gravis (MG) and positive acetylcholine-receptor antibodies (AchR+) who was transferred to our neurological intensive care unit with worsening generalized weakness, dysphagia, and respiratory distress. The crisis was triggered by pneumonia due to dysphagia. He was diagnosed with myasthenic crisis and treated with intravenous pyridostigmine, plasmapheresis (PLEX), and continued prednisone. Initial improvement was followed by deterioration, requiring readmission and additional PLEX. After a further decline, efgartigimod was administered, leading to significant improvement within 48 hours, as evidenced by reduced MG-ADL and QMG scores. The patient continued to improve and was stable enough for transfer to a rehabilitation facility. This case illustrates the potential of efgartigimod as a novel treatment for refractory myasthenic crises.

Association of Clinical Relapses With Disease Outcomes in Multiple Sclerosis Patients Older Than 50 Years.

BACKGROUND AND OBJECTIVES: Relapse and MRI activity usually decline with aging but are replaced by progression independent of relapse activity (PIRA) in patients with multiple sclerosis (PwMS). However, several older PwMS continue to experience clinical relapses, and the impact on their disease remains undetermined. We aimed to determine the impact of an index relapse on disease outcomes in patients older than 50 years and to identify risk factors of disadvantageous outcomes. METHODS: We performed a secondary analysis from 3 prospective cohorts in Germany. We evaluated all PwMS 50 years and older with a relapse ≤60 days before a baseline visit and at least 18 months of follow-up compared with a control cohort of PwMS without a relapse. Patients were stratified according to age ("50-54" vs "55-59" vs "60+") or disease outcomes ("stable" vs "active" vs "progressive," according to the Lublin criteria). We analyzed relapses, MRI activity, relapse-associated worsening, and PIRA. Regression analysis was performed to evaluate the association of specific baseline risk factors and treatment regimen changes with disease outcomes at month 18. RESULTS: A total of 681 patients were included in the "relapse cohort" (50+: 361; 55+: 220; 60+: 100). The "control cohort" comprised 232 patients (50+: 117; 55+: 71; 60+: 44). Baseline epidemiologic parameters were balanced among cohorts and subgroups. We observed increased abundance of inflammatory activity and relapse-independent disability progression in the "relapse" vs "control" cohort. In the "relapse" cohort, we identified 273 patients as "stable" (59.7%), 114 patients as "active" (24.9%), and 70 patients as "progressive" (15.3%) during follow-up. Cardiovascular risk factors (CVRFs) and older age at baseline were identified as risk factors of progressive, whereas disease-modifying treatment (DMT) administration at baseline favored stable disease. DMT during follow-up was associated with stable over active, but not over progressive disease. DISCUSSION: A relapse-suggesting underlying active disease-in PwMS older than 50 years was associated with continued disease activity and increased risk of PIRA. Presence of CVRF and absence of DMT at baseline appeared as risk factors of disadvantageous disease courses. An escalation of DMT switch was associated with stable over active but not progressive disease.

Decompressive craniectomy plus best medical treatment versus best medical treatment alone for spontaneous severe deep supratentorial intracerebral haemorrhage: a randomised controlled clinical trial.

BACKGROUND: It is unknown whether decompressive craniectomy improves clinical outcome for people with spontaneous severe deep intracerebral haemorrhage. The SWITCH trial aimed to assess whether decompressive craniectomy plus best medical treatment in these patients improves outcome at 6 months compared to best medical treatment alone. METHODS: In this multicentre, randomised, open-label, assessor-blinded trial conducted in 42 stroke centres in Austria, Belgium, Finland, France, Germany, the Netherlands, Spain, Sweden, and Switzerland, adults (18-75 years) with a severe intracerebral haemorrhage involving the basal ganglia or thalamus were randomly assigned to receive either decompressive craniectomy plus best medical treatment or best medical treatment alone. The primary outcome was a score of 5-6 on the modified Rankin Scale (mRS) at 180 days, analysed in the intention-to-treat population. This trial is registered with ClincalTrials.gov, NCT02258919, and is completed. FINDINGS: SWITCH had to be stopped early due to lack of funding. Between Oct 6, 2014, and April 4, 2023, 201 individuals were randomly assigned and 197 gave delayed informed consent (96 decompressive craniectomy plus best medical treatment, 101 best medical treatment). 63 (32%) were women and 134 (68%) men, the median age was 61 years (IQR 51-68), and the median haematoma volume 57 mL (IQR 44-74). 42 (44%) of 95 participants assigned to decompressive craniectomy plus best medical treatment and 55 (58%) assigned to best medical treatment alone had an mRS of 5-6 at 180 days (adjusted risk ratio [aRR] 0·77, 95% CI 0·59 to 1·01, adjusted risk difference [aRD] -13%, 95% CI -26 to 0, p=0·057). In the per-protocol analysis, 36 (47%) of 77 participants in the decompressive craniectomy plus best medical treatment group and 44 (60%) of 73 in the best medical treatment alone group had an mRS of 5-6 (aRR 0·76, 95% CI 0·58 to 1·00, aRD -15%, 95% CI -28 to 0). Severe adverse events occurred in 42 (41%) of 103 participants receiving decompressive craniectomy plus best medical treatment and 41 (44%) of 94 receiving best medical treatment. INTERPRETATION: SWITCH provides weak evidence that decompressive craniectomy plus best medical treatment might be superior to best medical treatment alone in people with severe deep intracerebral haemorrhage. The results do not apply to intracerebral haemorrhage in other locations, and survival is associated with severe disability in both groups. FUNDING: Swiss National Science Foundation, Swiss Heart Foundation, Inselspital Stiftung, and Boehringer Ingelheim.

Aluminium Chloride instead of Ferric chloride for inducing superior sagittal sinus thrombosis to reduce ferromagnetic artifacts on MRI-imaging in experimental models.

Using ferric chloride (FeCl3) to induce experimental superior sagittal sinus (SSS) thrombosis might interfere with magnetic resonance imaging (MRI)-assisted visualization and evaluation of the thrombus, the brain parenchyma, and the quality of the occlusion. The aim of this study was to investigate whether aluminum chloride (AlCl3)-induced thrombosis of the SSS has comparable properties to those of FeCl3 without causing artifacts in MRI. SSS thrombosis was induced in 14 male Wistar rats by exposure of the SSS and subsequent topical application of a filter paper strip soaked in AlCl3 (n = 7) or FeCl3 (n = 7) over a period of 15 min. The animals with AlCl3-induced SSS thrombosis showed a constant and complete occlusion with in histological analysis large thrombi. Blood flow measurements indicated a significant reduction on the first and seventh postoperative day compared to preoperative measurements. MRI enabled visualization and subsequent evaluation of the thrombus and the surrounding parenchyma. In comparison, FeCl3-induced SSS thrombosis could not be evaluated by MRI due to artifacts caused by the paramagnetic properties and increased susceptibility of FeCl3. The occluded sinus and the surrounding area appeared hypointense. The quality of SSS occlusion by AlCl3 was comparable to that of FeCl3. AlCl3 therefore represents a significant alternative substance in experimental SSS thrombosis ideally suited for studies using MRI.

Comparison of vascular risk profile and clinical outcomes among patients with central (branch) retinal artery occlusion versus amaurosis fugax.

BACKGROUND: Retinal artery occlusions lead to sudden, painless vision loss, affecting millions globally. Despite their significance, treatment strategies remain unestablished, contrasting with acute ischemic stroke (AIS), where IVT has proven efficacy. Similar to AIS, retinal artery occlusions demand urgent evaluation and treatment, reflecting the principle "time is retina". Even for patients with transient monocular vision loss, also known as amaurosis fugax (AF), pertinent guidelines meanwhile recommend immediate emergency assessment in a specialized facility. However, data on the clinical benefit and comparability with persistent occlusions are missing. This study aimed to compare the results of a comprehensive stroke-workup among patients with persistent retinal artery occlusions (RAO), including both central retinal (CRAO) and branch retinal artery occlusion (BRAO) and those with AF. METHODS: Conducted at the University Hospital Giessen, Germany, this exploratory cross-sectional study enrolled patients with transient or permanent unilateral vision loss of non-arteritic origin. The primary outcome were differences between the two groups RAO and AF with regard to cardiovascular risk profiles and comorbidities, vascular and pharmacological interventions and clinical neurological and ophthalmological outcomes. Secondary outcome was a sub-group analysis of patients receiving IVT. RESULTS: Out of 166 patients assessed, 76 with RAO and 40 with AF met the inclusion criteria. Both groups exhibited comparable age, gender distribution, and cardiovascular risk profiles. Notably, RAO patients did not show significantly more severe vascular comorbidities than AF patients. However, AF patients received vascular interventions more frequently. Pharmacological intervention rates were similar across groups. RAO patients had slightly worse neurological outcomes, and IVT did not yield favorable ophthalmological outcomes within any observed patients. CONCLUSION: The study found similar vascular burden and risk factors in patients with RAO and AF, with implications for clinical workflows. IVT for RAO may only be effective in very early treatment windows. This emphasizes the need for public awareness and collaborative protocols between ophthalmologists and neurologists to improve outcomes.

Ontario dairy producers' and veterinarians' perspectives: Barriers to biosecurity implementation.

Implementing biosecurity protocols is necessary to reduce the spread of disease on dairy farms. In Ontario biosecurity implementation is variable among farms, and the barriers to implementing biosecurity are unknown. Thirty-five semistructured interviews were conducted between July 2022 and January 2023 with dairy producers (n = 17) and veterinarians (n = 18). Participants also completed a demographic survey. Thematic analysis was performed with constructivist and grounded theory paradigms. Thematic coding was done inductively using NVivo software. Dairy producers' understanding of the definition of biosecurity varied, with all understanding that it was to prevent the spread of disease. Furthermore, the most common perception was that biosecurity prevented the spread of disease onto the farm. Both veterinarians and producers stated that closed herds were one of the most important biosecurity protocols. Barriers to biosecurity implementation included a lack of resources, internal and external business influencers, individual perceptions of biosecurity, and a lack of industry initiative. Understanding the barriers producers face provides veterinarians with the chance to tailor their communication to ensure barriers are reduced or for other industry members to reduce the barriers.

Graduate Student Literature Review: Perceptions of biosecurity in a Canadian dairy context.

The objective of this review was to outline current implementation of biosecurity, the impact of biosecurity on the industry, and producers' and veterinarians' perceptions of biosecurity, with a focus on the Canadian dairy industry. Biosecurity has an important role in farm safety by reducing the spread of pathogens and contaminants, improving animal health and production, and maintaining human safety. Implementation of biosecurity practices varies among farms and countries. Because Canada's supply management system is different than other countries, different barriers and perceptions of biosecurity may exist. Producers may have negative perspectives on biosecurity, such as it being expensive or time consuming. Producers are motivated or deterred from biosecurity implementation for many reasons, including perceived value, disease risk, and financial incentives or deterrents. In addition, because veterinarians are a trusted source of information, their approaches to discussions on biosecurity implementation are important to understand. Veterinarians and producers appear to have differing opinions on the importance of biosecurity and approaches to discussing biosecurity. Improving biosecurity implementation requires a multifactorial approach, such as individualized education and awareness for producers, further research into efficacy of and barriers to biosecurity, and development of strategies for effective communication between veterinarians and producers.

Knockdown of NEAT1 prevents post-stroke lipid droplet agglomeration in microglia by regulating autophagy.

BACKGROUND: Lipid droplets (LD), lipid-storing organelles containing neutral lipids like glycerolipids and cholesterol, are increasingly accepted as hallmarks of inflammation. The nuclear paraspeckle assembly transcript 1 (NEAT1), a long non-coding RNA with over 200 nucleotides, exerts an indispensable impact on regulating both LD agglomeration and autophagy in multiple neurological disorders. However, knowledge as to how NEAT1 modulates the formation of LD and associated signaling pathways is limited. METHODS: In this study, primary microglia were isolated from newborn mice and exposed to oxygen-glucose-deprivation/reoxygenation (OGD/R). To further explore NEAT1-dependent mechanisms, an antisense oligonucleotide (ASO) was adopted to silence NEAT1 under in vitro conditions. Studying NEAT1-dependent interactions with regard to autophagy and LD agglomeration under hypoxic conditions, the inhibitor and activator of autophagy 3-methyladenine (3-MA) and rapamycin (RAPA) were used, respectively. In a preclinical stroke model, mice received intraventricular injections of ASO NEAT1 or control vectors in order to yield NEAT1 knockdown. Analysis of readout parameters included qRT-PCR, immunofluorescence, western blot assays, and behavioral tests. RESULTS: Microglia exposed to OGD/R displayed a temporal pattern of NEAT1 expression, peaking at four hours of hypoxia followed by six hours of reoxygenation. After effectively silencing NEAT1, LD formation and autophagy-related proteins were significantly repressed in hypoxic microglia. Stimulating autophagy in ASO NEAT1 microglia under OGD/R conditions by means of RAPA reversed the downregulation of LD agglomeration and perilipin 2 (PLIN2) expression. On the contrary, application of 3-MA promoted repression of both LD agglomeration and expression of the LD-associated protein PLIN2. Under in vivo conditions, NEAT1 was significantly increased in mice at 24 h post-stroke. Knockdown of NEAT1 significantly alleviated LD agglomeration and inhibited autophagy, resulting in improved cerebral perfusion, reduced brain injury and increased neurological recovery. CONCLUSION: NEAT1 is a key player of LD agglomeration and autophagy stimulation, and NEAT1 knockdown provides a promising therapeutic value against stroke.

Weaning and extubation failure in myasthenic crisis: a multicenter analysis.

Myasthenic crisis (MC) requiring mechanical ventilation is a serious complication of myasthenia gravis (MG). Here we analyze the frequency and risk factors of weaning- and extubation failure as well as its impact on the clinical course in a large cohort. We performed a retrospective chart review on patients treated for MC in 12 German neurological departments between 2006 and 2015. Weaning failure (WF) was defined as negative spontaneous breathing trial, primary tracheostomy, or extubation failure (EF) (reintubation or death). WF occurred in 138 episodes (64.2%). Older Age (p = 0.039), multiple comorbidities (≥ 3) (p = 0.007, OR = 4.04), late-onset MG (p = 0.004, OR = 2.84), complications like atelectasis (p = 0.008, OR = 3.40), pneumonia (p < 0.0001, OR = 3.45), cardio-pulmonary resuscitation (p = 0.005, OR = 5.00) and sepsis (p = 0.02, OR = 2.57) were associated with WF. WF occurred often in patients treated with intravenous immungloblins (IVIG) (p = 0.002, OR = 2.53), whereas WF was less often under first-line therapy with plasma exchange or immunoadsorption (p = 0.07, OR = 0.57). EF was observed in 58 of 135 episodes (43.0%) after first extubation attempt and was related with prolonged mechanical ventilation, intensive care unit stay and hospital stay (p ≤ 0.0001 for all). Extubation success was most likely in a time window for extubation between day 7 and 12 after intubation (p = 0.06, OR = 2.12). We conclude that WF and EF occur very often in MC and are associated with poor outcome. Older age, multiple comorbidities and development of cardiac and pulmonary complications are associated with a higher risk of WF and EF. Our data suggest that WF occurs less frequently under first-line plasma exchange/immunoadsorption compared with first-line use of IVIG.

TREM2 regulates microglial lipid droplet formation and represses post-ischemic brain injury.

Triggering receptor expressed on myeloid cells 2 (TREM2) is a transmembrane receptor protein predominantly expressed in microglia within the central nervous system (CNS). TREM2 regulates multiple microglial functions, including lipid metabolism, immune reaction, inflammation, and microglial phagocytosis. Recent studies have found that TREM2 is highly expressed in activated microglia after ischemic stroke. However, the role of TREM2 in the pathologic response after stroke remains unclear. Herein, TREM2-deficient microglia exhibit an impaired phagocytosis rate and cholesteryl ester (CE) accumulation, leading to lipid droplet formation and upregulation of Perilipin-2 (PLIN2) expression after hypoxia. Knockdown of TREM2 results in increased lipid synthesis (PLIN2, SOAT1) and decreased cholesterol clearance and lipid hydrolysis (LIPA, ApoE, ABCA1, NECH1, and NPC2), further impacting microglial phenotypes. In these lipid droplet-rich microglia, the TGF-ß1/Smad2/3 signaling pathway is downregulated, driving microglia towards a pro-inflammatory phenotype. Meanwhile, in a neuron-microglia co-culture system under hypoxic conditions, we found that microglia lost their protective effect against neuronal injury and apoptosis when TREM2 was knocked down. Under in vivo conditions, TREM2 knockdown mice express lower TGF-ß1 expression levels and a lower number of anti-inflammatory M2 phenotype microglia, resulting in increased cerebral infarct size, exacerbated neuronal apoptosis, and aggravated neuronal impairment. Our work suggests that TREM2 attenuates stroke-induced neuroinflammation by modulating the TGF-ß1/Smad2/3 signaling pathway. TREM2 may play a direct role in the regulation of inflammation and also exert an influence on the post-ischemic inflammation and the stroke pathology progression via regulation of lipid metabolism processes. Thus, underscoring the therapeutic potential of TREM2 agonists in ischemic stroke and making TREM2 an attractive new clinical target for the treatment of ischemic stroke and other inflammation-related diseases.

Rendezvous intervention using combined surgical carotid endarterectomy followed by endovascular thrombectomy in patients with acute tandem occlusions: a proof-of-concept experience at a tertiary care center.

BACKGROUND: Endovascular thrombectomy (EVT) is highly effective in acute stroke patients with intracranial large vessel occlusion (LVO), however, presence of concomitant cervical occlusion of the internal carotid artery (ICA) may limit the endovascular access. This study describes feasibility and efficacy of a surgical carotid access (cutdown) to perform interdisciplinary recanalization therapy including carotid endarterectomy (CEA) followed by EVT for recanalization of intracranial LVO in stroke patients with tandem occlusions. METHODS: We identified stroke patients with tandem occlusions who underwent a combined surgical-endovascular approach over a 5-year period. Surgical cutdown was provided by a cardiovascular surgery team at the angio-suite followed by EVT performed by the neuroradiological team. Demographics, stroke characteristics, treatments including antithrombotic management, procedure times, and clinical follow-up were assessed. RESULTS: Four patients with acute stroke because of tandem occlusions received CEA followed by EVT (two patients after frustrating femoral catheterization, two as first-line approach). Successful recanalization (TICI ≥ 2b) via endovascular thrombectomy was achieved in all patients at a median of 28 min after successful surgical CEA. Intraprocedural complication was observed in one case (25%; i.e. ICA dissection). CONCLUSIONS: This small study provides evidence that a combined interdisciplinary approach of CEA followed by EVT in the angio-suite in acute stroke patients with tandem occlusions is a feasible procedure in patients otherwise not accessible to endovascular recanalizing therapy and, therefore, high likelihood of developing large hemispheric infarction. Prospective data are warranted to identify patients who benefit from this combined approach as first-line therapy.

TGF-ß1 Decreases Microglia-Mediated Neuroinflammation and Lipid Droplet Accumulation in an In Vitro Stroke Model.

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)-ß1 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-ß1 patterns under such conditions, a TGF-ß1 siRNA and an exogenous recombinant TGF-ß1 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-ß1 levels were significantly increased, whereas LPS stimulation yielded decreased levels. Elevating TGF-ß1 expression proved highly effective in suppressing inflammation and reducing LD accumulation in microglia exposed to LPS. Conversely, inhibition of TGF-ß1 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-ß1 and LD levels significantly affected the resistance of co-cultured neurons. This study provides novel insights by demonstrating that TGF-ß1 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.

Peak Edema Extension Distance: An Edema Measure Independent from Hematoma Volume Associated with Functional Outcome in Intracerebral Hemorrhage.

BACKGROUND: Our objective was to test the association between hematoma volume and long-term (> 72 h) edema extension distance (EED) evolution and the association between peak EED and early EED increase with functional outcome at 3 months in patients with intracerebral hemorrhage (ICH). METHODS: This retrospective cohort study included patients with spontaneous supratentorial ICH between January 2006 and January 2014. EED, an edema measure defined as the distance between the hematoma border and the outer edema border, was calculated by using absolute hematoma and edema volumes. We used multivariable logistic regression accounting for age, ICH volume, and location and receiver operating characteristic analysis for assessing measures associated with functional outcome and EED evolution. Functional outcome after 3 months was assessed by using the modified Rankin Scale (0-3 = favorable, 4-6 = unfavorable). To identify properties associated with peak EED multivariable linear and logistic regression analyses were conducted. RESULTS: A total of 292 patients were included. Median age was 70 years (interquartile range [IQR] 62-78), median ICH volume on admission 17.7 mL (IQR 7.9-40.2), median peak perihemorrhagic edema (PHE) volume was 37.5 mL (IQR 19.1-60.6), median peak EED was 0.67 cm (IQR 0.51-0.84) with an early EED increase up to 72 h (EED72-0) of 0.06 cm (- 0.02 to 0.15). Peak EED was found to be independent of ICH volume (R2 = 0.001, p = 0.6). In multivariable analyses, peak EED (odds ratio 0.224, 95% confidence interval [CI] [0.071-0.705]) and peak PHE volume (odds ratio 0.984 [95% CI 0.973-0.994]) were inversely associated with favorable functional outcome at 3 months. Receiver operating characteristic analysis identified a peak PHE volume of 26.8 mL (area under the curve 0.695 [95% CI 0.632-0.759]; p ≤ 0.001) and a peak EED of 0.58 cm (area under the curve 0.608 [95% CI 0.540-0.676]; p = 0.002) as best predictive values for outcome discrimination. CONCLUSIONS: Compared with absolute peak PHE volume, peak EED represents a promising edema measure in patients with ICH that is largely hematoma volume-independent and nevertheless associated with functional outcome.

Tracking cell turnover in human brain using 15N-thymidine imaging mass spectrometry.

Microcephaly is often caused by an impairment of the generation of neurons in the brain, a process referred to as neurogenesis. While most neurogenesis in mammals occurs during brain development, it thought to continue to take place through adulthood in selected regions of the mammalian brain, notably the hippocampus. However, the generality of neurogenesis in the adult brain has been controversial. While studies in mice and rats have provided compelling evidence for neurogenesis occurring in the adult rodent hippocampus, the lack of applicability in humans of key methods to demonstrate neurogenesis has led to an intense debate about the existence and, in particular, the magnitude of neurogenesis in the adult human brain. Here, we demonstrate the applicability of a powerful method to address this debate, that is, the in vivo labeling of adult human patients with 15N-thymidine, a non-hazardous form of thymidine, an approach without any clinical harm or ethical concerns. 15N-thymidine incorporation into newly synthesized DNA of specific cells was quantified at the single-cell level with subcellular resolution by Multiple-isotype imaging mass spectrometry (MIMS) of brain tissue resected for medical reasons. Two adult human patients, a glioblastoma patient and a patient with drug-refractory right temporal lobe epilepsy, were infused for 24 h with 15N-thymidine. Detection of 15N-positive leukocyte nuclei in blood samples from these patients confirmed previous findings by others and demonstrated the appropriateness of this approach to search for the generation of new cells in the adult human brain. 15N-positive neural cells were easily identified in the glioblastoma tissue sample, and the range of the 15N signal suggested that cells that underwent S-phase fully or partially during the 24 h in vivo labeling period, as well as cells generated therefrom, were detected. In contrast, within the hippocampus tissue resected from the epilepsy patient, none of the 2,000 dentate gyrus neurons analyzed was positive for 15N-thymidine uptake, consistent with the notion that the rate of neurogenesis in the adult human hippocampus is rather low. Of note, the likelihood of detecting neurogenesis was reduced because of (i) the low number of cells analyzed, (ii) the fact that hippocampal tissue was explored that may have had reduced neurogenesis due to epilepsy, and (iii) the labeling period of 24 h which may have been too short to capture quiescent neural stem cells. Yet, overall, our approach to enrich NeuN-labeled neuronal nuclei by FACS prior to MIMS analysis provides a promising strategy to quantify even low rates of neurogenesis in the adult human hippocampus after in vivo15N-thymidine infusion. From a general point of view and regarding future perspectives, the in vivo labeling of humans with 15N-thymidine followed by MIMS analysis of brain tissue constitutes a novel approach to study mitotically active cells and their progeny in the brain, and thus allows a broad spectrum of studies of brain physiology and pathology, including microcephaly.

Usage of Inhalative Sedative for Sedation and Treatment of Patient with Severe Brain Injury in Germany, a Nationwide Survey.

Brain injured patients often need deep sedation to prevent or treat increased intracranial pressure. The mainly used IV sedatives have side effects and/or high context-sensitive half-lives, limiting their use. Inhalative sedatives have comparatively minor side effects and a brief context-sensitive half-life. Despite the theoretical advantages, evidence in this patient group is lacking. A Germany-wide survey with 21 questions was conducted to find out how widespread the use of inhaled sedation is. An invitation for the survey was sent to 226 leaders of intensive care units (ICU) treating patients with brain injury as listed by the German Society for Neurointensive Care. Eighty-nine participants answered the questionnaire, but not all items were responded to, which resulted in different absolute counts. Most of them (88%) were university or high-level hospital ICU leaders and (67%) were leaders of specialized neuro-ICUs. Of these, 53/81 (65%) use inhalative sedation, and of the remaining 28, 17 reported interest in using this kind of sedation. Isoflurane is used by 43/53 (81%), sevoflurane by 15/53 (28%), and desflurane by 2. Hypotension and mydriasis are the most common reported side effects (25%). The presented survey showed that inhalative sedatives were used in a significant number of intensive care units in Germany to treat severely brain-injured patients.