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Atherosklerotische Stenosen der Karotiden sind eine häufige Erkrankung mit variablem Verlauf und stellen durch ihre potentielle Emboligenität einen wichtigen Risikofaktor für zerebrale Ischämien dar. Klinische und paraklinische Parameter helfen, das individuelle Schlaganfallrisiko bei Patienten mit hochgradigen ACI-Stenosen einzuschätzen, das unmittelbar nach einem thrombembolischen Ereignis besonders hoch ist. Als histomorphologisches Korrelat dieser "Vulnerabilität" wird die Ruptur der fibrotischen Deckplatte der Plaque propagiert, die häufiger bei symptomatischen Patienten nachzuweisen ist. Sie korreliert mit der Infiltration der Gefäßwand durch aktivierte Leukozyten, die über molekulare und zelluläre Interaktionen die Zell- und Bindegewebskomposition der Plaque verändern können. Die strukturelle Integrität atherosklerotischer Läsionen beruht auf der extrazellulären Vernetzung von kollagenem Bindegewebe, das überwiegend von phänotypisch veränderten glatten Gefäßmuskelzellen produziert wird. Eine Hypothese besagt, dass die im Rahmen der Inflammation stattfindende Zunahme proapoptotischer Mediatoren über eine Ausdünnung der zellulären und bindegewebigen Strukturen zu einem Verlust an mechanischer Stabilität führt und somit eine symptomatische Ruptur begünstigt. Da der Nachweis einer Ruptur mit Exponierung des thrombogenen nekrotischen Kerns allerdings nur in einem Teil der symptomatischen Plaques und umgekehrt auch in einem Teil der asymptomatischen nachgewiesen werden kann, ist aber bislang unklar, ob o.g. Abläufe in der humanen Karotis-Atherosklerose tatsächlich mit einer klinischen Relevanz einhergehen. In der vorliegenden Arbeit wurde daher das Auftreten der Apoptose von glatten Gefäßmuskelzellen (mittels DNA in situ end labeling Technik, TUNEL-Färbung) in 38 prospektiv gesammelten Endarterektomie-Präparaten hochgradiger Karotisstenosen quantitativ erfasst und statistisch in Beziehung gesetzt zu Parametern der Plaque-Instabilität, klinisch definiert durch kürzliche (< 60 Tage zurückliegende) ischämische Ereignisse (n=19) und histopathologisch definiert über den Nachweis einer Plaque-Ruptur (n=14). Außerdem wurde eine morphometrische Analyse der einzelnen Plaque-Komponenten durchgeführt und deren Ergebnisse zu den zellulären und klinischen Parametern in Beziehung gesetzt. Die Morphometrie ergab keine signifikanten Unterschiede zwischen symptomatischen vs. asymptomatischen und rupturierten vs. unrupturierten Plaques was die Größe der fibrotischen Deckplatte, die durchschnittliche Dicke (Kern-Lumen-Distanz) und die dünnsten bzw. dicksten Stellen der Deckplatte anbelangt. Anzahl und Konzentration apoptotischer glatter Muskelzellen war deutlich (p<0,001) erhöht in symptomatischen, klinisch instabilen, Karotisplaques. Allerdings waren die Apoptose-Raten in Präparaten, die eine Plaque-Ruptur aufwiesen, nicht signifikant erhöht. Darüber hinaus fand sich kein Hinweis darauf, dass erhöhte Apoptose-Raten zu einem quantifizierbaren Verlust glatter Gefäßmuskelzellen in der fibrotischen Deckplatte führen. Auf dem Boden dieser Ergebnisse kann gefolgert werden, dass erhöhten Apoptose-Raten glatter Gefäßmuskelzellen in der humanen Atherosklerose offenbar eine tragende Bedeutung bei der Entwicklung thrombembolischer Ereignisse zukommt. Allerdings wird die Annahme, dass erhöhte Apoptose-Raten über einen Verlust an glatten Gefäßmuskelzellen Einfluss auf die morphometrischen Eigenschaften der fibrotischen Deckplatte atherosklerotischer Karotis-Läsionen nehmen und zu deren Ausdünnung führen durch die vorliegende Untersuchung nicht gestützt. Vielmehr scheint es plausibel, dass die Apoptose glatter Muskelzellen im Rahmen inflammatorischer Prozesse Einfluss auf die Komposition der Karotisplaque nimmt und so über eine Desintegration der zellulären und bindegewebigen Bestandteile zu reduzierter mechanischer Widerstandskraft und Rupturneigung führt.
In dieser Studie wurden Patienten untersucht, die einen malignen Hirninfarkt erlitten hatten und mit Hilfe der dekompressiven Hemikraniektomie behandelt wurden. Es wurden die funktionelle Beeinträchtigung, die Körperbehinderung und die Lebensqualität untersucht. Die Patienten wurden sechs Monate nach dem Ereignis kontaktiert, um eine Nachuntersuchung durchzuführen. Dabei wurden die Patienten bezüglich ihrer Beeinträchtigung, Körperbehinderung und Lebensqualität beurteilt. Die Studie beinhaltete 36 Patienten. Daraus resultiert eine Überlebensrate von 64%. Bei 10 Patienten wurde die Beeinträchtigung mit dem Barthel Index mit 50 Punkten beurteilt. In drei Fällen betrug der BI 90 Punkte. Die Mehrheit der Patienten (12) zeigte ernste Beeinträchtigungen (BI<50). Die Behinderung korrelierte negativ mit dem Patientenalter. 16 Patienten waren nicht in der Lage zu gehen und benötigten bei der täglichen Arbeit Hilfe, was einen mRS von 4 oder 5 Punkten entspricht. Keiner der Patienten erreichte einen unabhängigen Status. Patienten, die eine höhere BI-Punktezahl hatten, waren signifikant jünger, hatten weniger schwere Beeinträchtigungen bei der Krankenhausaufnahme, wurden kürzer mechanisch ventiliert und verließen die Intensivstation früher. Die Schwere der Angst oder der Depression korrelierte dabei signifikant mit der Schwere der Behinderung. Die dekompressive Hemikraniektomie verbessert die Überlebensrate dramatisch, reduziert aber nicht die Größe des Infarktvolumens. Die Mehrzahl der Patienten wurde durch den Infarkt deutlich in ihrem Leben beeinträchtigt. Insgesamt ist die Lebensqualität reduziert.
Background: Sphingolipids are versatile signaling molecules derived from membrane lipids of eukaryotic cells. Ceramides regulate cellular processes such as proliferation, differentiation and apoptosis and are involved in cellular stress responses. Experimental evidence suggests a pivotal role of sphingolipids in the pathogenesis of cardiovascular diseases, including ischemic stroke. A neuroprotective effect has been shown for beta-adrenergic antagonists in rodent stroke models and supported by observational clinical data. However, the exact underlying pathophysiological mechanisms are still under investigation. We aimed to examine the influence of propranolol on the ceramide metabolism in the stroke-affected brain.
Methods: Mice were subjected to 60 or 180 min transient middle cerebral artery occlusion (tMCAO) and infarct size, functional neurological deficits, glucose tolerance, and brain ceramide levels were assessed after 12, 24, and 72 h to evaluate whether the latter two processes occur in a similar time frame. Next, we assessed the effects of propranolol (10 mg/kg bw) at 0, 4 and 8 h after tMCAO and FTY720 (fingolimod; 1 mg/kg) on infarct size, functional outcome, immune cell counts and brain ceramide levels at 24 h after 60 min tMCAO.
Results: We found a temporal coincidence between stroke-associated impaired glucose tolerance and brain ceramide accumulation. Whereas propranolol reduced ischemic lesion size, improved functional outcome and reduced brain ceramide accumulation without an effect on circulating immune cells, FTY720 showed the known neuroprotective effect and strong reduction of circulating immune cells without affecting brain ceramide accumulation.
Conclusions: Propranolol ameliorates both stroke-associated impairment of glucose tolerance and brain ceramide accumulation which are temporally linked, strengthening the evidence for a role of the sympathetic nervous system in regulating post-stroke glucose metabolism and its metabolic consequences in the brain.
Introduction: Acute stroke care delivered by interdisciplinary teams is time-sensitive. Simulation-based team training is a promising tool to improve team performance in medical operations. It has the potential to improve process times, team communication, patient safety, and staff satisfaction. We aim to assess whether a multi-level approach consisting of a stringent workflow revision based on peer-to-peer review and 2–3 one-day in situ simulation trainings can improve acute stroke care processing times in high volume neurocenters within a 6 months period.
Methods and Analysis: The trial is being carried out in a pre-test-post-test design at 7 tertiary care university hospital neurocenters in Germany. The intervention is directed at the interdisciplinary multiprofessional stroke teams. Before and after the intervention, process times of all direct-to-center stroke patients receiving IV thrombolysis (IVT) and/or endovascular therapy (EVT) will be recorded. The primary outcome measure will be the “door-to-needle” time of all consecutive stroke patients directly admitted to the neurocenters who receive IVT. Secondary outcome measures will be intervention-related process times of the fraction of patients undergoing EVT and effects on team communication, perceived patient safety, and staff satisfaction via a staff questionnaire.
Interventions: We are applying a multi-level intervention in cooperation with three “STREAM multipliers” from each center. First step is a central meeting of the multipliers at the sponsor's institution with the purposes of algorithm review in a peer-to-peer process that is recorded in a protocol and an introduction to the principles of simulation training and debriefing as well as crew resource management and team communication. Thereafter, the multipliers cooperate with the stroke team trainers from the sponsor's institution to plan and execute 2–3 one-day simulation courses in situ in the emergency department and CT room of the trial centers whereupon they receive teaching materials to perpetuate the trainings.
Clinical Trial Registration: STREAM is a registered trial at https://clinicaltrials.gov/ct2/show/NCT03228251.
Background: Cerebral O2 saturation (ScO2) reflects cerebral perfusion and can be measured noninvasively by near-infrared spectroscopy (NIRS). Objectives: In this pilot study, we describe the dynamics of ScO2 during TAVI in nonventilated patients and its impact on procedural outcome. Methods and Results: We measured ScO2 of both frontal lobes continuously by NIRS in 50 consecutive analgo-sedated patients undergoing transfemoral TAVI (female 58%, mean age 80.8 years). Compared to baseline ScO2 dropped significantly during RVP (59.3% vs. 53.9%, p < .01). Five minutes after RVP ScO2 values normalized (post RVP 62.6% vs. 53.9% during RVP, p < .01; pre 61.6% vs. post RVP 62.6%, p = .53). Patients with an intraprocedural pathological ScO2 decline of >20% (n = 13) had higher EuroSCORE II (3.42% vs. 5.7%, p = .020) and experienced more often delirium (24% vs. 62%, p = .015) and stroke (0% vs. 23%, p < .01) after TAVI. Multivariable logistic regression revealed higher age and large ScO2 drops as independent risk factors for delirium. Conclusions: During RVP ScO2 significantly declined compared to baseline. A ScO2 decline of >20% is associated with a higher incidence of delirium and stroke and a valid cut-off value to screen for these complications. NIRS measurement during TAVI procedure may be an easy to implement diagnostic tool to detect patients at high risks for cerebrovascular complications and delirium.
Sphingosine 1-phosphate (S1P), derived from membrane sphingolipids, is a pleiotropic bioactive lipid mediator capable of evoking complex immune phenomena. Studies have highlighted its importance regarding intracellular signaling cascades as well as membrane-bound S1P receptor (S1PR) engagement in various clinical conditions. In neurological disorders, the S1P–S1PR axis is acknowledged in neurodegenerative, neuroinflammatory, and cerebrovascular disorders. Modulators of S1P signaling have enabled an immense insight into fundamental pathological pathways, which were pivotal in identifying and improving the treatment of human diseases. However, its intricate molecular signaling pathways initiated upon receptor ligation are still poorly elucidated. In this review, the authors highlight the current evidence for S1P signaling in neurodegenerative and neuroinflammatory disorders as well as stroke and present an array of drugs targeting the S1P signaling pathway, which are being tested in clinical trials. Further insights on how the S1P–S1PR axis orchestrates disease initiation, progression, and recovery may hold a remarkable potential regarding therapeutic options in these neurological disorders.
Emerging evidence suggests a complex relationship between sphingosine 1-phosphate (S1P) signaling and stroke. Here, we show the kinetics of S1P in the acute phase of ischemic stroke and highlight accompanying changes in immune cells and S1P receptors (S1PR). Using a C57BL/6 mouse model of middle cerebral artery occlusion (MCAO), we assessed S1P concentrations in the brain, plasma, and spleen. We found a steep S1P gradient from the spleen towards the brain. Results obtained by qPCR suggested that cells expressing the S1PR type 1 (S1P1+) were the predominant population deserting the spleen. Here, we report the cerebral recruitment of T helper (TH) and regulatory T (TREG) cells to the ipsilateral hemisphere, which was associated with differential regulation of cerebral S1PR expression patterns in the brain after MCAO. This study provides insight that the S1P-S1PR axis facilitates splenic T cell egress and is linked to the cerebral recruitment of S1PR+ TH and TREG cells. Further insights by which means the S1P-S1PR-axis orchestrates neuronal positioning may offer new therapeutic perspectives after ischemic stroke.
With increasing distribution of endovascular stroke therapies, transient middle cerebral artery occlusion (tMCAO) in mice now more than ever depicts a relevant patient population with recanalized M1 occlusion. In this case, the desired therapeutic effect of blood flow restauration is accompanied by breakdown of the blood-brain barrier (BBB) and secondary reperfusion injury. The aim of this study was to elucidate short and intermediate-term transcriptional patterns and the involved pathways covering the different cellular players at the neurovascular unit after transient large vessel occlusion. To achieve this, male C57Bl/6J mice were treated according to an intensive post-stroke care protocol after 60 min occlusion of the middle cerebral artery or sham surgery to allow a high survival rate. After 24 h or 7 days, RNA from microvessel fragments from the ipsilateral and the contralateral hemispheres was isolated and used for mRNA sequencing. Bioinformatic analyses allowed us to depict gene expression changes at two timepoints of neurovascular post-stroke injury and regeneration. We validated our dataset by quantitative real time PCR of BBB-associated targets with well-characterized post-stroke dynamics. Hence, this study provides a well-controlled transcriptome dataset of a translationally relevant mouse model 24 h and 7 days after stroke which might help to discover future therapeutic targets in cerebral ischemia/reperfusion injury.
Objectives: To assess tolerability and efficacy of lacosamide in adults with cerebrovascular epilepsy etiology (CVEE).
Materials and methods: Exploratory post hoc analyses of a double‐blind, initial monotherapy trial of lacosamide vs carbamazepine‐controlled release (carbamazepine‐CR) (SP0993; NCT01243177); a double‐blind conversion to lacosamide monotherapy trial (SP0902; NCT00520741); and an observational study of adjunctive lacosamide added to one antiepileptic drug (SP0973 VITOBA; NCT01098162). Patients with CVEE were identified based on epilepsy etiology recorded at baseline.
Results: In the initial monotherapy trial, 61 patients had CVEE (lacosamide: 27; carbamazepine‐CR: 34). 20 (74.1%) patients on lacosamide (27 [79.4%] on carbamazepine‐CR) reported treatment‐emergent adverse events (TEAEs), most commonly (≥10%) headache, dizziness, and fatigue (carbamazepine‐CR: headache, dizziness). A numerically higher proportion of patients on lacosamide than carbamazepine‐CR completed 6 months (22 [81.5%]; 20 [58.8%]) and 12 months (18 [66.7%]; 17 [50.0%]) treatment without seizure at last evaluated dose. In the conversion to monotherapy trial, 26/30 (86.7%) patients with CVEE reported TEAEs, most commonly (≥4 patients) dizziness, convulsion, fatigue, headache, somnolence, and cognitive disorder. During lacosamide monotherapy, 17 (56.7%) patients were 50% responders and six (20.0%) were seizure‐free. In the observational study, 36/83 (43.4%) patients with CVEE reported TEAEs, most commonly (≥5%) fatigue and dizziness. Effectiveness was assessed for 75 patients. During the last 3 months, 60 (80%) were 50% responders and 42 (56.0%) were seizure‐free.
Conclusions: These exploratory post hoc analyses suggested lacosamide was generally well tolerated and effective in patients with CVEE, with data from the initial monotherapy trial suggesting numerically better efficacy than carbamazepine‐CR.
Transcatheter left atrial appendage occlusion (LAAO) is non-inferior to vitamin K antagonists (VKAs) in preventing thromboembolic events in atrial fibrillation (AF). Non-vitamin K antagonists (NOACs) have an improved safety profile over VKAs; however, evidence regarding their effect on cardiovascular and neurological outcomes relative to LAAO is limited. Up-to-date randomized trials or propensity-score-matched data comparing LAAO vs. NOACs in high-risk patients with AF were pooled in our study. A total of 2849 AF patients (LAAO: 1368, NOACs: 1481, mean age: 75 ± 7.5 yrs, 63.5% male) were enrolled. The mean CHA2DS2-VASc score was 4.3 ± 1.7, and the mean HAS-BLED score was 3.4 ± 1.2. The baseline characteristics were comparable between the two groups. In the LAAO group, the success rate of device implantation was 98.8%. During a mean follow-up of 2 years, as compared with NOACs, LAAO was associated with a significant reduction of ISTH major bleeding (p = 0.0002). There were no significant differences in terms of ischemic stroke (p = 0.61), ischemic stroke/thromboembolism (p = 0.63), ISTH major and clinically relevant minor bleeding (p = 0.73), cardiovascular death (p = 0.63), and all-cause mortality (p = 0.71). There was a trend toward reduction of combined major cardiovascular and neurological endpoints in the LAAO group (OR: 0.84, 95% CI: 0.64–1.11, p = 0.12). In conclusion, for high-risk AF patients, LAAO is associated with a significant reduction of ISTH major bleeding without increased ischemic events, as compared to “contemporary NOACs”. The present data show the superior role of LAAO over NOACs among high-risk AF patients in terms of reduction of major bleeding; however, more randomized controlled trials are warranted.