Search

Publisher Copyright: © 2022 The Authors Background and aims: Glutamine synthetase (GLUL), the sole generator of glutamine, is a metabolic nexus molecule also involved in atherosclerosis. We recently demonstrated a 2.2-fold upregulation of GLUL mRNA in stroke-causing carotid plaques when compared with plaques from asymptomatic patients. Here we compared in the same cohort GLUL mRNA expression with plaque gross morphology, and the colocalization of immunodetectable GLUL protein with histopathological changes and molecular and mechanical mediators linked to plaque development. Methods: Endarterectomy specimens from 19 asymptomatic and 24 stroke patients were sectioned longitudinally and immunostained for GLUL, CD68, α-smooth muscle actin, iron, heme oxygenase-1 and CD163, and graded semiquantitatively in every 1 mm2. The amounts of cholesterol clefts and erythrocytes were graded. The fibrous cap thickness within each 1 mm2 area was measured. The association between the local pathological findings was analyzed by a hierarchical mixed modelling approach. Results: The previously found correlation between GLUL mRNA and clinical symptomatology was supported by the increased GLUL mRNA in diseased tissue and increased local GLUL immunoreactivity in areas with multiple different atherosclerotic changes. A longer symptom-to-operation time correlated with lower GLUL mRNA (Rs = −0.423, p=0.050) but few outliers had a significantly higher GLUL mRNA levels, which persisted throughout the post-symptomatic period. Plaque ulceration associated with 1.8-fold higher GLUL mRNA (p=0.006). Macrophages were the main GLUL immunoreactive cells. GLUL immunostaining colocalized with erythrocytes, iron, CD163, and heme oxygenase-1. The correlations between local variables were consistent in both asymptomatic and stroke-causing plaques. An inverse correlation was found between the fibrous cap thickness and local GLUL immunoreactivity (p=0.012). Considerable variability in interplaque expression pattern of GLUL was present. Conclusions: Our results link connect macrophage GLUL expression with carotid plaque features characterizing plaque vulnerability.

Fatty-acid binding protein 4 (FABP4) is implicated in the pathogenesis of cardiometabolic disorders. Pharmacological inhibition or genetic deletion of FABP4 improves cardiometabolic health and protects against atherosclerosis in preclinical models. As cardiovascular disease (CVD) is common in type 1 diabetes, we examined the role of FABP4 for the development of complications in type 1 diabetes, focusing on a functional, low-expression, variant (rs77878271) in the promoter of the FABP4 gene. For this, we assessed the risk of CVD, stroke, coronary artery disease (CAD), end-stage kidney disease (ESKD), and mortality using Cox proportional-hazard models for the FABP4 rs77878271 in 5,077 Finnish individuals with type 1 diabetes. The low-expression G-allele of rs77878271 increased the risk of CVD, independently of confounders. Findings were tested for replication in 852 Danish and 3,678 Finnish individuals with type 1 diabetes. In the meta-analysis, each G-allele increased the risk of stroke by 26% (p=0.04), CAD by 26% (p=0.006), and CVD by 17% (p=0.003). In Mendelian Randomization, a decrease in FABP4 increased CAD 2.4-fold. Hence, in contrast to the general population, the low-expression G-allele of rs77878271 increased CVD risk in type 1 diabetes, suggesting that genetically low FABP4 levels may be detrimental in the context of type 1 diabetes.

PURPOSE To compare subfoveal choroidal thickness (SFCT) and associated clinical variables in patients with carotid stenosis (CS) before and 6 months after carotid endarterectomy (CEA). METHODS The prospective non-randomized Helsinki Carotid Endarterectomy Study - Brain and Eye Sub-sTudy included seventy patients (81% male, mean age 69 years) and 40 control subjects (77% male, 68 years), from March 2015 to December 2018. Ophthalmological examination included SFCT measured with enhanced-depth imaging-optical coherence tomography. Carotid stenosis (CS) was more severe (≥70% stenosis in 92%) ipsilateral to the CEA than contralaterally (

Purpose Retinal vascular function was assessed in patients with carotid stenosis (CS) before and six months after carotid endarterectomy (CEA) and in controls at a six-month interval. Methods We studied 68 patients (81% male, mean age 69) and 41 healthy non-medicated controls (77%, 68) from March 2015 to December 2018. Our ophthalmological examination included flicker-induced arteriolar and venular measurements with a Dynamic Vessel Analyser in both eyes. Results At baseline, flicker-induced arteriolar and venular dilation was reduced in the ipsilateral eyes of the patients compared with dilation in the controls (arteriolar 1.0% versus 2.6%, p = 0.001 and venular 2.2% versus 2.8%, p = 0.049). These differences subsided after CEA. In patients' ipsilateral eyes, flicker-induced arteriolar dilation was borderline postoperatively (preoperative 1.0% versus postoperative 1.6%, p = 0.06), whereas venular dilation increased (2.2% versus 2.8%, p = 0.025). We found various tentative associations with the change in flicker-induced dilations after CEA, but not with the preoperative dilations. Conclusions Postoperative recovery of the reduced flicker-induced arteriolar and venular dilatation in the ipsilateral eye shows that, after CEA, the activity-dependent vascular reactivity of haemodynamically compromised retinal tissue can improve.

Purpose We describe hypoperfusion-related and embolic ocular signs of carotid stenosis (CS) before and six months after carotid endarterectomy (CEA) in a CS population. Methods We enrolled prospectively 70 CEA patients (81% male, mean age 69) and 41 non-medicated control subjects (76%, 68), from March 2015 to December 2018, assessing intraocular pressure (IOP), best-corrected visual acuity (BCVA) in logMAR units and performing a bio-microscopy examination. Results Main index symptoms included amaurosis fugax (Afx) (29, 41%) and hemispheric TIA (17, 24%), and 17 (24%) were asymptomatic. Of the 70, 17 patients (24%, 95% CI 16-36) showed ocular signs of CS. Of four embolic (Hollenhorst plaques) findings, one small macular plaque disappeared postoperatively. Four had hypoperfusion, that is ocular ischaemic syndrome (OIS), requiring panretinal photocoagulation: one for multiple mid-peripheral haemorrhages, two for iris neovascularization and one for neovascular glaucoma (NVG); only the NVG proved irreversible. Nine (de novo in three) showed mild OIS, that is only few mid-peripheral haemorrhages, ranging pre- /postoperatively in ipsilateral eyes from one to eleven (median two)/ one to two (median one), and in contralateral eyes from three to nine (median five)/ one to six (median three). Pre- and postoperative median BCVA was 0 or better, and mean IOP was normal, except in the NVG patient. Temporary visual impairment from 0 to 0.3 occurred in one eye soon after CEA due to ocular hyperperfusion causing macular oedema. Conclusions Ocular signs of CS are common in CEA patients, ranging from few mid-peripheral haemorrhages to irreversible NVG. Clinicians should be aware of these signs in detecting CS.

Background Accurate identification of acute stroke by Emergency Medical Dispatchers (EMD) is essential for timely and purposeful deployment of Emergency Medical Services (EMS), and a prerequisite for operating mobile stroke units. However, precision of EMD stroke recognition is currently modest. Aims We sought to identify targets for improving dispatcher stroke identification. Methods Dispatch codes and EMS patient records were cross-linked to investigate factors associated with an incorrect dispatch code in a prospective observational cohort of 625 patients with a final diagnosis of acute stroke or transient ischemic attack (TIA), transported to our stroke center as candidates for recanalization therapies. Call recordings were analyzed in a subgroup that received an incorrect low-priority dispatch code indicating a fall or unknown acute illness ( n = 46). Results Out of 625 acute stroke/TIA patients, 450 received a high-priority stroke dispatch code (sensitivity 72.0%; 95% CI, 68.5–75.5). Independent predictors of dispatcher missed acute stroke included a bystander caller (aOR, 3.72; 1.48–9.34), confusion (aOR, 2.62; 1.59–4.31), fall at onset (aOR, 1.86; 1.24–2.78), and older age (aOR [per year], 1.02; 1.01–1.04). Of the analyzed call recordings, 71.7% revealed targets for improvement, including failure to recognize a Face Arm Speech Time (FAST) test symptom (21/46 cases, 18 with speech disturbance), or failure to thoroughly evaluate symptoms (12/46 cases). Conclusions Based on our findings, efforts to improve dispatcher stroke identification should primarily focus on improving recognition of acute speech disturbance, and implementing screening of FAST-symptoms in emergency phone calls revealing a fall or confusion. Clinical Trial Registration URL: http://www.clinicaltrials.gov . Unique identifier: NCT02145663.

Background Plasma glial fibrillary acidic protein (GFAP) and tau are promising markers for differentiating acute cerebral ischemia (ACI) and hemorrhagic stroke (HS), but their prehospital dynamics and usefulness are unknown. Methods We performed ultra-sensitivite single-molecule array (Simoa®) measurements of plasma GFAP and total tau in a stroke code patient cohort with cardinal stroke symptoms [National Institutes of Health Stroke Scale (NIHSS) ≥3]. Sequential sampling included 2 ultra-early samples, and a follow-up sample on the next morning. Results We included 272 cases (203 ACI, 60 HS, and 9 stroke mimics). Median (IQR) last-known-well to sampling time was 53 (35–90) minutes for initial prehospital samples, 90 (67–130) minutes for secondary acute samples, and 21 (16–24) hours for next morning samples. Plasma GFAP was significantly higher in patients with HS than ACI (P 410 pg/mL, or prehospital GFAP 90–410 pg/mL together with GFAP release >0.6 pg/mL/minute) enabled ruling out HS with high certainty (NPV 98.4%) in 68% of patients with ACI (sensitivity for HS 96.6%, specificity 68%, PPV 50%). Conclusions In comparison to single-point measurement, monitoring the prehospital GFAP release rate improves ultra-early differentiation of stroke subtypes. With serial measurement GFAP has potential to improve future prehospital stroke diagnostics.

Fatty acid binding protein 4 (FABP4) is implicated in the pathogenesis of cardiometabolic disorders. Pharmacological inhibition or genetic deletion of FABP4 improves cardiometabolic health and protects against atherosclerosis in preclinical models. As cardiovascular disease (CVD) is common in type 1 diabetes, we examined the role of FABP4 in the development of complications in type 1 diabetes, focusing on a functional, low-expression variant (rs77878271) in the promoter of the

Background and purpose Basilar artery occlusion (BAO) leads to high rates of morbidity and mortality, despite successful recanalization. The discordance between flow restoration and long-term functional status clouds clinical decision-making regarding further aggressive care. We sought to develop and validate a practical, prognostic tool for the prediction of 3-month favorable outcome after acute reperfusion therapy for BAO. Methods This retrospective, multicenter, observational study was conducted at four high-volume stroke centers in the USA and Europe. Multivariate regression analysis was performed to identify predictors of favorable outcome (90-day modified Rankin scale scores 0-2) and derive a clinically applicable prognostic model (the Pittsburgh Outcomes after Stroke Thrombectomy-Vertebrobasilar (POST-VB) score). The POST-VB score was evaluated and internally validated with regard to calibration and discriminatory ability. External validity was assessed in patient cohorts at three separate centers. Results In the derivation cohort of 59 patients, independent predictors of favorable outcome included smaller brainstem infarct volume on post-procedure magnetic resonance imaging (P = 125. Conclusions The POST-VB score effectively predicts 3-month functional outcome following acute reperfusion therapy for BAO and may aid in guiding post-procedural care.

Background The data on long-term outcome after basilar artery occlusion (BAO) are scarce. Little is known about BAO survivors ' outcome over decades. Aim We set out to investigate long-term survival and causes of death in BAO patients with up to two decades of follow-up. We also evaluated differences in outcome trends. Methods Two hundred and seven BAO patients treated with intravenous thrombolysis (IVT) at the Department of Neurology, Helsinki University Hospital, between 1995 and 2016, were analyzed. Short-term outcome was assessed by modified Rankin Scale (mRS) at 3 months. Long-term cumulative survival rate was analyzed using Kaplan-Meier analysis. Factors associated with mortality were analyzed with Cox regression. Results Moderate outcome (mRS 0-3) was achieved in 41.1% and good outcome (mRS 0-2) in 30.4% of patients at 3 months. Three-month mortality was 39.6%, of which 89% died within the first month. The median follow-up time in 3-month survivors was 8.9 years (maximum 21.8 years). Total mortality during follow-up was 52.2%. Cumulative mortality rate was 25.7%. Older age, coronary artery disease and more extensive ischemic changes on admission brain imaging were independently associated with long-term mortality. After the acute phase, the rate of other vascular causes of death increased in relation to stroke. Conclusions The described evolution of a large, single-center BAO cohort shows a trend towards a higher rate of good and/or moderate outcome during later years in IVT-treated patients. Survivors showed relative longevity, and the rate of cardiac and other vascular causes of death increased in relation to stroke sequelae over the long term.

Haptoglobin (Hp) is a plasma protein that binds free hemoglobin and protects tissues from oxidative damage. An Hp2 allele has been associated with an increased risk of cardiovascular complications. On the other hand, recent studies have suggested that Hp1 allele increases risk to develop severe cerebral small vessel disease. We aimed to replicate this finding in a first-ever stroke patient cohort. Hp was genotyped by PCR and gel electrophoresis in the Helsinki Stroke Aging Memory Study in patients with DNA and magnetic resonance imaging (MRI) available (SAM, n = 316). Lacunar infarcts and white matter lesions (WML) classified by Fazekas grading from brain MRI were associated with Hp genotypes. As population controls, we used participants of Cardiovascular diseases&mdash, a sub study of Health 2000 Survey (n = 1417). In the SAM cohort, 63.0% of Hp1-1 carriers (n = 46), 52.5% of Hp1-2 carriers (n = 141) and 51.2% of Hp2-2 carriers (n = 129) had severe WML (p = 0.372). There was no difference in severe WMLs between Hp1-1 vs. Hp1-2 and Hp2-2 carriers (p = 0.201). In addition, 68.9% of Hp1-1 carriers (n = 45), 58.5% of Hp1-2 carriers (n = 135), and 61.8% of Hp2-2 carriers (n = 126) had one or more lacunar lesions (p = 0.472). There was no difference in the number of patients with at least one lacunar infarct between Hp1-1 vs. Hp1-2 and Hp2-2 groups (p = 0.322). Neither was there any difference when diabetic patients (type I and II) were examined separately. Hp1 allele is not associated with an increased risk for cerebral small vessel disease in a well-characterized Finnish stroke patient cohort.

Objective Across stroke subtypes, carotid artery stroke carries the highest risk of recurrence. Despite initiation of best medical therapy (BMT), some patients suffer recurrent neurological events before undergoing carotid endarterectomy (CEA). The aim was to identify clinical predictors of early recurrent events in patients with symptomatic carotid stenosis (sCS) awaiting CEA on modern BMT. Methods The Helsinki Carotid Endarterectomy Study 2 (HeCES2) is a cross sectional, longitudinal, prospective, and consecutive cohort study, which enrolled 500 symptomatic or asymptomatic patients with carotid stenosis scheduled for CEA in a tertiary stroke centre. Symptomatic patients were included for this analysis (n = 324). Results Of all 324 patients with sCS, 39 (12%) had a recurrent cerebrovascular event at a median of six days after the index symptom: four had an ischaemic stroke (1.2%), 16 a hemispheric transient ischaemic attack (TIA; 4.9%), and 19 amaurosis fugax (AFX; 5.9%). The recurrence rate was 4.0 % (n = 13) within 48 h and 9.9% (n = 32) within two weeks. None of the patients (n = 108) presenting with ocular symptoms (AFX or retinal artery occlusion) suffered recurrent hemispheric TIA or stroke. In Cox regression analysis, comorbid hypertension (hazard ratio [HR] 6.58, 95% confidence interval [CI] 1.33–32.47), hemispheric TIA as the index symptom (HR 3.42, 95% CI 1.70–6.90), the number of prior attacks (HR 1.12, 95% CI 1.08–1.15), and high low density lipoprotein/high density lipoprotein ratio (HR 1.51, 95% CI 1.09–2.11) were independently associated with an increased risk of recurrent event, while a history of major cardiovascular event (HR 0.33, 95% CI 0.11–0.96) and high serum fibrinogen level (HR 0.59, 95% CI 0.41–0.86) were associated with a decreased risk. Conclusion More than every tenth patient with sCS experienced an early recurrent cerebrovascular event prior to scheduled CEA, despite optimal medication. However, stroke recurrence was lower than in earlier observational studies, which could be explained by improved care pathways, more aggressive medication, and expedited CEA. All recurrent strokes occurred in patients initially presenting with minor stroke.

Introduction: Every fifth ischemic stroke is caused by thromboembolism originating from an atherosclerotic carotid artery plaque. While prevention is the most cost-effective stroke therapy, antiplatelet and cholesterol-lowering drugs have a ceiling effect in their efficacy. Therefore, discovery of novel pathophysiologic targets are needed to improve the primary and secondary prevention of stroke. This article provides a detailed study design and protocol of HeCES2, an observational prospective cohort study with the objective to investigate the pathophysiology of carotid atherosclerosis.Materials and Methods: Recruitment and carotid endarterectomies of the study patients with carotid atherosclerosis were performed from October 2012 to September 2015. After brain and carotid artery imaging, endarterectomised carotid plaques (CPs) and blood samples were collected from 500 patients for detailed biochemical and molecular analyses.Findings to date: We developed a morphological grading for macroscopic characteristics within CPs. The dominant macroscopic CP characteristics were: smoothness 62%, ulceration 61%, intraplaque hemorrhage 60%, atheromatous gruel 59%, luminal coral-type calcification 34%, abundant (44%) and moderate (39%) intramural calcification, and symptom-causing hot spot area 53%.Future plans: By combining clinically oriented and basic biomedical research, this large-scale study attempts to untangle the pathophysiological perplexities of human carotid atherosclerosis.Key MessagesThis article is a rationale and design of the HeCES2 study that is an observational prospective cohort study with the objective to investigate the pathophysiology of carotid atherosclerosis.The HeCES2 study strives to develop diagnostic algorithms including radiologic imaging to identify carotid atherosclerosis patients who warrant surgical treatment.In addition, the study aims at finding out new tools for clinical risk stratification as well as novel molecular targets for drug development.

Background and aims: Subendothelial interaction of LDL with extracellular matrix drives atherogenesis. This interaction can be strengthened by proteolytic modification of LDL. Mast cells (MCs) are present in atherosclerotic lesions, and upon activation, they degranulate and release a variety of neutral proteases. Here we studied the ability of MC proteases to cleave apoB-100 of LDL and affect the binding of LDL to proteoglycans. Methods: Mature human MCs were differentiated from human peripheral blood-derived CD34(+) progenitors in vitro and activated with calcium ionophore to generate MC-conditioned medium. LDL was incubated in the MC-conditioned medium or with individual MC proteases, and the binding of native and modified LDL to isolated human aortic proteoglycans or to human atherosclerotic plaques ex vivo was determined. MC proteases in atherosclerotic human coronary artery lesions were detected by immunofluorescence and qPCR. Results: Activated human MCs released the neutral proteases tryptase, chymase, carboxypeptidase A3, cathepsin G, and granzyme B. Of these, cathepsin G degraded most efficiently apoB-100, induced LDL fusion, and enhanced binding of LDL to isolated human aortic proteoglycans and human atherosclerotic lesions ex vivo. Double immunofluoresence staining of human atherosclerotic coronary arteries for tryptase and cathepsin G indicated that lesional MCs contain cathepsin G. In the lesions, expression of cathepsin G correlated with the expression of tryptase and chymase, but not with that of neutrophil proteinase 3. Conclusions: The present study suggests that cathepsin G in human atherosclerotic lesions is largely derived from MCs and that activated MCs may contribute to atherogenesis by enhancing LDL retention. (C) 2018 Elsevier B.V. All rights reserved.

Background and Purpose— Haptoglobin (Hp) is an acute phase plasma protein protecting tissues from oxidative damage. It exists in 2 variant alleles ( hp1/hp2 ) giving rise to 3 protein isoforms with different biochemical properties and efficiency to limit oxidative stress. We previously found that hp2 variant is associated with stroke risk in the patients with carotid stenosis and the risk of ischemic cardiovascular events in a general population cohort. This study examined the hypothesis that Hp genotype is associated with general cardiovascular risk in patients with stroke. Methods— Hp was genotyped in SAM study (Helsinki Stroke Aging Memory, n=378). A total of 1426 individuals ascertained from a nationally representative cross-sectional health survey served as population controls. Results— Hp genotype frequencies were 15.6% ( hp1-1 ), 44.2% ( hp1-2 ), and 40.2% ( hp2-2 ) in patients with stroke. During a mean of 7.5-year follow-up after first-ever stroke, hp2 carriers had a substantially higher rate of cardiac deaths (24.5% versus 8.5%; P =0.006) and a trend toward more fatal strokes (23.5% versus 13.6%; P =0.122). The combined risk of ischemic cardiovascular deaths was 2.4-fold higher among hp2 carriers (95% confidence interval, 1.28–4.43) after adjustment for major cardiovascular risk factors. Conclusions— Hp2 allele is associated with premature ischemic cardiovascular deaths after first-ever ischemic stroke.

Objective: The aim of this study was to analyze brain pathologies which cause dementia in the oldest old population. Methods: All 601 persons aged >= 85 years living in the city of Vantaa (Finland), on April 1st, 1991 formed the study population of the Vantaa85 + study, 300 of whom were autopsied during follow-up (79.5% females, mean age-at-death 92 +/- 3.7 years). Alzheimer's disease (AD) pathology (tau and beta-amyloid [Ab]), cerebral amyloid angiopathy (CAA) and Lewy-related pathologies were analyzed. Brain infarcts were categorized by size ( 15 mm) and by location. Brain hemorrhages were classified as microscopic ( 2 mm cortical and subcortical infarcts, and (3)

OBJECTIVES Blood-based biomarkers could enable early and cost-effective diagnostics for acute stroke patients in the prehospital setting to support early initiation of treatments. To facilitate development of ultra-acute biomarkers, we set out to implement large-scale prehospital blood sampling and determine feasibility and diagnostic timesavings of this approach. MATERIALS AND METHODS Emergency medical services (EMS) personnel of the Helsinki metropolitan area were trained to collect prehospital blood samples from thrombolysis candidates using a cannula adapter technique. Time delays, sample quality, and logistics were investigated between May 20, 2013 and May 19, 2014. RESULTS Prehospital blood sampling and study recruiting were successfully performed for 430 thrombolysis candidates, of which 50% had ischemic stroke, 14.4% TIA, 13.5% hemorrhagic stroke, and 22.1% stroke mimics. A total of 66.3% of all samples were collected during non-office hours. The median (interquartile range) emergency call to prehospital sample time was 33 minutes (25-41), and the median time from reported symptom onset or wake-up to prehospital sample was 53 minutes (38-85; n=394). Prehospital sampling was performed 31 minutes (25-42) earlier than hospital admission blood sampling and 37 minutes (30-47) earlier than admission neuroimaging. Hemolysis rate in serum and plasma samples was 6.5% and 9.3% for EMS samples, and 0.7% and 1.6% for admission samples. CONCLUSIONS Prehospital biomarker sampling can be implemented in all EMS units and provides a median timesaving of more than 30 minutes to first blood sample. Large prehospital sample sets will enable development of novel ambulance biomarkers to improve early differential diagnosis and treatment of thrombolysis candidates.

Background and aims Basilar artery occlusion is a most devastating form of stroke, and the current practice is to reverse it with revascularization therapies. Pharmacological thrombolysis, intravenous or intraarterial, has been adjuncted or replaced with invasive, endovascular thrombectomy procedures. The preferred approach remains unknown and many recanalizations are futile with no clinical benefit. We sought to determine reasons for futility and weigh the existing reports to find whether endovascular mechanical interventions provide superior outcomes over pharmacological thrombolysis alone. Methods After analyzing systematically the reports of outcomes produced by variable basilar artery occlusion recanalization protocols, information was retrieved and reconciled from 15 reports published from year 2005 comprising 803 patients in 17 cohorts. In the largest single-center cohort (162, Helsinki), predictors of futile recanalization (three-month modified Rankin Scale score 4 to 6) were determined. Results Good outcome was reported by mechanical approaches either alone or on demand more frequently than by pharmacological, intravenous or intraarterial thrombolysis protocols (35.5% versus 24.4%, p Conclusions Endovascular mechanical approaches have been reported to provide superior outcomes over pharmacological thrombolysis in basilar artery occlusion. Stricter patient selection, most notably to exclude victims of already extended ischemia, would assist in translating excellent recanalization rates into improved clinical outcomes and more acceptable futility rates.

Basilar artery occlusion (BAO) is one of the most devastating forms of stroke and few patients have good outcomes without recanalization. Most centers apply recanalization therapies for BAO up to 12-24 hours after symptom onset, which is a substantially longer time window than the 4.5 hours used in anterior circulation stroke. In this speculative synthesis, we discuss recent advances in BAO treatment in order to understand why and under which circumstances longer symptom duration might not necrotize the brainstem and turn therapeutic attempts futile. We raise the possibility that distinct features of the posterior circulation, e.g., highly developed, persistent collateral arterial network, reverse filling of the distal basilar artery, and delicate plasma flow siding the clot, might sustain brittle patency of brainstem perforators in the face of stepwise growth of the thrombus. Meanwhile, the tissue clock characterizing the rapid necrosis of a typical anterior circulation penumbra will not start. During this perilous time period, recanalization at any point would salvage the brainstem from eventual necrosis caused by imminent reinforcement and further building up of the clot.

Background and Purpose— Significant portion of the prehospital delay consists of minutes spent on the scene with the patient. We implemented a training program for the emergency medical services personnel with the aim to optimize the on-scene time (OST) and to study the impact of different elements of prehospital practice to the OST duration. Methods— In this prospective interventional study, key operational emergency medical service performance variables were analyzed from all thrombolysis candidates transported to the Helsinki University Hospital emergency department. The catchment period was 4 months before and 4 months after the implementation. Results— One hundred and forty-one patients were managed as thrombolysis candidates before and 148 patients after the training program implementation. The OST duration for the groups was 25 (20.5–31) and 22.5 (18–28.5) minutes, respectively ( P Conclusions— Implementation of the emergency medical services training program successfully decreased the OST of thrombolysis candidates by 10%. Higher expertise level of the ambulance crew was associated with shorter OST, and decisions to consult a physician via telephone were reflected by longer OST.

ObjectivesTo clarify diagnostic accuracy and consequences of misdiagnosis in the admission evaluation of stroke-code patients in a neurologic emergency department with less than 20-minute door-to-thrombolysis times.MethodsAccuracy of admission diagnostics was studied in an observational cohort of 1,015 stroke-code patients arriving by ambulance as candidates for recanalization therapy between May 2013 and November 2015. Immediate admission evaluation was performed by a stroke neurologist or a neurology resident with dedicated stroke training, primarily utilizing CT-based imaging.ResultsThe rate of correct admission diagnosis was 91.1% (604/663) for acute cerebral ischemia (ischemic stroke/TIA), 99.2% (117/118) for hemorrhagic stroke, and 61.5% (144/234) for stroke mimics. Of the 150 (14.8%) misdiagnosed patients, 135 (90.0%) had no acute findings on initial imaging and 100 (67.6%) presented with NIH Stroke Scale score 0 to 2. Misdiagnosis altered medical management in 70 cases, including administration of unnecessary treatments (thrombolysis n = 13, other n = 24), omission of thrombolysis (n = 5), delays to specific treatments of stroke mimics (n = 13, median 56 [31–93] hours), and delays to antiplatelet medication (n = 14, median 1 [1–2] day). Misdiagnosis extended emergency department stay (median 6.6 [4.7–10.4] vs 5.8 [3.7–9.2] hours; p = 0.001) and led to unnecessary stroke unit stay (n = 10). Detailed review revealed 8 cases (0.8%) in which misdiagnosis was possible or likely to have worsened outcomes, but no death occurred as a result of misdiagnosis.ConclusionsOur findings support the safety of highly optimized door-to-needle times, built on thorough training in a large-volume, centralized stroke service with long-standing experience. Augmented imaging and front-loaded specialist engagement are warranted to further improve rapid stroke diagnostics.

The gelatinase enzymes, matrix metalloproteinases -2 and -9, are central mediators of blood–brain barrier disruption, actively studied in experimental models of neurological disease. Staining with in situ zymography (ISZ) allows visualization of gelatinase activity directly in brain tissue sections. However, quantifying microvascular gelatinase activity from ISZ-images is challenging and time consuming, as surrounding cell types often show significant confounding activity. We describe validation and performance of a workflow for automated image analysis of cerebromicrovascular gelatinase activity, now released for open-access use. In comparison to manual analysis, the automated workflow showed superior accuracy, was faster to execute and allows for more detailed analysis of heterogeneity in the microvasculature. We further suggest recommendations for quantifying and reporting this type of activity in experimental studies, focusing on ischemic stroke.

Cerebral amyloid angiopathy (CAA) predisposes to symptomatic intracerebral hemorrhage (sICH) after combined thrombolytic and anticoagulant treatment of acute myocardial infarction. However, the role of CAA in stroke thrombolysis has not been established. Here, we describe a confirmed case of CAA-related hemorrhage in a patient receiving thrombolysis for acute ischemic stroke. On autopsy, immunohistochemistry revealed amyloid-β positive staining in thickened cortical and meningeal arteries at sites of hemorrhage. Further research is urgently needed to determine the hemorrhage risk related to CAA in stroke thrombolysis and develop better diagnostic tools to identify CAA in the emergency room.

The beneficial effects of intravenous thrombolysis in ischemic stroke, reperfusion and improved outcome, have been directly correlated to time from onset to treatment. Recanalization of occluded intracranial arteries by tissue-type plasminogen activator (alteplase) has been shown to be effective only for the first few hours after symptom onset. Measured by transcranial Doppler monitoring, the effect of alteplase decreases over time, and treatment delay beyond 4.5 hours predicts lack of recanalization, especially in distal occlusions.1 Will the more fibrin-specific and longer acting fibrinolytics correct this problem in patients admitted beyond the accepted thrombolysis time window of ≤3 to 4.5 hours? A recent report by Albers et al2 provided the outcomes of patients treated with intravenous desmoteplase to reverse occlusion or high-grade stenosis of major cerebral arteries (Desmoteplase in Acute Ischemic Stroke [DIAS]-3 trial) but failed to give support to this idea. This first prospective, randomized, controlled phase 3 trial was designed to detect a possible benefit of a single intravenous bolus of 90 µg/kg of desmoteplase given 3 to 9 hours after onset in patients with confirmed major artery occlusion without substantial ischemic damage.2 Desmoteplase failed to improve functional outcomes at 90 days. It did not increase the rates of symptomatic brain hemorrhage, symptomatic brain edema, and death. On the other hand, significant (nominal P 7 hours after onset of stroke symptoms after a prespecified ordinal analysis.2 In view of a superb safety profile, it should be noted that a previous DIAS-2 trial had tested also a higher dose, 125 µg/kg, in the same time window and observed elevated mortality, albeit predominantly unrelated to the study …

Lipid accumulation is a key characteristic of advancing atherosclerotic lesions. Herein, we analyzed the ultrastructure of the accumulated Lipids in endarterectomized human carotid atherosclerotic plaques using three-dimensional (3D) electron microscopy, a method never used in this context before. 3D electron microscopy revealed intracellular lipid droplets and extracellular Lipoprotein particles. Most of the particles were aggregated, and some connected to needle-shaped or sheet-like cholesterol crystals. Proteomic analysis of isolated extracellular Lipoprotein particles revealed that apolipoprotein B is their main protein component, indicating their origin from low-density lipoprotein, intermediate-density Lipoprotein, very-Low-density lipoprotein, lipoprotein (a), or chylomicron remnants. The particles also contained small exchangeable apolipoproteins, complement components, and immunoglobulins. Lipidomic analysis revealed differences between plasma lipoproteins and the particles, thereby indicating involvement of lipolytic enzymes in their generation. Incubation of human monocyte-derived macrophages with the isolated extracellular lipoprotein particles or with plasma lipoproteins that had been Lipolytically modified in vitro induced intracellular Lipid accumulation and triggered inflammasome activation in them. Taken together, extracellular Lipids accumulate in human carotid plaques as distinct 3D structures that include aggregated and fused lipoprotein particles and cholesterol crystals. The particles originate from plasma lipoproteins, show signs of lipolytic modifications, and associate with cholesterol crystals. By inducing intracellular cholesterol accumulation (ie, foam cell formation) and inflammasome activation, the extracellular lipoprotein particles may actively enhance atherogenesis.

Background and Purpose— In middle cerebral artery occlusion, probability of recanalization after intravenous tissue-type plasminogen activator thrombolysis (IVT) was reported to drop Methods— We evaluated 164 consecutive patients with angiography-proven basilar artery occlusion and available thrombus length. We excluded 24 patients who underwent endovascular treatment. All included patients (n=140) received IVT. Thrombolysis in myocardial infarction 2 to 3 was considered as successful recanalization. Results— Of the 140 included patients, 37 (26.4%) lacked post-treatment angiography, mostly because of early death. Of the remaining 103 patients, those with recanalization had shorter thrombi (median, 5.5 mm and mean, 9.7 mm) when compared with those with nonrecanalized (median, 15.0 mm and mean, 16.6 mm; P 30 mm long thrombi had probabilities of 50% to 70%, 30% to 50%, and 20% to 30%, respectively. Patients with thrombi P =0.01). In multivariable analysis, thrombus length was independently associated with recanalization ( P =0.001). Their relationship remained linear across all lengths. Conclusions— Although recanalization of basilar artery occlusion with IVT depends on thrombus length, its probability even in patients with thrombi >30 mm (20%–30%) was substantially higher than minimal recanalization of middle cerebral artery thrombi exceeding 8 mm. There was no threshold length, beyond which basilar artery occlusion recanalization with IVT could ad hoc be deemed hopeless.

Objective: Intraplaque hemorrhages (IPH) may predispose to unstable atherosclerotic disease and its atherothrombotic complications, ischemic stroke and coronary syndromes. However, the discriminative value of IPH has been limited in histological and imaging studies suggesting that confounding factors modulate the response to IPH. We studied whether common variants of haptoglobin (Hp), which facilitates the removal of free hemoglobin and protects tissues from heme-iron induced oxidative damage, would modify the inflammatory response to IPH and the risk of unstable carotid stenosis (CS) and major cardiovascular diseases. Methods: We genotyped Hp polymorphism in 91 patients with a high-grade CS from Helsinki Carotid Endarterectomy Study (HeCES) and in 1417 individuals from Health 2000, a Finnish epidemiological cross-sectional health survey, and determined heme oxygenase-1 (HO1) expression in relation to Hp genotypes in carotid plaques. Results: In the Health 2000 cohort, Hp genotype frequencies were 0.143 (hp1-1), 0.486 (hp1-2) and 0.371 (hp2-2) consistent with HardyeWeinberg equilibrium and those reported from other Caucasian populations. Among patients with unstable CS, the frequency of hp2-2 genotype was higher than in the control population (0.516 vs. 0.371, P ¼ 0.025). Hp genotypes correlated with HO1 expression in the plaque (r ¼ 0.47, P ¼ 0.027). In the Health 2000 cohort, hp2 allele was associated with an increased risk of major cardiovascular diseases (ischemic stroke, TIA, myocardial infarction, coronary heart disease) with an adjusted OR of 1.46 (95% CI 1.03e2.06). Conclusion: Common haptoglobin variants modulate the inflammatory response to IPH and associate with the risk of unstable carotid stenosis and major ischemic cardiovascular events.

Objective To evaluate the impact of extensive baseline ischemic changes on functional outcome after thrombolysis of basilar artery occlusion (BAO), and to study the effect of time to treatment in the absence of such findings. Methods We prospectively evaluated 184 consecutive patients with angiography-proven BAO. The majority of patients received intravenous alteplase and concomitant full-dose heparin. Extensive baseline ischemia was defined as posterior circulation Acute Stroke Prognosis Early CT score (pc-ASPECTS)

Knowledge builds on steps considered scientific truths,which shall endure the test of time and variations in cir-cumstances. For decades, neuropathologists have used thesequence of cellular changes including immune cell reac-tion in infarcted brain tissue for timing the development ofthe infarction [1, 13]. A generally accepted concept hasbeen that polymorphonuclear neutrophils (PMN) can causeplugging of microvessels within the vascular territory of anoccluded artery even when reperfused [2], and theyextravasate and invade the brain parenchyma at earlystages of infarction (within 15–24 h; e.g., [1, 10, 11, 13, 15,17]. The infiltration of PMNs into ischemic infarcts has ledto the hypothesis that besides adhering to the endotheliumand plugging microvessels before extravasation (no-reflowphenomenon), PMNs release a palette of neurotoxic sub-stances, which contribute to neuronal cell death as acomponent of ischemia–reperfusion injury. Having beenconfirmed in many experimental brain ischemia studies,this hypothesis has stimulated trials of therapeutic inter-ventions based on combatting this PMN response byvarious means (e.g., [5, 14]). Such therapeutic trials tar-geting PMNs have given inconsistent results in bothexperimental studies and clinical trials.This has prompted Drs. Engelhardt and Sorokin torecruit—as the authors state it—a multicenter team com-prising stroke researchers, neuropathologists and basicscientists for collaborative investigation to determine thetemporo-spatial relationship between immune cells andblood vessel microarchitecture in the mouse and humanbrain at early (acute) stages after ischemia. The authorshave applied a wide arsenal of elaborate methods. Tran-sient focal ischemia was induced in mice by occluding themiddle cerebral artery for 30–90 min with a microfilamentfollowed by recirculation from 6 h up to 2 weeks. Com-parison with human cases was performed by assessingbrain histopathology in 25 human victims of stroke. Inaddition, under in vitro flow conditions, they have testedPMN migration across the endothelial monolayer exposedto oxygen and glucose deprivation.The results of the study of Enzmann et al. [6] arechallenging to neuropathologists, who for decades haveobserved PMN infiltration and interpreted it as an inherentcomponent in the sequence of events in infarct maturation.Using specific markers for inflammatory cells and forstructures of the neurovascular unit, Enzmann et al. putforth that in their experimental ischemia model PMNs

Near-occlusion of the internal carotid artery (ICA) is a significant luminal diameter (LD) reduction beyond a tight atherosclerotic carotid stenosis (CS). Recognition of even subtle near-occlusions is essential to prevent underestimation of the stenosis degree. Our goal was to investigate the prevalence of near-occlusion among CS patients using a single standard criterion to facilitate its recognition, even when distal ICA LD reduction is not visually evident in computed tomography angiography (CTA). We analysed carotid artery CTAs of 467 patients with moderate-to-severe CS scheduled for endarterectomy. We performed measurements of the bilateral distal ICA LDs from thin axial source images and utilized a 1.0 mm intra-individual side-to-side distal ICA LD difference to distinguish near-occlusions, based on a previous study, aware of the vagaries of measurement. For analysis stratification, we excluded cases with significant carotid pathology affecting LD measurements. We discovered 126 near-occlusions fulfilling our criterion of ipsilateral near-occlusion: the mean LD side-to-side difference (mm) with 95% confidence interval being 1.8 (1.6, 1.9) and a standard deviation of 0.8 mm. Among the 233 cases not meeting our near-occlusion criterion, we found 140 moderate (50–69%) and 93 severe (70–99%) ipsilateral stenoses. The utilization of 1.0 mm cut-off value for the intra-individual distal ICA LD side-to-side difference to distinguish atherosclerotic ICA near-occlusion leads to a relatively high incidence of near-occlusion. In CTA, recently suggested to be used for near-occlusion diagnosis, a discriminatory 1.0 mm cut-off value could function as a pragmatic tool to enhance the detection of even subtle near-occlusions.

Background and purpose: Blood-based biomarkers could enable early and cost-effective diagnostics for acute stroke patients in the prehospital setting to support early initiation of treatments. However, large prehospital sample sets required for biomarker discovery and validation are missing, and the feasibility of large-scale blood sampling by emergency medical services (EMS) has not been determined. We set out to establish extensive prehospital blood sampling of thrombolysis candidates in the catchment area of our comprehensive stroke center, with a 1.5 million population base. Methods: EMS personnel were trained to collect prehospital blood samples using a cannula-adapter technique. Time delays, sample quality and performance bottlenecks were investigated between May 20, 2013 and May 19, 2014. Results: Prehospital blood sampling and study recruitment were successfully performed in 430 thrombolysis candidates, of which 55.3% were admitted outside office hours. The median (interquartile range) emergency call to prehospital sample time was 33 minutes (25-41), and the median time from reported symptom onset or wake-up to prehospital sample was 53 minutes (38-85; n=394). Prehospital sampling was performed 31 minutes (25-42) earlier than admission blood sampling, and 37 minutes (30-47) earlier than admission neuroimaging. Quality control data from 25 participating EMS units indicated a 4-minute increase in median transport time (from arrival on-scene to hospital door) for study patients compared to patients of the preceding year. The hemolysis rate in serum and plasma samples was 6.5% and 9.3% for EMS samples, and 0.7% and 1.6% for admission samples collected with venipuncture. Conclusions: Prehospital biomarker sampling is feasible in standard EMS units and provides a median timesaving of over 30 minutes to obtain first blood samples. Large biobanks of prehospital blood samples will facilitate development of ultra-acute stroke biomarkers.

Mast cells (MCs) are resident inflammatory cells positioned in the proximity of vascular basal lamina in the cerebral cortex, meninges, and certain deep cerebral structures. MCs are most commonly regarded as key effectors in the pathogenesis of allergic diseases and anaphylaxis, but have been linked to a number of chronic diseases with an autoimmune component in their pathophysiology. MCs produce effects by rapid release or de novo synthesis of various cytokines such as TNF-α, potent proteases such as chymase and tryptase, chemokines, vasoactive substances such as histamine and eicosanoids, and regulators of hemostasis such as heparin and tissue plasminogen activator. They also produce and release matrix metalloproteases. This chapter will review recent experimental research suggesting that MCs and their nominal responses increasing the permeability of the vascular wall play a significant, deleterious role following acute cerebral ischemia. Inhibition of MC effects by pharmacological agents or gene manipulation has been demonstrated to alleviate postischemic blood–brain barrier (BBB) failure, expansive edema, inflammation, neuroinjury, and neurologic dysfunction in models of experimental cerebral ischemia. MCs should be regarded as a potent ischemia-responding cell type that can interact within the neurovascular unit via a multitude of mediators and signalosomes. MCs are a promising novel pharmacologic target in the quest to limit early inflammation and vasculopathic deteriorations within the acute phase of cerebral ischemia.

The most important signs of danger of a headache patient include exceptionally intense or acute headache, transient loss or progressive impairment of consciousness, and neurological deficit symptoms. These patients are referred to an urgent assessment by a physician. Computed tomography scanning of the head is carried out in the case of suspected hemorrhage of a headache patient. Routine diagnosis employing cerebrospinal fluid analysis can be abandoned when excluding subarachnoid hemorrhage in a patient with headache symptoms, if blood is with certainty not observed in the CT scan of the head and no more than six hours have passed after the onset of the symptom. If subarachnoid hemorrhage is detected, cerebral CT angiography will be performed at the same time and a neurosurgeon consulted about the need of operative treatment.

Background and Purpose— Basilar artery occlusion has a high mortality rate (85% to 95%) if untreated. We describe a large single-center cohort treated mostly with intravenous alteplase and heparin. Methods— The cohort included 116 patients with angiography-verified basilar artery occlusion. We studied baseline characteristics, frequencies of recanalization and symptomatic intracranial hemorrhage, and 3-month outcome (modified Rankin Scale [mRS]). Results— Thirty patients (25.9%) had mRS 0 to 2, 42 patients (36.2%) had moderate outcome (mRS, 0–3), 26 patients (22.4%) required daily help (mRS, 4–5), and 48 patients (41.4%) died. Eighteen patients (15.7%) developed symptomatic intracranial hemorrhage. In patients with post-treatment angiogram available (n=91), 59 patients (64.8%) had a complete or partial recanalization. Radiological location of basilar artery occlusion was known in 55 of 91 instances, and recanalization was associated directly with clot location at the top-of-basilar (odds ratio, 4.8 [1.1–22]; P =0.048). Independent outcome (mRS 0-2) was associated with lower age and National Institutes of Health Stroke Scale (NIHSS) score at baseline. Age, nil or minimal recanalization, and symptomatic intracranial hemorrhage were independently associated with fatal outcome. Sixteen of 71 patients (22.5%) who presented with coma eventually reached moderate outcome, and additional 8 patients (11.3%) progressed to mRS 4. Conclusions— Whereas recanalization after intravenous thrombolysis strongly predicts survival and moderate outcome, therapeutic techniques should concentrate on clot location. Although most adverse baseline variables, age, symptom severity, but also coma are beyond control, it should not preclude thrombolysis, which may permit independent survival.

Diabetes mellitus predicts an increased risk of stroke, and acute hyperglycemia during acute stroke predicts the presence of undiagnosed diabetes mellitus. Based on recent investigations, 28% of previously nondiabetic stroke or transient ischemic attack patients have undetected diabetes mellitus, and 29% have impaired glucose tolerance, while only 43% have normal glycemic control. Oral glucose tolerance test is a far more sensitive and reliable test of diabetes mellitus than fasting blood glucose or HbA1c, and is recommended in the World Health Organization criteria for diagnosing diabetes mellitus and impaired glucose tolerance. Secondary prevention of stroke is different in patients with diabetes mellitus and the detection of impaired glucose tolerance would ring alarm bells of impending diabetes mellitus and promote lifestyle changes. As screening with inexpensive oral glucose tolerance test would have a hit rate of one in three patients in revealing undetected diabetes mellitus and another one in three in revealing impaired glucose tolerance, it should be implemented in guidelines as an inexpensive test for monitoring stroke and transient ischemic attack patients.