Endovascular Thrombectomy for Anterior Circulation Stroke

Movement disorders following mechanical thrombectomy resulting in ischemic lesions of the basal ganglia: An emerging clinical entity

BACKGROUND AND PURPOSE

Post-stroke movement disorders (PMDs) following ischemic lesions of the basal ganglia (BG) are a known entity, but data regarding their incidence are lacking. Ischemic strokes secondary to proximal middle cerebral artery (MCA) occlusion treated with thrombectomy represent a model of selective damage to the BG. The aim of this study was to assess the prevalence and features of movement disorders after selective BG ischemia in patients with successfully reperfused acute ischemic stroke (AIS).

METHODS

We enrolled 64 consecutive subjects with AIS due to proximal MCA occlusion treated with thrombectomy. Patients were clinically evaluated by a movement disorders specialist for PMDs onset at baseline, and after 6 and 12 months.

RESULTS

None of the patients showed an identifiable movement disorder in the subacute phase of the stroke. At 6 and 12 months, respectively, 7/25 (28%) and 7/13 (53.8%) evaluated patients developed PMDs. The clinical spectrum of PMDs encompassed parkinsonism, dystonia and chorea, either isolated or combined. In most patients, symptoms were contralateral to the lesion, although a subset of patients presented with bilateral involvement and prominent axial signs.

CONCLUSION

Post-stroke movement disorders are not uncommon in long-term follow-up of successfully reperfused AIS. Follow-up conducted by a multidisciplinary team is strongly advisable in patients with selective lesions of the BG after AIS, even if asymptomatic at discharge.

Association of large core middle cerebral artery stroke and hemorrhagic transformation with hospitalization outcomes

Historically, investigators have not differentiated between patients with and without hemorrhagic transformation (HT) in large core ischemic stroke at risk for life-threatening mass effect (LTME) from cerebral edema. Our objective was to determine whether LTME occurs faster in those with HT compared to those without. We conducted a two-center retrospective study of patients with ≥ 1/2 MCA territory infarct between 2006 and 2021. We tested the association of time-to-LTME and HT subtype (parenchymal, petechial) using Cox regression, controlling for age, mean arterial pressure, glucose, tissue plasminogen activator, mechanical thrombectomy, National Institute of Health Stroke Scale, antiplatelets, anticoagulation, temperature, and stroke side. Secondary and exploratory outcomes included mass effect-related death, all-cause death, disposition, and decompressive hemicraniectomy. Of 840 patients, 358 (42.6%) had no HT, 403 (48.0%) patients had petechial HT, and 79 (9.4%) patients had parenchymal HT. LTME occurred in 317 (37.7%) and 100 (11.9%) had mass effect-related deaths. Parenchymal (HR 8.24, 95% CI 5.46-12.42, p < 0.01) and petechial HT (HR 2.47, 95% CI 1.92-3.17, p < 0.01) were significantly associated with time-to-LTME and mass effect-related death. Understanding different risk factors and sequelae of mass effect with and without HT is critical for informed clinical decisions.

Callers' Descriptions of Stroke Symptoms during Emergency Calls in Victims Who Have Fallen or Been Found Lying Down: A Qualitative Content Analysis

Early identification of stroke symptoms is essential. The rate of stroke identification by call-takers at emergency medical communication centres (EMCCs) varies, and patients who are found in a lying down position are often not identified as having an ongoing stroke.

OBJECTIVES

this study aimed to explore signs and symptoms of stroke in patients who had fallen or were found in a lying position.

DESIGN

a retrospective exploratory qualitative study design was used.

METHOD

a total of 29 emergency calls to EMCCs regarding patients discharged with a stroke diagnosis from a large teaching hospital in Stockholm, Sweden, in January-June 2011, were analysed using qualitative content analysis.

RESULTS

during the emergency calls, the callers described a sudden change in the patient's health status including signs such as the patient's loss of bodily control, the patient's perception of a change in sensory perception, and the callers' inability to communicate with the patient.

CONCLUSIONS

The callers' descriptions of stroke in a person found in a lying position are not always as described in assessment protocols describing the onset of a stroke. Instead, the symptom descriptions are much vaguer. Therefore, to increase identification of stroke during emergency calls, there is a need for an increased understanding of how callers describe stroke symptoms and communicate with the call-takers.

Basal ganglia ischaemic infarction after thrombectomy: cognitive impairment at acute stage

BACKGROUND AND PURPOSE

After successful mechanical thrombectomy for middle cerebral artery occlusion, basal ganglia infarction is commonly detectable. Whilst the functional outcome of these patients is often good, less knowledge is available about the cognitive outcome. The aim of our study was to assess the presence of cognitive impairment within 1 week after thrombectomy.

METHODS

In all, 43 subjects underwent a general cognitive assessment using the Montreal Cognitive Assessment and an extensive battery of tests. Patients were classified as cognitively impaired (CImp) or not (noCImp) according to a Montreal Cognitive Assessment score below 18.

RESULTS

Cognitively impaired and noCImp subjects did not differ either in their National Institutes of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) at admittance, or in their Fazekas score and Alberta Stroke Program Early Computed Tomography Score. At discharge, CImp subjects showed higher scores than noCImp subjects on NIHSS (p = 0.002) and mRS (p < 0.001). The percentage of pathological performances on each neuropsychological test in the whole sample and in CImp and noCImp patients shows a similar cognitive profile between the groups.

CONCLUSIONS

Some patients who underwent thrombectomy experienced a detectable cognitive impairment that probably led to worse NIHSS and mRS. The neuropsychological profile of such cognitive impairment at the acute stage consists of wide deficits in numerous cognitive domains, suggesting that basal ganglia damage may lead to complex functional impairments.

Door-to-needle times for patients with ischaemic stroke treated with alteplase by on-site and off-site on-duty neurologists. PRISA study

BACKGROUND

Hospital on-call neurology shifts are frequently on-site, but some on-call services may be off-site or mixed. Intravenous tissue plasminogen activator (tPA) is one of the main reperfusion treatments for acute ischaemic stroke (AIS). This study assesses door-to-needle times (DNT) when the neurologist is on-site or off-site.

METHODS

We performed a prospective, observational study from 2012 to 2017, including patients with AIS and treated with tPA. Data were collected on sex, age, door-to-scan time, scan-to-needle time, and DNT. The on-duty neurologist was on-site from 08:00 to 20:00, and on call but off-site from 20:00 to 8:00. Three groups were formed: on-site, off-site, and off-site with resident present.

RESULTS

Our sample included 138 patients. The mean age was 69.7 years, and 45.7% of patients were women. Ninety-six patients were admitted during the on-site shift, 25 during the off-site shift, and 17 during the off-site-resident present shift. Patients admitted during the on-site and off-site shifts presented DNTs of 59 and 72minutes, respectively (P=.003). DNTs were 59, 74, and 68minutes (P=.001), respectively, for the on-site, off-site, and off-site-resident present shifts; the difference between DNTs for on-site and off-site shifts was statistically significant. No differences were observed between DNTs according to time of day (morning, afternoon, or night), or between weekdays and weekends.

CONCLUSION

DNT is influenced by whether the on-duty neurologist is on- or off-site at the time of code stroke activation. The presence of a neurology resident can reduce DNT.

Five-Year Outcomes After Endovascular Treatment for Large Vessel Occlusion Stroke

Background

The long-term outcomes of acute large vessel occlusion (LVO) in anterior circulation treated by endovascular treatment (EVT) remains to be determined. The aim of this study was to assess the 5-year outcomes of patients with LVO who underwent EVT.

Methods

This study was an observational, nationwide registry of consecutive patients with acute LVO who received EVT in 28 comprehensive stroke centers in China. The primary outcome was the proportion of favorable outcome [modified Rankin Scale score (mRS) 0–2] at 5 years. Secondary outcomes included proportions of patients with excellent outcome (mRS 0–1), all-cause mortality and risk of stroke recurrence at 5 years.

Results

A total of 807 patients were included into the study and had 90-day follow-up data, 657 patients had 5-year follow-up data. At 90 days, 218 patients (27.0%) had an excellent outcome, 349 patients (43.2%) had a favorable functional outcome. 199 patients (24.7%) died. At 5 years, 190 patients (28.9%) had an excellent outcome, 261 patients (39.7%) had a favorable functional outcome, 317 patients (48.2%) died and 129 (28.2%) had stroke recurrence. Because of missing 5-year follow-up data, among available 269 patients who achieved functional independence at 90 days, 208 (77.3%) maintained favorable outcome, 19 (7.1%) had disability (mRS 3–5) and 42 (15.6%) died at 5 years. Furthermore, among available 189 patients with mRS 3–5 at 90 days, 53 (28.0%) patients achieved favorable functional outcome, 60 (31.7%) patients maintained unfavorable functional outcome and 76 (40.2%) patients died within 5 years. Multivariate analyses identified that younger age [odds ratio (OR): 0.96; 95% CI, 0.93–0.99; P = 0.009], lower mRS at 90 days (OR: 0.15; 95% CI, 0.10–0.23; P < 0.001) and absence of stroke recurrence (OR: 0.001; 95% CI, 0.000–0.006; P < 0.001) were significantly associated with favorable outcome at 5 years. Advanced age (OR: 1.06, 95% CI, 1.04–1.08; P < 0.001), higher mRS at 90 days (OR: 0.84; 95% CI, 0.73–0.98; P = 0.021) and atrial fibrillation (OR: 1.63; 95% CI, 1.02–2.60; P = 0.04) were independent factors for stroke recurrence.

Conclusion

Our results indicated that the beneficial effect of EVT in patients with acute LVO can be sustained during the course of at least 5 years. Reducing the risk of stroke recurrence by anticoagulation for atrial fibrillation may be a crucial strategy to improve long-term outcome.

Predictors of Symptomatic Hemorrhage After Endovascular Treatment for Anterior Circulation Occlusions: Turkish Endovascular Stroke Registry

We evaluated the predictive factors of symptomatic intracranial hemorrhage (SICH) in endovascular treatment of stroke. We included 975 ischemic stroke patients with anterior circulation occlusion. Patients that had hemorrhage and an increase of ≥4 points in their National Institutes of Health Stroke Scale (NIHSS) after the treatment were considered as SICH. The mean age of patients was 65.2±13.1 years and 469 (48.1%) were women. The median NIHSS was 16 (13-18) and Alberta Stroke Program Early CT 9 (8-10). In 420 patients (43.1%), modified Rankin Scale was favorable (0-2) and mortality was observed in 234 (24%) patients at the end of the third month. Patients with high diastolic blood pressure (P<.05) had significantly higher SICH. SICH was significantly higher in those with high NIHSS scores (P<.001), high blood glucose (P<.001), and leukocyte count at admission (P<.05). Diabetes mellitus (DM) (OR 1.90; P<.001), NIHSS (OR 1.07; P<.05), adjuvant intra-arterial thrombolytic therapy (IA-rtPA) (OR, 1.60; P<.05), and puncture-recanalization time (OR 1.01; P<.05) were independent factors of SICH. Higher baseline NIHSS score, longer procedure time, multiple thrombectomy maneuvers, administration of IA-rtPA, and the history of DM are independent predictors of SICH in anterior circulation occlusion.

Regional Disparity of Reperfusion Therapy for Acute Ischemic Stroke in Japan: A Retrospective Analysis of Nationwide Claims Data from 2010 to 2015

Background

We aimed to determine whether a regional disparity exists in usage of reperfusion therapy (intravenous recombinant tissue plasminogen activator [IV rt‐PA] and endovascular thrombectomy [EVT]) and post‐reperfusion 30‐day mortality in patients with acute ischemic stroke, and which regional factors are associated with their usage.

Methods and Results

We retrospectively investigated 69 948 patients (mean age±SD, 74.9±12.0 years; women, 41.4%) with acute ischemic stroke treated with reperfusion therapy between April 2010 and March 2016 in Japan using nationwide claims data. Regional disparity was evaluated using Gini coefficients for age‐ and sex‐adjusted usage of reperfusion therapy and 30‐day post‐reperfusion in‐hospital death ratio in 47 administrative regions. The association between regional factors and reperfusion therapy usage was evaluated with fixed‐effects regression models. During the study period, Gini coefficients showed low inequality (0.11–0.15) for use of IV rt‐PA monotherapy and IV rt‐PA and/or EVT and extreme inequality (0.49) for EVT usage in 2010, which became moderate inequality (0.25) by 2015. The densities of stroke centers and endovascular specialists, as well as market concentration, were associated with increased usage of reperfusion therapy whereas the proportion of rural residents and delayed ambulance transport were negatively associated with usage. Inequality in the standardized death ratio after EVT was extreme (0.86) in 2010 but became moderate (0.29) by 2015; inequality was low to moderate (0.17–0.23) for IV rt‐PA monotherapy and IV rt‐PA and/or EVT.

Conclusions

Scrutinizing existing data sources revealed regional disparity in reperfusion therapy for acute ischemic stroke and its associated regional factors in Japan.

Finite element analysis of blood clots based on the nonlinear visco-hyperelastic model

Mechanical thrombectomy has become the standard treatment for patients with an acute ischemic stroke. In this approach, to remove blood clots, mechanical force is applied using thrombectomy devices, in which the interaction between the clot and the device could significantly affect the clot retrieval performance. It is expected that the finite element method (FEM) could visualize the mechanical interaction by the visualization of the stress transmission from the device to the clot. This research was aimed at verifying the constitutive theory by implementing FEM based on the visco-hyperelastic theory, using a three-dimensional clot model. We used the visco-hyperelastic FEM to reproduce the mechanical behavior of blood clots, as observed in experiments. This study is focused on the mechanical responses of clots under tensile loading and unloading because in mechanical thrombectomy, elongation is assumed to occur locally on the clots during the retrieval process. Several types of cylindrical clots were created by changing the fibrinogen dose. Tensile testing revealed that the stiffness (E_0.45-value) of clots with fibrinogen could be more than three times higher than that of clots without fibrinogen. It was also found that the stiffness was not proportional to the fibrinogen dose. By fitting to the theoretical curve, it was revealed that the Mooney-Rivlin model could reproduce the hyperelastic characteristics of clots well. From the stress-relaxation data, the three-chain Maxwell model could accurately fit the experimental viscoelastic data. FEM, taking the theoretical models into account, was then carried out, and the results matched well with the experimental visco-hyperelastic characteristics of clots under tensile load, reproducing the mechanical hysteresis during unloading, the stress dependence on the strain rate, and the time-dependent stress decrease in the stress-relaxation test.

Door-to-needle times in patients treated by on-site and off-site on-call neurologists. PRISA study

BACKGROUND

Hospital on-call neurology shifts are frequently on-site, but some on-call services may be off-site or mixed. Intravenous tissue plasminogen activator (tPA) is one of the main reperfusion treatments for acute ischaemic stroke (AIS). This study assesses door-to-needle times (DNT) when the neurologist is on-site or off-site.

METHODS

We performed a prospective, observational study from 2012 to 2017, including patients with AIS and treated with tPA. Data were collected on sex, age, door-to-scan time, scan-to-needle time, and DNT. The on-duty neurologist was on-site from 08:00 to 20:00, and on call but off-site from 20:00 to 8:00. Three groups were formed: on-site, off-site, and off-site with resident present.

RESULTS

Our sample included 138 patients. The mean age was 69.7 years, and 45.7% of patients were women. Ninety-six patients were admitted during the on-site shift, 25 during the off-site shift, and 17 during the off-site-resident present shift. Patients admitted during the on-site and off-site shifts presented DNTs of 59 and 72 minutes, respectively (P =  .003). DNTs were 59, 74, and 68 minutes (P =  .001), respectively, for the on-site, off-site, and off-site-resident present shifts; the difference between DNTs for on-site and off-site shifts was statistically significant. No differences were observed between DNTs according to time of day (morning, afternoon, or night), or between weekdays and weekends.

CONCLUSION

DNT is influenced by whether the on-duty neurologist is on- or off-site at the time of code stroke activation. The presence of a neurology resident can reduce DNT.

Mapping access to endovascular stroke care in the USA and implications for transport models

BACKGROUND

The purpose of this cross-sectional study was to determine the percentage of the US population with 60 min ground or air access to accredited or state-designated endovascular-capable stroke centers (ECCs) and non-endovascular capable stroke centers (NECCs) and the percentage of NECCs with an ECC within a 30 min drive.

METHODS

Stroke centers were identified and classified broadly as ECCs or NECCs. Geographic mapping of stroke centers was performed. The population was divided into census blocks, and their centroids were calculated. Fastest air and ground travel times from centroid to nearest ECC and NECC were estimated.

RESULTS

Overall, 49.6% of US residents had 60 min ground access to ECCs. Approximately 37.7% (113 million) lack 60 min ground or air access to ECCs. Approximately 84.4% have 60 min access to NECCs. Ground-only access was available to 77.9%. Approximately 738 NECCs (45.4%) had an ECC within a 30 min drive.

CONCLUSION

Nearly one-third of the US population lacks 60 min access to endovascular stroke care, but this is highly variable. Transport models and planning of additional centers should be tailored to each state depending on location and proximity of existing facilities.

Effects of mechanical thrombectomy for post-stroke patients with upper limb hemiparesis: Use of Propensity Score Matching

BACKGROUND

Mechanical Thrombectomy (MT) is a recommended approach for post-cerebral ischemia in acute settings. Although a large amount of evidence suggests the use of MT, existing evidence has primarily focused on assessing lower limb performance or gait performance as an outcome measure.

METHODS

This study was to investigate whether MT would be an effective approach for improving upper limb performance in post-stroke patients.This case control was divided into two groups: 154 patients as a control group only given conventional rehabilitation; and 25 patients as an intervention group given MT and conventional rehabilitation. Outcome variables were measured by calculating the change of Fugl-Meyer Assessment score at the last intervention compared with the beginning of the intervention.

RESULT

By comparing the FMA scores after, the propensity matching compared between before receiving therapy intervention and after, the intervention group showed as follows: 30.4 ± 26.4-44.3 ± 25.4, p = 0.0019, r = 0.59. The control group showed as follows: 39.9 ± 24.1-49.1 ± 21.3, p = 0.002, r = 0.69. Lastly, a comparison of the intervention group with the control group about their FMA score change indicates as follows: intervention group: 13.9 ± 19.4, control group 9.2 ± 10.0, p = 0.2967, r = 0.15.

CONCLUSION

This study indicated that there was no significant difference between MT and a conventional approach for improving UE function. However, this is the first study to investigate the course of recovery of UE function in the acute phase after MT, and this finding supports the need for further research.

Is Endovascular Treatment Still Good for Ischemic Stroke in Real World?: A Meta-Analysis of Randomized Control Trial and Observational Study in the Last Decade

BACKGROUND AND PURPOSE

Although endovascular treatment (EVT) for acute ischemic stroke is classified as I evidence, outcomes after EVT in real-world practice appear to be less superior than those in randomized clinical trials (RCTs). Additionally, the effect of EVT is unclear compared with medical treatment (MT) for patients with mild symptoms defined by National Institutes of Health Stroke Scale score <6 or with severe symptoms defined by Alberta Stroke Program Early CT Score <6.

METHODS

Literatures were searched in big databases and major meetings from December 6, 2009, to December 6, 2019, including RCTs and observational studies comparing EVT against MT for patients with acute ischemic stroke. Observational studies were precategorized into 3 groups based on imaging data on admission: mild stroke group with National Institutes of Health Stroke Scale score <6, severe stroke group with Alberta Stroke Program Early CT Score <6 or ischemic core ≥50 mL, and normal stroke group for all others. Outcome was measured as modified Rankin Scale score of 0 to 2, mortality at 90 days, and symptomatic intracranial hemorrhage (sICH) at 24 hours.

RESULTS

Fifteen RCTs (n=3694) and 37 observational studies (n=9090) were included. EVT was associated with higher modified Rankin Scale 0 to 2 rate and lower mortality in RCTs and normal stroke group, whereas EVT was associated with higher sICH rate in normal stroke group, and no difference of sICH rate appeared between EVT and MT in RCTs. In severe stroke group, EVT was associated with higher modified Rankin Scale 0 to 2 rate and lower mortality, whereas no difference of sICH rate was found. In mild stroke group, there was no difference in modified Rankin Scale 0 to 2 rate between EVT and MT, whereas EVT was associated with higher mortality and sICH rate.

CONCLUSIONS

Evidence from RCTs and observational studies supports the use of EVT as the first-line choice for eligible patients corresponding to the latest guideline. For patients with Alberta Stroke Program Early CT Score <6, EVT showed superiority over MT, also in line with the guidelines. On the contrary to the guideline, our data do not support EVT for patients with National Institutes of Health Stroke Scale score <6.

Transcranial Doppler sonography for detecting stenosis or occlusion of intracranial arteries in people with acute ischaemic stroke

BACKGROUND

An occlusion or stenosis of intracranial large arteries can be detected in the acute phase of ischaemic stroke in about 42% of patients. The approved therapies for acute ischaemic stroke are thrombolysis with intravenous recombinant tissue plasminogen activator (rt-PA), and mechanical thrombectomy; both aim to recanalise an occluded intracranial artery. The reference standard for the diagnosis of intracranial stenosis and occlusion is intra-arterial angiography (IA) and, recently, computed tomography angiography (CTA) and magnetic resonance angiography (MRA), or contrast-enhanced MRA. Transcranial Doppler (TCD) and transcranial colour Doppler (TCCD) are useful, rapid, noninvasive tools for the assessment of intracranial large arteries pathology. Due to the current lack of consensus regarding the use of TCD and TCCD in clinical practice, we systematically reviewed the literature for studies assessing the diagnostic accuracy of these techniques compared with intra-arterial IA, CTA, and MRA for the detection of intracranial stenosis and occlusion in people presenting with symptoms of ischaemic stroke.

OBJECTIVES

To assess the diagnostic accuracy of TCD and TCCD for detecting stenosis and occlusion of intracranial large arteries in people with acute ischaemic stroke.

SEARCH METHODS

We limited our searches from January 1982 onwards as the transcranial Doppler technique was only introduced into clinical practice in the 1980s. We searched MEDLINE (Ovid) (from 1982 to 2018); Embase (Ovid) (from 1982 to 2018); Database of Abstracts of Reviews of Effects (DARE); and Health Technology Assessment Database (HTA) (from 1982 to 2018). Moreover, we perused the reference lists of all retrieved articles and of previously published relevant review articles, handsearched relevant conference proceedings, searched relevant websites, and contacted experts in the field.

SELECTION CRITERIA

We included all studies comparing TCD or TCCD (index tests) with IA, CTA, MRA, or contrast-enhanced MRA (reference standards) in people with acute ischaemic stroke, where all participants underwent both the index test and the reference standard within 24 hours of symptom onset. We included prospective cohort studies and randomised studies of test comparisons. We also considered retrospective studies eligible for inclusion where the original population sample was recruited prospectively but the results were analysed retrospectively.

DATA COLLECTION AND ANALYSIS

At least two review authors independently screened the titles and abstracts identified by the search strategies, applied the inclusion criteria, extracted data, assessed methodological quality (using QUADAS-2), and investigated heterogeneity. We contacted study authors for missing data.

MAIN RESULTS

A comprehensive search of major relevant electronic databases (MEDLINE and Embase) from 1982 to 13 March 2018 yielded 13,534 articles, of which nine were deemed eligible for inclusion. The studies included a total of 493 participants. The mean age of included participants was 64.2 years (range 55.8 to 69.9 years). The proportion of men and women was similar across studies. Six studies recruited participants in Europe, one in south America, one in China, and one in Egypt. Risk of bias was high for participant selection but low for flow, timing, index and reference standard. The summary sensitivity and specificity estimates for TCD and TCCD were 95% (95% CI = 0.83 to 0.99) and 95% (95% CI = 0.90 to 0.98), respectively. Considering a prevalence of stenosis or occlusion of 42% (as reported in the literature), for every 1000 people who receive a TCD or TCCD test, stenosis or occlusion will be missed in 21 people (95% CI = 4 to 71) and 29 (95% CI = 12 to 58) will be wrongly diagnosed as harbouring an intracranial occlusion. However, there was substantial heterogeneity between studies, which was no longer evident when only occlusion of the MCA was considered, or when the analysis was limited to participants investigated within six hours. The performance of either TCD or TCCD in ruling in and ruling out a MCA occlusion was good. Limitations of this review were the small number of identified studies and the lack of data on the use of ultrasound contrast medium.

AUTHORS' CONCLUSIONS

This review provides evidence that TCD or TCCD, administered by professionals with adequate experience and skills, can provide useful diagnostic information for detecting stenosis or occlusion of intracranial vessels in people with acute ischaemic stroke, or guide the request for more invasive vascular neuroimaging, especially where CT or MR-based vascular imaging are not immediately available. More studies are needed to confirm or refute the results of this review in a larger sample of stroke patients, to verify the role of contrast medium and to evaluate the clinical advantage of the use of ultrasound.

Accuracy and Reliability of the Recommendation for IV Thrombolysis in Acute Ischemic Stroke Based on Interpretation of Head CT on a Smartphone or a Laptop

OBJECTIVE. The objective of this study was to assess the accuracy and reliability of IV thrombolysis recommendations made after interpretation of head CT images of patients with symptoms of acute stroke displayed on smartphone or laptop reading systems compared with those made after interpretation of images displayed on a medical workstation monitor. MATERIALS AND METHODS. This retrospective study was institutional review board-approved, and the requirement for informed consent was waived. We used a factorial design including 2256 interpretations (188 patients, four neuroradiologists, and three reading systems). To evaluate the reliability, we calculated the intraobserver and interobserver agreements using the intraclass correlation coefficient (ICC) and the following interpretation variables: hemorrhagic lesions, intraaxial neoplasm, stroke dating (acute, subacute, and chronic), hyperdense arteries, and infarct size assessment. Accuracy equivalence tests were performed for the IV thrombolysis recommendation; for this variable, sensitivity, specificity, and ROC curves were evaluated. RESULTS. Good or very good interobserver and intraobserver agreements were obtained after interpretation of each variable. The IV thrombolysis recommendation showed very good interobserver agreements (ICC ≥ 0.85) and very good intraobserver agreements (ICC ≥ 0.81). For the IV thrombolysis recommendation, the AUC values (0.83-0.84) and sensitivities (0.94-0.95) were equivalent among all the reading systems at a 5% equivalent threshold. CONCLUSION. Our study found that mobile devices are reliable and accurate to help stroke teams to decide whether to administer IV thrombolysis in patients with acute stroke.

Anesthetic Management of Emergency Endovascular Thrombectomy for Acute Ischemic Stroke, Part 1: Patient Characteristics, Determinants of Effectiveness, and Effect of Blood Pressure on Outcome

In the United States, stroke ranks fifth among all causes of death and is the leading cause of serious long-term disability. The 2018 American Heart Association stroke care guidelines consider endovascular thrombectomy to be the standard of care for patients who have acute ischemic stroke in the anterior circulation when arterial puncture can be made within 6 hours of symptom onset or within 6-24 hours of symptom onset when specific eligibility criteria are satisfied. The aim of this 2-part review is to provide practical perspective on the clinical literature regarding anesthesia care of patients treated with endovascular thrombectomy. Part 1 (this article) reviews the development of endovascular thrombectomy and the determinants of endovascular thrombectomy effectiveness irrespective of method of anesthesia. The first aim of part 1 is to explain why rapid workflow and maintenance of blood pressure are necessary to help support the ischemic brain until, as a result of endovascular thrombectomy, reperfusion is accomplished. The second aim of part 1, understanding the nonanesthesia factors determining endovascular thrombectomy effectiveness, is necessary to identify numerous biases present in observational reports regarding anesthesia for endovascular thrombectomy. With this background, in part 2 (the companion to this article), the observational literature is briefly summarized, largely to identify its weaknesses, but also to develop hypotheses derived from it that have been recently tested in 3 randomized clinical trials of sedation versus general anesthesia for endovascular thrombectomy. In part 2, these 3 trials are reviewed both from a functional outcomes perspective (meta-analysis) and a methodological perspective, providing specifics regarding anesthesia and hemodynamic management. Part 2 concludes with a pragmatic approach to anesthesia decision making (sedation versus general anesthesia) and acute phase anesthesia management of patients treated with endovascular thrombectomy.

Guidelines for the Early Management of Patients With Acute Ischemic Stroke: 2019 Update to the 2018 Guidelines for the Early Management of Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

Background and Purpose- The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations in a single document for clinicians caring for adult patients with acute arterial ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 Acute Ischemic Stroke (AIS) Guidelines and are an update of the 2018 AIS Guidelines. Methods- Members of the writing group were appointed by the American Heart Association (AHA) Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. An update of the 2013 AIS Guidelines was originally published in January 2018. This guideline was approved by the AHA Science Advisory and Coordinating Committee and the AHA Executive Committee. In April 2018, a revision to these guidelines, deleting some recommendations, was published online by the AHA. The writing group was asked review the original document and revise if appropriate. In June 2018, the writing group submitted a document with minor changes and with inclusion of important newly published randomized controlled trials with >100 participants and clinical outcomes at least 90 days after AIS. The document was sent to 14 peer reviewers. The writing group evaluated the peer reviewers' comments and revised when appropriate. The current final document was approved by all members of the writing group except when relationships with industry precluded members from voting and by the governing bodies of the AHA. These guidelines use the American College of Cardiology/AHA 2015 Class of Recommendations and Level of Evidence and the new AHA guidelines format. Results- These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings. Conclusions- These guidelines provide general recommendations based on the currently available evidence to guide clinicians caring for adult patients with acute arterial ischemic stroke. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Impact of basal ganglia damage after successful endovascular recanalization for acute ischemic stroke involving lenticulostriate arteries

OBJECTIVE

Regional ischemic vulnerability of the brain reportedly differs between the cortex and basal ganglia and has been poorly assessed in the setting of endovascular mechanical thrombectomy. This study was conducted to determine the fate of an ischemic basal ganglia and its contribution to the clinical outcome after successful endovascular recanalization for acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries.

METHODS

Clinical and radiological findings were retrospectively analyzed in consecutive patients with acute ischemic stroke characterized by large vessel occlusion involving the lenticulostriate arteries. Mechanical thrombectomy was performed in all patients using a stent retriever. The fate of ischemic basal ganglia based on location (lentiform nucleus, caudate nucleus, and internal capsule) and insular cortex was assessed according to the Alberta Stroke Programme Early CT Score (ASPECTS).

RESULTS

Of 170 patients with large intracranial vessel occlusion who achieved successful endovascular recanalization, defined as a thrombolysis in cerebral infarction grade of ≥ 2B, involvement of the lenticulostriate arteries was seen in 55 patients (internal carotid artery, n = 35; proximal middle cerebral artery, n = 20). Preoperative infarction was detected in the lentiform nucleus (66.7%), internal capsule (11.1%), and caudate nucleus (33.3%), all of which showed secondary advancement despite successful recanalization (85.4%, 27.3%, and 54.5%, respectively; p < 0.05). Lenticulostriate arteries with a lateral proximal and/or medial proximal origin significantly affected the development of mature infarction in the lentiform nucleus. Postoperative hemorrhagic transformation was detected in 25 of 55 patients, mostly in the lentiform nucleus. Involvement of insular ribbon infarction was significantly high in patients with hemorrhagic transformation in the basal ganglia. Age, initial National Institutes of Health Stroke Scale (NIHSS) score, initial ASPECTS, postoperative ASPECTS, postoperative infarction in the insular ribbon, and lesions in the middle cerebral artery area (M1-M6) were significantly different between patients with good and poor modified Rankin Scale scores. Interestingly, no differences were detected in postoperative infarction or hemorrhagic transformation in the basal ganglia. Multivariate analysis showed that only age (p = 0.02, OR 0.88) and the initial NIHSS score (p = 0.01, OR 0.86) independently affected favorable clinical outcomes.

CONCLUSIONS

The basal ganglia are vulnerable and readily develop secondary infarction and hemorrhagic transformation despite successful recanalization. However, this does not have a significant impact on the clinical outcome of acute ischemic stroke with large vessel occlusion involving the lenticulostriate arteries.

Long-Term Outcomes of Mechanical Thrombectomy for Stroke: A Meta-Analysis

Mechanical thrombectomy (MT) has become the standard treatment for large vessel occlusion (LVO) in acute ischemic stroke (AIS). Few studies have investigated long-term outcomes for AIS treated with MT. Therefore, a pooled meta-analysis using data from randomized clinical trials (RCT) was performed to assess for long-term clinical outcomes. A systematic literature search was conducted on 27 September 2017, by searching the English literature in the Cochrane Library, MEDLINE, and Embase for RCTs investigating long-term outcomes (greater than standard 3-month timepoint) of endovascular intervention versus medical management for patients with AIS. The study was carried out according to PRISMA guidelines and random effects analysis was carried out to account for heterogeneity. Three trials were included: IMS III, MR CLEAN, and REVASCAT, comprising a total of 1,362 patients. Long-term clinical outcomes were available for 1-year follow-up in IMS III and REVASCAT and at 2 years in MR CLEAN. Functional independence at long-term follow-up favored endovascular stroke intervention (OR 1.51; p = 0.02). When stratified by LVO inclusion criteria, greater endovascular functional independence benefits were observed (OR 1.85; p = 0.0005). There was a significant difference between the 2 arms in favor of endovascular therapy for the quality of life at long-term follow-up (mean difference 0.11; p = 0.0002). No difference in mortality at long-term follow-up was observed (OR 0.82; p = 0.12). We conclude that endovascular therapy results in favorable outcomes at long-term follow-up for patients with acute ischemic stroke compared to standard medical treatment alone and that the 90-day timepoint offers a fair representation of the long-term outcomes.

The safety and efficacy of dexmedetomidine versus propofol for patients undergoing endovascular therapy for acute stroke: A prospective randomized control trial

BACKGROUND

It is uncertain if dexmedetomidine has more favorable pharmacokinetic profile than the traditional sedative drug propofol in patients who undergo endovascular therapy for acute stroke. We conducted a prospective randomized control trial to compare the safety and efficacy of dexmedetomidine with propofol for patients undergoing endovascular therapy for acute stroke.

METHODS

A total of 80 patients who met study inclusion criteria were received either propofol (n = 45) or dexmedetomidine (n = 35) between January 2016 and August 2018. We recorded the favorable neurologic outcome (modified Rankin score <3) both at discharge and 3 months after stroke, National Institute of Health Stroke scale (NIHSS) at 48 hours post intervention, modified thrombolysis in myocardial infarction score on digital subtraction angiography, intraprocedural hemodynamics, recovery time, relevant time intervals, satisfaction score of the surgeon, mortality, and complications.

RESULTS

There were no significant differences between the 2 groups (P > .05) with respect to heart rate, respiratory rate, and SPO2 during the procedure. The mean arterial pressure (MAP) was significantly low in the propofol group until 15 minutes after anesthesia was induced. No difference was recorded between the groups at the incidence of fall in MAP >20%, MAP >40% and time spent with MAP fall >20% from baseline MAP. In the propofol group, the time spent with MAP fall >40% from baseline MAP was significantly long (P < .05). Midazolam and fentanyl were similar between the 2 groups (P > .05) that used vasoactive drugs. The time interval from stroke onset to CT room, from stroke onset to groin puncture, and from stroke onset to recanalization/end of the procedure, was not significantly different between the 2 groups (P > .05). The recovery time was longer in the dexmedetomidine group (P < .05). There was no difference between the groups with respect to complications, favorable neurological outcome, and mortality both at hospital discharge and 3 months later, successful recanalization and NIHSS score after 48 hours (P > .05). However, the satisfaction score of the surgeon was higher in the dexmedetomidine group (P < .05).

CONCLUSIONS

Dexmedetomidine was undesirable than propofol as a sedative agent during endovascular therapy in patients with acute stroke for a long-term functional outcome, though the satisfaction score of the surgeon was higher in the dexmedetomidine group.

Mobile device for thrombolysis decisions for telestroke

Aim:

This study compares the reliability of brain CT interpretations performed using a diagnostic workstation and a mobile tablet computer in a telestroke context.

Methods:

A factorial design with 1,452 interpretations was used. Reliability was evaluated using the Fleiss’ kappa coefficient on the agreements of the interpretation results on the lesion classification, presence of imaging contraindications to the intravenous recombinant tissue-type plasminogen activator (t-PA) administration, and on the Alberta Stroke Program Early CT Score (ASPECTS).

Results:

The intra-observer agreements were as follows: good agreement on the overall lesion classification (κ= 0.63, p<0.001), very good agreement on hemorrhagic lesions (κ= 0.89, p<0.001), and moderate agreements on both without acute lesion classification and acute ischemic lesion classification (κ= 0.59 and κ= 0.58 respectively, p<0.001). There was good intra-observer agreement on the dichotomized-ASPECTS (κ= 0.65, p<0.001).

Conclusions:

The results of our study allow us to conclude that the reliability of the mobile solution for interpreting brain CT images of patients with acute stroke was assured, which would allow efficient and low-cost telestroke services.

Predictive and individualized management of stroke-success story in Czech Republic

The model of centralized stroke care in the Czech Republic was created in 2010-2012 by Ministry of Health (MH) in cooperation with professional organization-Cerebrovascular Section of the Czech Neurological Society (CSCNS). It defines priorities of stroke care, stroke centers, triage of suspected stroke patients, stroke care quality indicators, their monitoring, and reporting. Thirteen complex cerebrovascular centers (CCC) provide sophisticated stroke care, including intravenous thrombolysis (IVT), mechanical thrombectomy (MTE), as well as other endovascular (stenting, coiling) and neurosurgical procedures. Thirty-two stroke centers (SC) provide stroke care except endovascular procedures and neurosurgery. The triage is managed by emergency medical service (EMS). The most important quality indicators of stroke care are number of hospitalized stroke patients, number of IVT, number of MTE, stenting and coiling, number of neurosurgical procedures, and percentage of deaths within 30 days. Indicators provided into the register of stroke care quality (RES-Q) managed by CSCNS are time from stroke onset to hospital admission, door-to-needle time, door-to-groin time, type of ischemic stroke, and others. Data from RES-Q are shared to all centers. Within the last 5 years, the Czech Republic becomes one of the leading countries in acute stroke care. The model of centralized stroke care is highly beneficial and effective. The quality indicators serve as tool of control of stroke centers activities. The sharing of quality indicators is useful tool for mutual competition and feedback control in each center. This comprehensive system ensures high standard of stroke care. This system respects the substantial principles of personalized medicine-individualized treatment of acute stroke and other comorbidities at the acute disease stage; optimal prevention, diagnosis and treatment of possible complications; prediction of further treatment and outcome; individualized secondary prevention, exactly according to the stroke etiology. The described model of stroke care optimally meets criteria of predictive, preventive, and personalized medicine (PPPM), and could be used in other countries as well with the aim of improving stroke care quality in general.

Comparative transcriptome of neurons after oxygen-glucose deprivation: Potential differences in neuroprotection versus reperfusion

In the context of ischemic stroke, rescuing neurons can be theoretically achieved with either reperfusion or neuroprotection. Reperfusion works via the rapid restoration of oxygen and glucose delivery. Neuroprotection comprises molecular strategies that seek to block excitotoxicity, oxidative stress or various cell death pathways. Here, we propose the hypothesis that neurons rescued with reperfusion are different from neurons rescued with molecular neuroprotection. Neurons were subjected to oxygen-glucose deprivation (OGD) and then treated with "in vitro reperfusion" (i.e. energetic rescue via restoration of oxygen and glucose) or Z-VADfmk (to block apoptosis) or MK-801 (to block excitotoxicity). Levels of injury were titrated so that equivalent levels of neuronal salvage were achieved with reperfusion or neuroprotection. Gene arrays showed that OGD significantly altered the transcriptomic profiles of surviving neurons. Pathway analysis confirmed that a large spectrum of metabolic, inflammation, and signaling genes were perturbed. In spite of the fact that equal levels of neuronal salvage were achieved, energetic rescue renormalized the transcriptomic profiles in surviving neurons to a larger degree compared to neuroprotection with either Z-VADfmk or MK-801. These findings suggest that upstream reperfusion may bring salvaged neurons back "closer to normal" compared to downstream molecular neuroprotection.

Systematic review of organizational models for intra-arterial treatment of acute ischemic stroke

Background

Intra-arterial treatment of acute ischemic stroke requires changes to acute stroke services since most hospitals do not have on-site intra-arterial treatment facilities.

Aim

To identify models for delivery of intra-arterial treatment and to compare process performance and clinical and radiological outcomes of the different models.

Methods

We systematically searched the literature and contacted experts in the field. We performed a qualitative synthesis to identify models, and a quantitative review and meta-analysis of clinical and radiological outcomes under different organizational models.

Summary of review

The searches retrieved 148 publications, of which 27 were used for the identification and description of models, and 9 for the comparison of the different models. We identified four main models: the mother-ship, drip-and ship, mobile interventionist, and mobile stroke unit models. There were no randomized-controlled trials of the different models, but non-randomized comparisons were possible using data from 8 observational studies and 1 randomized-controlled trial of intra-arterial therapy, of a total of 4127 patients. Comparison between the mother-ship and drip-and-ship models showed no difference in survival (OR 0.81; 95% CI 0.63–1.03), favorable functional outcome (OR 0.96; 95% CI 0.73–1.25), or arterial patency (OR 0.89; 95% CI 0.73–1.08).

Conclusions

Different organizational models exist for intra-arterial treatment of acute ischemic stroke, but there is insufficient evidence to recommend a particular, universal model. Until one model can be shown to be superior, the choice of model should depend on local factors and patient characteristics.

In vivo imaging biomarkers of neuroinflammation in the development and assessment of stroke therapies - towards clinical translation

Modulation of the inflammatory microenvironment after stroke opens a new avenue for the development of novel neurorestorative therapies in stroke. Understanding the spatio-temporal profile of (neuro-)inflammatory imaging biomarkers in detail thereby represents a crucial factor in the development and application of immunomodulatory therapies. The early integration of quantitative molecular imaging biomarkers in stroke drug development may provide key information about (i) early diagnosis and follow-up, (ii) spatio-temporal drug-target engagement (pharmacodynamic biomarker), (iii) differentiation of responders and non-responders in the patient cohort (inclusion/exclusion criteria; predictive biomarkers), and (iv) the mechanism of action. The use of targeted imaging biomarkers for may thus allow clinicians to decipher the profile of patient-specific inflammatory activity and the development of patient-tailored strategies for immunomodulatory and neuro-restorative therapies in stroke. Here, we highlight the recent developments in preclinical and clinical molecular imaging biomarkers of neuroinflammation (endothelial markers, microglia, MMPs, cell labeling, future developments) in stroke and outline how imaging biomarkers can be used in overcoming current translational roadblocks and attrition in order to advance new immunomodulatory compounds within the clinical pipeline.

2018 Guidelines for the Early Management of Patients With Acute Ischemic Stroke: A Guideline for Healthcare Professionals From the American Heart Association/American Stroke Association

BACKGROUND AND PURPOSE

The purpose of these guidelines is to provide an up-to-date comprehensive set of recommendations for clinicians caring for adult patients with acute arterial ischemic stroke in a single document. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators. These guidelines supersede the 2013 guidelines and subsequent updates.

METHODS

Members of the writing group were appointed by the American Heart Association Stroke Council's Scientific Statements Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained. Members were not allowed to participate in discussions or to vote on topics relevant to their relations with industry. The members of the writing group unanimously approved all recommendations except when relations with industry precluded members voting. Prerelease review of the draft guideline was performed by 4 expert peer reviewers and by the members of the Stroke Council's Scientific Statements Oversight Committee and Stroke Council Leadership Committee. These guidelines use the American College of Cardiology/American Heart Association 2015 Class of Recommendations and Levels of Evidence and the new American Heart Association guidelines format.

RESULTS

These guidelines detail prehospital care, urgent and emergency evaluation and treatment with intravenous and intra-arterial therapies, and in-hospital management, including secondary prevention measures that are appropriately instituted within the first 2 weeks. The guidelines support the overarching concept of stroke systems of care in both the prehospital and hospital settings.

CONCLUSIONS

These guidelines are based on the best evidence currently available. In many instances, however, only limited data exist demonstrating the urgent need for continued research on treatment of acute ischemic stroke.

Novel and emerging technologies for endovascular thrombectomy

Endovascular thrombectomy device improvements in recent years have served a pivotal role in improving the success and safety of the thrombectomy procedure. As the intervention gains widespread use, developers have focused on maximizing the reperfusion rates and reducing procedural complications associated with these devices. This has led to a boom in device development. This review will cover novel and emerging technologies developed for endovascular thrombectomy.

Endogenous regeneration: Engineering growth factors for stroke

Despite the efforts in developing therapeutics for stroke, recombinant tissue plasminogen activator (rtPA) remains the only FDA approved drug for ischemic stroke. Regenerative medicine targeting endogenous growth factors has drawn much interest in the clinical field as it provides potential restoration for the damaged brain tissue without being limited by a narrow therapeutic window. To date, most of the translational studies using regenerative medicines have encountered problems and failures. In this review, we discuss the effects of some trophic factors which include of erythropoietin (EPO), brain derived neurotrophic factor (BDNF), granulocyte-colony stimulating factor (G-CSF), vascular endothelial growth factor (VEGF), fibroblast growth factor (FGF), epidermal growth factor (EGF) and heparin binding epidermal growth factor (HB-EGF) in experimental ischemic stroke models and elaborate the lost in translation of the candidate growth factors from bench to bedside. Several new methodologies have been developed to overcome the caveats in translational studies. This review highlights the latest bioengineering approaches including the controlled release and delivery of growth factors by hydrogel-based scaffolds and the enhancement of half-life and selectivity of growth factors by a novel approach facilitated by glycosaminoglycans.

Relationship between functional disability and costs one and two years post stroke

BACKGROUND AND PURPOSE

Stroke affects mortality, functional ability, quality of life and incurs costs. The primary objective of this study was to estimate the costs of stroke care in Sweden by level of disability and stroke type (ischemic (IS) or hemorrhagic stroke (ICH)).

METHOD

Resource use during first and second year following a stroke was estimated based on a research database containing linked data from several registries. Costs were estimated for the acute and post-acute management of stroke, including direct (health care consumption and municipal services) and indirect (productivity losses) costs. Resources and costs were estimated per stroke type and functional disability categorised by Modified Rankin Scale (mRS).

RESULTS

The results indicated that the average costs per patient following a stroke were 350,000SEK/€37,000-480,000SEK/€50,000, dependent on stroke type and whether it was the first or second year post stroke. Large variations were identified between different subgroups of functional disability and stroke type, ranging from annual costs of 100,000SEK/€10,000-1,100,000SEK/€120,000 per patient, with higher costs for patients with ICH compared to IS and increasing costs with more severe functional disability.

CONCLUSION

Functional outcome is a major determinant on costs of stroke care. The stroke type associated with worse outcome (ICH) was also consistently associated to higher costs. Measures to improve function are not only important to individual patients and their family but may also decrease the societal burden of stroke.

Neuroprotective effects of adjunctive treatments for acute stroke thrombolysis: a review of clinical evidence

The narrow therapeutic time window and risk of intracranial hemorrhage largely restrict the clinical application of thrombolysis in acute ischemic stroke. Adjunctive treatments added to rt-PA may be beneficial to improve the capacity of neural cell to withstand ischemia, and to reduce the hemorrhage risk as well. This review aims to evaluate the neuroprotective effects of adjunctive treatments in combination with thrombolytic therapy for acute ischemic stroke. Relevant studies were searched in the PubMed, Web of Science and EMBASE database. In this review, we first interpret the potential role of adjunctive treatments to thrombolytic therapy in acute ischemic stroke. Furthermore, we summarize the current clinical evidence for the combination of intravenous recombinant tissue plasminogen activator and various adjunctive therapies in acute ischemic stroke, either pharmacological or non-pharmacological therapy, and discuss the mechanisms of some promising treatments, including uric acid, fingolimod, minocycline, remote ischemic conditioning, hypothermia and transcranial laser therapy. Even though fingolimod, minocycline, hypothermia and remote ischemic conditioning have yielded promising results, they still need to be rigorously investigated in further clinical trials. Further trials should also focus on neuroprotective approach with pleiotropic effects or combined agents with multiple protective mechanisms.

Reactive astrogliosis in stroke: Contributions of astrocytes to recovery of neurological function

Alterations in neuronal connectivity, particularly in the "peri-infarct" tissue adjacent to the region of ischemic damage, are important contributors to the spontaneous recovery of function that commonly follows stroke. Peri-infarct astrocytes undergo reactive astrogliosis and play key roles in modulating the adaptive responses in neurons. This reactive astrogliosis shares many features with that induced by other forms of damage to the central nervous system but also differs in details that potentially influence neurological recovery. A subpopulation of astrocytes within a few hundred micrometers of the infarct proliferate and are centrally involved in the development of the glial scar that separates the damaged tissue in the infarct from surrounding normal brain. The intertwined processes of astrocytes adjacent to the infarct provide the core structural component of the mature scar. Interventions that cause early disruption of glial scar formation typically impede restoration of neurological function. Marked reactive astrogliosis also develops in cells more distant from the infarct but these cells largely remain in the spatial territories they occupied prior to stroke. These cells play important roles in controlling the extracellular environment and release proteins and other molecules that are able to promote neuronal plasticity and improve functional recovery. Treatments manipulating aspects of reactive astrogliosis can enhance neuronal plasticity following stroke. Optimising these treatments for use in human stroke would benefit from a more complete characterization of the specific responses of peri-infarct astrocytes to stroke as well as a better understanding of the influence of other factors including age, sex, comorbidities and reperfusion of the ischemic tissue.

The Role of Vascular Imaging in the Initial Assessment of Patients with Acute Ischemic Stroke

Over the last few years, improvement in radiological imaging and treatment has changed the management of acute ischemic stroke. We have made significant advances in not only the imaging modalities themselves but also in identifying imaging parameters that can help us predict patient outcomes with both intravascular thrombolysis and endovascular thrombectomy. In this review, we describe the added utility of baseline vascular imaging including computed tomography angiography and magnetic resonance angiography in the diagnosis and management of patients with acute ischemic stroke. We focus on information these imaging modalities provide on clot characteristics, tissue state, collateral status, and endovascular planning. We also highlight the benefits of newer imaging modalities like dynamic computed tomography angiography (CTA) and multi-phase CTA. Lastly, we also describe some of the disadvantages of vascular imaging in ischemic stroke.

Thomas Willis Lecture

Based on research, mainly in rodents, tremendous progress has been made in our basic understanding of the pathophysiology of stroke. After many failures, however, few scientists today deny that bench-to-bedside translation in stroke has a disappointing track record. I here summarize many measures to improve the predictiveness of preclinical stroke research, some of which are currently in various stages of implementation: We must reduce preventable (detrimental) attrition. Key measures for this revolve around improving preclinical study design. Internal validity must be improved by reducing bias; external validity will improve by including aged, comorbid rodents of both sexes in our modeling. False-positives and inflated effect sizes can be reduced by increasing statistical power, which necessitates increasing group sizes. Compliance to reporting guidelines and checklists needs to be enforced by journals and funders. Customizing study designs to exploratory and confirmatory studies will leverage the complementary strengths of both modes of investigation. All studies should publish their full data sets. On the other hand, we should embrace inevitable NULL results. This entails planning experiments in such a way that they produce high-quality evidence when NULL results are obtained and making these available to the community. A collaborative effort is needed to implement some of these recommendations. Just as in clinical medicine, multicenter approaches help to obtain sufficient group sizes and robust results. Translational stroke research is not broken, but its engine needs an overhauling to render more predictive results.

Analysis of the new code stroke protocol in Asturias after one year. Experience at one hospital

INTRODUCTION

Prehospital code stroke (CS) systems have been proved effective for improving access to specialised medical care in acute stroke cases. They also improve the prognosis of this disease, which is one of the leading causes of death and disability in our setting. The aim of this study is to analyse results one year after implementation of the new code stroke protocol at one hospital in Asturias.

PATIENTS AND METHODS

We prospectively included patients who were admitted to our tertiary care centre as per the code stroke protocol for the period of one year.

RESULTS

We analysed 363 patients. Mean age was 69 years and 54% of the cases were men. During the same period in the previous year, there were 236 non-hospital CS activations. One hundred forty-seven recanalisation treatments were performed (66 fibrinolysis and 81 mechanical thrombectomies or combined treatments), representing a 25% increase with regard to the previous year.

CONCLUSIONS

Recent advances in the management of acute stroke call for coordinated code stroke protocols that are adapted to the needs of each specific region. This may result in an increased number of patients receiving early care, as well as revascularisation treatments.

Endovascular thrombectomy after large-vessel ischaemic stroke: a meta-analysis of individual patient data from five randomised trials

BACKGROUND

In 2015, five randomised trials showed efficacy of endovascular thrombectomy over standard medical care in patients with acute ischaemic stroke caused by occlusion of arteries of the proximal anterior circulation. In this meta-analysis we, the trial investigators, aimed to pool individual patient data from these trials to address remaining questions about whether the therapy is efficacious across the diverse populations included.

METHODS

We formed the HERMES collaboration to pool patient-level data from five trials (MR CLEAN, ESCAPE, REVASCAT, SWIFT PRIME, and EXTEND IA) done between December, 2010, and December, 2014. In these trials, patients with acute ischaemic stroke caused by occlusion of the proximal anterior artery circulation were randomly assigned to receive either endovascular thrombectomy within 12 h of symptom onset or standard care (control), with a primary outcome of reduced disability on the modified Rankin Scale (mRS) at 90 days. By direct access to the study databases, we extracted individual patient data that we used to assess the primary outcome of reduced disability on mRS at 90 days in the pooled population and examine heterogeneity of this treatment effect across prespecified subgroups. To account for between-trial variance we used mixed-effects modelling with random effects for parameters of interest. We then used mixed-effects ordinal logistic regression models to calculate common odds ratios (cOR) for the primary outcome in the whole population (shift analysis) and in subgroups after adjustment for age, sex, baseline stroke severity (National Institutes of Health Stroke Scale score), site of occlusion (internal carotid artery vs M1 segment of middle cerebral artery vs M2 segment of middle cerebral artery), intravenous alteplase (yes vs no), baseline Alberta Stroke Program Early CT score, and time from stroke onset to randomisation.

FINDINGS

We analysed individual data for 1287 patients (634 assigned to endovascular thrombectomy, 653 assigned to control). Endovascular thrombectomy led to significantly reduced disability at 90 days compared with control (adjusted cOR 2.49, 95% CI 1.76-3.53; p<0.0001). The number needed to treat with endovascular thrombectomy to reduce disability by at least one level on mRS for one patient was 2.6. Subgroup analysis of the primary endpoint showed no heterogeneity of treatment effect across prespecified subgroups for reduced disability (pinteraction=0.43). Effect sizes favouring endovascular thrombectomy over control were present in several strata of special interest, including in patients aged 80 years or older (cOR 3.68, 95% CI 1.95-6.92), those randomised more than 300 min after symptom onset (1.76, 1.05-2.97), and those not eligible for intravenous alteplase (2.43, 1.30-4.55). Mortality at 90 days and risk of parenchymal haematoma and symptomatic intracranial haemorrhage did not differ between populations.

INTERPRETATION

Endovascular thrombectomy is of benefit to most patients with acute ischaemic stroke caused by occlusion of the proximal anterior circulation, irrespective of patient characteristics or geographical location. These findings will have global implications on structuring systems of care to provide timely treatment to patients with acute ischaemic stroke due to large vessel occlusion.

FUNDING

Medtronic.

Endovascular treatment versus medical care alone for ischaemic stroke: systematic review and meta-analysis

OBJECTIVES

To evaluate the efficacy and safety of endovascular treatment, particularly adjunctive intra-arterial mechanical thrombectomy, in patients with ischaemic stroke.

DESIGN

Systematic review and meta-analysis.

DATA SOURCES

Medline, Embase, Cochrane Central Register of Controlled Trials, Web of Science, SciELO, LILACS, and clinical trial registries from inception to December 2015. Reference lists were crosschecked.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Randomised controlled trials in adults aged 18 or more with ischaemic stroke comparing endovascular treatment, including thrombectomy, with medical care alone, including intravenous recombinant tissue plasminogen activator (rt-PA). Trial endpoints were functional outcome (modified Rankin scale scores of ≤2) and mortality at 90 days after onset of symptoms. No language or time restrictions applied.

RESULTS

10 randomised controlled trials (n=2925) were included. In pooled analysis endovascular treatment, including thrombectomy, was associated with a higher proportion of patients experiencing good (modified Rankin scale scores ≤2) and excellent (scores ≤1) outcomes 90 days after stroke, without differences in mortality or rates for symptomatic intracranial haemorrhage, compared with patients randomised to medical care alone, including intravenous rt-PA. Heterogeneity was high among studies. The more recent studies (seven randomised controlled trials, published or presented in 2015) proved better suited to evaluate the effect of adjunctive intra-arterial mechanical thrombectomy on its index disease owing to more accurate patient selection, intravenous rt-PA being administered at a higher rate and earlier, and the use of more efficient thrombectomy devices. In most of these studies, more than 86% of the patients were treated with stent retrievers, and rates of recanalisation were higher (>58%) than previously reported. Subgroup analysis of these seven studies yielded a risk ratio of 1.56 (95% confidence interval 1.38 to 1.75) for good functional outcomes and 0.86 (0.69 to 1.06) for mortality, without heterogeneity among the results of the studies. All trials were open label. Risk of bias was moderate across studies. The full results of two trials are yet to be published.

CONCLUSIONS

Moderate to high quality evidence suggests that compared with medical care alone in a selected group of patients endovascular thrombectomy as add-on to intravenous thrombolysis performed within six to eight hours after large vessel ischaemic stroke in the anterior circulation provides beneficial functional outcomes, without increased detrimental effects.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015019340.

Logistical and financial obstacles for endovascular therapy of acute stroke implementation

After publication of the recent positive randomized clinical endovascular trials, several questions and obstacles for wide spread implementation remain. We address specific issues namely efficacy, safety, logistics, timing, sedation, numbers, imaging, manpower, centers, geographics, and economical aspects of endovascular therapy. As we move forward, a high degree of collaboration will be crucial to implement a therapy with established overwhelming treatment efficacy for severe acute stroke patients.

Mechanical thrombectomy in pediatric acute ischemic stroke: Clinical outcomes and literature review

There are limited data on outcomes of mechanical thrombectomy for pediatric stroke using modern devices. In this study, we report two cases of pediatric acute ischemic stroke treated with mechanical thrombectomy, both with good angiographic result (TICI 3) and clinical outcome (no neurological deficits at 90 days). In addition, we conducted a literature review of all previously reported cases describing the use of modern thrombectomy devices. Including our two cases, the aggregate rate of partial or complete vessel recanalization was 100% (22/22), and the aggregate rate of favorable clinical outcome was 91% (20/22). This preliminary evidence suggests that mechanical thrombectomy with modern devices may be a safe and effective treatment option in pediatric patients with acute ischemic stroke.