Importance of cerebral artery recanalization in patients with stroke with and without neurological improvement after intravenous thrombolysis

A comprehensive review for artificial intelligence on neuroimaging in rehabilitation of ischemic stroke

Stroke is the second leading cause of death worldwide, with ischemic stroke accounting for a significant proportion of morbidity and mortality among stroke patients. Ischemic stroke often causes disability and cognitive impairment in patients, which seriously affects the quality of life of patients. Therefore, how to predict the recovery of patients can provide support for clinical intervention in advance and improve the enthusiasm of patients for rehabilitation treatment. With the popularization of imaging technology, the diagnosis and treatment of ischemic stroke patients are often accompanied by a large number of imaging data. Through machine learning and Deep Learning, information from imaging data can be used more effectively. In this review, we discuss recent advances in neuroimaging, machine learning, and Deep Learning in the rehabilitation of ischemic stroke.

Neurological Improvement by One-Thirds Is Associated With Early Recanalization in Stroke With Large Vessel Occlusion

BACKGROUND

A proportion of large vessel occlusion strokes demonstrate early recanalization, obviating the initial intention to proceed to endovascular thrombectomy. Neurological improvement is a possible surrogate marker for reperfusion. We aimed to determine the optimal threshold of neurological improvement, as defined by the National Institutes of Health Stroke Scale (NIHSS), which best associates with early recanalization.

METHODS

We retrospectively analyzed consecutive patients with large vessel occlusion transferred from primary stroke centers to a tertiary comprehensive stroke center in Melbourne, Australia, for possible endovascular thrombectomy from January 2018 to December 2022. Absolute and percentage changes in NIHSS between transfer, as well as other definitions of neurological improvement, were compared using receiver operating characteristic curve analysis for association with recanalization as defined by the absence of occlusion in the internal carotid artery, middle cerebral artery (M1 or M2 segments), or basilar artery on repeat vascular imaging.

RESULTS

Six hundred and fifty-four transferred patients with large vessel occlusion were included in the analysis: mean age was 68.8±14.0 years, 301 (46.0%) were women, and 338 (52%) received intravenous thrombolytics. The proportion of extracranial internal carotid artery, intracranial internal carotid artery, M1, proximal M2, and basilar artery occlusion was 18.8%, 13.6%, 48.3%, 15.0%, and 4.3%, respectively, on initial computed tomography angiogram. Median NIHSSprimary stroke center and NIHSScomprehensive stroke center scores were 15 (interquartile range, 9-18) and 13 (interquartile range, 8-19), respectively. Early recanalization occurred in 82 (13%) patients. NIHSS reduction of ≥33% was the best tradeoff between sensitivity (64%) and specificity (83%) for identifying recanalization. NIHSS reduction of ≥33% had the highest discriminative ability to predict recanalization (area under the curve, 0.735) in comparison with other definitions of neurological improvement.

CONCLUSIONS

One-third neurological improvement between the primary hospital and tertiary center was the best predictor of early recanalization.

Safety and efficacy of N-acetylcysteine (NAC) as an adjunct to standard treatment in patients with acute ischemic stroke: a randomized controlled pilot trial (NACTLYS)

There is a pressing clinical need for thrombolytic agents that can effectively disaggregate arterial thrombi in acute ischemic stroke without significantly increasing the risk of bleeding. This pilot study aimed to investigate the safety and efficacy of N-acetylcysteine (NAC) as an adjunctive therapy to intravenous recombinant tissue plasminogen activator (rtPA or alteplase). A randomized, open-label, blinded assessor pilot study was conducted. Patients presenting with an acute ischemic stroke within 4.5 h from onset were randomized into two groups: intravenous NAC and rtPA or rtPA alone. Primary outcomes included intracerebral hemorrhage, symptomatic intracerebral hemorrhage, extracranial bleeding, and adverse reactions. Secondary outcomes comprised major neurological improvement assessed by (National Institute of Health Stroke Scale) NIHSS at 24 h, recanalization on first run of angiography in patients who underwent thrombectomy or on repeat vascular imaging at 24 h, modified Rankin scale, and three-month mortality. Forty patients were enrolled, with 21 receiving only rtPA and 19 receiving NAC with rtPA. Baseline characteristics were comparable among groups. No significant differences were observed in adverse events (p = 0.99), intracranial hemorrhage (p = 0.21), symptomatic intracerebral hemorrhage (p = 0.47), or extracranial bleeding (p = 0.21). Median NIHSS at 24 h was significantly lower in the intervention group (p = 0.03). Functional outcomes and three-month mortality were similar between groups (p = 0.85 and p = 0.99 respectively). The co-administration of N-acetylcysteine with alteplase did not significantly alter safety profiles, morbidity, or mortality at 3 months. While no substantial differences were noted, a slightly improved early neurological outcome was observed in the intervention arm. The study's findings were constrained by a small sample size, emphasizing the necessity for future large-scale trials to comprehensively evaluate the safety and efficacy of N-acetylcysteine as a thrombolytic agent in acute ischemic stroke.Trial Registration Clinical Trials Registry India-CTRI/2019/05/019305.

Reocclusion after successful endovascular treatment in acute ischemic stroke: systematic review and meta-analysis

BACKGROUND

Endovascular treatment (EVT) is the standard of care for selected patients with acute ischemic stroke (AIS) due to large vessel occlusion (LVO).

OBJECTIVE

To systematically review the available data on: (1) incidence, predictors, and outcomes of patients with reocclusion after successful EVT for AIS and, (2) the characteristics, complications, and outcomes of patients with reocclusion treated with repeated EVT (rEVT) within 30 days of the first procedure.

METHODS

PubMed was searched (between January 2012 and April 2021) to identify studies reporting reocclusion following successful EVT (Thrombolysis in Cerebral Infarction ≥2b) in patients with AIS due to LVO. Pooled incidence of reocclusion per 100 patients with successful recanalization following EVT was calculated using a random-effects model with Freeman-Tukey double arcsine transformation. Extracted incidences of reocclusion according to etiology and use of intravenous thrombolysis were pooled using random-effects meta-analytic models.

RESULTS

A total of 840 studies was identified and seven studies qualified for the quantitative analysis, which described 91 same-vessel reocclusions occurring within the first 7 days after treatment among 2067 patients (4.9%; 95% CI 3% to 7%, I2=70.2%). Large vessel atherosclerosis was associated with an increased risk of reocclusion (OR=3.44, 95% CI 1.12 to 10.61, I2=50%). We identified 90 patients treated with rEVT for recurrent LVO, described in five studies. The rates of procedural complications, mortality, and unfavorable functional outcome at 3 months were 18.0%, 18.9%, and 60.3%, respectively.

CONCLUSION

In cohorts of patients with AIS due to LVO, 5% of patients experienced reocclusion within 7 days after successful EVT. Repeated EVT can be a safe and effective treatment for selected patients with reocclusion.

Tirofiban for Stroke without Large or Medium-Sized Vessel Occlusion

BACKGROUND

The effects of the glycoprotein IIb/IIIa receptor inhibitor tirofiban in patients with acute ischemic stroke but who have no evidence of complete occlusion of large or medium-sized vessels have not been extensively studied.

METHODS

In a multicenter trial in China, we enrolled patients with ischemic stroke without occlusion of large or medium-sized vessels and with a National Institutes of Health Stroke Scale score of 5 or more and at least one moderately to severely weak limb. Eligible patients had any of four clinical presentations: ineligible for thrombolysis or thrombectomy and within 24 hours after the patient was last known to be well; progression of stroke symptoms 24 to 96 hours after onset; early neurologic deterioration after thrombolysis; or thrombolysis with no improvement at 4 to 24 hours. Patients were assigned to receive intravenous tirofiban (plus oral placebo) or oral aspirin (100 mg per day, plus intravenous placebo) for 2 days; all patients then received oral aspirin until day 90. The primary efficacy end point was an excellent outcome, defined as a score of 0 or 1 on the modified Rankin scale (range, 0 [no symptoms] to 6 [death]) at 90 days. Secondary end points included functional independence at 90 days and a quality-of-life score. The primary safety end points were death and symptomatic intracranial hemorrhage.

RESULTS

A total of 606 patients were assigned to the tirofiban group and 571 to the aspirin group. Most patients had small infarctions that were presumed to be atherosclerotic. The percentage of patients with a score of 0 or 1 on the modified Rankin scale at 90 days was 29.1% with tirofiban and 22.2% with aspirin (adjusted risk ratio, 1.26; 95% confidence interval, 1.04 to 1.53, P = 0.02). Results for secondary end points were generally not consistent with the results of the primary analysis. Mortality was similar in the two groups. The incidence of symptomatic intracranial hemorrhage was 1.0% in the tirofiban group and 0% in the aspirin group.

CONCLUSIONS

In this trial involving heterogeneous groups of patients with stroke of recent onset or progression of stroke symptoms and nonoccluded large and medium-sized cerebral vessels, intravenous tirofiban was associated with a greater likelihood of an excellent outcome than low-dose aspirin. Incidences of intracranial hemorrhages were low but slightly higher with tirofiban. (Funded by the National Natural Science Foundation of China; RESCUE BT2 Chinese Clinical Trial Registry number, ChiCTR2000029502.).

Improving neurological outcome for acute basilar artery occlusion with sufficient recanalization after thrombectomy by intraarterial tenecteplase (INSIST-IT): Rationale and design

BACKGROUND

The potential benefit of intraarterial tenecteplase in acute basilar artery occlusion (BAO) patients with successful reperfusion following endovascular treatment (EVT) has not been studied.

AIMS

To explore the efficacy and safety of intraarterial tenecteplase in acute BAO patients with successful reperfusion after EVT.

SAMPLE SIZE ESTIMATES

A maximum of 228 patients are required to test the superiority hypothesis with 80% power according to a two-side 0.05 level of significance, stratified by center.

DESIGN

We will conduct a prospective, randomized, adaptive-enrichment, open-label, blinded-end point, multicenter trial. Eligible BAO patients with successful recanalization after EVT [modified Thrombolysis in Cerebral Infarction (mTICI) 2b-3] will be randomly assigned into the experimental and control group with a 1:1 ratio. Patients in the experimental group will receive intraarterial tenecteplase (0.2-0.3 mg/min for 20-30 min), while patients in the control group will receive routine treatment according to the usual practice of each center. Patients in both groups will receive standard guideline-based medical treatment.

OUTCOME

The primary efficacy endpoint is a favorable functional outcome, defined as the modified Rankin Scale 0-3 at 90 days after randomization. The primary safety endpoint is symptomatic intracerebral hemorrhage, defined as National Institutes of Health Stroke Scale score increase ⩾4 caused by intracranial hemorrhage within 48 h after randomization. Subgroup analysis of the primary outcome will be performed by age, gender, baseline NIHSS score, baseline pc-ASPECTS, intravenous thrombolysis, time from estimated symptom onset to treatment, mTICI, blood glucose, and stroke etiology.

CONCLUSIONS

The results of this study will provide evidence of whether adjunct use of intraarterial tenecteplase after successful reperfusion with EVT is associated with better outcomes for acute BAO patients.

Futile Recanalization After Endovascular Treatment in Patients With Acute Basilar Artery Occlusion

BACKGROUND

It is estimated that >50% of acute basilar artery occlusion (ABAO) patients with successful reperfusion after endovascular treatment (EVT) have futile recanalization. However, few studies investigated the reasons behind this.

OBJECTIVE

To identify the factors associated with futile recanalization in ABAO after successful reperfusion.

METHODS

We recruited patients with successful reperfusion (expanded Thrombolysis In Cerebral Infarction score of ≥2b) after EVT from the Basilar Artery Occlusion Study registry. Patients were divided into meaningful recanalization (90-day modified Rankin Scale 0-3) and futile recanalization (90-day modified Rankin Scale 4-6) groups. Multivariable logistic regression analyses were used to identify the predictors of futile recanalization.

RESULTS

A total of 522 patients with successful reperfusion were selected. Of these, 328 patients had futile recanalization and 194 had meaningful recanalization. Multivariable logistic regression shows that higher neutrophil-to-lymphocyte ratio ( P = .01), higher baseline National Institutes of Health Stroke Scale score ( P < .001), longer puncture to recanalization time ( P = .02), lower baseline posterior circulation Alberta Stroke Program Early CT score ( P < .001), lower posterior circulation collateral score ( P = .02), incomplete reperfusion ( P < .001), and diabetes mellitus ( P < .001) were predictors of futile recanalization.

CONCLUSION

Higher neutrophil-to-lymphocyte ratio, longer puncture to recanalization time, incomplete reperfusion, stroke severity, lower baseline posterior circulation Alberta Stroke Program Early CT score, poor collaterals, and diabetes mellitus were independent predictors of futile recanalization in patients with ABAO with successful reperfusion after EVT. Moreover, multiple stent retriever passes were associated with a high proportion of futile recanalization in patients with late time windows.

Association Between Neutrophil-to-Lymphocyte Ratio/Lymphocyte-to-Monocyte Ratio and In-Hospital Clinical Outcomes in Ischemic Stroke Treated with Intravenous Thrombolysis

Objective

Investigations on neutrophil-to-lymphocyte ratio (NLR) and lymphocyte-to-monocyte ratio (LMR) in patients with ischemic stroke are insufficient. We aimed to investigate the relationship of NLR and LMR with in-hospital clinical outcomes at different time points in ischemic stroke patients treated with intravenous tissues plasminogen activator (IV tPA).

Methods

We retrospectively enrolled patients who received IV tPA therapy within 4.5 hours from symptoms onset. Demographics, clinical characteristics, imaging measures, and the in-hospital clinical outcomes including early neurological improvement (ENI, defined as NIHSS score reduction within 24 hours ≥4 points or decreased to the baseline) and favorable functional outcome (defined as modified Rankin scale 0–1) were collected. Multivariable logistic regression analyses were performed to test whether NLR or LMR was an independent predictor for the in-hospital clinical outcomes.

Results

One hundred and two patients treated with IV tPA were included. NLR at 24 hours proved to be an independent predictor of ENI (adjusted OR=0.85, 95% CI=0.75–0.95, P=0.04). NLR at 48 hours and LMR at 48 hours proved to be independent predictors of mRS 0–1 at discharge (NLR at 48 hours: adjusted OR=0.64, 95% CI=0.49–0.83, P=0.01; LMR at 48 hours: adjusted OR=1.50, 95% CI=1.08–2.09, P=0.02). The AUC of NLR at 48 hours to predict favorable functional outcome at discharge was 0.79 (95% CI=0.70–0.88, P<0.001) and the optimal cut-off was 5.69 (sensitivity=0.52, specificity=0.63).

Conclusion

In our study, NLR at 24 hours was correlated with ENI. Both NLR and LMR at 48 hours were closely associated with favorable functional outcomes at discharge.

The Relationship Between Admission Blood Pressure and Clinical Outcomes for Acute Basilar Artery Occlusion

Background and Purpose

Optimal blood pressure management of patients with basilar artery occlusion (BAO) remains uncertain. This study aimed to investigate the relationship between admission blood pressure and clinical outcomes following acute BAO.

Materials and Methods

We analyzed data from a prospective, nationwide cohort study of 829 patients with acute BAO and posterior circulation stroke. Baseline systolic blood pressure (SBP) and diastolic blood pressure (DBP) were recorded on admission. The primary outcome was neurological functional disability based on the modified Rankin Scale (mRS) score at 90 days. Secondary outcomes included successful reperfusion, mortality within 90 days, and National Institutes of Health Stroke Scale (NIHSS) score change. Multivariable logistic regression was used to assess the associations of SBP and DBP with outcomes.

Results

We include 829 patients with posterior circulation stroke and BAO between January 2014 and May 2019. Multivariate logistic regression showed high SBP and DBP correlated with unfavorable outcomes. The favorable prognosis (mRS ≤ 3) rates of the low-to-normal and the hypertension groups were 34.8 and 23.9%, respectively. After adjusting for covariates, multivariate regression analysis demonstrated that an SBP > 140 mm Hg was associated with a poor functional outcome [adjusted OR (aOR), 1.509; 95% CI, 1.130–2.015] and mortality at 90 days (aOR, 1.447; 95% CI, 1.055–1.985), and predicted a lower probability of successful reperfusion (aOR, 0.550; 95% CI, 0.389–0.778). The risk of symptomatic intracranial hemorrhage and the NIHSS score at 24 h were not significantly different between the high SBP group and the low-to-normal blood pressure group. And the results for DBP were similar.

Conclusion

Among patients with acute BAO, higher systolic or DBP at admission was associated with poor stroke outcomes and had a lower probability of successful reperfusion, with an increased risk of mortality. Trail Registration: [http://www.chictr.org.cn], [ChiCTR1800014759].

Difficult questions of intravenous thrombolytic therapy in ischemic stroke

The article reflects the current achievements in the field of reperfusion therapy for ischemic stroke. The data are presented that allow a practicing neurologist to make informed decisions about intravenous thrombolysis in difficult clinical situations: minor stroke, suspected stroke "mask", atypical clinical picture, patient's age over 80 years, posterior circulation stroke, isolated dizziness, severe neurological deficit, large artery occlusion, chronic neuroimaging changes, polymorbidity and low functional level before stroke. It has been shown that an increase in the number of candidates for intravenous thrombolysis can be achieved by intensifying the selection of patients within the 4.5-hour therapeutic window, which primarily implies the optimization of local stroke treatment protocols with a reduction in the door-to-needle time, as well as, in the short term, expanding the therapeutic window. Approaches to reduce the risk of symptomatic hemorrhagic transformation are discussed. We are also talking about a rare but life-threatening complication angioedema. Thus, the intensification of intravenous thrombolysis, as well as an increase in its effectiveness and safety are the primary tasks of each stroke department.

Frailty is an outcome predictor in patients with acute ischemic stroke receiving endovascular treatment

INTRODUCTION

Frailty is a disorder of multiple physiological systems impairing the capacity of the organism to cope with insult or stress. It is associated with poor outcomes after acute illness. Our aim was to study the impact of frailty on the functional outcome of patients with acute ischemic stroke (AIS) submitted to endovascular stroke treatment (EST).

METHODS

We performed a retrospective study of patients with AIS of the anterior circulation submitted to EST between 2012 and 2017, based on a prospectively collected local registry of consecutive patients. The Hospital Frailty Risk Score (HFRS) at discharge was calculated for each patient. We compared groups of patients with and without favourable 3-month outcome after index AIS (modified Rankin Scale 0-2 and 3-6, respectively). A multivariable logistic regression model was used to identify variables independently associated with favourable 3-month outcome. Diagnostic test statistics were used to compare HFRS with other prognostic scores for AIS.

RESULTS

We included 489 patients with median age 75.6 years (interquartile range [IQR] = 65.3-82.3) and median NIHSS 15 (IQR = 11-19). About 29.7% presented a high frailty risk (HFRS >15 points). Patients with favourable 3-month outcome presented lower HFRS and lower prevalence of high frailty risk. High frailty risk was independently associated with decreased likelihood of favourable 3-month outcome (adjusted odds ratio = 0.48, 95% confidence interval = 0.26-0.89). Diagnostic performances of HFRS and other prognostic scores (THRIVE and PRE scores, SPAN-100 index) for outcome at 3-months were similar.

DISCUSSION

Frailty is an independent predictor of outcome in AIS patients submitted to EST.

Neurological Instability in Ischemic Stroke: Relation with Outcome, Latency Time, and Molecular Markers

The National Institutes of Health Stroke Scale (NIHSS) is commonly used to evaluate stroke neurological deficits and to predict the patient’s outcome. Neurological instability (NI), defined as the variation of the NIHSS in the first 48 h, is a simple clinical metric that reflects dynamic changes in the area of the brain affected by the ischemia. We hypothesize that NI may represent areas of cerebral instability known as penumbra, which could expand or reduce brain injury and its associated neurological sequels. In this work, our aim was to analyze the association of NI with the functional outcome at 3 months and to study clinical biomarkers associated to NI as surrogate biomarkers of ischemic and inflammatory penumbrae in ischemic stroke (IS) patients. We included 663 IS patients in a retrospective observational study. Neutral NI was defined as a variation in the NI scale between − 5 and 5% (37.1%). Positive NI is attributed to patients with an improvement of > 5% NI after 48 h (48.9%), while negative NI is assigned to patients values lower than − 5% (14.0%). Poor outcome was assigned to patients with mRS ≥ 3 at 3 months. We observed an inverse association of poor outcome with positive NI (OR, 0.35; 95%CI, 0.18–0.67; p = 0.002) and a direct association with negative NI (OR, 6.30; 95%CI, 2.12–18.65; p = 0.001). Negative NI showed a higher association with poor outcome than most clinical markers. Regarding good functional outcome, positive NI was the marker with the higher association (19.31; CI 95%, 9.03–41.28; p < 0.0001) and with the highest percentage of identified patients with good functional outcome (17.6%). Patients with negative NI have higher glutamate levels compared with patients with neutral and positive NI (p < 0.0001). IL6 levels are significantly lower in patients with positive NI compared with neutral NI (p < 0.0001), while patients with negative NI showed the highest IL6 values (p < 0.0001). High glutamate levels were associated with negative NI at short latency times, decreasing at higher latency times. An opposite trend was observed for inflammation, and IL6 levels were similar in patients with positive and negative NI in the first 6 h and then higher in patients with negative NI. These results support NI as a prognosis factor in IS and the hypothesis of the existence of a delayed inflammatory penumbra, opening up the possibility of extending the therapeutic window for IS.

[Endovascular treatment of acute basilar artery occlusions]

BACKGROUND

Since the publication of the large randomized controlled thrombectomy trials, endovascular treatment (EVT) has become the standard of care for acute stroke patients with anterior circulation large vessel occlusion (acLVO); however, the treatment of patients with an intracranial occlusion in the posterior circulation and in particular of the basilar artery has not been proven. Thus, there is uncertainty regarding the indications for EVT due to the poor evidence situation.

OBJECTIVE

This review article addresses the current data on EVT in the posterior circulation and the most recent study results. Furthermore, the pathophysiological aspects, indications and specific features in the treatment of these patients are also discussed.

RESULTS

Despite limited evidence for EVT, this treatment modality has gained significant clinical relevance for the treatment of stroke patients with vascular occlusions in the posterior circulation. From a technical point of view, vascular occlusions in the posterior circulation and particularly of the basilar artery are easily accessible, although the etiology of occlusions and necessary techniques differ compared to occlusions in the anterior circulation.

CONCLUSION

Compared to acLVO, EVT in the posterior circulation differs with respect to the current evidence, indications and technique. As current data have not proven its effectiveness for improved clinical outcome, treatment decisions must still be made individually based on institutional protocols, particularly for patients in the late time window or for patients already with signs of extensive infarction on baseline imaging.

Assessment of Endovascular Treatment for Acute Basilar Artery Occlusion via a Nationwide Prospective Registry

Importance

Several randomized clinical trials have recently established the safety and efficacy of endovascular treatment (EVT) of acute ischemic stroke in the anterior circulation. However, it remains uncertain whether patients with acute basilar artery occlusion (BAO) benefit from EVT.

Objective

To evaluate the association between EVT and clinical outcomes of patients with acute BAO.

Design, Setting, and Participants

This nonrandomized cohort study, the EVT for Acute Basilar Artery Occlusion Study (BASILAR) study, was a nationwide prospective registry of consecutive patients presenting with an acute, symptomatic, radiologically confirmed BAO to 47 comprehensive stroke centers across 15 provinces in China between January 2014 and May 2019. Patients with acute BAO within 24 hours of estimated occlusion time were divided into groups receiving standard medical treatment plus EVT or standard medical treatment alone.

Main Outcomes and Measures

The primary outcome was the improvement in modified Rankin Scale scores (range, 0 to 6 points, with higher scores indicating greater disability) at 90 days across the 2 groups assessed as a common odds ratio using ordinal logistic regression shift analysis, adjusted for prespecified prognostic factors. The secondary efficacy outcome was the rate of favorable functional outcomes defined as modified Rankin Scale scores of 3 or less (indicating an ability to walk unassisted) at 90 days. Safety outcomes included symptomatic intracerebral hemorrhage and 90-day mortality.

Results

A total of 1254 patients were assessed, and 829 patients (of whom 612 were men [73.8%]; median [interquartile] age, 65 [57-74] years) were recruited into the study. Of these, 647 were treated with standard medical treatment plus EVT and 182 with standard medical treatment alone. Ninety-day functional outcomes were substantially improved by EVT (adjusted common odds ratio, 3.08 [95% CI, 2.09-4.55]; P < .001). Moreover, EVT was associated with a significantly higher rate of 90-day modified Rankin Scale scores of 3 or less (adjusted odds ratio, 4.70 [95% CI, 2.53-8.75]; P < .001) and a lower rate of 90-day mortality (adjusted odds ratio, 2.93 [95% CI, 1.95-4.40]; P < .001) despite an increase in symptomatic intracerebral hemorrhage (45 of 636 patients [7.1%] vs 1 of 182 patients [0.5%]; P < .001).

Conclusions and Relevance

Among patients with acute BAO, EVT administered within 24 hours of estimated occlusion time is associated with better functional outcomes and reduced mortality.

Efficacy and safety of rescue angioplasty and/or stenting for acute large artery occlusion with underlying intracranial atherosclerosis: A systematic review and meta-analysis

PURPOSE

Intracranial angioplasty and/or stenting implantation is an important rescue treatment for the management of intracranial atherosclerosis-related occlusion (ICAS-O) after mechanical thrombectomy failure, but its safety and efficacy remain unclear. We investigated the safety and efficacy of rescue intracranial angioplasty and/or stenting for emergent large artery occlusion (LAO) with underlying ICAS.

METHODS

We searched for relevant full-text articles in EMBASE, PubMed and the Cochrane Central Register of Controlled Trials from inception to March 1, 2020. We calculated the odds ratios (ORs) using random-effects models for symptomatic intracranial hemorrhage (sICH), mortality, recanalization rate and favorable clinical outcome at 90 days between ICAS-O group treated by rescue therapy and Non ICAS-O group. RStudio software 1.3.959 was used to perform this meta-analysis.

RESULTS

Ten studies were included with a total of 1639 patients, of which 450 (27.5 %) were in the ICAS-O group treated with intracranial angioplasty and/or stenting, and 1189 (72.5 %) were in the Non ICAS-O group. Overall, intracranial angioplasty and/or stenting did not improve the recanalization rate (OR, 0.67 [0.26-1.76]; p = 0.419) or favorable functional outcome (OR, 1.01 [0.64-1.58]; p = 0.97) in patients with underlying ICAS-O, and the risk of sICH (OR, 0.99 [0.59-1.68]; p = 0.983) and mortality (OR, 1.26 [0.87-1.83]; p = 0.225) did not significantly differ between ICAS-O and Non ICAS-O.

CONCLUSIONS

From these observational study results, rescue intracranial angioplasty and/or stenting seems safe in patients with emergent LAO after attempted thrombectomy, but further rigorous studies are warranted to confirm its efficacy.

Early clinical surrogates for outcome prediction after stroke thrombectomy in daily clinical practice

BACKGROUND AND PURPOSE

To investigate early clinical surrogates for long-term independency of patients treated with thrombectomy for large vessel occlusion stroke in daily clinical routine.

METHODS

All patients with anterior circulation stroke enrolled in the German Stroke Registry-Endovascular Treatment from 07/2015 to 04/2018 were analysed. National Institute of Health Stroke Scale (NIHSS) on admission, NIHSS percentage change, NIHSS delta and NIHSS at 24 hours as well as existing binary definitions of early neurological improvement (ENI; improvement of 8 (major ENI)/10 (dramatic ENI) NIHSS points or reaching 0/1 were compared for predicting functional outcome at 90 days using the modified Rankin Scale (mRS). Excellent and favourable outcome were defined as 0-1 and 0-2, respectively.

RESULTS

Among 2262 endovasculary treated patients with acute ischaemic anterior circulation stroke, NIHSS at 24 hours had the highest discriminative ability to predict excellent (receiver operator characteristics (ROC)_{NIHSS 24 hours} area under the curve (AUC) 0.86 (0.84-0.88)) and favourable long-term functional outcome (ROC_{NIHSS 24 hours} AUC 0.86 (0.85-0.88)) in comparison to NIHSS percentage change (ROC_{% change} AUC mRS ≤1: 0.81 (0.78-0.83) mRS ≤2: 0.81 (0.79-0.83)), NIHSS delta change (ROC_{Δ change} AUC mRS ≤1: 0.74 (0.72-0.77), mRS ≤2: 0.77 (0.74-0.79)) and NIHSS admission (ROC_Adm AUC mRS ≤1: 0.70 (0.68-0.73), mRS ≤2: 0.67 (0.68-0.71)). Advanced age was the only independent predictor (adjusted OR 1.05, 95% CI 1.03 to 1.07, p<0.001) for turning the outcome prognosis from favourable (mRS ≤2) to poor (mRS ≥4) at 90 days.

CONCLUSION

The NIHSS at 24 hours postintervention with a threshold of ≤8 points serves best as a surrogate for long-term functional outcome after thrombectomy for anterior circulation stroke in daily clinical practice. Only advanced age significantly decreases its predictive value.

Postcontrast CT to Estimate Arteriosclerotic Stenosis at the Site of Occlusion before Emergency Endovascular Treatment for Vertebral-Basilar Artery Occlusion

Objective

Thrombectomy may be an effective therapy for vertebrobasilar artery (VBA) occlusion in addition to carotid or middle cerebral artery occlusion. Underlying arterial stenosis can be a cause of failure in thrombectomy; however, it is difficult to identify candidates with VBA occlusion before thrombectomy. The purpose of our study was to investigate whether postcontrast computed tomography (pcCT) is useful for identifying candidates with VBA occlusion for thrombectomy.

Methods

In this retrospective study, we included patients who 1) were admitted to our institution between January 1, 2013, and July 1, 2019; 2) underwent pcCT; and 3) underwent emergency endovascular therapy for VBA occlusion. We defined no opacification of the top of the basilar artery (BA) in reconstructed coronal images of pcCT scans as distal BA occlusion and opacification of the top of the BA as distal BA open. We assessed the presence of underlying arterial stenosis at the site of occlusion according to angiographic findings during endovascular procedures. We also evaluated the relationship between the distal BA findings and the presence of underlying arterial stenosis.

Results

Thirty-two patients met our inclusion criteria and were analyzed. Among 19 patients with distal BA occlusion, none (0%) had ischemic stroke with underlying arterial stenosis. Among 13 patients with distal BA open, 4 (31%) were diagnosed with ischemic stroke without underlying arterial stenosis and 9 (69%) with underlying arterial stenosis (p <0.001).

Conclusion

Distal basilar-artery findings in reconstructed coronal postcontrast CT images were useful for identifying candidates with VBA occlusion for thrombectomy.

Factors influencing early neurological improvement after mechanical thrombectomy among patients with acute basilar artery occlusion: a single center prospective observational cohort study

The predictive value of and the influencing factors associated with early neurological improvement (ENI) among patients with acute basilar artery occlusion (BAO) have not been well studied. The present study aimed to evaluate whether ENI predicted a better functional outcome and to identify the influencing factors of ENI. We performed a prospective observational analysis among 187 patients with acute BAO who underwent endovascular treatment (EVT) in Beijing Tiantan Hospital from January 2012 to July 2018. ENI was defined as having a drop on the National Institutes of Health Stroke Scale (NIHSS) by 8 or more scores or having a NIHSS of 0-1 within 24 h after EVT. A multivariate logistic regression model with backward selection was used to identify the influencing factors associated with ENI. ENI had a sensitivity of 0.69 and a specificity of 0.68 to predict a favorable outcome at 90 days after EVT. In addition, patients with ENIs had lower modified Rankin Scale score (mRS) (median: 2.0 vs. 5.0, p < 0.001) and were more likely to survive (95.2% vs. 72.0%, p < 0.001) and achieve functional independence (74.2% vs. 36.8%, p < 0.001). NIHSS before EVT, complete recanalization, white blood cell counts and general anesthetics were significant factors associated with ENI. A one-unit higher NIHSS and complete recanalization were associated with 1.04 (95% CI 1.01-1.08) and 2.71 (95% CI 1.14-6.45) times higher odds of achieving ENI, respectively. In conclusion, in patients with acute BAO, ENI within 24 hours after EVT can predict favorable outcomes at 90 day. Patients with higher NIHSS, lower white blood cell counts before surgery, without general anesthetics and patients with complete recanalization were more likely to achieve ENIs.

Clinical improvement within 24 hours from mechanical thrombectomy as a predictor of long-term functional outcome in a multicenter population-based cohort of patients with ischemic stroke

BACKGROUND

Single-center studies have suggested that the early clinical course after mechanical thrombectomy (MT) in patients with ischemic stroke is a clinical predictor of long-term outcome.

OBJECTIVE

To analyze the prognostic value of clinical improvement within 24 hours in a population-based multicenter cohort.

METHODS

From a total of 3792 patients with acute ischemic stroke in Catalonia (CICAT registry), 1951 patients were treated with MT. The National Institutes of Health Stroke Scale (NIHSS) score within 24 hours, and follow-up was available in 1666 patients. Percentage variation in the NIHSS score was calculated in relation to a baseline assessment. Good outcome was defined as a modified Rankin Scale score ≤2 at 90 days. Predictive values of clinical improvement and adjusted OR to predict good outcomes were assessed in the whole cohort and the subgroup of patients with posterior circulation stroke (n=166).

RESULTS

Good outcome was achieved in 656/1666 patients (39%) overall. Percentage improvements both at the end of MT and at 24 hours predicted good outcome, with higher predictive capacity at 24 hours (C-statistic, 0.85 vs 0.73, p<0.001). Positive and negative predictive values were 70% and 74% for the >30% cut-off point at the end of MT, and 69% and 84% for the >50% cut-off point at 24 hours, respectively. The adjusted OR for good outcome was 5.8 (95% CI 4.2 to 8.1) and 12.9 (95% CI 9.7 to 17.1), respectively. In patients with posterior circulation stroke, the predictive value of the improvement at 24 hours was similar (C-statistic 0.90).

CONCLUSION

Clinical improvement of patients within 24 hours of MT is a reliable and robust predictor of long-term prognosis, including patients with posterior circulation occlusions.

Nonatrial Fibrillation was Associated With Early Neurological Improvement After Intravenous Thrombolysis With rt-PA in Patients With Acute Ischemic Stroke

BACKGROUND

Intravenous thrombolysis is the only approved pharmacological treatment for acute ischemic stroke (AIS) patients, but the immediate response to thrombolysis varies by patient.

OBJECTIVE

To investigate the factors associated with early neurological improvement (ENI) after the administration of intravenous recombinant tissue plasminogen activator (rt-PA) treatment to AIS patients within 4.5 hours of onset.

METHODS

Demographics, onset to treatment time, risk factors, and clinical and laboratory data of 209 AIS patients undergoing intravenous rt-PA therapy at a Chinese hospital between January 2013 and August 2016 were retrospectively analyzed. The National Institutes of Health Stroke Scale (NIHSS) score was recorded before thrombolytic therapy, 24 hours after the treatment, and 7 days after the treatment to evaluate the recovery of neurological function. ENI was defined as a ≥4-point decrease in NIHSS score compared with baseline or a score of 0 or 1 at 24 hours and 7 days. A multivariate logistic regression analysis was performed to assess the outcomes.

RESULTS

Of the 209 AIS patients treated by intravenous thrombolysis with rt-PA, low-density lipoprotein (LDL) levels were significantly lower (P<0.05) in patients with ENI. The multivariable analysis showed that non-atrial fibrillation (AF) was independently associated with ENI at 24 hours and 7 days after thrombolysis. An overall 40.3% non-AF patients had ENI 24 hours after thrombolysis (odds ratio=2.501, 95% confidence interval: 1.204-5.198; P=0.014), and 65.9% non-AF patients had ENI 7 days after thrombolysis (odds ratio=2.953, 95% confidence interval: 1.434-6.081; P=0.003). Onset to treatment time was an independent predictor (P<0.05) for ENI at 7 days after thrombolysis. The NIHSS score and diastolic blood pressure on admission were associated with symptomatic intracerebral hemorrhagic transformation.

CONCLUSIONS

Non-AF was independently associated with ENI after intravenous thrombolysis in AIS patients, but non-AF was not associated with the occurrence of symptomatic intracerebral hemorrhage. Onset to treatment time was an independent predictor of ENI at 7 days after thrombolysis in AIS patients.

The potential of drug repurposing combined with reperfusion therapy in cerebral ischemic stroke: A supplementary strategy to endovascular thrombectomy

Stroke is the major cause of adult disability and the second or third leading cause of death in developed countries. The treatment options for stroke (thrombolysis or thrombectomy) are restricted to a small subset of patients with acute ischemic stroke because of the limited time for an efficacious response and the strict criteria applied to minimize the risk of cerebral hemorrhage. Attempts to develop new treatments, such as neuroprotectants, for acute ischemic stroke have been costly and time-consuming and to date have yielded disappointing results. The repurposing approved drugs known to be relatively safe, such as statins and minocycline, may provide a less costly and more rapid alternative to new drug discovery in this clinical condition. Because adequate perfusion is thought to be vital for a neuroprotectant to be effective, endovascular thrombectomy (EVT) with advanced imaging modalities offers the possibility of documenting reperfusion in occluded large cerebral vessels. An examination of established medications that possess neuroprotective characters using in a large-vessel occlusive disorder with EVT may speed the identification of new and more broadly efficacious medications for the treatment of ischemic stroke. These approaches are highlighted in this review along with a critical assessment of drug repurposing combined with reperfusion therapy as a supplementary means for halting or mitigating stroke-induced brain damage.

Worse Outcome in Stroke Patients Treated with rt-PA Without Early Reperfusion: Associated Factors

Based on preclinical studies suggesting that recombinant tissue plasminogen activator (rt-PA) may promote ischemic brain injuries, we investigated in patients the possible risk of worse clinical outcome after rt-PA treatment as a result of its inability to resolve cerebral ischemia. Here, we designed a cohort study using a retrospective analysis of patients who received treatment with intravenous (4.5-h window) or intraarterial rt-PA, without or with thrombectomy. Controls were consecutive patients who did not receive recanalization treatment, who met all inclusion criteria. As a marker of reperfusion, we defined the variable of early neurological improvement as the difference between the score of the National Institute of Health Stroke Scale (NIHSS) (at admission and 24 h). The main variable was worsening of the patient’s functional situation in the first 3 months. To compare quantitative variables, we used Student’s t test or the Mann-Whitney test. To estimate the odds ratios of each independent variable in the patient’s worsening in the first 3 months, we used a logistic regression model. We included 1154 patients; 577 received rt-PA, and 577 served as controls. In the group of patients treated with rt-PA, 39.4% who did not present clinical reperfusion data developed worsening within 3 months after stroke compared with 3.5% of patients with reperfusion (P < 0.0001). These differences were not significant in the control group. In summary, administration of rt-PA intravenously or intraarterially without reperfusion within the first 24 h may be associated with a higher risk of functional deterioration in the first 3 months.

Impact of hyperlipidemia and atrial fibrillation on the efficacy of endovascular treatment for acute ischemic stroke: a meta-analysis

Introduction

Stroke is the crucial cause of death annually. Inconsistent results from the randomized controlled trials (RCTs) aroused controversy on efficacy of endovascular treatment (EVT).

Materials and Methods

To evaluate the efficacy of EVT in stroke patients. We searched three databases including PubMed, Web of science and the Cochrane Library from Jan 2011 to Apr 2017. Eligible studies were RCTs comparing EVT versus standard medical therapy alone. The primary outcomes were favorable functional outcomes (modified Rankin Scale score, 0–2) at 3 months. Meta regression analysis and subgroup analysis were used to explore potential influence factors responsible for the effectiveness of EVT.

Results

Eleven RCTs involving 3018 patients were included in our study. EVT showed better functional outcomes at 90 days (OR, 1.71; 95% CI, 1.28–2.28; P < 0.001) and a higher recanalization rate at 24h (OR, 6.49; 95% CI, 4.79–8.79; P < 0.001). In meta-regression and subgroup analysis, primary outcomes were significantly better among patients with atrial fibrillation (Adj R-squared 46.30%, P = 0.054; OR, 2.40; 95% CI, 1.81–3.19; P < 0.001), patients without hyperlipidemia (Adj R-squared 35.21%, P = 0.159; OR, 2.34; 95% CI, 1.80–3.04; P < 0.001) and when new generation thrombectomy device was used (Adj R-squared 72.21%, P = 0.011; OR, 2.14; 95% CI, 1.75–2.61; P < 0.001).

Conclusions

EVT showed superior clinical outcomes compared with standard medical therapy. The rate of using new generation thrombectomy device was the critical factor influencing therapeutic outcome. Hyperlipidemia and atrial fibrillation may also cause the potential effect.

Reciprocal Interaction of 24-Hour Blood Pressure Variability and Systolic Blood Pressure on Outcome in Stroke Thrombolysis

BACKGROUND AND PURPOSE

Significance and management of blood pressure (BP) changes in acute stroke care are unclear. Here, we aimed to investigate the impact of 24-hour BP variability (BPV) on outcome in patients with acute ischemic stroke treated with intravenous thrombolysis.

METHODS

From the Safe Implementation of Treatment in Stroke International Stroke Thrombolysis registry, 28 976 patients with documented pre-treatment systolic BP at 2 and 24 hours were analyzed. The primary measure of BP variability was successive variability. Data were preprocessed using coarsened exact matching. We assessed early neurological improvement, symptomatic intracerebral hemorrhage (SICH), and long-term functional outcome (modified Rankin Scale [mRS] at 90 days) by binary and ordinal regression analyses.

RESULTS

Attempts to explain successive variation for analysis of BPV with patients characteristics at admission found systolic BP (5.5% variance) to be most influential, yet 92% of BPV variance remained unexplained. Independently from systolic BP, successive variation for analysis of BPV was associated with poor functional outcome mRS score of 0 to 2 (odds ratio [OR], 0.94; 95% confidence interval [CI], 0.90-0.98), disadvantage across the shift of mRS (OR, 1.04; 95% CI, 1.01-1.08), mortality (OR, 1.10; 95% CI, 1.01-1.08), SICH_SITS (OR, 1.14; 95% CI, 1.06-1.23), and SICH_ECASS (OR, 1.24; 95% CI, 1.10-1.40; ECASS [European Cooperative Acute Stroke Study 2]). Analyzing successive variation for analysis of BPV as a function of pre-treatment, systolic BP significantly improved the prediction of functional outcome (mRS score of 0-1, mRS score of 0-2, neurological improvement, mRS-shift: all P_interaction<0.01). Excluding patients with atrial fibrillation in a sensitivity analysis gave consistent results overall.

CONCLUSIONS

This study suggests the need for a more individual BP management accounting for pre-treatment BP and the acute BP course (ie, BPV) to achieve best possible outcome for the patient.

Efficacy of Stent-Retriever Thrombectomy in Magnetic Resonance Imaging Versus Computed Tomographic Perfusion-Selected Patients in SWIFT PRIME Trial (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke)

BACKGROUND AND PURPOSE

The majority of patients enrolled in SWIFT PRIME trial (Solitaire FR With the Intention for Thrombectomy as Primary Endovascular Treatment for Acute Ischemic Stroke) had computed tomographic perfusion (CTP) imaging before randomization; 34 patients were randomized after magnetic resonance imaging (MRI).

METHODS

Patients with middle cerebral artery and distal carotid occlusions were randomized to treatment with tPA (tissue-type plasminogen activator) alone or tPA+stentriever thrombectomy. The primary outcome was the distribution of the modified Rankin Scale score at 90 days. Patients with the target mismatch profile for enrollment were identified on MRI and CTP.

RESULTS

MRI selection was performed in 34 patients; CTP in 139 patients. Baseline National Institutes of Health Stroke Scale score was 17 in both groups. Target mismatch profile was present in 95% (MRI) versus 83% (CTP). A higher percentage of the MRI group was transferred from an outside hospital (P=0.02), and therefore, the time from stroke onset to randomization was longer in the MRI group (P=0.003). Time from emergency room arrival to randomization did not differ in CTP versus MRI-selected patients. Baseline ischemic core volumes were similar in both groups. Reperfusion rates (>90%/TICI [Thrombolysis in Cerebral Infarction] score 3) did not differ in the stentriever-treated patients in the MRI versus CTP groups. The primary efficacy analysis (90-day mRS score) demonstrated a statistically significant benefit in both subgroups (MRI, P=0.02; CTP, P=0.01). Infarct growth was reduced in the stentriever-treated group in both MRI and CTP groups.

CONCLUSIONS

Time to randomization was significantly longer in MRI-selected patients; however, site arrival to randomization times were not prolonged, and the benefits of endovascular therapy were similar.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01657461.

Thrombelastography does not predict clinical response to rtPA for acute ischemic stroke

Thrombelastography (TEG) measures coagulation in venous blood. We hypothesized that TEG, by reflecting clot subtype and ex vivo fibrinolysis, might predict fibrinolytic response to tPA as reflected by rapid clinical improvement or hemorrhagic transformation of the infarct. 171 acute ischemic stroke patients treated with tPA were prospectively enrolled. Venous blood for TEG was drawn before and 10 min after tPA bolus. We measured rapid clinical improvement (RCI = 8 point improvement on NIHSS or total NIHSS of 0, 1 at 36 h), Hemorrhagic transformation (HT = any blood on imaging within 36 h), and hyperdense middle cerebral artery sign (HDMCA = biomarker for erythrocyte-rich clot). Multivariable regression models compared TEG parameters after adjusting for potential confounders. No differences in pre- or post-tPA TEG were found between patients with or without RCI. Also, there was no correlation between TEG and HDMCA. Clotting was slightly prolonged in patients with HT (p = 0.046). We failed to find a robust association between TEG and clinical response to tPA. It is likely that arterial clot lysis is determined by factors unrelated to coagulation status as measured by TEG in the venous circulation. It is unlikely that TEG will be useful to predict clinical response to tPA, but may help predict bleeding.

Outcomes of stent retriever thrombectomy in basilar artery occlusion: an observational study and systematic review

BACKGROUND

Basilar artery occlusion (BAO) remains one of the most devastating subtypes of stroke with high mortality and poor outcome. Early recanalisation is the most powerful predictor of favourable outcome in patients with stroke, and may be improved with mechanical thrombectomy using stent retriever devices. However, the benefit in functional outcome and safety of stent retrievers are not yet well known. The aim of this study was to assess efficacy and safety profiles of stent retriever thrombectomy in BAO patients with stroke.

METHODS

We analysed data retrospectively from our consecutive clinical series and conducted a systematic review and meta-analysis of all previous studies of stent retriever thrombectomy in BAO patients with stroke between November 2010 and April 2014.

RESULTS

From March 2010 to March 2013, 22 patients with acute BAO were treated with a Solitaire stent retriever in our series. Favourable outcome was significantly associated with younger age and distal BAO. The literature search identified 15 previous studies involving a total of 312 subjects. In the meta-analysis, including our series data, the recanalisation rate (Thrombolysis In Cerebral Infarction (TICI) score ≥ 2b) reached 81% (95% CI 73% to 87%). The rate of symptomatic intracranial haemorrhage was 4% (95% CI 2% to 8%), favourable outcome (modified Rankin Scale (mRS) ≤ 2 at 3 months) was found in 42% (95% CI 36% to 48%) and mortality rate was 30% (95% CI 25% to 36%).

CONCLUSIONS

Stent retriever thrombectomy is a safe treatment modality for patients with stroke presenting with BAO. Although the stent retrievers showed a good recanalisation rate, there are currently no randomised clinical trials to assess its clinical efficacy in comparison with the reference treatment.

Analyses of the Turkish National Intravenous Thrombolysis Registry

BACKGROUND

The relatively late approval of use of recombinant tissue plasminogen activator (rt-PA) for acute ischemic stroke in Turkey has resulted in obvious underuse of this treatment. Here we present the analyses of the nationwide registry, which was created to prompt wider use of intravenous thrombolysis, as well as to monitor safe implementation of the treatment in our country.

METHODS

Patients were registered prospectively in our database between 2006 and 2013. Admission and 24-hour National Institutes of Health Stroke Scale and 3-month modified Rankin Scale scores were recorded. A "high-volume center" was defined as a center treating 10 or more patients with rt-PA per year.

RESULTS

A total of 1133 patients were enrolled into the registry by 38 centers in 18 cities. A nearly 4-fold increase in the study population and in the number of participating centers was observed over the 6 years of the study. The mean baseline NIHSS score was 14.5 ± 5.7, and the prevalence of symptomatic hemorrhage was 4.9%. Mortality at 3 months decreased from 22% to 11% in the 6 years of enrollment, and 65% of cases were functionally independent. Age older than 70 years, an NIHSS score higher than 14 upon hospital admission, and intracranial hemorrhage were independently associated with mortality, and being treated in a high-volume center was related to good outcome.

CONCLUSIONS

We observed a decreasing trend in mortality and an acceptable prevalence of symptomatic hemorrhage over 6 years with continuous addition of new centers to the registry. The first results of this prospective study are encouraging and will stimulate our efforts at increasing the use of intravenous thrombolysis in Turkey.

Tissue plasminogen activator followed by antioxidant-loaded nanoparticle delivery promotes activation/mobilization of progenitor cells in infarcted rat brain

Inherent neuronal and circulating progenitor cells play important roles in facilitating neuronal and functional recovery post stroke. However, this endogenous repair process is rather limited, primarily due to unfavorable conditions in the infarcted brain involving reactive oxygen species (ROS)-mediated oxidative stress and inflammation following ischemia/reperfusion injury. We hypothesized that during reperfusion, effective delivery of antioxidants to ischemic brain would create an environment without such oxidative stress and inflammation, thus promoting activation and mobilization of progenitor cells in the infarcted brain. We administered recombinant human tissue-type plasminogen activator (tPA) via carotid artery at 3 h post stroke in a thromboembolic rat model, followed by sequential administration of the antioxidants catalase (CAT) and superoxide dismutase (SOD), encapsulated in biodegradable nanoparticles (nano-CAT/SOD). Brains were harvested at 48 h post stroke for immunohistochemical analysis. Ipsilateral brain slices from animals that had received tPA + nano-CAT/SOD showed a widespread distribution of glial fibrillary acidic protein-positive cells (with morphology resembling radial glia-like neural precursor cells) and nestin-positive cells (indicating the presence of immature neurons); such cells were considerably fewer in untreated animals or those treated with tPA alone. Brain sections from animals receiving tPA + nano-CAT/SOD also showed much greater numbers of SOX2- and nestin-positive progenitor cells migrating from subventricular zone of the lateral ventricle and entering the rostral migratory stream than in t-PA alone treated group or untreated control. Further, animals treated with tPA + nano-CAT/SOD showed far fewer caspase-positive cells and fewer neutrophils than did other groups, as well as an inhibition of hippocampal swelling. These results suggest that the antioxidants mitigated the inflammatory response, protected neuronal cells from undergoing apoptosis, and inhibited edema formation by protecting the blood-brain barrier from ROS-mediated reperfusion injury. A longer-term study would enable us to determine if our approach would assist progenitor cells to undergo neurogenesis and to facilitate neurological and functional recovery following stroke and reperfusion injury.

Brain imaging in acute ischemic stroke—MRI or CT?

In acute stroke, imaging provides different technologies to demonstrate stroke subtype, tissue perfusion and vessel patency. In this review, we highlight recent clinical studies that are likely to guide therapeutic decisions. Clot length in computed tomography (CT) and clot burden in MR, imaging of leptomeningeal collaterals and indicators for active bleeding are illustrated. Imaging-based concepts for treatment of stroke at awakening and pre-hospital treatment in specialized ambulances offer new potentials to improve patient outcome.

Clinical results of intraarterial thrombolysis according to tPA administration and perfusion/diffusion mismatching

BACKGROUND

IA-Tx and advanced dynamic imaging studies have been adopted for ischemic stroke patient treatment. Many patients are treated with IV-tPA, but this treatment is not always feasible. In this study, IA-Tx was used for patients for whom IV-tPA was not indicated or when IV-tPA did not result in recanalization.

METHODS

A total of 156 patients treated with IA-Tx were retrospectively reviewed. Of these, 72 patients were treated with a full dose of IV-tPA before receiving the IA-Tx; the remaining 84 patients only received IA-Tx. An initial imaging study using CTA and acute stroke MRI followed. Patients' demographics and clinical results were recorded and compared according to P/D mismatching and IV-tPA.

RESULTS

Among P/D-mismatched patients, the recanalization rate was 80 % and the symptomatic intracranial hemorrhage rate was 14.5 %, while among P/D-matched patients, the rates were 63 % and 41.3 % respectively (p < 0.05). A favorable clinical outcome occurred in 49.1 % of P/D-mismatched, but only in 21.7 % of P/D-matched patients (p < 0.05). Among patients who were treated with IV-tPA before undergoing IA-Tx, the recanalization rate was 79.2 % and the sICH rate was 27.8 %, while it was 71.4 % and 17.9 % in patients who did not receive IV-tPA (p < 0.05).

CONCLUSIONS

Patients who have P/D mismatching and are treated with IA-Tx have higher recanalization rates and a greater probability of a favorable outcome than patients who have P/D matching and receive IA-Tx. For patients who do not undergo successful recanalization after IV-tPA or who are not indicated for IV-tPA, the authors recommend IA-Tx after undergoing appropriate imaging evaluation.

Endovascular Treatment and the Outcomes of Atherosclerotic Intracranial Stenosis in Patients With Hyperacute Stroke

BACKGROUND:

The importance of underlying atherosclerotic intracranial artery stenosis (ICAS) in hyperacute stroke patients who receive endovascular therapy remains unknown.

OBJECTIVE:

To report and compare the outcomes of multimodal endovascular therapy in patients with hyperacute stroke with and without underlying ICAS.

METHODS:

A total of 172 consecutive patients with acute stroke were treated with multimodal endovascular therapy that was heavily weighted toward stent-based thrombectomy. Patients with ICAS underwent emergent intracranial angioplasty or stenting. Data were compared between patients with and without ICAS. Revascularization was defined as Thrombolysis in Cerebral Infarction grade ≥2b. A favorable outcome was defined as a modified Rankin Scale score ⩽2 or equal to the premorbid modified Rankin Scale score at 3 months.

RESULTS:

ICAS was responsible for acute ischemic symptoms in 40 patients (22.9%). Revascularization and favorable outcome occurred more frequently in the ICAS group than in the control group (95% vs 81.8%, P = .04; 65% vs 40.2%, P = .01, respectively). The median baseline National Institutes of Health Stroke Scale score was significantly lower in the ICAS group compared with the control group (10 vs 12; P = .002). There were no significant differences between the 2 groups in the rates of symptomatic hemorrhage and mortality.

CONCLUSION:

Emergent intracranial angioplasty with or without stenting is safe and feasible and yields a high rate of revascularization and favorable outcome in patients with hyperacute stroke and underlying ICAS. Patients with underlying ICAS have less severe infarctions at presentation and higher successful revascularization after multimodal endovascular therapy in the setting of hyperacute stroke compared with those with other stroke subtypes.

Evolution of endovascular mechanical thrombectomy for acute ischemic stroke

Acute ischemic stroke (AIS) is a common medical problem associated with significant morbidity and mortality worldwide. A small proportion of AIS patients meet eligibility criteria for intravenous thrombolysis (IVT) with recombinant tissue plasminogen activator, and its efficacy for large vessel occlusion is poor. Therefore, an increasing number of patients with AIS are being treated with endovascular mechanical thrombectomy when IVT is ineffective or contraindicated. Rapid advancement in catheter-based and endovascular device technology has led to significant improvements in rates of cerebral reperfusion with these devices. Stentrievers and modern aspiration catheters have now surpassed earlier generation devices in the degree and rapidity of revascularization. This progress has been achieved with no concurrent increase in risk of major complications or mortality, both when used alone or in combination with IVT. The initial randomized controlled trials comparing endovascular therapy to IVT for AIS failed to show superior outcomes with endovascular treatment, but key limitations of each trial may limit the significance of these results to current practice. While endovascular devices and operator experience continue to evolve, we are optimistic that this will be accompanied by improvements in patient outcomes. This review highlights the major endovascular devices used in current practice and the trials which have investigated their efficacy.

The ischemic penumbra: the location rather than the volume of recovery determines outcome

PURPOSE OF REVIEW

The clinical efficiency of thrombolysis is explained by the rescue of ischemic penumbra areas resulting from early arterial recanalization. The perfusion-diffusion weighted imaging mismatch is a commonly used MRI surrogate of the ischemic penumbra. However, the randomized trials testing the mismatch hypothesis have been negative. We will review the 'mismatch concept' and the recent studies that aim to localize the clinically eloquent areas of penumbra in middle cerebral artery (MCA) infarcts.

RECENT FINDINGS

New methods of image analysis have shown that poor outcomes after MCA stroke are related to infarction of an extremely well localized area of the periventricular white matter and adjacent internal capsule, where projections and association tracts are crossing and converging. This area almost colocalizes with the area salvaged by early arterial recanalization and is located extremely close to the initial ischemic core.

SUMMARY

The location of the area that correlates with disability in MCA stroke patients and that is salvaged by early arterial recanalization is in the same specific region of the deep white matter, close to the initial ischemic core. These findings may have important implications for designing new recanalization trials and support the importance of basic research on white-matter neuroprotection.