Validity and reliability of a quantitative computed tomography score in predicting outcome of hyperacute stroke before thrombolytic therapy. ASPECTS Study Group. Alberta Stroke Programme Early CT Score

Can diffusion-weighted imaging-fluid-attenuated inversion recovery mismatch (positive diffusion-weighted imaging/negative fluid-attenuated inversion recovery) at 3 Tesla identify patients with stroke at <4.5 hours?

BACKGROUND AND PURPOSE

At 1.5 T, diffusion-weighted imaging-fluid-attenuated inversion recovery (DWI-FLAIR) mismatch helps identify strokes within 4.5 hours of onset. However, at 3T, studies have found divergent results. The goal of this study was to determine whether DWI-FLAIR mismatch at 3T would also be helpful for identifying patients within 4.5 hours of symptom onset.

METHODS

All patients presenting with an ischemic stroke in the middle cerebral artery territory and explored with 3T MRI within 12 hours between November 2007 and April 2012 were included in this retrospective study. Two readers analyzed the DWI and FLAIR images. Logistic regression was performed to determine independent predictors of FLAIR visibility. Also, the predictive values of a mismatch for identifying patients with stroke onset ≤4.5 hours were estimated.

RESULTS

The study included 194 patients. The only predictive factor of FLAIR visibility was delayed MRI acquisition. The DWI-FLAIR mismatch was able to identify patients within 4.5 hours of stroke onset with relatively low sensitivity (0.55; 95% confidence interval, 0.48-0.63), low specificity (0.60; 95% confidence interval, 0.42-0.77), high positive predictive value (0.88; 95% confidence interval, 0.82-0.94), and very low negative predictive value (0.19; 95% confidence interval, 0.11-0.28). In addition, 44.5% of patients had a positive FLAIR sequence within 4.5 hours.

CONCLUSIONS

This study improves our understanding of DWI-FLAIR mismatch as an imaging biomarker for wake-up management of patients with stroke. At 3T, the presence of a DWI-FLAIR mismatch was able to identify stroke onset of <4.5 hours. However, 44.5% of such stroke cases demonstrated FLAIR signal changes.

Magnetic Resonance Imaging-DRAGON Score

Background and Purpose—

The DRAGON score, which includes clinical and computed tomographic scan parameters, showed a high specificity to predict 3-month outcome in patients with acute ischemic stroke treated by intravenous tissue plasminogen activator. We adapted the score for patients undergoing MRI as the first-line diagnostic tool.

Methods—

We reviewed patients with consecutive anterior circulation ischemic stroke treated ≤4.5 hour by intravenous tissue plasminogen activator between 2003 and 2012 in our center, where MRI is systematically implemented as first-line diagnostic work-up. We derived the MRI-DRAGON score keeping all clinical parameters of computed tomography-DRAGON (age, initial National Institutes of Health Stroke Scale and glucose level, prestroke handicap, onset to treatment time), and considering the following radiological variables: proximal middle cerebral artery occlusion on MR angiography instead of hyperdense middle cerebral artery sign, and diffusion-weighted imaging Alberta Stroke Program Early Computed Tomography Score (DWI ASPECTS) ≤5 instead of early infarct signs on computed tomography. Poor 3-month outcome was defined as modified Rankin scale >2. We calculated c-statistics as a measure of predictive ability and performed an internal cross-validation.

Results—

Two hundred twenty-eight patients were included. Poor outcome was observed in 98 (43%) patients and was significantly associated with all parameters of the MRI-DRAGON score in multivariate analysis, except for onset to treatment time (nonsignificant trend). The c-statistic was 0.83 (95% confidence interval, 0.78–0.88) for poor outcome prediction. All patients with a MRI-DRAGON score ≤2 (n=22) had a good outcome, whereas all patients with a score ≥8 (n=11) had a poor outcome.

Conclusions—

The MRI-DRAGON score is a simple tool to predict 3-month outcome in acute stroke patients screened by MRI then treated by intravenous tissue plasminogen activator and may help for therapeutic decision.

Association between cerebral lesions and emotional changes in acute ischemic stroke patients

Controversies and interest are present in the associations between specific brain locations and depression or anxiety. This study investigated the association between stroke location and emotional changes in stroke patients. This prospective observational study analyzed the neuroimages and neuropsychiatric conditions of 26 patients with acute middle cerebral artery infarction. Each patient's neurological and psychiatric condition was evaluated 1 week as well as 1 month after the stroke. We found that the right superior and middle temporal gyrus was associated with anxiety at 1 month after stroke. Moreover, better mentality is associated with deterioration of anxiety within 1 month after stroke, and larger lesion volume is associated with deterioration of depression within 1 month after stroke.

Imaging and treatment of patients with acute stroke: an evidence-based review

Evidence-based medicine has emerged as a valuable tool to guide clinical decision-making, by summarizing the best possible evidence for both diagnostic and treatment strategies. Imaging plays a critical role in the evaluation and treatment of patients with acute ischemic stroke, especially those who are being considered for thrombolytic or endovascular therapy. Time from stroke-symptom onset to treatment is a strong predictor of long-term functional outcome after stroke. Therefore, imaging and treatment decisions must occur rapidly in this setting, while minimizing unnecessary delays in treatment. The aim of this review was to summarize the best available evidence for the diagnostic and therapeutic management of patients with acute ischemic stroke.

Mechanical thrombectomy with the solitaire stent at Lyon, France

BACKGROUND/AIMS

The Solitaire stent has been suggested as a promising device to perform intracranial thrombectomy in large vessels. We report our experience.

METHODS

Consecutive patients in whom a thrombectomy with Solitaire stent had been performed for acute ischemic stroke in the Lyon Stroke Unit, France, from November 2009 to November 2010 were enrolled.

RESULTS

There were 12 patients with a mean age of 66 years and a mean baseline National Institutes of Health Stroke Scale score of 17.5. There were 10 cases of anterior cerebral artery and 2 cases of basilar artery occlusion. The mean time from onset of symptoms to recanalization was 306 min. Partial or total recanalization was obtained in 91.6% of patients. One case of periprocedural asymptomatic arterial dissection and 1 case of symptomatic cerebral hemorrhage occurred. At 90 days, 4 patients (33.3%) were dead and 5 patients (41.6%) had a modified Rankin Scale ≤2.

CONCLUSIONS

In this case series, thrombectomy using Solitaire stent in stroke related to large vessel occlusion appears to be feasible, safe and potentially effective. Randomized controlled trials are needed to demonstrate the superiority of thrombectomy alone or in combination with intravenous tPA over intravenous tPA alone in ischemic stroke patients with large intracranial arterial occlusion.

Tissue characterization using mean gray value analysis in deep infiltrating endometriosis

OBJECTIVES

To investigate differences in tissue characterization using three-dimensional sonographic mean gray value (MGV) between retrocervical and rectosigmoid deeply infiltrating endometriosis, and to assess intra- and interobserver concordance in MGV quantification.

METHODS

In this retrospective study, stored ultrasound volumes from 50 premenopausal women (mean age, 32 years) with 57 histologically confirmed nodules of deep endometriosis were retrieved from our database for analysis. A single experienced operator had acquired all volumes. For each nodule, the MGV was evaluated using virtual organ computer-aided analysis (VOCAL) software with semiautomated sphere-sampling (1 cm3) from the central part of the nodule. In these patients the MGV was also quantified from the myometrium of the fundal part of the uterus. In addition, two observers calculated the MGV in a subset of 24 volumes in order to quantify inter- and intraobserver agreement using intraclass correlation coefficients (ICC).

RESULTS

Mean MGV was significantly higher in rectosigmoid nodules (n = 34) than in nodules with a retrocervical location (n = 23) (23.863 vs. 17.705; P < 0.001). MGV of the myometrium was significantly higher in comparison with that of nodules in both locations (P < 0.001 for both). Intra- and interobserver measurement reproducibility was excellent (ICC > 0.95).

CONCLUSIONS

Retrocervical and rectosigmoid endometriotic nodules display significantly different MGVs. Measurement of MGV is highly reproducible and its clinical value in the diagnosis and assessment of distribution of deep endometriosis should be assessed in future studies.

CT angiography in an acute stroke protocol: correlation between occlusion site and outcome of intravenous thrombolysis

Thrombolysis with intravenous rt-PA is the current therapy for acute ischemic stroke. Unlike other outcome factors, relatively little is known about the prognostic value of the occlusion site on treatment outcome. We compared the effectiveness and safety of intravenous thrombolysis in patients with different levels of occlusion identified by CT angiography (CTA) in anterior circulation stroke, and analyzed the influence of the occlusion site on treatment outcome in relation to other outcome factors. We selected 71 patients from a stroke database collected between June 2007 and December 2011 at our hospital. All of the studied patients had anterior circulation stroke with intracranial occlusion detected by CTA and were treated with intravenous rt-PA. They were divided into two groups according to the site of occlusion along the middle cerebral artery course: proximal (carotid "T", complete M1 and mild M1 occlusions) and distal (M2/M3 occlusions). Treatment effectiveness was assessed by modified Rankin Scale (mRS) at three months, considering a positive outcome a mRS value ≤ 2. Treatment safety was assessed by evaluating the rate of hemorrhagic complications seen on unenhanced CT at 24 hours. Binary logistic regression was performed to evaluate the interaction between occlusion site and other variables such as sex, age, ASPECT score on admission and baseline NIHSS value in determining treatment outcome. The degree of effectiveness and safety differed when considering patients with proximal and distal occlusions. The percentage of successfully treated cases was 28.6% in the first group compared to 72% in the second, and the rate of hemorrhagic complications was 28.6% and 6% respectively. After adjustment for sex, age, ASPECT score on admission and baseline NIHSS value, occlusion site was the only variable significantly influencing treatment safety and, together with baseline NIHSS value, the only valid predictor of treatment effectiveness. We demonstrated a correlation between the site of arterial occlusion and outcome of intravenous thrombolysis. By helping the choice of the best therapeutic strategy depending on the identified occlusion site, CTA could be usefully added to the examinations included in the Stroke Protocol for the baseline evaluation of patients with suspected acute stroke.

Diffusion-weighted magnetic resonance imaging may underestimate acute ischemic lesions: cautions on neglecting a computed tomography-diffusion-weighted imaging discrepancy

BACKGROUND AND PURPOSE

Diffusion-weighted imaging sometimes fails to detect early computed tomography (CT) ischemic lesions in acute ischemic stroke patients, which is termed reversed discrepancy (RD), but its clinical significance remains unclear. The incidence and factors associated with RD in acute ischemic stroke patients within 3 hours of onset were examined.

METHODS

A total of 164 consecutive patients with acute anterior circulation ischemic stroke was enrolled. All patients underwent both magnetic resonance imaging and CT within 3 hours of onset and before treatment. Their early ischemic changes were evaluated with the Alberta Stroke Program Early CT Score. RD was defined as present when the early ischemic change detected on CT was not seen on diffusion-weighted imaging.

RESULTS

RD was found in 40 patients (24%). RD group patients were older (78.7 ± 9.6 versus 74.1 ± 12.1 years; P=0.03) and had a higher admission National Institutes of Health Stroke Scale score (median, 22 versus 11; P<0.01), higher rates of atrial fibrillation (75% versus 42%; P<0.01), a higher rate of internal carotid artery/middle cerebral artery proximal occlusion (55% versus 28%; P<0.01), and lower CT-Alberta Stroke Program Early CT Score (median 5 versus 10; P<0.01) and diffusion-weighted imaging-Alberta Stroke Program Early CT Score (7 versus 9; P<0.01) than patients in the non-RD group. Multivariate logistic regression analysis demonstrated that atrial fibrillation was independently associated with the presence of RD (odds ratio, 2.47; 95% CI, 1.05-6.12).

CONCLUSIONS

RD is observed in a quarter of acute ischemic stroke patients. RD should be taken into consideration, especially in patients with atrial fibrillation, to prevent underestimating the extent of ischemic lesions.

"Picture to puncture": a novel time metric to enhance outcomes in patients transferred for endovascular reperfusion in acute ischemic stroke

BACKGROUND

Comprehensive stroke centers allow for regionalization of subspecialty stroke care. Efficacy of endovascular treatments, however, may be limited by delays in patient transfer. Our goal was to identify where these delays occurred and to assess the impact of such delays on patient outcome.

METHODS AND RESULTS

This was a retrospective study evaluating patients treated with endovascular therapy from November 2010 to July 2012 at our institution. We compared patients transferred from outside hospitals with locally treated patients with respect to demographics, imaging, and treatment times. Good outcomes, as defined by 90-day modified Rankin Scale scores of 0 to 2, were analyzed by transfer status as well as time from initial computed tomography to groin puncture ("picture-to-puncture" time). A total of 193 patients were analyzed, with a mean age of 65.8 ± 14.5 years and median National Institutes of Health Stroke Scale score of 19 (interquartile range, 15-23). More than two thirds of the patients (132 [68%]) were treated from referring facilities. Outside transfers were noted to have longer picture-to-puncture times (205 minutes [interquartile range, 162-274] versus 89 minutes [interquartile range, 70-119]; P<0.001), which was attributable to the delays in transfer. This corresponded to fewer patients with favorable Alberta Stroke Program Early CT Scores on preprocedural computed tomographic imaging (Alberta Stroke Program Early CT Scores >7: 50% versus 76%; P<0.001) and significantly worse clinical outcomes (29% versus 51%; P=0.003). In a logistic regression model, picture-to-puncture times were independently associated with good outcomes (odds ratio, 0.994; 95% confidence interval, 0.990-0.999; P=0.009).

CONCLUSIONS

Delays in picture-to-puncture times for interhospital transfers reduce the probability of good outcomes among treated patients. Strategies to reduce such delays herald an opportunity for hospitals to improve patient outcomes.

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 authors present an overview of the current evidence and management recommendations for evaluation and treatment of adults with acute ischemic stroke. The intended audiences are prehospital care providers, physicians, allied health professionals, and hospital administrators responsible for the care of acute ischemic stroke patients within the first 48 hours from stroke onset. These guidelines supersede the prior 2007 guidelines and 2009 updates.

METHODS

Members of the writing committee were appointed by the American Stroke Association Stroke Council's Scientific Statement Oversight Committee, representing various areas of medical expertise. Strict adherence to the American Heart Association conflict of interest policy was maintained throughout the consensus process. Panel members were assigned topics relevant to their areas of expertise, reviewed the stroke literature with emphasis on publications since the prior guidelines, and drafted recommendations in accordance with the American Heart Association Stroke Council's Level of Evidence grading algorithm.

RESULTS

The goal of these guidelines is to limit the morbidity and mortality associated with stroke. The guidelines support the overarching concept of stroke systems of care and detail aspects of stroke care from patient recognition; emergency medical services activation, transport, and triage; through the initial hours in the emergency department and stroke unit. The guideline discusses early stroke evaluation and general medical care, as well as ischemic stroke, specific interventions such as reperfusion strategies, and general physiological optimization for cerebral resuscitation.

CONCLUSIONS

Because many of the recommendations are based on limited data, additional research on treatment of acute ischemic stroke remains urgently needed.

Protocol for the perfusion and angiography imaging sub-study of the Third International Stroke Trial (IST-3) of alteplase treatment within six-hours of acute ischemic stroke

RATIONALE

Intravenous thrombolysis with recombinant tissue Plasminogen Activator improves outcomes in patients treated early after stroke but at the risk of causing intracranial hemorrhage. Restricting recombinant tissue Plasminogen Activator use to patients with evidence of still salvageable tissue, or with definite arterial occlusion, might help reduce risk, increase benefit and identify patients for treatment at late time windows.

AIMS

To determine if perfusion or angiographic imaging with computed tomography or magnetic resonance help identify patients who are more likely to benefit from recombinant tissue Plasminogen Activator in the context of a large multicenter randomized trial of recombinant tissue Plasminogen Activator given within six-hours of onset of acute ischemic stroke, the Third International Stroke Trial.

DESIGN

Third International Stroke Trial is a prospective multicenter randomized controlled trial testing recombinant tissue Plasminogen Activator (0·9 mg/kg, maximum dose 90 mg) started up to six-hours after onset of acute ischemic stroke, in patients with no clear indication for or contraindication to recombinant tissue Plasminogen Activator. Brain imaging (computed tomography or magnetic resonance) was mandatory pre-randomization to exclude hemorrhage. Scans were read centrally, blinded to treatment and clinical information. In centers where perfusion and/or angiography imaging were used routinely in stroke, these images were also collected centrally, processed and assessed using validated visual scores and computational measures.

STUDY OUTCOMES

The primary outcome in Third International Stroke Trial is alive and independent (Oxford Handicap Score 0-2) at 6 months; secondary outcomes are symptomatic and fatal intracranial hemorrhage, early and late death. The perfusion and angiography study additionally will examine interactions between recombinant tissue Plasminogen Activator and clinical outcomes, infarct growth and recanalization in the presence or absence of perfusion lesions and/or arterial occlusion at presentation. The study is registered ISRCTN25765518.

Neurosonographic monitoring of haemodynamic changes in tandem middle cerebral and internal carotid artery occlusion due to arterial dissection

A middle-aged man with pain in the right eye and right side of the neck was brought to the emergency department one hour after the onset of left-sided weakness. Computed tomography (CT) showed hyperdense right middle cerebral artery (MCA). On transcranial Doppler (TCD), occlusion of the right MCA and right internal carotid artery (ICA) was found. Thirty minutes after thrombolytic therapy was initiated, engagement of collateral circulation through the anterior communicating artery (AComA) was shown by TCD. Caro-tid duplex examination confirmed occlusion of the right ICA with intimal flap and intramural haematoma. CT angiography revealed flame-like occlusion of the right ICA, and occlusion of the right MCA with collateral supply from the left to right anterior cerebral artery through the AComA. Recanalization of the MCA and ICA was evident on both CT and ultrasound. Frequent ultrasound monitoring is useful for haemodynamic evaluation of carotid artery dissection, while TCD plays an important role in real-time monitoring of flow changes of intracranial vasculature.

Interobserver Agreement of ASPECT Score Distribution for Noncontrast CT, CT Angiography, and CT Perfusion in Acute Stroke

Background and Purpose—

The Alberta Stroke program early CT score (ASPECTS) is a semiquantative scale for estimating extent and distribution of early ischemic changes within the MCA territory in the acute stroke setting. Good interobserver agreement of total ASPECTS is demonstrated for noncontrast CT (NCCT) and other imaging modalities. Our purpose is to assess interobserver agreement for individual ASPECTS regions for different imaging modalities.

Methods—

One hundred and eighty-one consecutive patients presenting with acute stroke symptoms within 4.5 hours of onset were included. Four readers assigned total and individual ASPECTS for NCCT, CT angiography source images (CTA-SI), and CTP maps of cerebral blood volume (CTP-CBV). Interobserver agreement was assessed by measuring internal consistency and concordance of total and individual ASPECTS using Cronbach’s α and intraclass correlation coefficient, respectively.

Results—

Total ASPECTS demonstrated very good concordance and internal consistency for all 3 modalities. Intraclass correlation coefficient and Cronbach’s α were 0.834 and 0.859 for NCCT, 0.876 and 0.894 for CTA, and 0.903 and 0.911 for CTP-CBV, respectively. Performance for individual ASPECTS regions was inferior to total ASPECTS, but incremental improvement in interobserver reliability was demonstrated for NCCT, CTA-SI, and CTP-CBV, respectively. Highest concordance was shown for caudate, lentiform, and M1–M3, whereas performance for internal capsule and M4–M6 was poorer.

Conclusions—

CTP-CBV demonstrates the highest interobserver agreement for individual ASPECTS regions.

Severe stroke: patient profile and predictors of favorable outcome

BACKGROUND

Severe stroke carries high rates of mortality and morbidity. The aims of this study were to determine the characteristics of patients who initially presented with severe ischemic stroke, and to identify acute and subacute predictors of favorable clinical outcome in these patients.

METHODS

An observational cohort study, Acute Stroke Registry and Analysis of Lausanne (ASTRAL), was analyzed, and all patients presenting with severe stroke - defined as a National Institute of Health Stroke Scale score of ≥ 20 on admission - were compared with all other patients. In a multivariate analysis, associations with demographic, clinical, pathophysiologic, metabolic and neuroimaging factors were determined. Furthermore, we analyzed predictors of favorable outcome (modified Rankin scale score of ≤ 3 at 3 months) in the subgroup of severe stroke patients.

RESULTS

  Of 1915 consecutive patients, 243 (12.7%) presented with severe stroke. This was significantly associated with cardio-embolic stroke mechanism (odds ratio [OR] 1.74, 95% confidence interval [CI] 1.19-2.54), unknown stroke onset (OR 2.35, 95% CI 1.14-4.83), more neuroimaging signs of early ischemia (mostly computed tomography; OR 2.65, 95% CI 1.79-3.92), arterial occlusions on acute imaging (OR 27.01, 95% CI 11.5-62.9), fewer chronic radiologic infarcts (OR 0.43, 95% CI 0.26-0.72), lower hemoglobin concentration (OR 0.97, 95% CI 0.96-0.99), and higher white cell count (OR 1.05, 95% CI 1.00-1.11). In the 68 (28%) patients with favorable outcomes despite presenting with severe stroke, this was predicted by lower age (OR 0.94, 95% CI 0.92-0.97), preceding cerebrovascular events (OR 3.00, 95% CI 1.01-8.97), hypolipemic pretreatment (OR 3.82, 95% CI 1.34-10.90), lower acute temperature (OR 0.43, 95% CI 0.23-0.78), lower subacute glucose concentration (OR 0.74, 95% CI 0.56-0.97), and spontaneous or treatment-induced recanalization (OR 4.51, 95% CI 1.96-10.41).

CONCLUSIONS

Severe stroke presentation is predicted by multiple clinical, radiologic and metabolic variables, several of which are modifiable. Predictors in the 28% of patients with favorable outcome despite presenting with severe stroke include hypolipemic pretreatment, lower acute temperature, lower glucose levels at 24 h, and arterial recanalization.

Collateral circulation on perfusion-computed tomography-source images predicts the response to stroke intravenous thrombolysis

BACKGROUND AND PURPOSE

Perfusion-computed tomography-source images (PCT-SI) may allow a dynamic assessment of leptomeningeal collateral arteries (LMC) filling and emptying in middle cerebral artery (MCA) ischaemic stroke. We described a regional LMC scale on PCT-SI and hypothesized that a higher collateral score would predict a better response to intravenous (iv) thrombolysis.

METHODS

We studied consecutive ischaemic stroke patients with an acute MCA occlusion documented by transcranial Doppler/transcranial color-coded duplex, treated with iv thrombolysis who underwent PCT prior to treatment. Readers evaluated PCT-SI in a blinded fashion to assess LMC within the hypoperfused MCA territory. LMC scored as follows: 0, absence of vessels; 1, collateral supply filling ≤ 50%; 2, between> 50% and < 100%; 3, equal or more prominent when compared with the unaffected hemisphere. The scale was divided into good (scores 2-3) vs. poor (scores 0-1) collaterals. The predetermined primary end-point was a good 3-month functional outcome, while early neurological recovery, transcranial duplex-assessed 24-h MCA recanalization, 24-h hypodensity volume and hemorrhagic transformation were considered secondary end-points.

RESULTS

Fifty-four patients were included (55.5% women, median NIHSS 10), and 4-13-23-14 patients had LMC score (LMCs) of 0-1-2-3, respectively. The probability of a good long-term outcome augmented gradually with increasing LMCs: (0) 0%; (1) 15.4%; (2) 65.2%; (3) 64.3%, P = 0.004. Good-LMCs was independently associated with a good outcome [OR 21.02 (95% CI 2.23-197.75), P = 0.008]. Patients with good LMCs had better early neurological recovery (P = 0.001), smaller hypodensity volumes (P < 0.001) and a clear trend towards a higher recanalization rate.

CONCLUSIONS

A higher degree of LMC assessed by PCT-SI predicts good response to iv thrombolysis in MCA ischaemic stroke patients.

Thrombolytic therapy for acute ischaemic stroke: what can we do to improve outcomes?

Constant efforts are being made in the stroke community to aim for maximum benefit from thrombolytic therapy since the approval of intravenous recombinant tissue plasminogen activator (rt-PA; alteplase) for the management of acute ischaemic stroke. However, fear of symptomatic haemorrhage secondary to thrombolytic therapy has been a major concern for treating physicians. Certain imaging and clinical variables may help guide the clinician towards better treatment decision making. Aggressive management of some predictive variables that have been shown to be surrogate outcome measures has been related to better clinical outcomes. Achieving faster, safer and complete recanalization with evolving endovascular techniques is routinely practiced to achieve better clinical outcomes. Selection of an 'ideal candidate' for thrombolysis can maximize functional outcomes in these patients. Although speed and safety are the key factors in acute management of stroke patients, there must also be a systematic and organized pattern to assist the stroke physician in making decisions to select the 'ideal candidate' for treatment to maximize results.

Intracerebral hemorrhage secondary to intravenous and endovascular intraarterial revascularization therapies in acute ischemic stroke: an update on risk factors, predictors, and management

Intracerebral hemorrhage (ICH) secondary to intravenous and intraarterial revascularization strategies for emergent treatment of acute ischemic stroke is associated with high mortality. ICH from systemic thrombolysis typically occurs within the first 24-36 hours of treatment initiation and is characterized by rapid hematoma development and growth. Pathophysiological mechanisms of revascularization therapy-induced ICH are complex and involve a combination of several distinct processes, including the direct effect of thrombolytic agents, disruption of the blood-brain barrier secondary to ischemia, and direct vessel damage from wire and microcatheter manipulations during endovascular procedures. Several definitions of ICH secondary to thrombolysis currently exist, depending on clinical or radiological characteristics used. Multiple studies have investigated clinical and laboratory risk factors associated with higher rates of ICH in this setting. Early ischemic changes seen on noncontrast CT scanning are strongly associated with higher rates of hemorrhage. Modern imaging techniques, particularly CT perfusion, provide rapid assessment of hemodynamic parameters of the brain. Specific patterns of CT perfusion maps can help identify patients who are likely to benefit from revascularization or to develop hemorrhagic complications. There are no established guidelines that describe management of revascularization therapy-induced ICH, and great variability in treatment protocols currently exist. General principles that apply to the management of spontaneous ICH might not be as effective for revascularization therapy-induced ICH. In this article, the authors review current knowledge of risk factors and radiological predictors of ICH secondary to stroke revascularization techniques and analyze medical and surgical management strategies for ICH in this setting.

Timing of thrombolysis for acute ischemic stroke: "timing is everything" or "everyone is different"

It is indisputable that in the first 2 to 3 hours of an acute ischemic, the best strategy to maximize recovery is robustly time-based and depends on getting the artery open as soon as possible. The second law of thermodynamics and the underappreciated effect of clot consistency and size must be accounted for in our efforts to minimize time to recanalization within the first 2 to 3 hours. It is also clear that at later time intervals, beyond 4.5 hours, few patients completely recover even with sustained complete recanalization, and that the ability to recover depends more on physiologic tissue issues than on the duration of the occlusion. Clinical factors as well as imaging should be used to select patients who may benefit from delayed attempts at reperfusion.

Imaging-based selection in acute ischemic stroke trials - a quest for imaging sweet spots

Ischemic stroke is a very heterogeneous disease that limits the efficacy of acute stroke treatments. Future trials will require advanced imaging to select patients for specific treatments. The most well-established imaging tools are the use of CT to exclude hemorrhage and diffusion-weighted MRI to demonstrate ischemia. While perfusion imaging is one option for patient selection, it has unresolved issues, including standardization and validation, that limit its value. As an alternative to mismatch when addressing stroke, one needs to know the size of the initial irreversible lesion (core), the presence and site/extent of occlusion (clot), and presence of leptomeningeal back filling and Willisian filling (collaterals). These can be summarized as the "3C" approach of core, clot, and collateral interpretation, which together can represent an imaging sweet spot, particularly for time-efficient endovascular treatment trial design.

Advanced multimodal CT/MRI approaches to hyperacute stroke diagnosis, treatment, and monitoring

Multimodal CT/MRI has dramatically changed the approach to ischemic stroke management, as noninvasive CT/MRI images detail brain tissue or parenchyma, angiography or vessel status, and collateral perfusion or blood flow in regions of the brain vulnerable to ischemic injury. Such snapshots of the dynamic process of cerebral ischemia may be used to gauge reversibility and therapeutic opportunities. Treatment of acute stroke may be rapidly tailored to clinical scenarios based on imaging correlation of ischemia, vessel status, and perfusion. Serial or repeated imaging from the initial presentation to later stages of the hospital course may illustrate infarct growth, persisting occlusion, reocclusion, recanalization, reperfusion, and hemorrhagic transformation. From acute stroke to rehabilitation phases and subsequent prevention, multimodal CT/MRI has emerged as a key tool to track the process of stroke and the impact of our therapeutic interventions.

Impact of telemedicine on acute management of stroke patients undergoing endovascular procedures

BACKGROUND

Telemedicine is improving acute stroke care in remote areas. Delay in hospital-to-hospital transfer is a common reason why acute ischemic stroke patients are excluded from interventional therapy. The progressive implementation of these procedures, requiring highly specialized professionals in comprehensive stroke centers, will certainly challenge even more the geographic equity in the access to the best acute stroke treatments. We aimed to assess the benefits of telemedicine in selecting stroke patients for endovascular treatments.

METHODS

In our Reference Comprehensive Stroke Center (RCSC), we perform urgent intra-arterial procedures in acute stroke patients. Patients may be primarily admitted (PA) or referred from community hospitals with (TMHs; 2 centers) or without telemedicine (nonTMHs; 7 centers). We prospectively studied all consecutive stroke patients undergoing urgent endovascular recanalization procedures in the RCSC. We studied different outcome measures according to the patients' initial admission: PA patients, TMH patients or nonTMH patients. For all patients, demographic and outcome data including serial National Institute of Health Stroke Scale (NIHSS) and modified Rankin Scale (mRS) scores at 3 months were recorded. Clinical improvement was defined as a decrease ≥4 points on the NIHSS at 7 days or discharge and favorable outcome as mRS ≤2 at 3 months. Whether an endovascular procedure was indicated was decided according to clinical, radiological and transcranial Doppler (TCD) data, independently of the patient's initial admission center.

RESULTS

During a 2-year period, 119 patients received endovascular treatment: PA patients 74 (63.1%), TMH patients 25 (20.5%), nonTM patients 20 (16.4%). The mean distance to the RCSC was 52 ± 15 km for TMHs and 34.5 ± 12 km for nonTMHs (p = 0.4). There were no differences in baseline characteristics including age (71, 71.6 and 66.5 years; p = 0.25), baseline NIHSS (18.5, 19 and 18; p = 0.57) and previous use of intravenous tissue plasminogen activator (56.5, 56.5 and 57.9%; p = 0.95). The rate of recanalization (modified Thrombolysis in Cerebral Infarction Score ≥2a) was similar in all groups (75, 66.6 and 68.4%; p = 0.682). TMH and PA patients had similar clinical improvement (61 vs. 63.8%; p = 0.51) and good functional outcome (36.8 vs. 35.3%; p = 0.722). Conversely, nonTMH patients presented a lesser degree of clinical improvement (31.3%) and poorer functional outcome (15.8%) than TMH (p = 0.019 and p = 0.046) and PA patients (p = 0.05 and p = 0.013). TMH patients had significantly shorter door-to-groin puncture times (47 vs. 69 min; p = 0.047).

CONCLUSIONS

Telemedicine assessment to select patients for endovascular procedures improves the efficiency in stroke management and possibly the early and long-term outcome in patients receiving intra-arterial reperfusion treatment.

Stent-Based Thrombectomy Versus Intravenous Tissue Plasminogen Activator in Patients With Acute Middle Cerebral Artery Occlusion

Background and Purpose—

Our goal was to compare outcomes of patients with proximal middle cerebral artery occlusions treated with intravenous tissue plasminogen activator (tPA) with those of patients treated with stent-based thrombectomy (SBT).

Methods—

Patients with proximal middle cerebral artery occlusions included in our prospective stroke registry were identified. Patients presenting with moderate to severe stroke defined as National Institutes of Health Stroke Scale score ≥10 were included. Patients treated with tPA were compared with those treated with SBT. Disability was measured with the modified Rankin Scale and shifts toward favorable outcomes (modified Rankin Scale ≤2) were analyzed. Logistic regression was used to determine outcome modifiers.

Results—

We included 22 patients treated with SBT and 66 treated with tPA. Patients treated with SBT had higher admission National Institutes of Health Stroke Scale scores (median 21 vs 14.5; P <0.001) and prolonged symptom onset-to-treatment times (median 240 vs 95 minutes; P <0.001). At discharge, the magnitude of change in National Institutes of Health Stroke Scale was larger in the thrombectomy group (median 12 vs 6 points; P <0.001). At 90 days poststroke there was a shift toward favorable outcome in the thrombectomy group (60% vs 37.5%; P =0.001). Treatment allocation did not impact outcome in the regression analysis.

Conclusions—

Treatment of patients with proximal middle cerebral artery occlusions with SBT resulted in a shift toward more favorable outcomes compared with tPA. Randomized controlled studies are needed to explore whether treatment with SBT should be used in patients presenting within the first hours after stroke.

Hyperintensity of distal vessels on FLAIR is associated with slow progression of the infarction in acute ischemic stroke

BACKGROUND

Hyperintensity of distal vessels on FLAIR-MRI has been associated with a higher grade of arterial collaterals and a smaller infarct volume in acute stroke patients. No studies analyze the influence of the hyperintense vessel (HV) sign on the speed of the ischemia progression during the first hours. Our aim was to study the association of the HV sign with progression of infarction in acute stroke patients.

METHODS

From a prospectively derived stroke database, we retrospectively selected acute stroke patients with a large artery occlusion of the anterior circulation admitted to our comprehensive stroke center with available baseline CT scan and a multimodal MRI carried out thereafter to make a decision about endovascular treatment. Progression of the ischemic area was calculated as the difference in the Alberta Stroke Program Early CT Scan (ASPECTS) score between CT scan and diffusion-weighted imaging (DWI). Slow progression was considered as no change or 1 point decrease on the ASPECTS score between both exams. The presence of HV on FLAIR sequence was graded as absent, subtle or prominent by two readers.

RESULTS

A total of 70 patients were included in the study. Mean time between baseline CT and MRI was 124 ± 82 min. ASPECTS score on baseline CT was 10 in 34% of patients, 9 in 49% and 8 or less in 17%. ASPECTS score was 2 (1-3) points lower in the DWI and this decrease did not correlate with the time elapsed between the two exams. Distal HV sign was observed in 57/70 (81%) patients (subtle in 33 and prominent in 24). HV was more frequently observed in patients with proximal artery occlusion. There were no differences regarding stroke severity, stroke subtype and ASPECTS score on baseline CT between groups. Patients with prominent HV showed a lower progression of the ischemic area [median ASPECTS score decrease, 1 (1-0)] compared with patients with subtle HV [median ASPECTS score decrease, 2 (2-1)] and patients with absence of HV [median ASPECTS score decrease, 3 (4-3)] (p < 0.001). Prominent HV was independently associated with slow progression of ischemia in a multivariate logistic regression analysis adjusted by systolic blood pressure on admission, site of occlusion and time elapsed between both neuroimaging exams compared to the absence of HV (OR, 16.2; 95% CI, 2.1-123.1) and to subtle HV sign (OR, 6.1; 95% CI, 1.5-23.9).

CONCLUSION

HV sign on FLAIR, especially if prominent, is associated with a slow progression of the ischemic area in acute stroke patients with cerebral artery occlusion of the anterior circulation. This radiological sign may predict the speed of the ischemia progression, opening an opportunity for reperfusion therapies in longer time windows.

Posterior cerebral artery laterality on magnetic resonance angiography predicts long-term functional outcome in middle cerebral artery occlusion

BACKGROUND AND PURPOSE

Prominent posterior cerebral artery (PCA) laterality upon 3-dimensional time-of-flight magnetic resonance angiography is often encountered in patients with middle cerebral artery occlusion. We hypothesized that this sign is correlated with improved functional outcome in patients with middle cerebral artery occlusion treated with intravenous recombinant tissue plasminogen activator.

METHODS

Fifty acute ischemic stroke patients with middle cerebral artery occlusion were treated with intravenous recombinant tissue plasminogen activator from April 2007 to October 2009. All patients routinely underwent initial (first 3 hours) magnetic resonance scans on admission, and additional follow-up (14-21 days after stroke onset) computed tomography scans. Two film readers blinded to all clinical information assessed the presence or absence of PCA laterality on magnetic resonance angiography. We retrospectively analyzed the clinical and radiologic data on all patients.

RESULTS

Out of 50 patients, 20 showed PCA laterality on magnetic resonance angiography. National Institute of Health Stroke Scale score 7 days after stroke onset was significantly lower (P=0.007), and infarct volume on follow-up computed tomography was significantly smaller (P=0.009) in patients with PCA laterality than in patients without this sign. Multivariate logistic regression analyses showed an adjusted odds ratio of 8.49 for a favorable outcome (modified Rankin Scale score 0-1 at 6 months) in patients with PCA laterality (95% CI: 1.82 to 55.8, P=0.005).

CONCLUSIONS

The presence of PCA laterality on magnetic resonance angiography before intravenous recombinant tissue plasminogen activator can be used as a predictor of favorable functional outcome in patients with middle cerebral artery occlusion, probably due to improvement of recanalization rate.

Platelet derived growth factor-CC isoform is associated with hemorrhagic transformation in ischemic stroke patients treated with tissue plasminogen activator

OBJECTIVE

Platelet derived growth factor-CC (PDGF-CC) isoform is activated by tissue plasminogen activator (tPA) regulating blood brain barrier permeability after ischemia. We aimed to study the association of PDGF isoforms serum levels with hemorrhagic transformation (HT) and edema after thrombolytic treatment in ischemic stroke.

METHODS

We studied 129 patients with ischemic stroke treated with tPA within the first 4.5 h (h) from stroke onset. CT was performed on admission and at 24-36 h. On the 2nd CT, HT was classified according to ECASS II criteria, and severe brain edema was diagnosed if extensive swelling causing any shifting of the structures of the midline was detected. PDGF-AA, PDGF-AB, PDGF-BB and PDGF-CC serum levels were analyzed by ELISA on admission (before tPA bolus), at 24 and 72 h.

RESULTS

Patients who developed HT showed only higher levels of PDGF-CC isoform on admission and at 24 h (all p < 0.0001). In the multivariate analysis, PDGF-CC levels on admission (OR, 1.02; CI 95%, 1.00-1.04) and at 24 h (OR, 1.05; CI 95%, 1.02-1.08) were independently associated with HT after adjustment by confounding factors. On the other hand, patients with severe edema showed also higher levels of PDGF-CC on admission and at 24 h (p < 0.0001), but this statistical association was lost in the logistic regression analysis. PDGF-CC levels ≥ 175 ng/mL at 24 h predict the development of PH with a sensitivity of 90% and specificity of 88% (area under the curve 0.936; p < 0.0001).

CONCLUSION

Increased PDGF-CC levels after tPA treatment is associated with HT.

Factors affecting pre- and post-stenting computed tomography perfusion in patients with middle cerebral artery stenosis

The aim of this study was to investigate the factors affecting pre- and post-stenting head computed tomography perfusion (CTP) in patients with middle cerebral artery stenosis. A total of 25 patients with severe middle cerebral artery stenosis were enrolled. CTP was performed prior to and following stenting. Scores were allocated to the time-to-peak (TTP) parameter of CTP using the Alberta stroke program early computed tomography scoring (ASPECTS) scale. The factors possibly affecting pre- and post-stenting CTP were analyzed. All the patients exhibited markedly prolonged TTP on the affected side prior to stenting, compared with the healthy side. Following surgery, the TTP was improved in all patients. The preoperative ASPECTS score was negatively correlated with the degree of middle cerebral artery stenosis with a correlation coefficient of −5.78. The preoperative vascular stenosis rate was positively correlated with the improvement degree of the ASPECTS score with a correlation coefficient of 1.137 (P=0.001). TTP is a sensitive parameter for evaluating the effect of stenting on middle cerebral artery stenosis. TTP prior to and following stenting may be quantitatively assessed using the ASPECTS scale. Patients with serious stenosis and/or good collateral circulation are able to benefit more from stenting.

Impact of Collateral Circulation on Early Outcome and Risk of Hemorrhagic Complications after Systemic Thrombolysis

Background

In stroke patients, collateral flow can rapidly be assessed on computed tomography angiography (CTA).

Aims

In this study, the impact of baseline collaterals on early outcome and risk of symptomatic intracerebral hemorrhages after systemic thrombolysis in patients with proximal arterial occlusions within the anterior circulation were analyzed.

Methods

Collateralization scores were determined on the CT angiography source images (0 = absent; 1 ≤ 50%, 2 > 50% but <100%, and 3 = 100% collateral filling) of patients with distal intracranial carotid artery and/or M1 segment occlusions treated from 2008 to December 2011. A collateral score of 0 to 1 was designated as poor and 2 to 3 as good collateral vessel status. Outcome variables included in hospital mortality, favorable outcome at discharge (modified Rankin score ≤ 2), and rates of symptomatic intracerebral hemorrhage based on the European–Australasian Acute Stroke Study II definition.

Results

Among 246 subjects (mean age of 74 years; median National Institutes of Health Stroke Scale N at admission 14), 205 patients (83%) had good collaterals, whereas 41 patients (17%) had poor collaterals, respectively. Patients with poor collaterals had significantly higher rates of in-hospital mortality (41% vs. 12%, P < 0·001), of symptomatic intracerebral hemorrhage (15% vs. 4·9%, P < 0·05) and had significantly lower rates of favorable early clinical outcome (0% vs. 28%, P < 0·001) compared with those with good collaterals. The grade of collateralization was independently associated with in-hospital mortality ( P < 0·001), early clinical outcome ( P < 0·01), and rates of symptomatic intracerebral hemorrhage ( P < 0·01).

Conclusion

Patients with proximal arterial occlusions within the anterior circulation and poor baseline collaterals have a poor early functional outcome and high rates of symptomatic intracerebral hemorrhage after systemic thrombolysis. Since similar findings have also been reported after endovascular therapy, strategies to improve collateral blood flow should be assessed in this patient population.

MRI profile and response to endovascular reperfusion after stroke (DEFUSE 2): a prospective cohort study

BACKGROUND

Whether endovascular stroke treatment improves clinical outcomes is unclear because of the paucity of data from randomised placebo-controlled trials. We aimed to establish whether MRI can be used to identify patients who are most likely to benefit from endovascular reperfusion.

METHODS

In this prospective cohort study we consecutively enrolled patients scheduled to have endovascular treatment within 12 h of onset of stroke at eight centres in the USA and one in Austria. Aided by an automated image analysis computer program, investigators interpreted a baseline MRI scan taken before treatment to establish whether the patient had an MRI profile (target mismatch) that suggested salvageable tissue was present. Reperfusion was assessed on an early follow-up MRI scan (within 12 h of the revascularisation procedure) and defined as a more than 50% reduction in the volume of the lesion from baseline on perfusion-weighted MRI. The primary outcome was favourable clinical response, defined as an improvement of 8 or more on the National Institutes of Health Stroke Scale between baseline and day 30 or a score of 0-1 at day 30. The secondary clinical endpoint was good functional outcome, defined as a modified Rankin scale score of 2 or less at day 90. Analyses were adjusted for imbalances in baseline predictors of outcome. Investigators assessing outcomes were masked to baseline data.

FINDINGS

138 patients were enrolled. 110 patients had catheter angiography and of these 104 had an MRI profile and 99 could be assessed for reperfusion. 46 of 78 (59%) patients with target mismatch and 12 of 21 (57%) patients without target mismatch had reperfusion after endovascular treatment. The adjusted odds ratio (OR) for favourable clinical response associated with reperfusion was 8·8 (95% CI 2·7-29·0) in the target mismatch group and 0·2 (0·0-1·6) in the no target mismatch group (p=0·003 for difference between ORs). Reperfusion was associated with increased good functional outcome at 90 days (OR 4·0, 95% CI 1·3-12·2) in the target mismatch group, but not in the no target mismatch group (1·9, 0·2-18·7).

INTERPRETATION

Target mismatch patients who had early reperfusion after endovascular stroke treatment had more favourable clinical outcomes. No association between reperfusion and favourable outcomes was present in patients without target mismatch. Our data suggest that a randomised controlled trial of endovascular treatment for patients with the target mismatch profile is warranted.

FUNDING

National Institute for Neurological Disorders and Stroke.

Selection of possible responders to thrombolytic therapy in acute ischemic stroke

Ischemic stroke is one of the leading causes of death and morbidity worldwide, and systemic thrombolytic treatment is still the first-line therapy within 4.5 h from symptom onset. Selecting patients for treatment response is mandatory in any time window but challenging as well. The authors aim to support stroke physicians in their individual decision making. Besides evidence from clinical trials, some suggestions included here exclusively reflect the authors' opinions. This article presents clinical and imaging criteria of selecting patients reasonably, offering causal therapy to a growing number of patients.

Treatment of acute ischemic stroke: systemic or local?

Systemic treatment of acute ischemic stroke currently means intravenous infusion of plasminogen activator in patients with the stroke syndrome after exclusion of brain hemorrhage irrespective of whether thrombotic arterial obstruction is present or not. In contrast, local intra-arterial treatment requires digital subtraction angiography and means direct treatment of the arterial pathology with the aim of recanalization and brain tissue reperfusion. Randomized controlled trials that test these two treatment approaches are missing. This paper discusses whether the time-saving systemic treatment approach is more promising for acute ischemic stroke patients than is the time-consuming endovascular local approach.

Aspectasaurus (A Dinosaur)?

There is mounting evidence that shows how poorly noncontrast computed tomography (NCCT) Alberta Stroke Program Early CT Score (ASPECTS) performs in the first three-hours after stroke onset compared to Diffusion weighted (DWI) magnetic resonance imaging (MRI). It is time to move into the 21st century and use more advanced imaging routinely in hyper-acute stroke assessment. While a useful tool if one is limited to NCCT alone, ASPECTS becomes somewhat superfluous as we now have rapid, validated, automated infarct core and penumbra volumes with either MRI or perfusion CT.

CT interpretation in a telestroke network: agreement among a spoke radiologist, hub vascular neurologist, and hub neuroradiologist

BACKGROUND AND PURPOSE

The American Stroke Association guidelines emphasized the need for further high-quality studies that assess agreement by radiologists and nonradiologists engaged in emergency telestroke assessments and decision-making. Therefore, the objective of this study was to determine the level of agreement of baseline brain CT scan interpretations of patients with acute stroke presenting to telestroke spoke hospitals between central reading committee neuroradiologists and each of 2 groups, spoke hospital radiologists and hub hospital vascular neurologists (telestrokologists).

METHODS

The Stroke Team Remote Evaluation Using a Digital Observation Camera Arizona trial was a prospective, urban single-hub, rural 2-spoke, randomized, blinded, controlled trial of a 2-way, site-independent, audiovisual telemedicine and teleradiology system designed for remote evaluation of adult patients with acute stroke versus telephone consultation to assess eligibility for treatment with intravenous thrombolysis. In the telemedicine arm, the subjects' CT scans were interpreted by the hub telestrokologist and in the telephone arm by the spoke radiologist. All subjects' CT scans were subsequently interpreted centrally, independently, and blindly by 2 hub neuroradiologists. The primary CT outcome was determination of a CT-based contraindication to thrombolytic treatment. Kappa statistics and exact agreement rates were used to analyze interobserver agreement.

RESULTS

Fifty-four subjects underwent random assignment. The overall agreement for the presence of radiological contraindications to thrombolysis was excellent (0.91) and did not differ substantially between the hub telestrokologist to neuroradiologist and spoke radiologist to neuroradiologist (0.92 and 0.89, respectively).

CONCLUSIONS

In the context of a telestroke network designed to assess patients with acute stroke syndromes, agreement over the presence or absence of radiological contraindications to thrombolysis was excellent whether the comparisons were between a telestrokologist and neuroradiologist or between spoke radiologist and neuroradiologist.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00623350.

Time Dependence of Reliability of Noncontrast Computed Tomography in Comparison to Computed Tomography Angiography Source Image in Acute Ischemic Stroke

There is no consensus on how the reliability and predictive ability of noncontrast computed tomography (NCCT) and computed tomography angiography source image (CTASI) change over time from acute ischemic stroke onset. We hypothesized that the reliability for detecting early ischemic changes (EIC) would be lower in early time periods and that changes identified on CTASI would be more reliable across examiners than changes identified on NCCT. To address this, we compared the relationships between CTASI, NCCT, and final infarct in patients with initial computed tomography (CT) imaging at different time points after stroke onset. Patients with acute ischemic stroke with proximal anterior circulation occlusions (internal carotid artery, middle carotid artery M1, proximal M2) from Calgary CT Angiography (CTA) database were studied. The cohort was categorized in four groups based on time from stroke onset to baseline NCCT/CTA: 0–90 mins ( n = 69), 91–180 mins ( n = 88), 181–360 mins ( n = 46), and >360 mins ( n = 58). Median scores of NCCT-Alberta Stroke Program Early CT Score (ASPECTS), CTASI ASPECTS, and follow-up ASPECTS among different time categories were compared. To determine reliability, a subsample of NCCT brain and CTASI were interpreted at separate sessions weeks apart by two neuroradiologists and two stroke neurologists in random order. Median and mean ASPECTS ratings on NCCT and CTASI were higher than final ASPECTS in each time category ( P < 0·001 for all comparisons). CTASI ASPECTS was lower than NCCT ASPECTS in each time category, and differences were significant at 0–90 mins and 91–180 mins ( P < 0·001). The least agreement among readers was in detection of EIC on NCCT brain in the ultra-early phase (<90 mins) [intraclass correlation coefficient (ICC) = 0·48. By contrast, there was excellent agreement on EIC on CTASI regardless of time period (ICC = 0·87–0·96). Using ASPECTS methodology, CTASI is more reliable than NCCT at predicting final infarct extent particularly in the early time windows.

Future trials of endovascular mechanical recanalisation therapy in acute ischemic stroke patients - a position paper endorsed by ESMINT and ESNR : part II: methodology of future trials

Based on current data and experience, the joint working group of the European Society of Minimally Invasive Neurological Therapy (ESMINT) and the European Society of Neuroradiology (ESNR) make suggestions on trial design and conduct aimed to investigate therapeutic effects of mechanical thrombectomy (MT). We anticipate that this roadmap will facilitate the setting up and conduct of successful trials in close collaboration with our neighbouring disciplines.

Endovascular treatment of acute ischemic stroke: current indications

Endovascular stroke therapy is an effective means of achieving reperfusion in stroke patients with proximal cerebral artery occlusions. However, current guideline recommendations express uncertainty regarding the clinical efficacy of catheter-based treatments, given the lack of supportive trial data. A critical problem is that it remains unclear which patients will benefit from endovascular therapy. As such, patient selection is likely highly variable in clinical practice. This article will review the existing data to discuss the clinical and imaging factors that are relevant to patient outcomes, and which may be used to guide endovascular treatment decisions. Anterior circulation strokes represent the primary focus of this review.

Neuroimaging in acute stroke: choosing the right patient for neurointervention

Although the non-contrast computed tomography head continues as the sole mandatory imaging technique before intravenous thrombolysis, the increased availability of advanced infarct/penumbral imaging techniques and confidence in their use have led many to adopt them into routine practice--most particularly before intra-arterial interventions. Computed tomography versus magnetic resonance-based routes to imaging the cerebral vasculature, cell death, and parenchymal perfusion have differing advantages in terms of speed, availability, exposures to contrast and radiation, sensitivity, and resolution. Continued refinement and future developments, such as the ability to quantitate perfusion, promise to lead to tailored treatment protocols that respect the individual variations in anatomy, physiology, and pathology. This should lead both to an extension of treatment to patients currently excluded by rigid time windows and the avoidance of futile therapies and their associated morbidities.

Modified Pediatric ASPECTS Correlates with Infarct Volume in Childhood Arterial Ischemic Stroke

Background and Purpose: Larger infarct volume as a percent of supratentorial brain volume (SBV) predicts poor outcome and hemorrhagic transformation in childhood arterial ischemic stroke (AIS). In perinatal AIS, higher scores on a modified pediatric version of the Alberta Stroke Program Early CT Score using acute MRI (modASPECTS) predict later seizure occurrence. The objectives were to establish the relationship of modASPECTS to infarct volume in perinatal and childhood AIS and to establish the interrater reliability of the score. Methods: We performed a cross sectional study of 31 neonates and 40 children identified from a tertiary care center stroke registry with supratentorial AIS and acute MRI with diffusion weighted imaging (DWI) and T2 axial sequences. Infarct volume was expressed as a percent of SBV using computer-assisted manual segmentation tracings. ModASPECTS was performed on DWI by three independent raters. The modASPECTS were compared among raters and to infarct volume as a percent of SBV. Results: ModASPECTS correlated well with infarct volume. Spearman rank correlation coefficients (ρ) for the perinatal and childhood groups were 0.76, p < 0.001 and 0.69, p < 0.001, respectively. Excluding one perinatal and two childhood subjects with multifocal punctate ischemia without large or medium sized vessel stroke, ρ for the perinatal and childhood groups were 0.87, p < 0.001 and 0.80, p < 0.001, respectively. The intraclass correlation coefficients for the three raters for the neonates and children were 0.93 [95% confidence interval (CI) 0.89–0.97, p < 0.001] and 0.94 (95% CI 0.91–0.97, p < 0.001), respectively. Conclusion: The modified pediatric ASPECTS on acute MRI can be used to estimate infarct volume as a percent of SBV with a high degree of validity and interrater reliability.

A meta-analysis of observational intra-arterial stroke therapy studies using the Merci device, Penumbra system, and retrievable stents

BACKGROUND AND PURPOSE

The time from arterial puncture to successful recanalization is an important milestone toward timely recanalization. With the significant improvement in recanalization rates by using thrombectomy devices, procedural time to recanalization is becoming a determinant factor in choosing among available devices. We aimed to assess the impact of time to recanalization on the outcome of intra-arterial stroke therapies.

MATERIALS AND METHODS

We conducted a meta-analysis of studies reporting procedural times in patients with stroke treated with the MD, PS, and RS.

RESULTS

We identified 16 eligible studies: 4 on the MD (n = 357), 8 on the PS (n = 455), and 4 on RS (n = 113). Merci device studies described total procedural duration, while PS and RS studies described puncture-to-recanalization times. With a random-effects model, mean procedural duration for the MD was 120 minutes (95% CI, 105.7-134.2 minutes). Mean puncture to recanalization time for the PS was 64.6 minutes (95% CI, 44.4-84.8 minutes) and 54.7 minutes for RS (95% CI, 47.3-62.2 minutes). Successful recanalization was achieved in 211 of 357 patients (59.1%) in the MD studies (95% CI, 49.3-77.7), 394 of 455 (86.6%) in the PS studies (95% CI, 84.1-93.8), and 105 of 113 (92.9%) in the RS studies (95% CI, 90.9-99.9). Functional independence (mRS ≤2) was achieved in 31.5% of patients in the MD studies, 36.6% in the PS studies, and 46.9% in the RS studies.

CONCLUSIONS

The use of the PS and RS was associated with comparable procedural time to recanalization. Available data did not allow this parameter to be determined for trials using the MD. Retrievable stents achieved the highest rate of successful recanalization and functional outcome and the lowest mortality.