The Alberta Stroke Program Early CT Score in Clinical Practice: What have We Learned?

Clearance rate of contrast extravasation after endovascular therapy is associated with functional outcome and mediated by cerebral edema

The brain's function of clearance and transport is closely related to the prognosis of acute ischemic stroke (AIS). In this study, we proposed a novel method, clearance rate of contrast extravasation (CROCE), to measure brain clearance and transport function in AIS patients undergoing endovascular therapy (EVT), and examined its association with cerebral edema and functional outcome. We conducted a pooled analysis of AIS patients of anterior circulation large vessel occlusion who underwent EVT in two academic hospitals. Patients who experienced contrast extravasation but not intracerebral hemorrhage following EVT were included. CROCE was defined as the mass of contrast agent cleared per hour on non-contrast CT (NCCT). Among the 215 patients finally included, we found that high CROCE was significantly associated with 90-day favorable functional outcome, and the association retained after adjustment for potential confounders. Different correlation analysis demonstrated a significant correlation between CROCE, cerebral edema, and functional outcome. Further mediation analysis revealed that cerebral edema mediated the effect of CROCE on functional outcome. These results revealed that CROCE may be a promising indicator of brain clearance function for patients who received EVT and had contrast extravasation.

Aphasia profiles and trajectories in acute ischemic stroke: An observational study

BACKGROUND

In acute ischemic stroke (AIS), neuropsychological deficits and their long-term impact are insufficiently studied. We studied pure aphasic AIS patients, their short-term aphasiological course, predictors of persisting aphasia, and their outcome.

METHODS

In the ASTRAL Registry, we assessed all pure aphasic AIS patients from 2003-2019, and reviewed their neuropsychological examination performed after 3-10 days. We identified factors associated with persistent significant aphasia in the subacute phase, and predictors of unfavourable functional outcome at 3 months (mRS≥ 2), using multivariate analyses (MVA).

RESULTS

Among 4513 consecutive AISs, 131 (2.9 %) had pure aphasia at admission. Eighty-one had a good quality neuropsychological examination and were analysed further (median age 76.3yrs; 44.4 % female; 6.2 % left-handed; 27.2 % treated by acute revascularization). Of these, 28.4 % still had significant aphasia in the subacute phase. Persistent aphasia was independently associated with cardioembolic (OR 13.6, 95 %CI 2.6-70.8) or atheromatous (OR 16.0, 95 %CI 1.9-132.1) stroke mechanisms, and with an executive function deficit on neuropsychological examination (OR 10.5, 95 %CI 2.0-54.4). At 3 months, female gender (OR 4.2, 95 %CI 1.2-15.3) and significant aphasia in the subacute phase (OR 12.0, 95 %CI 3.3-43.6) predicted an mRS≥2.

CONCLUSION

Pure aphasia was present in 2.9 % of all AIS patients and resolved in three-quarters in the subacute phase. Persistent aphasia was associated with embolic stroke mechanisms and concomitant executive function impairment, and poor 3 months outcome, with female gender and enduring subacute aphasia. These data may help with prognostication, management and rehabilitation planning.

KEY MESSAGE

Pure aphasic ischemic stroke is rare and most recover spontaneously within days, and persistent subacute aphasia is associated with defined embolic stroke mechanisms, and concomitant executive dysfunction. Unfavourable functional outcome at 3 months is present in women and if there is persistent subacute aphasia.

Multi-phase CT-Angiography outperforms angiographic careggi collateral score and predicts functional outcome in acute ischemic stroke

BACKGROUND

Collaterals are a strong determinant of clinical outcome in acute ischemic stroke (AIS) patients undergoing Endovascular Treatment (EVT). Careggi Collateral Score (CCS) is an angiographic score that demonstrated to be superior to the widely suggested ASITN/SIR score. Multi-phase CT-Angiography (mCTA) could be alternatively adopted for collateral assessment. We investigated whether mCTA had an equivalent predictive performance for functional outcome compared to CCS.

METHODS

Consecutive AIS patients undergoing EVT for large vessel occlusion within 24 h from onset were analyzed. Receiver operating characteristic curves and multivariable logistic regression were investigated to evaluate the predictive performance of mCTA collateral score (range 0-5) and CCS (range 0-4) for good functional outcome (three-months modified Rankin Scale 0-2).

RESULTS

We included 201 subjects (59.7% females, mean age 75), of whom 96 (47.7%) had good outcome at three-months. Both CCS (OR = 14.4, 95% CI = 6.3-33.8) and mCTA (OR = 23.8, 95% CI = 10.1-56.4) collateral scores were independent predictors of outcome. The AUC of CCS was 0.80 (95% CI 0.73-0.86) and the best cut-off was ≥ 3 (87% sensitivity, 71% specificity), while the AUC of mCTA collateral score was 0.84 (95% CI 0.78-0.90) with an optimal cut-off of ≥ 4 (85% sensitivity, 87% specificity). Patients with good mCTA collaterals experienced smaller (16.6 vs. 63.7 mL, p < 0.001) infarct lesion as compared to those with mCTA poor collaterals.

CONCLUSION

mCTA discriminative ability for three-months 0-2 mRS was found to be comparable to CCS. mCTA appears a valid, non-invasive imaging modality for evaluating collaterals of AIS patients potentially eligible for EVT.

Higher baseline subcortical net water uptake in computed tomography predicts malignant middle cerebral artery infarction in patients with acute ischemic stroke

AIM

The objective of this study was to assess the predictive performance of net water uptake (NWU) based on the Alberta stroke program early CT score (ASPECTS) from different ASPECT regions in relation to the development of malignant middle cerebral artery (MCA) infarction.

MATERIAL AND METHODS

Patients with acute ischemic stroke (AIS) of the MCA territory were retrospectively enrolled between January 2019 and July 2022. Patients were divided into two groups according to the follow-up CT after 24-48 hours: malignant and nonmalignant infarction. NWUs were measured on diverse ASPECT regions on admission non-contrast CT, namely affected ASPECTS-NWU (af-ASPECTS-NWU), subcortical ASPECTS-NWU (sc-ASPECTS-NWU), and cortical ASPECTS-NWU (c-ASPECTS-NWU). Baseline characteristics were collected for univariate analyses and multivariate regression analyses to explore the independent risk factors for malignant infarction. Receiver operating characteristic (ROC) curves were plotted and compared.

RESULTS

patients were included in the final analysis. Malignant MCA infarction was achieved in 42 (27.45%) patients and nonmalignant was 111 (72.55%). Compared with the nonmalignant infarction group, higher baseline National Institute of Health stroke scale (NIHSS) score, af-ASPECTS-NWU, c-ASPECTS-NWU, sc-ASPECTS-NWU, and lower ASPECTS were noted in the malignant infarction group (all P < 0.001). Multivariate logistic regression showed that only baseline sc-ASPECTS-NWU (>3.6%) was a positive factor for malignant MCA infarction. The ROC analysis indicated the highest predictive value of sc-ASPECTS-NWU for indicating malignant infarction with the area under ROC curve (AUC) 0.91.

CONCLUSION

Higher baseline sc-ASPECTS-NWU was a quantitative predictor for malignant MCA infarction in patients with AIS, which could be helpful for treatment decisions.

Hypoperfusion intensity ratio correlates with collaterals and predicts outcome and infarct volume in acute ischemic stroke patients

BACKGROUND

Hypoperfusion Intensity Ratio (HIR) is associated with collaterals and outcome in acute ischemic stroke (AIS). We investigated whether a combined assessment of HIR and collaterals could provide an added value.

METHODS

Retrospective single-center study, including AIS patients with large vessel occlusion and endovascular treatment 0-24 h from onset. Predictors of FIV and outcome (90 days modified Rankin Scale 0-1) were investigated with linear and logistic regression respectively. Subjects were stratified in three groups: poor collaterals (grade 0-3) with poor HIR (≥.4), good collaterals (grade 4-5) with poor HIR/poor collaterals with good HIR (<.4) and good collaterals with good HIR.

RESULTS

We included 337 patients (median age 77, 53.1% males), of whom 100 (29.7%) had excellent outcome. One hundred and forty five patients with favourable collateral and HIR profiles had smaller infarct (median poor collaterals with poor HIR 41 mL, good collaterals with poor HIR/poor collaterals with good HIR 21 mL and good collaterals with good HIR 11 mL, p <.001) and higher rates of excellent outcome (poor collaterals with poor HIR 15.7%, good collaterals with poor HIR/poor collaterals with good HIR 26.2% and good collaterals with good HIR 39.3% p =.001). Logistic regression showed that patients with favourable collateral and HIR profiles had the highest odds of good outcome (OR: 3.83, 95% CI 1.62-9.08, p =.002).

CONCLUSION

Collaterals and HIR are independent predictors of final infarct lesion and outcome in stroke patients and their integration provides an added value. These findings might inform clinical practice and future trials.

Computed tomography perfusion deficit volume predicts the functional outcome of endovascular therapy for basilar artery occlusion

OBJECTIVES

To investigate the relationship between baseline computed tomography perfusion deficit volumes and functional outcomes in patients with basilar artery occlusion (BAO) undergoing endovascular therapy.

METHODS

This was a single-center study in which the data of 64 patients with BAO who underwent endovascular therapy were retrospectively analyzed. All the patients underwent multi-model computed tomography on admission. The posterior-circulation Acute Stroke Prognosis Early Computed Tomography Score was applied to assess the ischemic changes. Perfusion deficit volumes were obtained using Syngo.via software. The primary outcome of the analysis was a good functional outcome (90-day modified Rankin Scale score ≤ 3). Logistic regression and receiver operating characteristic curves were used to explore predictors of functional outcome.

RESULTS

A total of 64 patients (median age, 68 years; 72 % male) were recruited, of whom 26 (41 %) patients achieved good functional outcomes, while 38 (59 %) had poor functional outcomes. Tmax > 10 s, Tmax > 6 s, and rCBF < 30 % volume were independent predictors of good functional outcomes (odds ratio range, 1.0-1.2; 95 % confidence interval [CI], 1.0-1.4]) and performed well in the receiver operating characteristic curve analyses, exhibiting positive prognostic value; the areas under the curve values were 0.85 (95 % CI, 0.75-0.94), 0.81 (95 % CI, 0.70-0.90), and 0.78 (95 % CI, 0.67-0.89).

CONCLUSION

Computed tomography perfusion deficit volume represents a valuable tool in predicting high risk of disability and mortality in patients with BAO after endovascular treatment.

Serial ASPECTS to predict stroke-associated pneumonia after thrombolysis in patients with acute ischemic stroke

Background

Stroke-associated pneumonia (SAP) is a serious complication in stroke patients, significantly increasing mortality. The Alberta Stroke Program Early CT Score (ASPECTS) is a recognized predictor of acute ischemic stroke outcomes. We aimed to investigate the performance of serial ASPECTS assessments (baseline ASPECTS, 24-h ASPECTS, and change in ASPECTS) for predicting SAP in patients with thrombolyzed acute anterior circulation ischemic stroke (AACIS).

Materials

A retrospective observational cohort study of adult patients with thrombolyzed AACIS was conducted. Baseline and 24-h ASPECTS using non-contrast computed tomography (NCCT), complications of stroke, including SAP and swallowing dysfunction using the Modified Water Swallowing test, were collected. Baseline and 24-h ASPECTS were evaluated by a certified neurologist and neuroradiologist. The predictive performance was determined based on the receiver operating characteristic curve (ROC). Multivariable logistic regression analyses were employed to assess the impact of serial ASPECTS assessment on predicting SAP.

Results

Of the 345 patients with thrombolyzed AACIS in our study, 18.4% (64/345) experienced SAP. The patients' median age was 62 years [interquartile range (IQR): 52-73], with 53.4% being male. The median NIHSS score was 11 points (IQR: 8-17). The ROC analysis revealed areas under the curve for predicting SAP with baseline ASPECTS, 24-h ASPECTS, and change in ASPECTS were 0.75 (95% CI, 0.69-0.82), 0.84 (95% CI, 0.79-0.89), and 0.82 (95% CI, 0.76-0.87), respectively. Of the three measures, 24-h ASPECTS was a better predictor of SAP (odds ratio: 5.33, 95%CI: 2.08-13.67, p < 0.001) and had a higher sensitivity (0.84 [95%CI, 0.74-0.92]) and specificity (0.79 [95%CI, 0.74-0.84]) than both baseline ASPECTS and change in ASPECTS.

Conclusion

24-h NCCT-ASPECTS outperformed both baseline ASPECTS and change in ASPECTS for predicting SAP. Notably, 24-h ASPECTS, with a cut-off value of ≤6, exhibited good predictive performance and emerged as the better predictor for SAP.

CT Perfusion Derived rCBV < 42% Lesion Volume Is Independently Associated with Followup FLAIR Infarct Volume in Anterior Circulation Large Vessel Occlusion

Pretreatment CT Perfusion (CTP) parameter rCBV < 42% lesion volume has recently been shown to predict 90-day mRS. In this study, we aim to assess the relationship between rCBV < 42% and a radiographic follow-up infarct volume delineated on FLAIR images. In this retrospective evaluation of our prospectively collected database, we included acute stroke patients triaged by multimodal CT imaging, including CT angiography and perfusion imaging, with confirmed anterior circulation large vessel occlusion between 9 January 2017 and 10 January 2023. Follow-up FLAIR imaging was used to determine the final infarct volume. Student t, Mann-Whitney-U, and Chi-Square tests were used to assess differences. Spearman's rank correlation and linear regression analysis were used to assess associations between rCBV < 42% and follow-up infarct volume on FLAIR. In total, 158 patients (median age: 68 years, 52.5% female) met our inclusion criteria. rCBV < 42% (ρ = 0.56, p < 0.001) significantly correlated with follow-up-FLAIR infarct volume. On multivariable linear regression analysis, rCBV < 42% lesion volume (beta = 0.60, p < 0.001), ASPECTS (beta = -0.214, p < 0.01), mTICI (beta = -0.277, p < 0.001), and diabetes (beta = 0.16, p < 0.05) were independently associated with follow-up infarct volume. The rCBV < 42% lesion volume is independently associated with FLAIR follow-up infarct volume.

New insight in massive cerebral infarction predictions after anterior circulation occlusion

To predict massive cerebral infarction (MCI) occurrence after anterior circulation occlusion (ACO) by cASPECTS-CTA-CS (combined ASPECTS and CTA-CS). Of 185 cerebral infarction patients with the ACO, their collateral circulation scores from CT angiography (CTA) images in two groups (MCI and non-MCI) were evaluated using Alberta Stroke Program Early CT Score (ASPECTS) and CT angiography collateral score (CTA-CS) approaches. The cASPECTS-CTA-CS was validated internally using the bootstrap sampling method with 1000 bootstrap repetitions and compared to CTA-CS. Receiver-operating characteristic curve (ROC), clinical impact curve (CIC), and decision curve analysis (DCA) strategies were used to assess the clinical practicality and predictability of both approaches (cASPECTS-CTA-CS and CTA-CS). Using net reclassification improvement (NRI) and integrated discrimination improvement (IDI) analyses, discrimination levels of the cASPECTS-CTA-CS were compared with CTA-CS. Classification and regression tree (CART) analyses was conducted to identify the best predictive values and identify subgroup of MCI. The discrimination ability of collateral circulation evaluation score using the cASPECTS-CTA-CS [AUC: 0.918, 95% confidence interval (CI): 0.869-0.967, P < 0.01; NRI: 0.200, 95% CI: -0.104 to 0.505, P = 0.197; and IDI: 0.107, 95% CI: 0.035-0.178, P = 0.004] was better than CTA-CS alone (AUC: 0.885, 95% CI: 0.833-0.937, P < 0.01). DCA indicated the net benefits of the cASPECTS-CTA-CS approach was higher than CTA-CS alone when the threshold probability range over 20%. CIC analyses showed that the number of high risks and true positives were in agreement when the threshold probability > 80%. Less than 23 of cASPECTS-CTA-CS by CART was important factor in determining MCI occurrence, and ASPECTS < 7 was followed factor. The cASPECTS-CTA-CS approach cumulatively predicted MCI after ACO.

Automated advanced imaging in acute ischemic stroke. Certainties and uncertainties

The purpose of this is study was to review pearls and pitfalls of advanced imaging, such as computed tomography perfusion and diffusion-weighed imaging and perfusion-weighted imaging in the selection of acute ischemic stroke (AIS) patients suitable for endovascular treatment (EVT) in the late time window (6-24 h from symptom onset). Advanced imaging can quantify infarct core and ischemic penumbra using specific threshold values and provides optimal selection parameters, collectively called target mismatch. More precisely, target mismatch criteria consist of core volume and/or penumbra volume and mismatch ratio (the ratio between total hypoperfusion and core volumes) with precise cut-off values. The parameters of target mismatch are automatically calculated with dedicated software packages that allow a quick and standardized interpretation of advanced imaging. However, this approach has several limitations leading to a misclassification of core and penumbra volumes. In fact, automatic software platforms are affected by technical artifacts and are not interchangeable due to a remarkable vendor-dependent variability, resulting in different estimate of target mismatch parameters. In addition, advanced imaging is not completely accurate in detecting infarct core, that can be under- or overestimated. Finally, the selection of candidates for EVT remains currently suboptimal due to the high rates of futile reperfusion and overselection caused by the use of very stringent inclusion criteria. For these reasons, some investigators recently proposed to replace advanced with conventional imaging in the selection for EVT, after the demonstration that non-contrast CT ASPECTS and computed tomography angiography collateral evaluation are not inferior to advanced images in predicting outcome in AIS patients treated with EVT. However, other authors confirmed that CTP and PWI/DWI postprocessed images are superior to conventional imaging in establishing the eligibility of patients for EVT. Therefore, the routine application of automatic assessment of advanced imaging remains a matter of debate. Recent findings suggest that the combination of conventional and advanced imaging might improving our selection criteria.

Microvascular dysfunction associated with unfavorable venous outflow in acute ischemic stroke patients

Unfavorable venous outflow (VO) is associated with cerebral edema, which represents microvascular dysfunction. This study estimated the relationship between VO and microvascular function in acute ischemic stroke patients. We retrospectively included 102 MCA/ICA occluded patients with anterior circulation infarction who underwent reperfusion therapy between July 2017 and April 2022. Unfavorable VO was defined as a cortical vein opacification score of 0-3 and favorable VO as that of 4-6. The clinical characteristics, collateral status, microvascular integrity, and outcomes were compared between patients with favorable and unfavorable VO. Multivariate analysis and receiver operator characteristic (ROC) analysis were used. The patients with unfavorable VO had higher extravascular-extracellular volume fraction (Ve) in the infarct core and a lower percentage of robust arterial collateral circulation. ROC analysis revealed that Ve in the infarct core predicts unfavorable VO (AUC = 0.67, sensitivity = 65.08%, specificity = 69.23%). The higher Ve in the infarct core (odds ratio = 1.011, 95% CI = 1.000-1.021, P = 0.046) and poor arterial collateral flow (odds ratio = 0.102, 95% CI = 0.032-0.327, P < 0.001) were independent predictors of unfavorable VO. This suggests that microvascular dysfunction may be one of the mechanisms underlying impaired VO.

Neuroimaging Modalities Used for Ischemic Stroke Diagnosis and Monitoring

Strokes are one of the global leading causes of physical or mental impairment and fatality, classified into hemorrhagic and ischemic strokes. Ischemic strokes happen when a thrombus blocks or plugs an artery and interrupts or reduces blood supply to the brain tissue. Deciding on the imaging modality which will be used for stroke detection depends on the expertise and availability of staff and the infrastructure of hospitals. Magnetic resonance imaging provides valuable information, and its sensitivity for smaller infarcts is greater, while computed tomography is more extensively used, since it can promptly exclude acute cerebral hemorrhages and is more favorable speed-wise. The aim of this article was to give information about the neuroimaging modalities used for the diagnosis and monitoring of ischemic strokes. We reviewed the available literature and presented the use of computed tomography, CT angiography, CT perfusion, magnetic resonance imaging, MR angiography and MR perfusion for the detection of ischemic strokes and their monitoring in different phases of stroke development.

Performance of serial CT ASPECTS for predicting stroke outcomes in patients with thrombolyzed acute ischemic stroke

Objectives

The objective of this study was to compare the sensitivity and specificity of serial ASPECTS for predicting IHM and unfavorable outcome defined by a modified Rankin Scale score ≥3 at the time of discharge from the hospital in thrombolyzed AACIS patients.

Materials and Methods

This retrospective study examined thrombolyzed AACIS patients admitted at Saraburi Hospital, a regional health-care facility in Thailand. The study was conducted between January 2015 and July 2022. The comparative predictive performance of the baseline ASPECTS, 24-h ASPECTS, and change in ASPECTS for IHM and unfavorable outcome was examined using the receiver operating characteristic (ROC) curves. The optimal cutoff values were identified based on Youden's index and the nonparametric method to compare the area under the ROC curve (AuROC) among the three scales. The potential confounders adjusted by multivariable logistic regression were reported odds ratio (OR) and 95% confidence interval (CI).

Results

Three hundred and forty-five patients with thrombolyzed AACIS were analyzed; the median age was 61.8 ± 15.2 years. 53.0% were male, and the median National Institutes of Health Stroke Scale score was 11 points (interquartile range: 8-17). The AuROC for predicting IHM was 0.823 for the baseline ASPECTS, 0.955 for 24-h ASPECTS, and 0.920 for the change in ASPECTS. For predicting unfavorable outcome, the AuROC was 0.744 for the baseline ASPECTS, 0.853 for 24-h ASPECTS, and 0.800 for the change in ASPECTS. After adjusting for other factors, the OR for predicting IHM was 14.38 (95% CI: 1.69-122.57) for 24-h ASPECTS and 16.7 (95% CI: 4.36-64.01) for the change in ASPECTS. Regarding unfavorable outcome, the adjusted OR was 5.58 (95% CI: 1.83-17.01) for 24-h ASPECTS and 4.85 (95% CI: 2.45-9.60) for the change in ASPECTS.

Conclusion

The 24-h ASPECTS and change in ASPECTS could be more precise predictors for predicting IHM and unfavorable outcome in patients with thrombolyzed AACIS.

Perioperative stroke in parapharyngeal space schwannoma: an unusual, dreaded complication

BACKGROUND

Post-styloid parapharyngeal space tumours (PPS) have a notorious course owing to their anatomy and proximity to neurovascular bundles. Nerve injuries are usual outcomes in schwannomas. Our case is the first documented complication of contralateral hemiplegia occurring in the postoperative period in a benign PPS tumour.

CASE REPORT

A 24-year-old presented with a swelling on the left lateral aspect of the neck, diagnosed as a PPS schwannoma. He underwent transcervical excision with mandibulotomy with extracapsular dissection of the tumour. Contralateral hemiplegia, as a dreaded complication, was encountered. He was managed conservatively according to ASPECTS stroke guidelines by the critical care team. On a regular follow-up, he noticed an improvement in the lower limb with subsequent upper limb power.

CONCLUSION

Perioperative stroke is a dreaded complication involving PPS in large benign tumours. To prevent unforeseen circumstances, necessary preoperative patient counselling and immense intraoperative care should be taken while dissecting the major vessels.

Mechanical thrombectomy via direct carotid artery approach for the treatment of acute anterior circulation large vessel occlusion

Background

Mechanical thrombectomy (MT) has become an important treatment method for acute anterior circulation large vessel occlusion. The carotid artery approach is a fast and effective alternative when the transfemoral approach is difficult due to vascular variation. The present study reports on seven cases of acute anterior circulation stroke where direct carotid approach was used to obtain vascular access.

Methods and materials

Patients with acute anterior circulation large vessel occlusion treated via carotid artery access between January 2018 and January 2020 were retrospectively analyzed. Brain computed tomography (CT) and angiographic imaging results, indications for carotid artery approach and technical aspects of the method, modified thrombolysis in cerebral infarction (mTICI), procedure-related complications, and patient outcomes were evaluated.

Results

Seven patients were treated using a direct carotid artery approach. Among the seven cases, four patients were treated using percutaneous carotid artery puncture, and two patients were treated with emergency carotid artery incision and thrombectomy. The remaining case involved carotid artery puncture for MCA thrombectomy, followed by carotid artery incision for carotid artery thrombectomy. The carotid artery puncture point was exposed via surgical incision and sutured after MT. Modified Rankin Scale (MRS) scores 90 days after surgery showed good prognosis in three patients, poor prognosis in four patients.

Conclusion

This case series highlights the advantage of using a transcarotid approach to bypass anatomical barriers to achieve faster reperfusion when the femoral approach is not possible. The carotid artery puncture point was surgically exposed and sutured to reduce the incidence of postoperative complications.

Predicting Penumbra Salvage and Infarct Growth in Acute Ischemic Stroke: A Multifactor Survival Game

BACKGROUND

Effective treatment of acute ischemic stroke requires reperfusion of salvageable tissue. We investigated the predictors of penumbra salvage (PS) and infarct growth (IG) in a large cohort of stroke patients.

METHODS

In the ASTRAL registry from 2003 to 2016, we selected middle cerebral artery strokes <24 h with a high-quality CT angiography and CT perfusion. PS and IG were correlated in multivariate analyses with clinical, biochemical and radiological variables, and with clinical outcomes.

RESULTS

Among 4090 patients, 551 were included in the study, 50.8% male, mean age (±SD) 66.3 ± 14.7 years, mean admission NIHSS (±SD 13.3 ± 7.1) and median onset-to-imaging-time (IQR) 170 (102 to 385) minutes. Increased PS was associated with the following: higher BMI and lower WBC; neglect; larger penumbra; absence of early ischemic changes, leukoaraiosis and other territory involvement; and higher clot burden score. Reduced IG was associated with the following: non-smokers; lower glycemia; larger infarct core; absence of early ischemic changes, chronic vascular brain lesions, other territory involvement, extracranial arterial pathology and hyperdense middle cerebral artery sign; and higher clot burden score. When adding subacute variables, recanalization was associated with increased PS and reduced IG, and the absence of haemorrhage with reduced IG. Collateral status was not significantly associated with IG nor with PS. Increased PS and reduced IG correlated with better 3- and 12-month outcomes.

CONCLUSION

In our comprehensive analysis, multiple factors were found to be responsible for PS or IG, the strongest being radiological features. These findings may help to better select patients, particularly for more aggressive or late acute stroke treatment.

Endovascular Thrombectomy for Anterior Circulation Large Vessel Occlusion Stroke: An Evolution of Trials

The last decade's progress in demonstrating the clinical benefit of endovascular thrombectomy (EVT) in patients with large vessel occlusion stroke has transformed the paradigm of care for these patients. This review presents the milestones in implementing EVT as standard of care, demonstrates the current state of evidence, provides guidance for identifying the candidate patient for EVT, and highlights unsolved and controversial issues. Ongoing trials investigate broadening of EVT indications for patients who present with large core infarction, adjunctive intra-arterial thrombolysis, medium vessel occlusion, low NIHSS, and tandem occlusion.

Correlation between clinical and brain computed tomography findings of stroke patients: A cross-sectional study

Background and Aims

In developing countries, the burden of stroke is growing and causing significant morbidity and disability with high mortality rates. Neuroimaging plays a crucial role in differentiating ischemic stroke from an intracerebral hemorrhage, as well as entities other than stroke. This study sought to determine the correlation between the clinical and brain CT scan findings of stroke patients attending three hospitals in Kampala, Uganda.

Methods

This was a cross-sectional study of clinically suspected stroke patients who were sent for brain CT scan at three selected hospitals in Kampala, Uganda. All brain CT scans of patients with suspected stroke were evaluated and the Alberta stroke program early CT score (ASPECTS) was used for middle cerebral artery (MCA) strokes. Univariate analysis was used to describe the clinico-demographic and brain CT features of stroke and summarized them as percentages. Bivariate and multivariate analysis were used to determine the adjusted odds ratios as a measure of association with a 95% confidence interval (CI).

Results

Of the 270 study participants, 141 (52.2%) were male. 162 (60%) had CT findings of stroke, and 90 (33.3%) had normal brain CT findings. Eighteen (6.7%) had other CT findings like tumor, dural hemorrhage, epidermoid cyst, and others. Ischemic stroke, hemorrhagic stroke, and subarachnoid hemorrhage accounted for 124 (45.9%), 34 (12.6%), and 4 (1.5%) respectively. Limb weakness (55.2%), headache (41.1%), and loss of consciousness (39.3%) were associated with stroke findings on CT. Among the acute ischemic strokes, 30 (73.2%) had a worse (0-7) ASPECT score. Those aged ≥65 years were associated with a worse ASPECTS [AOR: 22.01, (95% CI: 1.58-306.09) p = 0.021].

Conclusion

More than a third of patients with a clinical diagnosis of stroke had either no CT features of stroke or had other findings. The most commonly affected vascular territory was left MCA. Old age was strongly associated with having the worst ASPECTS score.

Can flat-detector CT after successful endovascular treatment predict long-term outcome in patients with large vessel occlusion? An Alberta Stroke Programme Early CT Score-based study

PURPOSE

Recent studies postulate a high prognostic value of the Alberta Stroke Programme Early CT Score (ASPECTS) applied on non-contrast whole-brain flat-detector CT (FDCT) after successful endovascular treatment (EVT). The aim of this study was the evaluation of long-term patient outcome after endovascular treatment using postinterventional FDCT.

METHODS

Using a local database (Stroke Research Consortium in Northern Bavaria, STAMINA), 517 patients with successful endovascular treatment (modified Thrombolysis in Cerebral Infarction (mTICI) ≥ 2B) due to acute ischaemic stroke (AIS) and large vessel occlusion (LVO) of the anterior circulation were recruited retrospectively. In all cases, non-contrast FDCT after EVT was analysed with special focus at ASPECTS. These results were correlated with the functional outcome in long-term (modified Rankin Scale (mRS) shift from pre-stroke to 90 days after discharge).

RESULTS

A significant difference in FDCT-ASPECTS compared to the subgroup of favourable vs. unfavourable outcome (Δ mRS) (median ASPECTS 10 (10-9) vs. median ASPECTS 9 (10-7); p = 0,001) could be demonstrated. Multivariable regression analysis revealed FDCT-ASPECTS (OR 0.234, 95% CI - 0.102-0.008, p = 0.022) along with the NHISS at admission (OR 0.169, 95% CI 0.003-0.018, p = 0.008) as independent factors for a favourable outcome. Cut-off point for a favourable outcome (Δ mRS) was identified at an ASPECTS ≥ 8 (sensitivity 90.6%, specificity 35%).

CONCLUSION

For patients with LVO and successful EVT, FDCT-ASPECTS was found to be highly reliable in predicting long-term outcome.

Effectiveness of smart health-based rehabilitation on patients with poststroke dysphagia: A brief research report

Objective

This study aimed to evaluate the effectiveness of smart health-based rehabilitation on patients with poststroke dysphagia (PSD).

Methods

We recruited 60 PSD patients and randomly allocated them to the intervention (n = 30) and control (n = 30) groups. The former received the smart health-based rehabilitation for 12 weeks, whereas the latter received routine rehabilitation. Water swallow test (WST), standardized swallowing assessment (SSA), swallow quality-of-life questionnaire (SWAL-QOL), stroke self-efficacy questionnaire (SSEQ), perceived social support scale (PSSS) and nutritional measurements including body weight, triceps skinfold thickness (TSF), total protein (TP), serum albumin (ALB) and serum prealbumin (PA) in both groups were measured.

Results

When the baseline WST, SSA, SWAL-QOL, SSEQ, PSSS and nutritional measurements were examined, there was no significant difference between the intervention group and the control group (P > 0.05). After rehabilitation interventions, the WST and SSA scores in the intervention group were significantly lower than those in the control group (P < 0.01). The SWAL-QOL, SSEQ and PSSS scores in the intervention group were significantly higher than in the control group (P < 0.01). Compared with the control group, the intervention group showed an increase in the serum levels of PA (P < 0.01). However, no statistically significant difference existed between the intervention group and the control group in terms of body weight, TSF, TP or ALB (P > 0.05).

Conclusions

Overall, our data revealed that smart health-based rehabilitation is significantly beneficial to the swallowing function, quality of life, self-efficacy, and social support for PSD patients when compared with routine rehabilitation. However, nutritional measurements were not significantly improved in such patients under the smart health-based rehabilitation when compared the routine rehabilitation. In the future, it is necessary to extend the intervention time to further evaluate the long-term efficacy of smart health-based rehabilitation on nutritional measurements of PSD patients.

Dysphagia assessment in ischemic stroke after mechanical thrombectomy: When and how?

Background

Dysphagia is a frequent symptom in acute ischemic stroke (AIS). Endovascular treatment (EVT) has become the standard of care for acute stroke secondary to large vessel occlusion. Although standardized guidelines for poststroke dysphagia (PSD) management exist, they do not account for this setting in which patients receive EVT under general anesthesia. Therefore, the aim of this study was to evaluate PSD prevalence and severity, as well as an appropriate time point for the PSD evaluation, in patients undergoing EVT under general anesthesia (GA).

Methods

We prospectively included 54 AIS patients undergoing EVT under GA. Fiberoptic Endoscopic Evaluation of Swallowing (FEES) was performed within 24 h post-extubation in all patients. Patients presenting significant PSD received a second FEES-assessment to determine the course of dysphagia deficits over time. Dysphagia severity was rated according the Fiberoptic Dysphagia Severity Scale (FEDSS).

Results

At first FEES (FEES 1) assessment, performed in the median 13 h (IQR 5-17) post-extubation, 49/54 patients (90.7%) with dysphagia were observed with a median FEDSS of 4 (IQR 3-6). Severe dysphagia requiring tube feeding was identified in 28/54 (51.9%) subjects, whereas in 21 (38.9%) patients early oral diet with certain food restrictions could be initiated. In the follow up FEES examination conducted in the median 72 h (IQR 70-97 h) after initial FEES 34/49 (69.4%) patients still presented PSD. Age (p = 0.030) and ventilation time (p = 0.035) were significantly associated with the presence of PSD at the second FEES evaluation. Significant improvement of dysphagia frequency (p = 0.006) and dysphagia severity (p = 0.001) could be detected between the first and second dysphagia assessment.

Conclusions

PSD is a frequent finding both immediately within 24 h after extubation, as well as in the short-term course. In contrast to common clinical practice, to delay evaluation of swallowing for at least 24 h post-extubation, we recommend a timely assessment of swallowing function after extubation, as 50% of patients were safe to begin oral intake. Given the high amount of severe dysphagic symptoms, we strongly recommend application of instrumental swallowing diagnostics due to its higher sensitivity, when compared to clinical swallowing examination. Furthermore, advanced age, as well as prolonged intubation, were identified as significant predictors for delayed recovery of swallowing function.

Posterior Circulation Alberta Stroke Program Early Computed Tomography Score (pc-ASPECT) for the Evaluation of Cerebellar Infarcts

BACKGROUND

Patients with cerebellar ischemic stroke may be misdiagnosed and may exhibit a delayed time to acute stroke treatment compared with patients with anterior circulation ischemic stroke. The posterior circulation Alberta stroke program early computed tomography score (pc-ASPECT) score has been used to evaluate hyperacute stroke, much as the ASPECT in anterior circulation stroke recently. Our main objective was to evaluate the associations of the clinical and etiological characteristics of ischemic cerebellar infarction patients on admission with their pc-ASPECT scores, as well as the correlations of the pc-ASPECT score with morbidity and mortality rates.

MATERIALS AND METHODS

We include 114 patients with cerebellar infarction who underwent 1 year of follow-up into the study.

RESULTS

Patients with a pc-ASPECT score <7 were more likely to present with impaired consciousness ( P <0.001), multiple posterior circulation infarcts ( P <0.001), hydrocephalus ( P <0.001), lesions of the vermis ( P =0.028), and peduncle ( P =0.024), perfusion deficits in the total of posterior inferior cerebellar artery, anterior inferior cerebellar artery, superior cerebellar artery ( P <0.05), and basilar artery stenosis ( P =0.005), ischemia in additional anatomical structures in the posterior circulation ( P <0.001) compared with those with a score ≥7.

CONCLUSIONS

Although the pc-ASPECT score alone is insufficient in some cases like vertebral artery dissection, using it together with the National Institutes of Health Stroke Scale (NIHSS) score and clinical findings may be beneficial during the hyperacute period of cerebellar ischemia. Presentation with impaired consciousness, basilar artery pathologies, vermian ischemia, and ischemia in additional anatomical structures in the posterior circulation other than the cerebellum appeared as important clinical and radiologic parameters predicting long-term prognosis.

Associations between early ischemic signs on non-contrast CT and time since acute ischemic stroke onset: A scoping review

PURPOSE

Onset to imaging (OTI) time is a crucial factor in determining treatment eligibility for acute ischemic stroke patients, since the treatments are time-dependent. Patients with an unknown OTI time are often excluded from treatment, or advanced imaging is needed, which is not widely and readily available. As non-contrast CT (NCCT) is part of the standard stroke protocol, estimating OTI time using only NCCT would be valuable for patients with an unknown OTI time. Early ischemic signs (EISs) visible on NCCT might be fit for this purpose if an association between these signs and OTI time exists. This scoping review aims to provide an overview of the literature that associated OTI time with qualitative or quantitative EISs, including the hyperdense artery sign (HAS), decrease in grey matter-white matter differentiation, hypodensity, and mass effect.

METHOD

The prevalence of the EISs at specific OTI times is assessed, and previously presented associations between the EISs and OTI time are reported.

RESULTS

The EIS prevalence varied between the studies. The HAS prevalence decreased after 6 h since onset. The hypodensity prevalence increased with increasing OTI time. Studies quantifying the extent of hypodensity could distinguish patients within and beyond treatment time windows, indicating its potential to estimate OTI time. Finally, mass effect prevalence was seen more often at later OTI times.

CONCLUSIONS

It is concluded that, despite the high prevalence variability between studies, some associations between EISs and OTI time can be observed. These are potentially valuable in estimating OTI time and supporting treatment decisions.

Feasibility of rescue stenting technique in patients with acute ischemic stroke due to middle cerebral artery occlusion after failed thrombectomy: A single-center retrospective experience

Background

Despite remarkable advancements in intra-arterial mechanical thrombectomy (IAT), recanalization failure rates up to 24% have been reported. Recently, permanent stent placement (rescue stent, RS) during IAT has been suggested as an optional modality for better reperfusion and outcomes in these patients. However, previous studies were limited owing to non-standardized procedure protocols and small sample sizes. Here, we aimed to determine the efficacy and safety of RS in patients with acute ischemic stroke (AIS) with middle cerebral artery (MCA) occlusion.

Methods

Of the 243 patients in our IAT database (2015–2021), 183 were identified as having MCA occlusion alone. Among them, we extracted 53 patients in whom the IAT failed to show thrombolysis in cerebral ischemia (TICI) scores of 2A or worse. Intraoperatively, RS was deployed in 22 patients (RS group), whereas 31 patients (no-stent group) received IAT without stenting. The baseline characteristics and radiologic and clinical outcomes were reviewed. Comparisons between the groups and multivariate logistic analyses for recanalization and good functional outcomes (modified Rankin Scale 0–2) were performed.

Results

No baseline differences were noted (RS vs. no-stent); however, the recanalization outcomes (59.1% vs. 25.8%, p = 0.15) and proportion of good modified Rankin Scale scores (45.5% vs. 19.4%, p = 0.041) were better in the RS group. The parameters of symptomatic ICH (9.7% vs. 9.4%) and mortality (6.5% vs. 5.7%) showed no significant difference. In the multivariate analyses, ‘hypertension’ and ‘RS deployment’ were identified as significantly associated factors with recanalization and good prognosis.

Conclusion

In select patients with MCA occlusion AIS after failed IAT, the RS technique can be an optional rescue treatment modality for acquiring better functional outcomes and delayed recanalization.

Tmax Volumes Predict Final Infarct Size and Functional Outcome in Ischemic Stroke Patients Receiving Endovascular Treatment

OBJECTIVE

The objective of this paper was to explore the utility of time to maximum concentration (T_max )-based target mismatch on computed tomography perfusion (CTP) in predicting radiological and clinical outcomes in patients with acute ischemic stroke (AIS) with anterior circulation large vessel occlusion (LVO) selected for endovascular treatment (EVT).

METHODS

Patients with AIS underwent CTP within 24 hours from onset followed by EVT. Critically hypoperfused tissue and ischemic core volumes were automatically calculated using T_max thresholds >9.5 seconds and >16 seconds, respectively. The difference between T_max  > 9.5 seconds and T_max  > 16 seconds volumes and the ratio between T_max  > 9.5 seconds and T_max  > 16 seconds volumes were considered ischemic penumbra and T_max mismatch ratio, respectively. Final infarct volume (FIV) was measured on follow-up non-contrast computed tomography (CT) at 24 hours. Favorable clinical outcome was defined as 90-day modified Rankin Scale 0 to 2. Predictors of FIV and outcome were assessed with multivariable logistic regression. Optimal T_max volumes for identification of good outcome was defined using receiver operating curves.

RESULTS

A total of 393 patients were included, of whom 298 (75.8%) achieved successful recanalization and 258 (65.5%) achieved good outcome. In multivariable analyses, all T_max parameters were independent predictors of FIV and outcome. T_max  > 16 seconds volume had the strongest association with FIV (beta coefficient = 0.596 p <0.001) and good outcome (odds ratio [OR] = 0.96 per 1 ml increase, 95% confidence interval [CI] = 0.95-0.97, p < 0.001). T_max  > 16 seconds volume had the highest discriminative ability for good outcome (area under the curve [AUC] = 0.88, 95% CI = 0.842-0.909). A T_max  > 16 seconds volume of ≤67 ml best identified subjects with favorable outcome (sensitivity = 0.91 and specificity = 0.73).

INTERPRETATION

T_max target mismatch predicts radiological and clinical outcomes in patients with AIS with LVO receiving EVT within 24 hours from onset. ANN NEUROL 2022;91:878-888.

Thrombectomy for anterior circulation stroke beyond 6 h from time last known well (AURORA): a systematic review and individual patient data meta-analysis

BACKGROUND

Trials examining the benefit of thrombectomy in anterior circulation proximal large vessel occlusion stroke have enrolled patients considered to have salvageable brain tissue, who were randomly assigned beyond 6 h and (depending on study protocol) up to 24 h from time last seen well. We aimed to estimate the benefit of thrombectomy overall and in prespecified subgroups through individual patient data meta-analysis.

METHODS

We did a systematic review and individual patient data meta-analysis between Jan 1, 2010, and March 1, 2021, of randomised controlled trials of endovascular stroke therapy. In the Analysis Of Pooled Data From Randomized Studies Of Thrombectomy More Than 6 Hours After Last Known Well (AURORA) collaboration, the primary outcome was disability on the modified Rankin Scale (mRS) at 90 days, analysed by ordinal logistic regression. Key safety outcomes were symptomatic intracerebral haemorrhage and mortality within 90 days.

FINDINGS

Patient level data from 505 individuals (n=266 intervention, n=239 control; mean age 68·6 years [SD 13·7], 259 [51·3%] women) were included from six trials that met inclusion criteria of 17 screened published randomised trials. Primary outcome analysis showed a benefit of thrombectomy with an unadjusted common odds ratio (OR) of 2·42 (95% CI 1·76-3·33; p<0·0001) and an adjusted common OR (for age, gender, baseline stroke severity, extent of infarction on baseline head CT, and time from onset to random assignment) of 2·54 (1·83-3·54; p<0·0001). Thrombectomy was associated with higher rates of independence in activities of daily living (mRS 0-2) than best medical therapy alone (122 [45·9%] of 266 vs 46 [19·3%] of 238; p<0·0001). No significant difference between intervention and control groups was found when analysing either 90-day mortality (44 [16·5%] of 266 vs 46 [19·3%] of 238) or symptomatic intracerebral haemorrhage (14 [5·3%] of 266 vs eight [3·3%] of 239). No heterogeneity of treatment effect was noted across subgroups defined by age, gender, baseline stroke severity, vessel occlusion site, baseline Alberta Stroke Program Early CT Score, and mode of presentation; treatment effect was stronger in patients randomly assigned within 12-24 h (common OR 5·86 [95% CI 3·14-10·94]) than those randomly assigned within 6-12 h (1·76 [1·18-2·62]; p_interaction=0·0087).

INTERPRETATION

These findings strengthen the evidence for benefit of endovascular thrombectomy in patients with evidence of reversible cerebral ischaemia across the 6-24 h time window and are relevant to clinical practice. Our findings suggest that in these patients, thrombectomy should not be withheld on the basis of mode of presentation or of the point in time of presentation within the 6-24 h time window.

FUNDING

Stryker Neurovascular.

Automated quantitative lesion water uptake in acute stroke is a predictor of malignant cerebral edema

OBJECTIVES

Net water uptake (NWU) has been shown to have a linear relationship with brain edema. Based on an automated-Alberta Stroke Program Early Computed Tomography Score (ASPECTS) technique, we automatically derived NWU from baseline multimodal computed tomography (CT), namely ASPECTS-NWU. We aimed to determine if ASPECTS-NWU can predict the development of malignant cerebral edema (MCE).

METHODS

One hundred and forty-six patients with large-vessel occlusion were retrospectively enrolled. Quantitative NWU based on automated-ASPECTS was measured both on nonenhanced CT (NECT) and CT angiography (CTA), namely NECT-ASPECT-NWU and CTA-ASPECTS-NWU. The correlation between ASPECTS-NWU and cerebral edema (CED) grades was calculated using Spearman rank correlation. Univariate logistic regression was used to assess the effect of radiological and clinical features on MCE, and a multivariable model with significant factors from the univariate regression analysis was built. Receiver operating characteristic (ROC) was obtained and area under curve (AUC) was compared.

RESULTS

CTA-ASPECTS-NWU had a moderate positive correlation with CED grades (r = 0.62; 95% confidence interval [CI], 0.51-0.71; p < 0.001). The CTA-ASPECTS-NWU performed better than the NECT-ASPECTS-NWU with AUC: 0.88 vs. 0.71 (p < 0.001). Multivariable logistic regression model integrating CTA-ASPECTS-NWU, collateral score, and age showed the CTA-ASPECTS-NWU was an independent predictor of MCE with an AUC of 0.94 (95% CI: 0.90-0.98; p < 0.001).

CONCLUSIONS

This study demonstrates that ASPECTS-NWU is a quantitative predictor of MCE after large-vessel occlusion of the middle cerebral artery territory. The multivariable logistic regression model may enhance the identification of patients with MCE needing anti-edematous treatment.

KEY POINTS

• The automated-ASPECTS technique can automatically detect the affected regions with early ischemic changes and NWU could be manually calculated. • The CTA-ASPECTS-NWU performs better than the NECT-ASPECTS-NWU on predicting the development of MCE. • The multivariable logistic regression model may enhance the identification of patients with MCE needing anti-edematous treatment.

Impact of Encephalomalacia and White Matter Hyperintensities on ASPECTS in Patients With Acute Ischemic Stroke: Comparison of Automated- and Radiologist-Derived Scores

Background: Automated software-based Alberta Stroke Program Early CT Score (ASPECTS) on unenhanced CT is associated with clinical outcomes after acute stroke. However, encephalomalacia or white matter hyperintensities (WMHs) may result in a falsely low automated ASPECTS if such findings are interpreted as early ischemia. Objective: To assess the impact of encephalomalacia and WMH on automated ASPECTS in patients with acute stroke, in comparison with radiologist-derived ASPECTS and clinical outcomes. Methods: This retrospective three-center study included 459 patients (322 men, 137 women; median age, 65 years) with acute ischemic stroke treated by IV thrombolysis who underwent baseline unenhanced CT within 6 hours after symptom onset and MRI within 24 hours after treatment. ASPECTS was determined by automated software and by three radiologists in consensus. Presence of encephalomalacia and extent of WMHs [categorized using the modified Scheltens scale (mSS)] were also determined using MRI. Kappa coefficients were used to compare ASPECTS between automated and radiologist-consensus methods. Multivariable logistic regression analyses and ROC analyses were performed to explore the predictive utility of baseline ASPECTS for unfavorable clinical outcome (90-day modified Rankin Scale score of 3-6) after thrombolysis. Results: Median automated ASPECTS was 9, and median radiologist-consensus ASPECTS was 10. Agreement between automated and radiologist-consensus ASPECTS, expressed as kappa, was 0.68, though was 0.76 in patients without encephalomalacia and 0.08 in patients with encephalomalacia. In patients without encephalomalacia, agreement decreased as the mSS score increased (e.g., 0.78 in subgroup with mSS score <10 vs 0.19 in subgroup with mSS >20). By anatomic region, agreement was highest for M5 (κ=0.52) and lowest for internal capsule (κ=0.18). In multivariable analyses, both automated (odds ratio=0.69) and radiologist-consensus (odds ratio=0.57) ASPECTS independently predicted unfavorable clinical outcome. For unfavorable outcome, automated ASPECTS had AUC of 0.70, sensitivity of 60.4%, and specificity of 71.0%, while radiologist-consensus ASPECTS had AUC of 0.72, sensitivity of 60.4%, and specificity of 80.5%. Conclusion: Presence of encephalomalacia or extensive WMH results in lower automated ASPECTS than radiologist-consensus ASPECTS, which may impact predictive utility of automated ASPECTS. Clinical Impact: When using automated ASPECTS, radiologists should manually confirm the score in patients with encephalomalacia or extensive leukoencephalopathy.

An automated ASPECTS method with atlas-based segmentation

BACKGROUND AND PURPOSE

As a simple and reliable systematic method to evaluate the early ischemic changes in the blood supply region of the middle cerebral artery of patients with ischemic stroke, the Alberta Stroke Program Early CT score (ASPECTS) can be used for rapid semi-quantitative evaluation of ischemic lesions, which is helpful to select potential candidates for intravenous and intra-arterial therapies, determine the thrombolytic effect and long-term prognosis. This method mainly relies on doctors' visual observation. However, due to different levels of doctor's experience, the poor inter-reader agreement may result in errors in the final ASPECTS. The purpose of this work was to propose an automated semi-quantitative method for the diagnosis of acute ischemic stroke based on non-contrast computed tomography (NCCT), to provide a reference for doctors in the diagnosis and evaluation.

METHODS

NCCT data from a total of 90 patients were included for auto-ASPECTS training and testing. After preprocessing CT images, the regions of interest (ROI) for ASPECTS were labeled using atlas-based segmentation. The mean difference, mean ratio and brain density shifts (BDS) of the corresponding regions of the contralateral brain were used as the standard for quantitative analysis. The auto-ASPECTS method was developed and validated to predict early ischemic changes whose performance was evaluated by the agreement (accuracy) of predictions and consensus scores of two observers.

RESULTS

A comparison was made among the results on mean difference, mean ratio, BDS and the combination of multiple parameters as the standard. The result of using BDS alone was relatively better than the result of using any other parameter alone or any combination of multiple parameters, and accuracy in the test set was 0.80. In the test set, accuracy with using different BDS thresholds increased by 6.67% compared with using the consistent BDS threshold. After dichotomy of auto-ASPECTS and consensus scores with the threshold of 7, the agreement of them was 83.3% and there was no significant difference between the two distributions (p = 0.344) in McNemar test.

CONCLUSIONS

The proposed auto-ASPECTS method for NCCT images can provide useful information for early diagnosis and evaluation of patients with acute ischemic stroke (AIS).

Cortical Venous Changes on Susceptibility-Weighted Imaging Predict the Cerebral Collateral Circulation as Confirmed by Digital Subtraction Angiography

Objective: Asymmetrical cortical vein sign (ACVS) shown on susceptibility-weighted imaging (SWI) can reflect regional hypoperfusion. We investigated if ACVS could predict the cerebral collateral circulation (CC) as assessed by digital subtraction angiography (DSA) in acute ischemic stroke patients with ipsilateral severe stenosis/occlusion of the anterior circulation.

Methods: Clinical data and imaging data of 62 acute ischemic stroke patients with ipsilateral severe stenosis or occlusion of the anterior circulation confirmed by DSA were collected retrospectively. Participants underwent magnetic resonance imaging, including an SWI sequence. ACVS was defined as more and/or larger venous signals in the cerebral cortex of one side of SWI than that in the contralateral side. ACVS was measured using the Alberta Stroke Program Early Computed Tomography score based on SWI. The grading of the cerebral CC was judged using DSA.

Results: Of the 62 patients, 30 patients (48.4%) had moderate-to-severe ACVS. According to DSA assessment, 19 patients (30.6%) had a good CC (grade 3–4), and 43 (69.4%) patients had a poor-to-moderate CC (grade 0–2). Among the 30 patients with moderate-to-severe ACVS, only three (10%) patients had a good CC, and 27 (90%) patients had a poor-to-moderate CC; among the 32 patients with none or mild ACVS, 16 (50%) of them had a good CC, and the other 50% had a moderate-to-severe CC. We constructed two logistic regression models with ACVS grading and none or mild ACVS entered into the models, respectively, together with age and large-artery occlusion. In model 1, no ACVS (compared with severe ACVS; OR = 40.329, 95%CI = 2.817–577.422, P = 0.006), mild ACVS (compared with severe ACVS; OR = 17.186, 1.735–170.224, 0.015) and large-artery occlusion (OR = 45.645, 4.603–452.592, 0.001) correlated with a good CC. In model 2, none or mild ACVS (OR = 36.848, 95%CI = 5.516–246.171, P < 0.001) was significantly associated with a good CC as judged by DSA, adjusted by age and large-artery occlusion.

Conclusions: Cortical venous changes in SWI may be a useful indicator for the cerebral CC as confirmed by DSA.

Evaluation of combining Alberta Stroke Program Early CT Score (ASPECTS) with mean platelet volume, plateletcrit, and platelet count in predicting short- and long-term prognosis of patients with acute ischemic stroke

BACKGROUND

There is controversy regarding Alberta Stroke Program Early CT Score (ASPECTS) and platelet indices as predictors of outcome in patients with acute ischemic stroke (AIS). We aimed to assess the prognostic value of ASPECTS, mean platelet volume (MPV), plateletcrit (PCT), and platelet count (Plt) in 3-month and 1-year functional outcomes of AIS patients, both independently and in combination.

METHODS

This prospective study was conducted in Shams Al-shomuos and Ghaem hospitals of Mashhad, Iran from June 2019 to January 2021. Overall, 553 patients above 18 years old with first-ever anterior circulation AIS met the eligibility criteria and were included. Clinical, hematologic, radiologic, and demographic data of patients were recorded at baseline. The 3-month and 1-year functional outcome was evaluated by modified Rankin Scale (mRS). Multivariate logistic regression was used to determine the independent predictors of poor functional outcome (mRS>2) and mortality.

RESULTS

The mean age of the patients was 65.50 ± 14.41 years and 282 patients (51%) were male. ASPECTS ≤ 7 was an independent predictor of both poor function (OR=1.94, 95%CI=1.04-3.62, P = 0.04) and mortality (OR=2.02, 95%CI=1.14-3.58, P = 0.02) at 1 year. MPV was also a strong predictor of 3-month (OR=3.88, 95%CI=2.04-7.38, P = 0.02) and 1-year (OR=3.32, 95%CI=1.91-5.78, P = 0.01) mortality, as well as 3-month (OR=3.25, 95%CI=1.80-5.86, P < 0.001) and 1-year (OR=4.35, 95%CI=2.36-8.02, P < 0.001) poor function. For 1-year poor function (OR=9.33, 95%CI=2.19-39.73, P = 0.003) and mortality (OR=6.40, 95%CI=2.09-19.64, P = 0.001), ASPECTS combined with all platelet indices found to be a more robust independent predictor compared to each variable alone.

CONCLUSION

Although MPV is an independent predictor of both 3-month and 1-year poor function and mortality in AIS patients, ASPECTS ≤ 7 was found to be a risk factor for 1-year poor function and mortality. Moreover, the prognostic value of both platelet indices and ASPECTS are greater when they are combined together in AIS patients.

Prediction of Intracerebral Hemorrhage After Endovascular Treatment of Acute Ischemic Stroke: Combining Quantitative Parameters on Dual-Energy CT with Clinical Related Factors

OBJECTIVES

To evaluate the predictive value of dual-energy CT (DECT) quantitative parameters and clinical influence factors for intracerebral hemorrhage (ICH) complications after endovascular treatment in patients with acute ischemic stroke (AIS).

METHODS

Seventy-two consecutive patients who underwent brain DECT immediately after endovascular treatment for AIS from November 2017 to October 2019 were included. Retrospectively, the volume of brain parenchymal hyperdensity area (HDA), the maximum iodine concentration, and maximum CT value on DECT images was evaluated and measured by two radiologists blinded to any clinical information independently. Follow-up CT imaging (24-72 h) were used to assess the development of ICH complications. DECT parameters and clinical influence factors were analyzed by Chi-square test or Fisher's exact test and Mann-Whitney U test. Receiver operating characteristic curves were generated for continuous variables.

RESULTS

Follow-up CT images confirmed that forty of 72 patients (55.6%) developed ICH. The volume of HDA, median maximum iodine concentration and maximum CT value between ICH group and non-ICH group were significantly different (P < 0.001). Combining the DECT quantitative parameters with clinical predictors, receiver operating characteristic analysis revealed an area under the curve of 0.985, for identifying patients developing ICH with sensitivity, specificity, positive predictive value and negative predictive value were 90%, 100%, 100% and 88.9%, respectively.

CONCLUSIONS

Three quantitative parameters of DECT and clinical predictors showed great predictive performance in identifing ICH complications in patients with brain parenchyma HDA after endovascular therapy, which may contribute to better clinical decision-making.

Mechanical thrombectomy beyond 6 hours in acute ischaemic stroke with large vessel occlusion in the carotid artery territory: experience at a tertiary hospital

INTRODUCTION

Thrombectomy in the carotid artery territory was recently shown to be effective up to 24 hours after symptoms onset.

METHODS

We conducted a retrospective review of a prospective registry of patients treated at our stroke reference centre between November 2016 and April 2019 in order to assess the safety and effectiveness of mechanical thrombectomy performed beyond 6 hours after symptoms onset in patients with acute ischaemic stroke and large vessel occlusion in the carotid artery territory.

RESULTS

Data were gathered from 59 patients (55.9% women; median age, 71 years). In 33 cases, stroke was detected upon awakening; 57.6% of patients were transferred from another hospital. Median baseline NIHSS score was 16, and median ASPECTS score was 8, with 94.9% of patients presenting > 50% of salvageable tissue. Satisfactory recanalisation was achieved in 88.1% of patients, beyond 24 hours after onset in 5 cases. At 90 days of follow-up, 67.8% were functionally independent; those who were not were older and presented higher prevalence of atrial fibrillation, greater puncture-to-recanalisation time, and higher NIHSS scores, both at baseline and at discharge.

CONCLUSION

In our experience, mechanical thrombectomy beyond 6 hours was associated with good 90-day functional outcomes. Age, NIHSS score, puncture-to-recanalisation time, and presence of atrial fibrillation affected functional prognosis. The efficacy of the treatment beyond 24 hours after onset merits study.

Mechanical thrombectomy beyond 6hours in acute ischaemic stroke with large vessel occlusion in the carotid artery territory: Experience at a tertiary hospital

INTRODUCTION

Thrombectomy in the carotid artery territory was recently shown to be effective up to 24hours after symptoms onset.

METHODS

We conducted a retrospective review of a prospective registry of patients treated at our stroke reference centre between November 2016 and April 2019 in order to assess the safety and effectiveness of mechanical thrombectomy performed beyond 6hours after symptoms onset in patients with acute ischaemic stroke and large vessel occlusion in the carotid artery territory.

RESULTS

Data were gathered from 59 patients (55.9% women; median age, 71 years). In 33 cases, stroke was detected upon awakening; 57.6% of patients were transferred from another hospital. Median baseline NIHSS score was 16, and median ASPECTS score was 8, with 94.9% of patients presenting>50% of salvageable tissue. Satisfactory recanalisation was achieved in 88.1% of patients, beyond 24hours after onset in 5 cases. At 90 days of follow-up, 67.8% were functionally independent; those who were not were older and presented higher prevalence of atrial fibrillation, greater puncture-to-recanalisation time, and higher NIHSS scores, both at baseline and at discharge.

CONCLUSION

In our experience, mechanical thrombectomy beyond 6hours was associated with good 90-day functional outcomes. Age, NIHSS score, puncture-to-recanalisation time, and presence of atrial fibrillation affected functional prognosis. The efficacy of the treatment beyond 24hours after onset merits study.

Correlation between ASPECTS and Core Volume on CT Perfusion: Impact of Time since Stroke Onset and Presence of Large-Vessel Occlusion

BACKGROUND AND PURPOSE

Both ASPECTS and core volume on CTP are used to estimate infarct volume in acute ischemic stroke. To evaluate the potential role of ASPECTS for acute endovascular treatment decisions, we studied the correlation between ASPECTS and CTP core, depending on the timing and the presence of large-vessel occlusion.

MATERIALS AND METHODS

We retrospectively reviewed all MCA acute ischemic strokes with standardized reconstructions of CTP maps entered in the Acute STroke Registry and Analysis of Lausanne (ASTRAL) registry. Correlation between ASPECTS and CTP core was determined for early (<6 hours) versus late (6-24 hours) times from stroke onset and in the presence versus absence of large-vessel occlusion. We used correlation coefficients and adjusted multiple linear regression models.

RESULTS

We included 1046 patients with a median age of 71.4 years (interquartile range, IQR = 59.8-79.4 years), an NIHSS score of 12 (IQR, 6-18), an ASPECTS of 9 (IQR, 7-10), and a CTP core of 13.6 mL (IQR, 0.6-52.8 mL). The overall correlation between ASPECTS and CTP core was moderate (ρ = -0.49, P < .01) but significantly stronger in the late-versus-early window (ρ = -0.56 and ρ = -0.48, respectively; P = .05) and in the presence versus absence of large-vessel occlusion (ρ = -0.40 and ρ = -0.20, respectively; P < .01). In the regression model, the independent association between ASPECTS and CTP core was confirmed and was twice as strong in late-arriving patients with large-vessel occlusion (β = -0.21 per 10 mL; 95% CI, -0.27 to -0.15; P < .01) than in the overall population (β = -0.10; 95% CI, -0.14 to -0.07; P < .01).

CONCLUSIONS

In a large cohort of patients with acute ischemic stroke, we found a moderate correlation between ASPECTS and CTP core. However, this was stronger in patients with large-vessel occlusion and longer delay from stroke onset. Our results could support the use of ASPECTS as a surrogate marker of CTP core in late-arriving patients with acute ischemic stroke with large-vessel occlusion.

Improved Reliability of Automated ASPECTS Evaluation Using Iterative Model Reconstruction from Head CT Scans

BACKGROUND AND PURPOSE

Iterative model reconstruction (IMR) has shown to improve computed tomography (CT) image quality compared to hybrid iterative reconstruction (HIR). Alberta Stroke Program Early CT Score (ASPECTS) assessment in early stroke is particularly dependent on high-image quality. Purpose of this study was to investigate the reliability of ASPECTS assessed by humans and software based on HIR and IMR, respectively.

METHODS

Forty-seven consecutive patients with acute anterior circulation large vessel occlusions (LVOs) and successful endovascular thrombectomy were included. ASPECTS was assessed by three neuroradiologists (one attending, two residents) and by automated software in noncontrast axial CT with HIR (iDose4; 5 mm) and IMR (5 and 0.9 mm). Two expert neuroradiologists determined consensus ASPECTS reading using all available image data including MRI. Agreement between four raters (three humans, one software) and consensus were compared using square-weighted kappa (κ).

RESULTS

Human raters achieved moderate to almost perfect agreement (κ = .557-.845) with consensus reading. The attending showed almost perfect agreement for 5 mm HIR (κ_HIR  = .845), while residents had mostly substantial agreements without clear trends across reconstructions. Software had substantial to almost perfect agreement with consensus, increasing with IMR 5 and 0.9 mm slice thickness (κ_HIR  = .751, κ_IMR  = .777, and κ_IMR0.9  = .814). Agreements inversely declined for these reconstructions for the attending (κ_HIR  = .845, κ_IMR  = .763, and κ_IMR0.9  = .681).

CONCLUSIONS

Human and software rating showed good reliability of ASPECTS across different CT reconstructions. Human raters performed best with the reconstruction algorithms they had most experience with (HIR for the attending). Automated software benefits from higher resolution with better contrasts in IMR with 0.9 mm slice thickness.

Efficacy and Safety of Timely Urgent Superficial Temporal Artery-to-Middle Cerebral Artery Bypass Surgery in Patients with Acute Ischemic Stroke: A Single-Institutional Prospective Study and a Pooled Analysis

BACKGROUND

Clinical outcome in patients with acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) is not satisfactory if reperfusion treatment fails or is not tried.

AIMS

We aimed to assess the efficacy and safety of urgent superficial temporal-to-middle cerebral artery (STA-MCA) bypass surgery in selected patients.

METHODS

Patients who were diagnosed with LVO-induced AIS in the anterior circulation but had a failed intra-arterial thrombectomy (IAT) or were not tried due to IAT contraindications were prospectively enrolled. Timely urgent STA-MCA bypass surgery was performed if they showed perfusion-diffusion mismatch or symptom-diffusion mismatch in the acute phase of disease. Clinical and radiological data of these patients were assessed to demonstrate the safety and efficacy of urgent bypass procedures. A pooled analysis of published data on urgent bypass surgery in acute stroke patients was conducted and analyzed.

RESULTS

In 18 patients who underwent timely bypass, the National Institutes of Health Stroke Scale (NIHSS) score improved from 12.11 ± 4.84 to 9.89 ± 6.52, 1 week after surgery. Three-month and long-term (9.72 ± 5.00 months) favorable outcomes (modified Rankin Scale [mRS] scores 0-2) were achieved in 50 and 75% of the patients, respectively. The pooled analysis (117 patients from 10 articles, including ours) identified favorable mRS scores in 71.79% patients at 3 months. A significant NIHSS score improvement from 11.51 ± 4.89 to 7.59 ± 5.50 was observed after surgery with significance. Major complications occurred in 3 patients (2.6%, 3/117) without mortality.

CONCLUSIONS

Urgent STA-MCA bypass surgery can be regarded as a safe optional treatment to prevent cerebral infarct expansion and to improve clinical and radiological outcomes in highly selected patients.

Neuroimaging in Acute Stroke

PURPOSE OF REVIEW

This article describes how imaging can be used by physicians in diagnosing, determining prognosis, and making appropriate treatment decisions in a timely manner in patients with acute stroke.

RECENT FINDINGS

Advances in acute stroke treatment, including the use of endovascular thrombectomy in patients with large vessel occlusion and, more recently, of IV thrombolysis in an extended time window, have resulted in a paradigm shift in how imaging is used in patients with acute stroke. This paradigm shift, combined with the understanding that "time is brain," means that imaging must be fast, reliable, and available around the clock for physicians to make appropriate clinical decisions. CT has therefore become the primary imaging modality of choice. Recognition of a large vessel occlusion using CT angiography has become essential in identifying patients for endovascular thrombectomy, and techniques such as imaging collaterals on CT angiography or measuring blood flow to predict tissue fate using CT perfusion have become useful tools in selecting patients for acute stroke therapy. Understanding the use of these imaging modalities and techniques in dealing with an emergency such as acute stroke has therefore become more important than ever for physicians treating patients with acute stroke.

SUMMARY

Imaging the brain and the blood vessels supplying it using modern tools and techniques is a key step in understanding the pathophysiology of acute stroke and making appropriate and timely clinical decisions.

Qualitative versus automatic evaluation of CT perfusion parameters in acute posterior circulation ischaemic stroke

Purpose

To compare the diagnostic accuracy (ACC) in the detection of acute posterior circulation strokes between qualitative evaluation of software-generated colour maps and automatic assessment of CT perfusion (CTP) parameters.

Methods

Were retrospectively collected 50 patients suspected of acute posterior circulation stroke who underwent to CTP (GE “Lightspeed”, 64 slices) within 24 h after symptom onset between January 2016 and December 2018. The Posterior circulation-Acute Stroke Prognosis Early CT Score (pc-ASPECTS) was used for quantifying the extent of ischaemic areas on non-contrast (NC)CT and colour-coded maps generated by CTP4 (GE) and RAPID (iSchemia View) software. Final pc-ASPECTS was calculated on follow-up NCCT and/or MRI (Philips Intera 3.0 T or Philips Achieva Ingenia 1.5 T). RAPID software also elaborated automatic quantitative mismatch maps.

Results

By qualitative evaluation of colour-coded maps, MTT-CTP4D and Tmax-RAPID showed the highest sensitivity (SE) (88.6% and 90.9%, respectively) and ACC (84% and 88%, respectively) compared with the other perfusion parameters (CBV, CBF). Baseline NCCT and CBF provided by RAPID quantitative perfusion mismatch maps had the lowest SE (29.6% and 6.8%, respectively) and ACC (38% and 18%, respectively). CBF and Tmax assessment provided by quantitative RAPID perfusion mismatch maps showed significant lower SE and ACC than qualitative evaluation. No significant differences were found between the pc-ASPECTSs assessed on colour-coded MTT and Tmax maps neither between the scores assessed on colour-coded CBV-CTP4D and CBF-RAPID maps.

Conclusion

Qualitative analysis of colour-coded maps resulted more sensitive and accurate in the detection of ischaemic changes than automatic quantitative analysis.

Towards subject-level cerebral infarction classification of CT scans using convolutional networks

Automatic evaluation of 3D volumes is a topic of importance in order to speed up clinical decision making. We describe a method to classify computed tomography scans on volume level for the presence of non-acute cerebral infarction. This is not a trivial task, as the lesions are often similar to other areas in the brain regarding shape and intensity. A three stage architecture is used for classification: 1) A cranial cavity segmentation network is developed, trained and applied. 2) Region proposals are generated 3) Connected regions are classified using a multi-resolution, densely connected 3D convolutional network. Mean area under curve values for subject level classification are 0.95 for the unstratified test set, 0.88 for stratification by patient age and 0.93 for stratification by CT scanner model. We use a partly segmented dataset of 555 scans of which 186 scans are used in the unstratified test set. Furthermore we examine possible dataset bias for scanner model and patient age parameters. We show a successful application of the proposed three-stage model for full volume classification. In contrast to black-box approaches, the convolutional network’s decision can be further assessed by examination of intermediate segmentation results.

Detection of ischemic changes on baseline multimodal computed tomography: expert reading vs. Brainomix and RAPID software

PURPOSE

The aim of the study was to compare the assessment of ischemic changes by expert reading and available automated software for non-contrast CT (NCCT) and CT perfusion on baseline multimodal imaging and demonstrate the accuracy for the final infarct prediction.

METHODS

Early ischemic changes were measured by ASPECTS on the baseline neuroimaging of consecutive patients with anterior circulation ischemic stroke. The presence of early ischemic changes was assessed a) on NCCT by two experienced raters, b) on NCCT by e-ASPECTS, and c) visually on derived CT perfusion maps (CBF<30%, Tmax>10s). Accuracy was calculated by comparing presence of final ischemic changes on 24-hour follow-up for each ASPECTS region and expressed as sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). The subanalysis for patients with successful recanalization was conducted.

RESULTS

Of 263 patients, 81 fulfilled inclusion criteria. Median baseline ASPECTS was 9 for all tested modalities. Accuracy was 0.76 for e-ASPECTS, 0.79 for consensus, 0.82 for CBF<30%, 0.80 for Tmax>10s. e-ASPECTS, consensus, CBF<30%, and Tmax>10s had sensitivity 0.41, 0.46, 0.49, 0.57, respectively; specificity 0.91, 0.93, 0.95, 0.91, respectively; PPV 0.66, 0.75, 0.82, 0.73, respectively; NPV 0.78, 0.80, 0.82, 0.83, respectively. Results did not differ in patients with and without successful recanalization.

CONCLUSION

This study demonstrated high accuracy for the assessment of ischemic changes by different CT modalities with the best accuracy for CBF<30% and Tmax>10s. The use of automated software has a potential to improve the detection of ischemic changes.

Multiple hypointense vessels on susceptibility-weighted imaging predict early neurological deterioration in acute ischaemic stroke patients with severe intracranial large artery stenosis or occlusion receiving intravenous thrombolysis

Background and purpose

Early neurological deterioration (END) is a common feature in patients with acute ischaemic stroke (AIS) receiving thrombolysis. This study aimed to investigate whether the presence of multiple hypointense vessels (MHVs) on susceptibility-weighted imaging (SWI) could predict END in patients with the anterior circulation AIS treated with recombinant tissue plasminogen activator (r-tPA).

Methods

This was a retrospective study focusing on AIS patients suffering from symptomatic stenosis or occlusion of the middle cerebral artery or internal carotid artery with r-tPA treatment. We collected clinical variables and initial haematological and neuroimaging findings. MHVs were measured on SWI performed after intravenous thrombosis and were defined as the presence of a greater number of veins or veins of a larger diameter with greater signal loss on SWI than those of the contralesional haemisphere. The degree of hyperintensity of MHVs was classified into four grades: none, subtle, moderate and extensive. END was defined as an increase in the National Institutes of Health Stroke Scale score by 2 points during the first 48 hours after the onset of symptoms. Multivariate logistic regressions were conducted to investigate the predictors of END.

Results

The study included 61 patients (51 males and 10 females) with a mean age of 62.4±12.6 years. Thirty-five (57.4%) patients presented with MHVs: 8 (13.1%) were graded as subtle MHVs, while 23 (37.7%) and 4 (6.6%) were graded as moderate or extensive MHVs, respectively. Twenty patients (32.8%) presented with END. Logistic regression analysis showed that compared with patients without MHVs, moderate MHVs (adjusted OR 5.446, 95% CI 1.360 to 21.800; p=0.017) and extensive MHVs (adjusted OR 15.240, 95% CI 1.200 to 193.544; p=0.036) were significantly associated with END.

Conclusions

MHVs might be a useful predictor of END in AIS patients with symptomatic large artery stenosis or occlusion after r-tPA treatment.

Clinical and molecular correlates of the ASPECTS in the acute phase of stroke

BACKGROUND

The Alberta Stroke Program Early CT Score (ASPECTS) scale was developed for monitoring early ischemic changes on CT, being associated with clinical outcomes. The ASPECTS can also associate with peripheral biomarkers that reflect the pathophysiological response of the brain to the ischemic stroke.

OBJECTIVE

To investigate the association between peripheral biomarkers with the Alberta Stroke Program Early CT Score (ASPECTS) in individuals after ischemic stroke.

METHODS

Patients over 18 years old with acute ischemic stroke were enrolled in this study. No patient was eligible for thrombolysis. The patients were submitted to non-contrast CT in the first 24 hours of admission, being the Alberta Stroke Program Early CT Score and clinical and molecular evaluations applied on the same day. The National Institutes of Health Stroke Scale (NIHSS), modified Rankin scale and the Mini-Mental State Examination for clinical evaluation were also applied to all subjects. Plasma levels of BDNF, VCAM-1, VEGF, IL-1β, sTNFRs and adiponectin were determined by ELISA.

RESULTS

Worse neurological impairment (NIHSS), cognitive (MEEM) and functional (Rankin) performance was observed in the group with changes in the NCTT. Patients with NCTT changes also exhibited higher levels of IL-1β and adiponectin. In the linear multivariate regression, an adjusted R coefficient of 0.515 was found, indicating adiponectin and NIHSS as independent predictors of ASPECTS.

CONCLUSION

Plasma levels of adiponectin are associated with the ASPECTS scores.

From "Time is Brain" to "Imaging is Brain": A Paradigm Shift in the Management of Acute Ischemic Stroke

Arterial recanalization to restore the blood supply and limit the brain damage is the primary goal in the management of acute ischemic stroke (AIS). Since the publication of pivotal randomized clinical trials in 2015, endovascular thrombectomy has become part of the standard of care in selected cases of AIS from large-vessel occlusions up to 6 hours after the onset of symptoms. However, the association between endovascular reperfusion and improved functional outcome is not strictly time dependent. Rather than on rigid time windows, candidates should be selected based on vascular and physiologic information. This approach places imaging data at the center of treatment decisions. Advances in imaging-based management of AIS provide crucial information about vessel occlusion, infarct core, ischemic penumbra, and degree of collaterals. This information is invaluable in identifying patients who are likely to benefit from reperfusion therapies and excluding those who are unlikely to benefit or are at risk of adverse effects. The approach to reperfusion therapies continues to evolve, and imaging is acquiring a greater role in the diagnostic work-up and treatment decisions as shown in recent clinical trials with extended time window. The 2018 American Heart Association/American Stroke Association guidelines reflect a paradigm shift in the management of AIS from "Time is Brain" to "Imaging is Brain." This review discusses the essential role of multimodal imaging developing from recent trials on therapy for AIS.

Comparison of the performance between Frontier ASPECTS software and different levels of radiologists on assessing CT examinations of acute ischaemic stroke patients

AIM

To compare the performance of Frontier Alberta Stroke Program Early CT Score (ASPECTS) software with different levels of radiologists in assessing computed tomography (CT) examinations of patients with early acute ischaemic stroke (AIS), and to evaluate whether this software can improve the performance of rating by less experienced radiologists.

MATERIALS AND METHODS

Unenhanced brain CT examinations of 55 patients with acute middle cerebral artery ischaemia were scored separately by Frontier, two senior radiologists, and two junior radiologists retrospectively and blinded to any clinical information. Two junior radiologists then scored again with the assist of Frontier. The reference standard was defined as the ASPECTS on Follow-up unenhanced CT scored by another two non-blinded independent experts on a consensus basis. Statistical analysis was performed using intraclass correlation coefficient (ICC) analysis and Bland-Altman plots.

RESULTS

Frontier and senior radiologists in ASPECTS reading have excellent agreement with the reference standard (r=0.842 and 0.803, respectively), while only a good agreement was found between junior radiologists and reference standard (r=0.680). Bland-Altman analysis revealed the mean ASPECTS difference and SD difference of junior radiologists were larger (mean difference=1.35; SD=1.42) than that of Frontier and senior radiologists with reference standard (mean difference=0.16, 0.22; SD=1.24, 1.13, respectively). However, with the assist of Frontier, the agreement between junior radiologists and reference standard was improved from good (r=0.680) to excellent (r =0.852), and the mean ASPECTS difference and SD difference were reduced.

CONCLUSION

High agreement in ASPECTS rating between senior radiologists, Frontier, and expert consensus reading was found. Moreover, Frontier can improve the performance of less experienced radiologists to assess the ASPECTS of patients with AIS.

Exploring Reperfusion Following Endovascular Thrombectomy

Background and Purpose- Cerebral perfusion in acute ischemic stroke patients is often assessed before endovascular thrombectomy (EVT), but rarely after. Perfusion data obtained following EVT may provide additional prognostic information. We developed a tool to quantitatively derive perfusion measurements from digital subtraction angiography (DSA) data and examined perfusion in patients following EVT. Methods- Source DSA images from acute anterior circulation stroke patients undergoing EVT were retrospectively assessed. Following deconvolution, maps of mean transit time (MTT) were generated from post-EVT DSA source data. Thrombolysis in Cerebral Infarction grades and MTT in patients with and without hemorrhagic transformation (HT) at 24 hours were compared. Receiver operating characteristic modeling was used to classify the presence/absence of HT at 24 hours by MTT. Results- Perfusion maps were generated in 50 patients using DSA acquisitions that were a median (interquartile range) of 9 (8-10) seconds in duration. The median post-EVT MTT within the affected territory was 2.6 (2.2-3.3) seconds. HT was observed on follow-up computed tomography in 16 (32%) patients. Thrombolysis in Cerebral Infarction grades did not differ in patients with HT from those without (P=0.575). Post-EVT MTT maps demonstrated focal areas of hyperperfusion (n=8) or persisting hypoperfusion (n=3) corresponding to the regions where HT later developed. The relationship between MTT and HT was U-shaped; HT occurred in patients at both the lowest and highest extremes of MTT. An MTT threshold <2 or >4 seconds was 81% sensitive and 94% specific for classifying the presence of HT at follow-up. Conclusions- Perfusion measurements can be obtained using DSA perfusion with minimal changes to current stroke protocols. Perfusion imaging post-recanalization may have additional clinical utility beyond visual assessment of source angiographic images alone.

Collaterals are a major determinant of the core but not the penumbra volume in acute ischemic stroke

PURPOSE

Determinants of early loss of ischemic tissue (core) or its prolonged survival (penumbra) in acute ischemic stroke (AIS) are poorly understood. We aimed to identify radiological associations of core and penumbra volumes on CT perfusion (CTP) in a large cohort of AIS.

METHODS

In the ASTRAL registry (2003-2016), we identified consecutive AIS patients with proximal middle cerebral artery (MCA) occlusion. We calculated core and penumbra volumes using established thresholds and the mismatch ratio (MR). We graded collaterals into three categories on CT-angiography. We used clot burden score (CBS) to quantify the clot length. We related CTP volumes to radiological variables in multivariate regression analyses, adjusted for time from stroke onset to first imaging.

RESULTS

The median age of the 415 included patients was 69 years (IQR = 21) and 49% were female. Median admission NIHSS was 16 (11) and median delay to imaging 2.2 h (1.9). Lower core volumes were associated with higher ASPECTS (hazard ratio = 1.08), absence of hyperdense MCA sign (HR = 0.70), higher CBS (i.e., smaller clot, HR = 1.10), and better collaterals (HR = 1.95). Higher penumbra volumes were related to lower CBS (i.e., longer clot, HR = 1.08) and proximal intracranial occlusion (HR = 1.47), but not to collaterals. Higher MR was found in absence of hyperdense MCA sign (HR = 1.28), absence of distal intracranial occlusion (HR = 1.39), and with better collaterals (HR = 0.52).

CONCLUSIONS

In AIS, better collaterals were associated with lower core volumes, but not with higher penumbra volumes. This suggests a major role of collaterals in early tissue loss and their limited significance as marker of salvageable tissue.