Perfusion and Diffusion Variables Predict Early Neurological Deterioration in Minor Stroke and Large Vessel Occlusion

Does imaging of the ischemic penumbra have value in acute ischemic stroke with large vessel occlusion?

PURPOSE OF REVIEW

In this review, we summarize current evidence regarding potential benefits and limitations of using perfusion imaging to estimate presence and extent of irreversibly injured ischemic brain tissue ('core') and severely ischemic yet salvageable tissue ('penumbra') in acute stroke patients with large vessel occlusion (LVO).

RECENT FINDINGS

Core and penumbra volumes are strong prognostic biomarkers in LVO patients. Greater benefits of both intravenous thrombolysis and endovascular therapy (EVT) are observed in patients with small core and large penumbra volumes. However, some current definitions of clinically relevant penumbra may be too restrictive and exclude patients who may benefit from reperfusion therapies. Alongside other clinical and radiological factors, penumbral imaging may enhance the discussion regarding the benefit/risk ratio of EVT in common clinical situations, such as patients with large core - for whom EVT's benefit is established but associated with a high rate of severe disability -, or patients with mild symptoms or medium vessel occlusions - for whom EVT's benefit is currently unknown. Beyond penumbral evaluation, perfusion imaging is clinically relevant for optimizing patient's selection for neuroprotection trials.

SUMMARY

In an emerging era of precision medicine, perfusion imaging is a valuable tool in LVO-related acute stroke.

Mechanical thrombectomy in minor stroke due to isolated M2 occlusion: a multicenter retrospective matched analysis

BACKGROUND

The purpose of this study was to evaluate the effectiveness of mechanical thrombectomy (MT) in patients with isolated M2 occlusion and minor symptoms and identify possible baseline predictors of clinical outcome.

METHODS

The databases of 16 high-volume stroke centers were retrospectively screened for consecutive patients with isolated M2 occlusion and a baseline National Institutes of Health Stroke Scale (NIHSS) score ≤5 who received either early MT (eMT) or best medical management (BMM) with the possibility of rescue MT (rMT) on early neurological worsening. Because our patients were not randomized, we used propensity score matching (PSM) to estimate the treatment effect of eMT compared with the BMM/rMT. The primary clinical outcome measure was a 90-day modified Rankin Scale score of 0-1.

RESULTS

388 patients were initially selected and, after PSM, 100 pairs of patients receiving eMT or BMM/rMT were available for analysis. We found no significant differences in clinical outcome and in safety measures between patients receiving eMT or BMM/rMT. Similar results were also observed after comparison between eMT and rMT. Concerning baseline predicting factors of outcome, the involvement of the M2 inferior branch was associated with a favorable outcome.

CONCLUSION

Our multicenter retrospective analysis has shown no benefit of eMT in minor stroke patients with isolated M2 occlusion over a more conservative therapeutic approach. Although our results must be viewed with caution, in these patients it appears reasonable to consider BMM as the first option and rMT in the presence of early neurological deterioration.

Effects of endovascular therapy for mild stroke due to proximal or M2 occlusions: meta-analysis

OBJECTIVE

To conduct a meta-analysis to evaluate the effect of endovascular therapy (EVT) in mild acute ischemic stroke (AIS) due to proximal versus distal occlusions.

METHODS

We searched PubMed, Embase, the Cochrane Library, and clinicaltrials.gov from January 2000 to September 2021 to identify studies comparing EVT versus best medical management (BMM) in AIS with National Institutes of Health Stroke Scale (NIHSS) scores ≤5 due to proximal internal carotid artery (ICA) or M1 versus distal M2 occlusions. We included studies that reported the number of patients with proximal or distal occlusions separately and reported the number of patients with freedom of disability (modified Rankin Scale (mRS) score 0-1) or functional independence (mRS score 0-2) at 90 days in proximal or M2 occlusions, respectively. OR with 95% CI was used.

RESULTS

We identified six studies with 653 proximal ICA and M1 occlusion patients and 666 distal M2 occlusion patients. Pooled results showed EVT versus BMM was associated with a higher rate of being disability-free in patients with proximal occlusions (OR 1.58, 95% CI 1.09 to 2.30), but was associated with a lower rate of being disability-free in patients with M2 occlusions (OR 0.70, 95% CI 0.49 to 0.99). Effect of EVT in proximal versus distal occlusions was substantially different (P for interaction=0.002). A similar pattern was seen for functional independence (P for interaction=0.05).

CONCLUSIONS

For patients with mild AIS, observational data suggest that EVT may be beneficial for proximal ICA or M1 but not for distal M2 occlusions. Randomized trials are needed to confirm these findings.

PROSPERO REGISTRATION NUMBER

CRD42021281034.

Association of Perfusion Lesion Variables With Functional Outcome in Patients With Mild Stroke and Large Vessel Occlusion Managed Medically

BACKGROUND AND OBJECTIVES

The best management of patients with mild stroke and large vessel occlusion (LVO) remains unclear. This study aimed to identify perfusion imaging predictors of poor functional outcome in such patients.

METHODS

This cohort study retrospectively selected patients enrolled in the International Stroke Perfusion Imaging Registry between August 2011 and April 2022. The registry enrolled patients with acute ischemic stroke and with baseline CT perfusion scanned within 24 hours of stroke onset. This study identified patients with mild symptoms, defined by an NIH Stroke Scale score of ≤5. Patients with LVO of anterior circulation were selected. This study further selected patients who received medical management and excluded patients who received endovascular treatment. The primary outcome was poor functional outcome defined as a modified Rankin Scale of 3-6 at 3 months. Perfusion lesion was defined by delay time > 3 seconds on CTP. Regression analyses were used to identify clinical and imaging variables that predicted poor functional outcome.

RESULTS

A total of 139 patients with mild stroke were included, of whom 27 (19%) had poor functional outcome. Patients with poor outcome, compared with those with good outcome, had much larger perfusion lesion volume (median 80 mL vs 41 mL, p < 0.001). Perfusion lesion was a significant predictor of poor outcome in either univariable regression (crude OR = 1.02, 95% CI = [1.01-1.03]) or multivariable regression model (adjusted OR = 1.01, 95% CI = [1.01-1.02]), adjusting for occlusion site, good collaterals, baseline stroke severity, age, IV thrombolysis (IVT), and onset to scan time. A perfusion lesion of 65 mL was the optimal cutpoint to identify poor functional outcome (sensitivity = 59%, specificity = 77%). Patients with perfusion lesion ≥65 mL, compared with patients with perfusion lesion <65 mL, showed a much higher rate of poor functional outcome (38% vs 11%, p < 0.001). Of the 139 patients in this study, 95 received IVT. Patients treated with or without IVT did not influence their outcomes (crude OR = 0.74, 95% CI = [0.31-1.78]).

DISCUSSION

A perfusion lesion of ≥65 mL predicted poor functional outcome in mild stroke patients with LVO.

Multiple chronic lacunes predicting early neurological deterioration and long-term functional outcomes according to TOAST classification in acute ischemic stroke

INTRODUCTION

Studies regarding multiple chronic lacunes (MCLs) and clinical outcome according to stroke etiology are scarce. We sought to evaluate the association between MCL and short-term/long-term clinical outcomes according to stroke etiology.

PATIENTS AND METHODS

We analyzed a prospectively collected stroke registry of acute ischemic stroke patients over 4 years. The enrolled patients were classified as having large artery atherosclerosis (LAA), small vessel occlusion (SVO), cardioembolic (CE) stroke, and other etiology. The early neurological deterioration (END) and favorable outcome at 3 months were assessed.

RESULTS

A total of 1070 patients were enrolled. Patients with MCL had significantly more END compared to those without MCL both in total population (adjusted odds ratio (OR), 1.7; 95% confidence interval [CI], 1.1-2.5; p = 0.013*) and in the LAA group (adjusted OR, 2.3; 95% CI, 1.3-4.2, p < 0.006). Patients with MCL had a significantly lower OR for favorable outcome at 3 months compared to those without MCL both in total population (adjusted OR, 0.7; 95% CI, 0.5-1.0, p = 0.035) and in the LAA group (adjusted OR, 0.6; 95% CI, 0.3-1.0, p = 0.043). However, MCL was not associated with END or long-term functional outcome in patients with SVO, CE, or other etiology.

CONCLUSIONS

The presence of MCL was an independent predictive factor for END as well as long-term poor functional outcome in acute ischemic stroke patients. These associations were only observed in patients with LAA, not in those with SVO, CE, or other etiology.

Early Response to Endovascular Thrombectomy after Stroke: Early, Late, and Very Late Time Windows

BACKGROUND AND PURPOSE

Endovascular thrombectomy (EVT) has benefits in selected patients 6-24 h after stroke onset. However, the response to EVT >24 h after stroke onset is still unclear. We compared the early response to EVT in patients with different time windows.

METHODS

Patients who underwent EVT in an emergency setting were enrolled and categorized according to when EVT was performed: within 6 (early), 6-24 (late), and >24 h (very late) after stroke onset. Early neurological improvement (ENI) and deterioration (END) were defined as improvement and worsening, respectively, of National Institutes of Health Stroke Scale (NIHSS) score by ≥4 points after EVT. The three groups' clinical characteristics and response to EVT were compared. We also investigated factors associated with ENI and END.

RESULTS

During study period, 274 patients underwent EVT (109 early, 104 late, and 61 very late). Patients who underwent EVT very late were younger (p = 0.007), had smaller ischemic cores, and had lower initial NIHSS scores (8 ± 5) than those who underwent EVT early (14 ± 6) and late (13 ± 7; p < 0.001). Stroke mechanisms also differed according to the time window (p < 0.001): cardioembolism was more common after early EVT, whereas large-artery atherosclerosis was more prevalent among patients who underwent EVT very late. ENI was significantly more common after early (60.6%) and late EVT (51.0%) than after very late EVT (29.5%; p = 0.001); however, rates of END did not differ (11.0%, 13.5%, and 4.9%, respectively). ENI was independently associated with male, higher NIHSS score, and early and late EVT. END was associated with failure of recanalization.

CONCLUSIONS

ENI was more observed and associated with early and late EVT. Highly selected patients receiving very late EVT may not benefit from ENI but may still have a chance to prevent END. The occurrence of END was associated not with time window but with failure of recanalization.

Early neurological deterioration in patients with acute ischemic stroke: a prospective multicenter cohort study

Background

There is still no precise knowledge of the causes of progression in patients with acute ischemic stroke (AIS), and we are unable to predict patients at risk.

Objective

To explore the frequency, predictive factors, and the prognosis of early neurological deterioration (END) in patients with AIS.

Methods

In this prospective multicenter observational study, we assessed patients with AIS admitted to 18 hospitals in Henan, China. We defined END as an increase of ⩾2 points in total National Institutes of Health Stroke Scale (NIHSS) score or ⩾1 point in the motor items of the NIHSS within 7 days after admission. Risk factors were analyzed using multivariate logistic regression models. Prognosis was evaluated using the modified Rankin Scale (mRS), with poor prognosis defined as mRS 3-6.

Results

A total of 9114 patients with AIS within 24 h of symptom onset were enrolled in the study. END occurred in 1286 (14.1%) patients. The highest incidence (62.5%) of END occurred within 24 h after admission. After adjusting potential confounders, age, body mass index, waist-hip ratio, systolic blood pressure, baseline NIHSS, disabled at baseline, history of atrial fibrillation, diabetes mellitus, intracranial arterial stenosis, infarct location in the lenticulostriate artery area and cerebral watershed, neutrophils, lymphocytes, uric acid, and triglycerides were identified as independent predictors for END. END was significantly associated with poor prognosis at 90 days, and the adjusted OR was 1.74 (95% CI: 1.53-1.97).

Conclusion

One in seven hospitalized patients with AIS may experience END within 24 h of onset. The highest incidence of END occurred within 24 h of admission and decreased steeply with time. Easily identifiable risk factors predict END and could help understand the causal mechanisms and thereby prevent END.

Biomarker of early neurological deterioration in minor stroke and proximal large vessel occlusion: A pilot study

BACKGROUND

Plasma neurofilament light chain (pNFL) represents one of the scaffolding proteins of central nervous system axonal injury. The aim of this study was to evaluate pNFL as a predictive biomarker for early neurological deterioration (END) in medically managed patients with large vessel occlusion (LVO) and mild presentation (NIHSS < 6).

METHODS

This retrospective study was developed from a prospectively collected stroke database, which was conducted at a large academic comprehensive stroke center in western China. Patients who first presented with acute ischemic stroke (AIS) within 24 h of symptom onset were continuously included. Stroke severity was analyzed at admission using the NIHSS score. The pNFL drawn on admission was analyzed with a novel ultrasensitive single-molecule array.

RESULTS

Thirty-nine consecutive patients were included in the analysis, and 19 (48.72%) patients experienced END. Patients who experienced END had significantly higher pNFL levels (mean, 65.20 vs. 48.28 pg/mL; P < 0.001) and larger infarct volume (mean, 15.46 vs. 9.56 mL; P < 0.001). pNFL was valuable for the prediction of END (OR, 1.170; 95% CI, 1.049-1.306; P = 0.005), even after adjusted for age and sex (OR, 1.178; 95% CI, 1.038-1.323; P = 0.006), blood sampling time, baseline NIHSS, TOAST classification, and infarct volume (OR, 1.168; 95% CI, 1.034-1.320; P = 0.012). The area under the ROC curve was 85.0% (95% CI, 0.731-0.970; P < 0.001). The sensitivity was 73.7%, and the specificity was 80%.

CONCLUSION

END in minor stroke with LVO was distinguishable from those without END following the determination of pNFL in the blood samples within 24 h of onset. The pNFL is a promising biomarker of END in minor stroke with LVO.

CLINICAL TRIAL REGISTRATION

ChiCTR1800020330.

Effectiveness and safety of EVT in patients with acute LVO and low NIHSS

Background and purpose

There is much uncertainty in endovascular treatment (EVT) decisions in patients with acute large vessel occlusion (LVO) and mild neurological deficits.

Methods

From a prospective, nationwide stroke registry, all patients with LVO and baseline NIHSS &lt;6 presenting within 24 h from the time last known well (LKW) were included. Early neurological deterioration (END) developed before EVT was prospectively collected as an increasing total NIHSS score ≥2 or any worsening of the NIHSS consciousness or motor subscores during hospitalization not related to EVT. Significant hemorrhage was defined as PH2 hemorrhagic transformation or hemorrhage at a remote site. The modified Rankin Scale (mRS) was prospectively collected at 3 months.

Results

Among 1,083 patients, 149 (14%) patients received EVT after a median of 5.9 [3.6–12.3] h after LKW. In propensity score-matched analyses, EVT was not associated with mRS 0-1 (matched OR 0.99 [0.63–1.54]) but increased the risk of a significant hemorrhage (matched OR, 4.51 [1.59–12.80]). Extraneous END occurred in 207 (19%) patients after a median of 24.5 h [IQR, 13.5–41.9 h] after LKW (incidence rate, 1.41 [95% CI, 1.23–1.62] per 100 person-hours). END unrelated to EVT showed a tendency to modify the effectiveness of EVT (P-for-interaction, 0.08), which decreased the odds of having mRS 0–1 in mild LVO patients without END (adjusted OR, 0.63 [0.40–0.99]).

Conclusions

The use of EVT in patients with acute LVO and low NIHSS scores may require the assessment of individual risks of early deterioration, hemorrhagic complications and expected benefit.

Meta-Analysis of Predictive Role of Early Neurological Deterioration after Intravenous Thrombolysis

With the popularization of intravenous thrombolysis, more and more people use intravenous thrombolysis to treat related diseases, but problems also arise. There are still a considerable number of patients with early disease after thrombolytic therapy not only not significantly improving, but also progressing, that is, early neurological deterioration (END). In view of this problem, the prediction of END after intravenous thrombolysis becomes very important. With the development of medical technology, research on the prediction of END after intravenous thrombolysis has gradually been carried out. Effective prediction is of great significance for the prevention and treatment of END after intravenous thrombolysis. This article aimed to carry out a meta-analysis of the predictive role of END after intravenous thrombolysis. Through an informed analysis of all studies of this type in this field, this article determines a method for predicting END after intravenous thrombolysis. The actual effect of its role is revealed in this paper, and its purpose is to promote the development of this field. This article addresses the same type of study on the predictive role of neurological deterioration after intravenous thrombolysis. The article performs test and meta-analysis of its role by conditionally searching for literature studies. It is explained using the relevant theoretical formulas. The analysis results show that the prediction of END after intravenous thrombolysis in this paper can effectively help make a preliminary judgment on the possible later neurological deterioration. Although there is an error between the predicted curve and the actual curve, the difference between the two is between 1% and 5%. It can basically effectively predict the occurrence of END. Therefore, the prediction of END after intravenous thrombolysis has a very large preventive effect on the END after intravenous thrombolysis.

Circular RNA FUNDC1 for Prediction of Acute Phase Outcome and Long-Term Survival of Acute Ischemic Stroke

Circular RNAs (CircRNAs) have shown promising potential in the diagnosis and the prediction of outcomes of stroke. This study aimed to explore the potential value of circRNAs for identifying acute neurological deterioration and estimating long-term survival for acute ischemic stroke (AIS). One hundred healthy controls and 200 patients with AIS within 72 h were recruited, 140 of whom were admitted within 24 h after onset. CircRNA levels in peripheral blood were measured by quantitative polymerase chain reaction (qPCR). Compared to the controls, the levels of three circRNAs were significantly increased in three subgroups of patients, including large artery atherosclerosis (LAA) stroke, small artery occlusion (SAO) stroke, and cardioembolism (CE) stroke (all P < 0.001). Among, LAA stroke patients had higher levels of circular RNA FUNDC1 (circFUNDC1) compared to SAO stroke patients (P = 0.015). CircFUNDC1 levels were positively correlated with National Institutes of Health Stroke Scale (NIHSS) scores on the 7th day only in LAA patients (P = 0.048, r = 0.226). It should be noted that the levels of circFUNDC1 in patients with early neurological deterioration (END), admitted within 24 h after onset, were significantly higher than those without END (P = 0.013). In addition, circFUNDC1 levels positively correlated with baseline NIHSS scores (P = 0.016, r = 0.203) or the 7th day NIHSS scores (P = 0.001, r = 0.289) in patients within 24 h after onset. Importantly, after 18 months of follow-up, a significant difference was observed on survival Kaplan-Meier curves (P = 0.042) between AIS patients with low (below cut-off) or high circFUNDC1 levels (above cut-off). Circulating circFUNDC1 could be a potential biomarker for predicting acute-phase outcome and long-term survival in AIS.

Perfusion profile evaluated by severity-weighted multiple Tmax strata predicts early neurological deterioration in minor stroke with large vessel occlusion

Minor stroke due to large vessel occlusion (LVO) is associated with poor outcomes. Hypoperfused tissue fate may be more accurately predicted by severity-weighted multiple perfusion strata than by a single perfusion threshold. We investigated whether poor perfusion profile evaluated by multiple Tmax strata is associated with early neurological deterioration (END) in patients with minor stroke with LVO. Ninety-four patients with a baseline National Institute of Health Stroke Scale score ≤5 and anterior circulation LVO admitted within 24 hours of onset were included. Tmax strata proportions (Tmax 2-4 s, 4-6 s, 6-8 s, 8-10 s, and >10 s) against the entire hypoperfusion volume (Tmax >2 s) were measured. The perfusion profile was defined as the shift of the distribution of the Tmax strata proportions towards worse hypoperfusion severity compared with that of the entire cohort using the Wilcoxon-Mann-Whitney generalised odds ratio (OR); its performance to predict END was tested. The area under the curve of perfusion profile was 0.785 (95% confidence interval [CI]: 0.691-0.878, p < 0.001). Poor perfusion profile (generalised OR >1.052) was independently associated with END (adjusted OR 13.42 [95% CI: 4.38-41.15], p < 0.001). Thus, perfusion profile with severity-weighted multiple Tmax strata may predict END in minor stroke and LVO.

The Clinical Features of In-Hospital Recurrence in Acute Ischaemic Stroke Patients over Time: A Real-World Observation at a Single Center

Acute ischaemic stroke (AIS) has a high risk of recurrence, particularly in the early stage. Our study aimed to assess the clinical characteristics and risk factors of in-hospital ischaemic recurrence in AIS patients in different periods. This study was a retrospective, single-center analysis. The patients were divided into two stages based on their admission time. The primary endpoint was recurrent stroke during hospitalization. In total, 978 patients in Stage 1 and 1047 patients in Stage 2 were included in this study. The in-hospital recurrence rate in Stage 1 was 5.9%, while that in Stage 2 was 4.0% (p = 0.046). A recurrence rate reduction mainly occurred in the minor stroke and large-artery atherosclerosis (LAA) stroke patients. Infection was an independent risk factor despite amelioration by antiplatelet therapy (p < 0.001). Diabetes patients also had a higher risk of in-hospital ischaemic recurrence among the minor stroke and large-artery atherosclerosis patients. A positive attitude towards antiplatelet therapy failed to completely halt recurrence of the disease. In conclusion, the rate of in-hospital ischaemic recurrence in AIS patients showed a decreasing trend over time, especially in the minor stroke and large-artery atherosclerosis stroke patients. Infection and diabetes were associated with a higher risk of stroke recurrence.

The length of susceptibility vessel sign predicts early neurological deterioration in minor acute ischemic stroke with large vessel occlusion

Background

Patients with acute large vessel occlusion (LVO) presenting with minor stroke are at risk of early neurological deterioration (END). The present study aimed to evaluate the frequency and potential predictors of END in patients with medical management and LVO presenting with minor stroke. The relationship between SVS length and END was also investigated.

Methods

This was a prospective multicenter study. Consecutive patients were collected with anterior circulation. LVO presented with minor stroke [National Institutes of Health Stroke Scale (NIHSS) ≤ 4] within 24 h following onset. END was defined as a deterioration of NIHSS ≥4 within 24 h, without parenchymal hemorrhage. The length of the susceptibility vessel sign (SVS) was measured using the T2* gradient echo imaging.

Results

A total of 134 consecutive patients with anterior circulation LVO presenting with minor stroke were included. A total of 27 (20.15%) patients experienced END following admission. Patients with END exhibited longer SVS and higher baseline glucose levels compared with subjects lacking END (P < 0.05). ROC curve analysis indicated that the optimal cutoff point SVS length for END was SVS ≥ 9.45 mm. Multivariable analysis indicated that longer SVS [adjusted odds ratio (aOR), 2.03; 95% confidence interval (CI), 1.45–2.84; P < 0.001] and higher baseline glucose (aOR,1.02; 95% CI, 1.01–1.03; P = 0.009) levels were associated with increased risk of END. When SVS ≥ 9.45 mm was used in the multivariate logistic regression, SVS ≥ 9.45 mm (aOR, 5.41; 95%CI, 1.00–29.27; P = 0.001) and higher baseline glucose [aOR1.01; 95%CI, 1.00–1.03; P = 0.021] were associated with increased risk of END.

Conclusions

END was frequent in the minor stroke patients with large vessel occlusion, whereas longer SVS and higher baseline glucose were associated with increased risk of END. SVS ≥ 9.45 mm was a powerful independent predictor of END.