The Hyperdense middle cerebral artery sign is associated with poor leptomeningeal collaterals in acute ischemic stroke: a retrospective study

Association between ischaemic stroke aetiology and leptomeningeal collateral status: a retrospective cohort study

INTRODUCTION

There is limited understanding of the pathomechanistic relationship between leptomeningeal collateral formation and ischaemic stroke aetiology. We aimed to assess the association of leptomeningeal collateral status and ischaemic stroke aetiology, using the widely recognised "Trial of Org 10172 in Acute Stroke Treatment" (TOAST) classification categorising strokes into five distinct aetiologies.

METHODS

Retrospective study of consecutively admitted adult ischaemic stroke patients at a Swiss stroke centre. Leptomeningeal collateral status was assessed on admission with single-phase CT-angiographies using a validated 4-point score. Patients were categorised into large-artery atherosclerosis (LAA), cardioembolic (CE), small-vessel disease (SVD) and cryptogenic (CG) according to the TOAST classification. We performed ordinal and binary (poor [collaterals filling ≤50% of the occluded territory] vs good [collaterals filling >50% of the occluded territory] collateralisation) logistic regression to evaluate the impact of TOAST aetiology on collateral status.

RESULTS

Among 191 patients, LAA patients had better collateral status compared to non-LAA aetiology (LAA: 2 vs CE: 2 vs SVD: 3 vs CG: 2, pLAA vs non-LAA = 0.04). In weighted multivariate logistic regression, LAA and SVD independently predicted better collateral status (binary models [adjusted odds ratio; aOR]: LAA: 3.72 [1.21-11.44] and SVD: 4.19 [1.21-14.52]; ordinal models [adjusted common odds ratio; acOR]: LAA: 2.26 [95% CI: 1.23-4.15] and SVD: 1.94 [1.03-3.66]), while CE predicted worse collateral status (binary models [aOR]: CE: 0.17 [0.07-0.41]; ordinal models [acOR]: CE: 0.24 [0.11-0.51]).

CONCLUSION

The aetiology of ischaemic stroke is associated with leptomeningeal collateral status on single-phase CT-angiography, with LAA and SVD predicting better and CE predicting worse collateral status.

Utilizing imaging parameters for functional outcome prediction in acute ischemic stroke: A machine learning study

BACKGROUND AND PURPOSE

We aimed to predict the functional outcome of acute ischemic stroke patients with anterior circulation large vessel occlusions (LVOs), irrespective of how they were treated or the severity of the stroke at admission, by only using imaging parameters in machine learning models.

METHODS

Consecutive adult patients with anterior circulation LVOs who were scanned with CT angiography (CTA) and CT perfusion were queried in this single-center, retrospective study. The favorable outcome was defined as a modified Rankin score (mRS) of 0-2 at 90 days. Predictor variables included only imaging parameters. CatBoost, XGBoost, and Random Forest were employed. Algorithms were evaluated using the area under the receiver operating characteristic curve (AUROC), the area under the precision-recall curve (AUPRC), accuracy, Brier score, recall, and precision. SHapley Additive exPlanations were implemented.

RESULTS

A total of 180 patients (102 female) were included, with a median age of 69.5. Ninety-two patients had an mRS between 0 and 2. The best algorithm in terms of AUROC was XGBoost (0.91). Furthermore, the XGBoost model exhibited a precision of 0.72, a recall of 0.81, an AUPRC of 0.83, an accuracy of 0.78, and a Brier score of 0.17. Multiphase CTA collateral score was the most significant feature in predicting the outcome.

CONCLUSIONS

Using only imaging parameters, our model had an AUROC of 0.91 which was superior to most previous studies, indicating that imaging parameters may be as accurate as conventional predictors. The multiphase CTA collateral score was the most predictive variable, highlighting the importance of collaterals.

The Role of Hyperdense Basilar Artery Sign in Predicting Outcome of Acute Basilar Artery Occlusion within Twelve Hours of Onset

BACKGROUND

The correlation between hyperdense basilar artery sign (HDBAS) and outcome after acute basilar artery occlusion (ABAO) is debated. Our objective was to determine the usefulness of HDBAS in predicting the outcomes of patients with ABAO after endovascular treatment (EVT), intravenous thrombolysis (IVT), and best medical treatment (BMT).

METHODS

The study participants were selected from the ATTENTION trial. The primary outcome of the study was a 90-day modified Rankin Scale (mRS) score, and the secondary outcome was the recanalization rate, any intracranial hemorrhage, and 90-day mortality.

RESULTS

The study comprised 276 participants, with cohorts for EVT (n = 188), IVT (n = 82), and BMT (n = 88). In the EVT cohort, HDBAS was not associated with 90-day mRS score (adjusted odds ratio [OR], 0.87; 95% confidence interval [CI], 0.51-1.48; P = 0.6029), the recanalization after 24 hours of onset (adjusted OR, 0.76; 95% CI, 0.30-3.61; P = 0.9422), and 90-day mortality (adjusted OR, 0.77; 95% CI, 0.41-1.46; P = 0.4238). In the IVT cohort, HDBAS was not associated with a 90-day mRS score (adjusted OR, 0.69; 95% CI, 0.31-1.56; P = 0.3742), the recanalization after 24 hours of onset (adjusted OR, 2.24; 95% CI, 0.47-10.78; P = 0.3132), and 90-day mortality (adjusted OR, 0.64; 95% CI, 0.26-1.57; P = 0.3264). Similarly, in the BMT cohort, HDBAS was not associated with 90-day mRS score (adjusted OR, 1.11; 95% CI, 0.47-2.63; P = 0.8152), the recanalization after 24 hours of onset (adjusted OR, 1.27; 95% CI, 0.40-4.02; P = 0.6874), and 90-day mortality (adjusted OR, 1.17; 95% CI, 0.46-2.96; P = 0.748).

CONCLUSIONS

HDBAS may not be a reliable predictor of outcomes for patients with ABAO, regardless of whether they received EVT, IVT, or BMT.

Absence of susceptibility vessel sign and hyperdense vessel sign in patients with cancer-related stroke

Background and aim

Identification of paraneoplastic hypercoagulability in stroke patients helps to guide investigations and prevent stroke recurrence. A previous study demonstrated an association between the absence of the susceptibility vessel sign (SVS) on brain MRI and active cancer in patients treated with mechanical thrombectomy. The present study aimed to confirm this finding and assess an association between the absence of the hyperdense vessel sign (HVS) on head CT and active cancer in all stroke patients.

Methods

SVS and HVS status on baseline imaging were retrospectively assessed in all consecutive stroke patients treated at a comprehensive stroke center between 2015 and 2020. Active cancer, known at the time of stroke or diagnosed within 1 year after stroke (occult cancer), was identified. Adjusted odds ratios (aOR) and their 95% confidence interval (CI) for the association between the thrombus imaging characteristics and cancer were calculated using multivariable logistic regression.

Results

Of the 2,256 patients with thrombus imaging characteristics available at baseline, 161 had an active cancer (7.1%), of which 36 were occult at the time of index stroke (1.6% of the total). The absence of SVS was associated with active cancer (aOR 3.14, 95% CI 1.45-6.80). No significance was reached for the subgroup of occult cancer (aOR 3.20, 95% CI 0.73-13.94). No association was found between the absence of HVS and active cancer (aOR 1.07, 95% CI 0.54-2.11).

Conclusion

The absence of SVS but not HVS could help to identify paraneoplastic hypercoagulability in stroke patients with active cancer and guide patient care.