Early Imaging Prediction of Malignant Cerebellar Edema Development in Acute Ischemic Stroke

Functional Outcomes in Conservatively vs Surgically Treated Cerebellar Infarcts

Importance

According to the current American Heart Association/American Stroke Association guidelines, decompressive surgery is indicated in patients with cerebellar infarcts that demonstrate severe cerebellar swelling. However, there is no universal definition of swelling and/or infarct volume(s) available to support a decision for surgery.

Objective

To evaluate functional outcomes in surgically compared with conservatively managed patients with cerebellar infarcts.

Design, Setting, and Participants

In this retrospective multicenter cohort study, patients with cerebellar infarcts treated at 5 tertiary referral hospitals or stroke centers within Germany between 2008 and 2021 were included. Data were analyzed from November 2020 to November 2023.

Exposures

Surgical treatment (ie, posterior fossa decompression plus standard of care) vs conservative management (ie, medical standard of care).

Main Outcomes and Measures

The primary outcome examined was functional status evaluated by the modified Rankin Scale (mRS) at discharge and 1-year follow-up. Secondary outcomes included the predicted probabilities for favorable outcome (mRS score of 0 to 3) stratified by infarct volumes or Glasgow Coma Scale score at admission and treatment modality. Analyses included propensity score matching, with adjustments for age, sex, Glasgow Coma Scale score at admission, brainstem involvement, and infarct volume.

Results

Of 531 included patients with cerebellar infarcts, 301 (57%) were male, and the mean (SD) age was 68 (14.4) years. After propensity score matching, a total of 71 patients received surgical treatment and 71 patients conservative treatment. There was no significant difference in favorable outcomes (ie, mRS score of 0 to 3) at discharge for those treated surgically vs conservatively (47 [66%] vs 45 [65%]; odds ratio, 1.1; 95% CI, 0.5-2.2; P > .99) or at follow-up (35 [73%] vs 33 [61%]; odds ratio, 1.8; 95% CI, 0.7-4.2; P > .99). In patients with cerebellar infarct volumes of 35 mL or greater, surgical treatment was associated with a significant improvement in favorable outcomes at 1-year follow-up (38 [61%] vs 3 [25%]; odds ratio, 4.8; 95% CI, 1.2-19.3; P = .03), while conservative treatment was associated with favorable outcomes at 1-year follow-up in patients with infarct volumes of less than 25 mL (2 [34%] vs 218 [74%]; odds ratio, 0.2; 95% CI, 0-1.0; P = .047).

Conclusions and Relevance

Overall, surgery was not associated with improved outcomes compared with conservative management in patients with cerebellar infarcts. However, when stratifying based on infarct volume, surgical treatment appeared to be beneficial in patients with larger infarct volumes, while conservative management appeared favorable in patients with smaller infarct volumes.

Prognostic value of the baseline magnetic resonance score in patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy

AIM

To investigate the prognostic value of the composite posterior circulation Acute Stroke Prognosis Early Computed tomography (CT) Score (ASPECTS)-Collaterals (pcASCO) score, which combines diffusion-weighted imaging (DWI) posterior circulation ASPECTS (pcASPECTS) and the magnetic resonance angiography (MRA)-collateral circulation score at baseline among patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.

MATERIALS AND METHODS

Patients with acute posterior circulation ischaemic stroke who underwent mechanical thrombectomy were analysed retrospectively. The DWI-pcASPECTS and MRA-collateral circulation score before treatment and the modified Rankin Scale (mRS) at 90 days after treatment were used as the endpoints. An mRS ≤2 was defined as a good prognosis, and an mRS ≥3 was defined as a poor prognosis. Multivariate logistic regression was used to analyse independent predictors of functional outcome 90 days after mechanical thrombectomy.

RESULTS

Mechanical thrombectomy was performed in 57 patients; 38 patients had a good prognosis, 19 patients had a poor prognosis, and 33 patients were successfully recanalised. Univariate logistic regression found that National Institute of Health Stroke Scale (NIHSS) score (OR: 1.18, p<0.001), pcASPECTS (OR: 1.91, p=0.028) and pcASCO score (OR: 0.51, p=0.001) were factors of good functional outcome. Receiver operating characteristic curve (ROC curve) analysis showed that the diagnostic efficiency of the NIHSS and pcASCO was better (AUC = 0.88, 0.83, p<0.05) than that of the pcASPECTS (AUC = 0.65). The prediction model was established by age, NIHSS, and pcASCO, and the diagnostic efficiency of the prediction model was better (AUC = 0.94).

CONCLUSIONS

The composite MR-pcASCO score can be used as an important predictor of the prognosis of patients with acute posterior circulation ischaemic stroke after mechanical thrombectomy.

Advancing edema detection: Harnessing the power of machine learning and near infrared spectroscopy for cerebral and cerebellar edema assessment

Edema, characterized by brain swelling, is a common response observed in various brain injuries. Timely detection of edema is crucial to mitigate the associated risks and improve patient care. This study evaluates the efficacy of CEREBO®, a non-invasive machine learning-powered near-infrared spectroscopy (mNIRS) based device, in detecting edema. The study was conducted on 234 participants with suspected head injuries who underwent simultaneous CEREBO® scans and CT head scans. The results of the study showed that CEREBO® effectively identified edematous lobes, achieving a sensitivity of 95.7%, specificity of 97%, and accuracy of 96.9% for cases with intracranial hemorrhage (ICH). Additionally, for cases without ICH, the device exhibited a sensitivity of 100%, specificity of 97.2%, and accuracy of 97.2%. Two cases were reported where CEREBO® failed to detect edematous ICH. The study highlights the potential of CEREBO® as a valuable tool for early detection of pre-symptomatic edema and ICH, enabling timely interventions and improved patient care. The findings support the reliability of near-infrared spectroscopy as a diagnostic modality for edema.

Cerebellar Stroke Score and Grading Scale for the Prediction of Mortality and Outcomes in Ischemic Cerebellar Stroke

BACKGROUND

Several individual predictors for outcomes in patients with cerebellar stroke (CS) have been previously identified. There is, however, no established clinical score for CS. Therefore, the aim of this study was to develop simple and accurate grading scales for patients with CS in an effort to better estimate mortality and outcomes.

METHODS

This multicentric retrospective study included 531 patients with ischemic CS presenting to 5 different academic neurosurgical and neurological departments throughout Germany between 2008 and 2021. Logistic regression analysis was performed to determine independent predictors related to 30-day mortality and unfavorable outcome (modified Rankin Scale score of 4-6). By weighing each parameter via calculation of regression coefficients, an ischemic CS-score and CS-grading scale (CS-GS) were developed and internally validated.

RESULTS

Independent predictors for 30-day mortality were aged ≥70 years (odds ratio, 5.2), Glasgow Coma Scale score 3 to 4 at admission (odds ratio, 2.6), stroke volume ≥25 cm3 (odds ratio, 2.7), and involvement of the brain stem (odds ratio, 3.9). When integrating each parameter into the CS-score, age≥70 years and brain stem stroke were assigned 2 points, Glasgow Coma Scale score 3 to 4, and stroke volume≥25 cm3 1 point resulting in a score ranging from 0 to 6. CS-score of 0, 1, 2, 3, 4, 5, and 6 points resulted in 30-day mortality of 1%, 6%, 6%, 17%, 21%, 55%, and 67%, respectively. Independent predictors for 30-day unfavorable outcomes consisted of all components of the CS-score with an additional variable focused on comorbidities (CS-GS). Except for Glasgow Coma Scale score 3 to 4 at admission, which was assigned 3 points, all other parameters were assigned 1 point resulting in an overall score ranging from 0 to 7. CS-GS of 0, 1, 2, 3, 4, 5, 6, and 7 points resulted in 30-day unfavorable outcome of 1%, 17%, 33%, 40%, 50%, 80%, 77%, and 100%, respectively. Both 30-day mortality and unfavorable outcomes increased with increasing CS-score and CS-GS (P<0.001).

CONCLUSIONS

The CS-score and CS-GS are simple and accurate grading scales for the prediction of 30-day mortality and unfavorable outcome in patients with CS. While the score systems proposed here may not directly impact treatment decisions, it may help discuss mortality and outcome with patients and caregivers.

Automated Supra- and Infratentorial Brain Infarct Volume Estimation on Diffusion Weighted Imaging Using the RAPID Software

Purpose

The present computerized techniques have limits to estimate the ischemic lesion volume especially in vertebrobasilar ischemia (VBI) automatically. We investigated the ability of the RAPID AI (RAPID) software on diffusion-weighted imaging (DWI) to estimate the infarct size in VBI in comparison to supratentorial ischemia (STI).

Methods

Among 123 stroke patients (39 women, 84 men, mean age 66 ± 11 years) having undergone DWI, 41 had had a VBI and 82 a STI. The infarct volume calculation by RAPID was compared to volume calculations by 2 neurologists using the ABC/2 method. For inter-reader and between-method analysis intraclass correlation coefficient (ICC), area under the curve (AUC) estimations, and Bland–Altman plots were used.

Results

ICC between the two neurologists and each neurologist and RAPID were &gt;0.946 (largest 95% CI boundaries 0.917–0.988) in the STI group, and &gt; 0.757 (95% CI boundaries between 0.544 and 0.982) in the VBI group. In the STI group, AUC values ranged between 0.982 and 0.999 (95% CI 0.971–1) between the 2 neurologists and between 0.875 and 1 (95% CI 0.787–1) between the neurologists and RAPID; in the VBI group, they ranged between 0.925 and 0.965 (95% CI 0.801–1) between the neurologists, and between 0.788 and 0.931 (95% CI 0.663–1) between RAPID and the neurologists. Compared to the visual DWI interpretation by the neurologists, RAPID did not recognize a substantial number of infarct volumes of ≤ 2 ml.

Conclusion

The ability of the RAPID software to depict strokes in the vertebrobasilar artery system seems close to its ability in the supratentorial brain tissue. However, small lesion volumes ≤ 2 ml remain still undetected in both brain areas.

Neutrophil Count Predicts Malignant Cerebellar Edema and Poor Outcome in Acute Basilar Artery Occlusion Receiving Endovascular Treatment: A Nationwide Registry-Based Study

Background

Acute basilar artery occlusion (ABAO) is known to have a poor outcome with a high rate of morbidity and mortality despite endovascular treatment (EVT), highlighting the necessities of exploring factors to limit the efficacy of EVT in these patients. Cerebellar infarctions in ABAO might progress to malignant cerebellar edema (MCE), a life-threatening complication after reperfusion, posing a secondary injury to the brainstem by mass effects. Therefore, the present research aimed to explore the impacts of MCE on a long-term outcome and investigate the prognostic factors for MCE among ABAO after EVT.

Methods

In the national BASILAR registry, a total of 329 ABO patients with cerebellar infarctions treated by EVT met the inclusion criteria. The presence of MCE defined by the Jauss scale ≥4 points, was evaluated on the computed tomography performed 72 h after EVT. The adjusted odds ratio and 95% CI were obtained by logistic regression models. A favorable outcome was defined as a 90-day modified Rankin Scale score of 0-3.

Results

MCE was statistically associated with the decreased incidence of a favorable outcome [adjusted odds ratio, 0.35(95% CI, 0.18-0.68), P=0.002]. The baseline National Institutes of Health Stroke Scale score, collateral circulation, neutrophil count at admission, and recanalization status were predictors for MCE and a favorable functional status at 90 days (all P<0.05). Among all inflammatory factors, the neutrophil count achieved the highest accuracy, sensitivity, and specificity for MCE. Adding the neutrophil count status into the baseline model obviously enhanced its prediction ability for MCE and favorable outcome by increasing the area under curve and achieving both net reclassification and integrated discrimination improvement (all P<0.05). Mediation analysis indicated that MCE mediated the association between the increased neutrophil count and worse functional outcome (P=0.026).

Discussion

MCE acted essential roles in worsening prognosis for ABAO after EVT. A high neutrophil count at admission was linked to MCE and a poor outcome among ABAO patients, which could be further incorporated into the clinical decision-making system and guide immunomodulation therapy.

New imaging score for outcome prediction in basilar artery occlusion stroke

OBJECTIVE

In ischemic posterior circulation stroke, the utilization of standardized image scores is not established in daily clinical practice. We aimed to test a novel imaging score that combines the collateral status with the rating of the posterior circulation Acute Stroke Prognosis Early CT score (pcASPECTS). We hypothesized that this score (pcASCO) predicts functional outcome and malignant cerebellar edema (MCE).

METHODS

Ischemic stroke patients with acute BAO who received multimodal-CT and underwent thrombectomy on admission at two comprehensive stroke centers were analyzed. The posterior circulation collateral score by van der Hoeven et al was added to the pcASPECTS to define pcASCO as a 20-point score. Multivariable logistic regression analyses were performed to predict functional independence at day 90, assessed using modified Rankin Scale scores, and occurrence of MCE in follow-up CT using the established Jauss scale score as endpoints.

RESULTS

A total of 118 patients were included, of which 84 (71%) underwent successful thrombectomy. Based on receiver operating characteristic curve analysis, pcASCO ≥ 14 classified functional independence with higher discriminative power (AUC: 0.83, 95%CI: 0.71-0.91) than pcASPECTS (AUC: 0.74). In multivariable logistic regression analysis, pcASCO was significantly and independently associated with functional independence (aOR: 1.91, 95%CI: 1.25-2.92, p = 0.003), and MCE (aOR: 0.71, 95%CI: 0.53-0.95, p = 0.02).

CONCLUSION

The pcASCO could serve as a simple and feasible imaging tool to assess BAO stroke patients on admission and might be tested as a complementary tool to select patients for thrombectomy in uncertain situations, or to predict clinical outcome.

KEY POINTS

• The neurological assessment of basilar artery occlusion stroke patients can be challenging and there are yet no validated imaging scores established in daily clinical practice. • The pcASCO combines the rating of early ischemic changes with the status of the intracranial posterior circulation collaterals. • The pcASCO showed high diagnostic accuracy to predict functional outcome and malignant cerebellar edema and could serve as a simple and feasible imaging tool to support treatment selection in uncertain situations, or to predict clinical outcome.

MRI Radiomics Features From Infarction and Cerebrospinal Fluid for Prediction of Cerebral Edema After Acute Ischemic Stroke

Neuroimaging biomarkers that predict the edema after acute stroke may help clinicians provide targeted therapies and minimize the risk of secondary injury. In this study, we applied pretherapy MRI radiomics features from infarction and cerebrospinal fluid (CSF) to predict edema after acute ischemic stroke. MRI data were obtained from a prospective, endovascular thrombectomy (EVT) cohort that included 389 patients with acute stroke from two centers (dataset 1, n = 292; dataset 2, n = 97), respectively. Patients were divided into edema group (brain swelling and midline shift) and non-edema group according to CT within 36 h after therapy. We extracted the imaging features of infarct area on diffusion weighted imaging (DWI) (abbreviated as DWI), CSF on fluid-attenuated inversion recovery (FLAIR) (CSF_FLAIR) and CSF on DWI (CSF_DWI), and selected the optimum features associated with edema for developing models in two forms of feature sets (DWI + CSF_FLAIR and DWI + CSF_DWI) respectively. We developed seven ML models based on dataset 1 and identified the most stable model. External validations (dataset 2) of the developed stable model were performed. Prediction model performance was assessed using the area under the receiver operating characteristic curve (AUC). The Bayes model based on DWI + CSF_FLAIR and the RF model based on DWI + CSF_DWI had the best performances (DWI + CSF_FLAIR: AUC, 0.86; accuracy, 0.85; recall, 0.88; DWI + CSF_DWI: AUC, 0.86; accuracy, 0.84; recall, 0.84) and the most stability (RSD% in DWI + CSF_FLAIR AUC: 0.07, RSD% in DWI + CSF_DWI AUC: 0.09), respectively. External validation showed that the AUC of the Bayes model based on DWI + CSF_FLAIR was 0.84 with accuracy of 0.77 and area under precision-recall curve (auPRC) of 0.75, and the AUC of the RF model based on DWI + CSF_DWI was 0.83 with accuracy of 0.81 and the auPRC of 0.76. The MRI radiomics features from infarction and CSF may offer an effective imaging biomarker for predicting edema.

Higher baseline blood glucose is associated with reduced likelihood for successful recanalization in patients with basilar artery occlusion

Purpose

Evidence regarding the effect of mechanical thrombectomy (MT) of basilar artery occlusion (BAO) stroke is yet sparse. As successful recanalization has been suggested as major determinant of outcome, the early identification of modifiable factors associated with successful recanalization could be of importance to improve functional outcome. Hyperglycemia has been associated with enhanced thrombin generation and unfavorably altered clot features.

Objective

We hypothesized that serum baseline glucose is associated with likelihood of vessel recanalization mediated by collateral quality and clot burden in BAO stroke.

Methods

BAO stroke patients who received multimodal CT on admission were analyzed. The association of vessel recanalization defined using modified Thrombolysis in cerebral infarction scale (mTICI) scores 2b-3, and baseline imaging and clinical parameters were tested in logistic regression analyses. Collateral quality and clot burden were evaluated using the Basilar Artery on CT-Angiography (BATMAN) score.

Results

Out of 117 BAO patients, 91 patients (78%) underwent MT. In 70 patients (77%), successful recanalization could be achieved (mTICI 2b/3). In multivariable logistic regression analysis, only a higher BGL (aOR 0.97, 95% CI 0.96–0.99, p = 0.03) and higher BATMAN score (aOR 1.77, 95% CI 1.11–2.82, p = 0.02) were independently associated with vessel recanalization. Application of alteplase, or time from symptom onset-imaging revealed no independent association with recanalization status.

Conclusion

Higher BGL was significantly associated with reduced likelihood for recanalization success besides BATMAN score as a measure of collateral quality and clot burden. BGL could be tested as a modifiable parameter to increase likelihood for recanalization in BAO stroke, aiming to improve functional outcome.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00415-021-10948-1.

Rate of Infarct-Edema Growth on CT Predicts Need for Surgical Intervention and Clinical Outcome in Patients with Cerebellar Infarction

BACKGROUND

Up to 20% of patients with cerebellar infarcts will develop malignant edema and deteriorate clinically. Radiologic measures, such as initial infarct size, aid in identifying individuals at risk. Studies of anterior circulation stroke suggest that mapping early edema formation improves the ability to predict deterioration; however, the kinetics of edema in the posterior fossa have not been well characterized. We hypothesized that faster edema growth within the first hours after acute cerebellar stroke would be an indicator for individuals requiring surgical intervention and those with worse neurological outcomes.

METHODS

Consecutive patients admitted to the neurological intensive care unit with acute cerebellar infarction were retrospectively identified. Hypodense regions of infarct and associated edema, "infarct-edema", were delineated by using ABC/2 for all computed tomography (CT) scans up to 14 days from last known well. To examine how rate of infarct-edema growth varied across clinical variables and surgical intervention status, nonlinear and linear mixed-effect models were performed over 2 weeks and 2 days, respectively. In patients with at least two CT scans, multivariable logistic regression examined clinical and radiological predictors of surgical intervention (defined as extraventricular drainage and/or posterior fossa decompression) and poor clinical outcome (discharge to skilled nursing facility, long-term acute care facility, hospice, or morgue).

RESULTS

Of 150 patients with acute cerebellar infarction, 38 (25%) received surgical intervention and 45 (30%) had poor clinical outcome. Age, admission National Institutes of Health Stroke Scale (NIHSS) score, and baseline infarct-edema volume did not differ, but bilateral/multiple vascular territory involvement was more frequent (87% vs. 50%, p < 0.001) in the surgical group than that in the medical intervention group. On 410 serial CTs, infarct-edema volume progressed rapidly over the first 2 days, followed by a subsequent plateau. Of 112 patients who presented within two days, infarct-edema growth rate was greater in the surgical group (20.1 ml/day vs. 8.01 ml/day, p = 0.002). Of 67 patients with at least two scans, after adjusting for baseline infarct-edema volume, vascular territory, and NIHSS, infarct-edema growth rate over the first 2 days (odds ratio 2.55; 95% confidence interval 1.40-4.65) was an independent, and the strongest, predictor of surgical intervention. Further, early infarct-edema growth rate predicted poor clinical outcome (odds ratio 2.20; 95% confidence interval 1.30-3.71), independent of baseline infarct-edema volume, brainstem infarct, and NIHSS.

CONCLUSIONS

Early infarct-edema growth rate, measured via ABC/2, is a promising biomarker for identifying the need for surgical intervention in patients with acute cerebellar infarction. Additionally, it may be used to facilitate discussions regarding patient prognosis.

Posterior circulation collateral flow modifies the effect of thrombectomy on outcome in acute basilar artery occlusion

BACKGROUND

In basilar artery occlusion stroke, the impact of the collateral circulation on infarct progression in the context of endovascular treatment is yet poorly studied.

AIM

This study investigates the impact of the posterior circulation collateral score (PCCS) on functional outcome according to the extent of early ischemic changes and treatment. We hypothesized that the presence of collaterals, quantified by the PCCS, mediates the effect of endovascular treatment on functional outcome in patients with acute basilar artery occlusion.

METHODS

In this multicenter observational study, patients with basilar artery occlusion and admission computed tomography were analyzed. At baseline, Posterior circulation Acute Stroke Prognosis Early Computed Tomography score (pcASPECTS) was assessed and PCCS was quantified using an established 10-point grading system. Logistic regression analyses were performed to identify factors associated with good functional outcome (modified Rankin Scale scores 0-2 at day 90).

RESULTS

A total of 151 patients were included, of which 112 patients (74%) underwent endovascular treatment. In patients with a better PCCS (>5), the rate of good outcome was significantly higher (55% vs. 11%; p = 0.001). After adjusting for PCCS, vessel recanalization was significantly associated with improved functional outcome (aOR: 4.53, 95%CI: 1.25-16.4, p = 0.02), while there was no association between recanalization status and outcome in univariable analysis. Patients with low pcASPECTS generally showed very poor outcomes (mean modified Rankin Scale score 5.3, 95%CI: 4.9-5.8).

CONCLUSION

PCCS modified the effect of recanalization on functional outcome, particularly in patients with less pronounced ischemic changes in admission computed tomography. These results should be validated to improve patient selection for endovascular treatment in basilar artery occlusion, particularly in uncertain indications, or to triage patients at risk for very poor outcomes.

Early space-occupying cerebellar oedema requiring decompressive craniectomy following a clinically minor stroke

We describe a patient presented with clinically a small cerebellar ischaemic stroke but required emergency decompression within 24 hours of symptoms onset after incidental finding of severe mass effect on imaging without any change in her mild clinical symptoms. Her initial multimodal acute stroke imaging, non-contrast CT of the brain and CT angiography from aortic arch to vertex were normal. CT perfusion showed a very small deficit only. The malignant mass effect was picked on an MRI scan performed routinely as part of a clinical trial, 32 hours after stroke. Our case highlights stroke evolution, and mass effect may be insidious and faster than anticipated in the posterior fossa. Cerebellar stroke of any severity diagnosed clinically and radiologically may benefit from routine follow-up imaging at 24 hours from onset.

Diagnostic and prognostic utility of computed tomography perfusion imaging in posterior circulation acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Computed tomography perfusion (CTP) imaging could be useful in the diagnosis of posterior circulation stroke (PCS) and in identifying patients who are likely to experience favorable outcomes following reperfusion therapy. The current study sought to investigate the diagnostic and prognostic capability of CTP in acute ischemic PCS by performing a systematic review and meta-analysis.

METHODS

Medline/PubMed and the Cochrane Library were searched using the terms: "posterior circulation", "CT perfusion", "acute stroke", and "reperfusion therapy". The following studies were included: (1) patients aged 18 years or above; (2) patients diagnosed with PCS; and (3) studies with good methodological design. Pooled sensitivity (SENS), specificity (SPEC), and area under the curve (AUC), computed using the summary receiver operating characteristic (SROC) curves, were used to determine diagnostic/prognostic capability.

RESULTS

Out of 14 studies included, a meta-analysis investigating diagnostic accuracy of CTP was performed on nine studies. Meta-analysis demonstrated comparable diagnostic accuracy of CTP to non-contrast computed tomography (NCCT) (AUC_CTP : 0.90 [95% CI 0.87-0.92] vs. AUC_NCCT : 0.96 [95% CI 0.94-0.97]); however, with higher pooled sensitivity (SENS_CTP : 72% [95% CI 57%-83%] vs. SENS_NCCT : 25% [95% CI 17%-35%]) and lower specificity (SPEC_CTP : 90% [95% CI 83%-94%] vs. SPEC_NCCT : 96% [95% CI 95%-98%]) than NCCT. Meta-analysis to determine prognostic capability of CTP could not be performed.

CONCLUSIONS

CTP has limited diagnostic utility in acute ischemic PCS, albeit with superior diagnostic sensitivity and inferior diagnostic specificity to NCCT. Further prospective trials are required to validate the prognostic capability of CTP-derived parameters in PCS.

Computed Tomography Perfusion Deficit Volumes Predict Functional Outcome in Patients With Basilar Artery Occlusion

[Figure: see text].

Early Prediction of Malignant Cerebellar Edema in Posterior Circulation Stroke Using Quantitative Lesion Water Uptake

BACKGROUND

Malignant cerebellar edema (MCE) is a life-threatening complication of ischemic posterior circulation stroke that requires timely diagnosis and management. Yet, there is no established imaging biomarker that may serve as predictor of MCE. Early edematous water uptake can be determined using quantitative lesion water uptake, but this biomarker has only been applied in anterior circulation strokes.

OBJECTIVE

To test the hypothesis that lesion water uptake in early posterior circulation stroke predicts MCE.

METHODS

A total 179 patients with posterior circulation stroke and multimodal admission CT were included. A total of 35 (19.5%) patients developed MCE defined by using an established 10-point scale in follow-up CT, of which ≥4 points are considered malignant. Posterior circulation net water uptake (pcNWU) was quantified in admission CT based on CT densitometry and compared with posterior circulation Acute Stroke Prognosis Early CT Score (pc-ASPECTS) as predictor of MCE using receiver operating curve (ROC) analysis and logistic regression analysis.

RESULTS

Acute pcNWU within the early ischemic lesion was 24.6% (±8.4) for malignant and 7.2% (±7.4) for nonmalignant infarctions, respectively (P < .0001). Based on ROC analysis, pcNWU above 14.9% identified MCE with high discriminative power (area under the curve: 0.94; 95% CI: 0.89-0.97). Early pcNWU (odds ratio [OR]: 1.28; 95% CI: 1.15-1.42, P < .0001) and pc-ASPECTS (OR: 0.71, 95% CI: 0.53-0.95, P = .02) were associated with MCE, adjusted for age and recanalization status.

CONCLUSION

Quantitative pcNWU in early posterior circulation stroke is an important marker for MCE. Besides pc-ASPECTS, lesion water uptake measurements may further support identifying patients at risk for MCE at an early stage indicating stricter monitoring and consideration for further therapeutic measures.

Multimodal Computed Tomography Increases the Detection of Posterior Fossa Strokes Compared to Brain Non-contrast Computed Tomography

Aims: Multimodal computed tomography (mCT) (non-contrast CT, CT angiography, and CT perfusion) is not routinely used to assess posterior fossa strokes. We described the area under the curve (AUC) of brain NCCT, WB-CTP automated core-penumbra maps and comprehensive CTP analysis (automated core-penumbra maps and all perfusion maps) for posterior fossa strokes. Methods: We included consecutive patients with signs and symptoms of posterior fossa stroke who underwent acute mCT and follow up magnetic resonance diffusion weighted imaging (DWI). Multimodal CT images were reviewed blindly and independently by two stroke neurologists and area under the receiver operating characteristic curve (AUC) was used to compare imaging modalities. Results: From January 2014 to December 2019, 83 patients presented with symptoms suggestive of posterior fossa strokes and had complete imaging suitable for inclusion (49 posterior fossa strokes and 34 DWI negative patients). For posterior fossa strokes, comprehensive CTP analysis had an AUC of 0.68 vs. 0.62 for automated core-penumbra maps and 0.55 for NCCT. For cerebellar lesions >5 mL, the AUC was 0.87, 0.81, and 0.66, respectively. Conclusion: Comprehensive CTP analysis increases the detection of posterior fossa lesions compared to NCCT and should be implemented as part of the routine imaging assessment in posterior fossa strokes.

Cerebellar Necrosectomy Instead of Suboccipital Decompression: A Suitable Alternative for Patients with Space-Occupying Cerebellar Infarction

OBJECTIVE

Space-occupying cerebellar ischemic strokes (SOCSs) often lead to neurological deterioration and require surgical intervention to release pressure from the posterior fossa. Current guidelines recommend suboccipital decompressive craniectomy (SDC) with dural expansion when medical therapy is not sufficient. However, no good-quality evidence is available to support this surgical practice, and the surgical timing and technique both remain controversial. We have described an alternative to SDC, surgical evacuation of infarcted tissue (necrosectomy) and its clinical outcomes.

METHODS

In the present retrospective, single-center study, 34 consecutive patients with SOCS undergoing necrosectomy via osteoplastic craniotomy were included. The patient characteristics and radiological findings were evaluated. To differentiate the effects of age on the functional outcomes, the patients were divided into 2 groups (group I, age ≤60 years; and group II, age >60 years). Functional outcomes were assessed using the Glasgow outcome scale, modified Rankin scale, and Barthel index at discharge and 30 days postoperatively.

RESULTS

In our cohort, we observed overall mortality of 21%, with good functional outcomes (Glasgow outcome scale score ≥4) for 76% of the patients. No statistically significant differences in mortality or functional outcomes were observed between the 2 patient groups. Comparing our data with a recent meta-analysis of SDC, the number of adverse events and unfavorable outcome showed equipoise between the 2 treatment modalities.

CONCLUSIONS

Necrosectomy appears to be a suitable alternative to SDC for SOCS, achieving comparable mortality and functional outcomes. Further trials are necessary to evaluate which surgical technique is more beneficial in the setting of SOCSs.

Incremental Value of Computed Tomography Perfusion for Final Infarct Prediction in Acute Ischemic Cerebellar Stroke

Background

The diagnosis of ischemic cerebellar stroke is challenging because of nonspecific symptoms and very limited accuracy of commonly applied computed tomography (CT) imaging. Advances in CT perfusion imaging provide increasing value in the detection of posterior circulation stroke, but the prognostic value remains unclear. We aimed to identify imaging parameters that predict morphologic outcome in cerebellar stroke patients using advanced CT including whole‐brain CT perfusion (WB‐CTP).

Methods and Results

We selected all subjects with cerebellar WB‐CTP perfusion deficits and follow‐up‐confirmed cerebellar infarction from a consecutive cohort with suspected stroke who underwent WB‐CTP. Posterior‐circulation‐Acute‐Stroke‐Prognosis‐Early‐CT‐Score (pc‐ASPECTS) was determined on noncontrast CT, CT angiography source images, and on parametric WB‐CTP maps. Cerebellar perfusion deficit volumes on all maps and the final infarction volume on follow‐up imaging were quantified. Uni‐ and multivariate regression analyses were performed. Sixty patients fulfilled the inclusion criteria. pc‐ASPECTS on CT angiography source images (ß, −9.239; 95% CI, −14.220 to −4.259; P<0.001) and cerebral blood flow deficit volume (ß, 0.886; 95% CI, 0.684 to 1.089; P<0.001) were significantly associated with final infarction volume in univariate linear regression analysis. The association of cerebral blood flow deficit volume (ß, 0.830; 95% CI, 0.605–1.055; P<0.001) was confirmed in a multivariate linear regression model adjusted for age, sex, pc‐ASPECTS on noncontrast CT, and CT angiography source images and the National Institutes of Health Stroke Scale score on admission. No other clinical or imaging parameters were associated with cerebellar stroke final infarction volume (P>0.05).

Conclusions

In contrast to noncontrast CT and CT angiography, WB‐CTP imaging contains prognostic information for morphologic outcome in patients with acute cerebellar stroke.