Uncommon Causes of Nontraumatic Intracerebral Hemorrhage.

Nontraumatic intracerebral hemorrhage is an important health issue. Although common causes such as hypertension and cerebral amyloid angiopathy predominantly affect the elderly, there exists a spectrum of uncommon etiologies that contribute to the overall incidence of intracerebral hemorrhage. The identification of these rare causes is essential for targeted clinical management, informed prognostication, and strategic secondary prevention where relevant. This topical review explores the uncommon intracerebral hemorrhage causes and provides practical clues for their clinical and imaging identification. By expanding the clinician's differential diagnosis, this review aims to bridge the gap between standard intracerebral hemorrhage classification systems and the nuanced reality of clinical practice.

Code ICH: A Call to Action.

Intracerebral hemorrhage is the most serious type of stroke, leading to high rates of severe disability and mortality. Hematoma expansion is an independent predictor of poor functional outcome and is a compelling target for intervention. For decades, randomized trials aimed at decreasing hematoma expansion through single interventions have failed to meet their primary outcomes of statistically significant improvement in neurological outcomes. A wide range of evidence suggests that ultra-early bundled care, with multiple simultaneous interventions in the acute phase, offers the best hope of limiting hematoma expansion and improving functional recovery. Patients with intracerebral hemorrhage who fail to receive early aggressive care have worse outcomes, suggesting that an important treatment opportunity exists. This consensus statement puts forth a call to action to establish a protocol for Code ICH, similar to current strategies used for the management of acute ischemic stroke, through which early intervention, bundled care, and time-based metrics have substantially improved neurological outcomes. Based on current evidence, we advocate for the widespread adoption of an early bundle of care for patients with intracerebral hemorrhage focused on time-based metrics for blood pressure control and emergency reversal of anticoagulation, with the goal of optimizing the benefit of these already widely used interventions. We hope Code ICH will endure as a structural platform for continued innovation, standardization of best practices, and ongoing quality improvement for years to come.

Intensive Blood Pressure Reduction is Associated with Reduced Hematoma Growth in Fast Bleeding Intracerebral Hemorrhage.

OBJECTIVE: Patients with spontaneous intracerebral hemorrhage (ICH) at the highest risk of hematoma growth are those with the most potential to benefit from anti-expansion treatment. Large clinical trials have not definitively shown a clear benefit of blood pressure (BP) reduction. We aim to determine whether intensive blood pressure reduction could benefit patients with fast bleeding ICH. METHODS: An exploratory analysis of data from the Antihypertensive Treatment of Acute Cerebral Hemorrhage 2 (ATACH-2) randomized controlled trial was performed. In order to capture not just early bleeding (even if a small amount), but the rate of bleeding (ml/hour), we restricted the study to "Fast bleeding ICH," defined as an ICH volume/onset to computed tomography (CT) time >5 ml/hr. Hematoma growth, as defined as an increase of hematoma volume > 33% between baseline and 24 hours. RESULTS: A total of 940 patients were included (mean age = 62.1 years, 61.5% men), of whom 214 (22.8%) experienced hematoma expansion. Of these, 567 (60.3%) met the definition of "fast bleeding" with baseline ICH volume/time to presentation of at least 5 ml/hr. Intensive BP reduction was associated with a significantly lower rate of hematoma growth in fast bleeding patients (20.6% vs 31.0%, p = 0.005). In a subgroup of 266 (46.9%) fast-bleeding patients who received treatment within 2 hours after symptom onset, intensive BP lowering was associated with improved functional independence (odds ratio [OR] = 1.98, 95% confidence interval [CI] = 1.06-3.69, p = 0.031). INTERPRETATION: Our results suggest that early use of intensive BP reduction may reduce hematoma growth and improve outcome in fast bleeding patients. ANN NEUROL 2023.

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.

Clinical and imaging manifestations of intracerebral hemorrhage in brain tumors and metastatic lesions: a comprehensive overview.

PURPOSE: This observational study aims to provide a detailed clinical and imaging characterization/workup of acute intracerebral hemorrhage (ICH) due to either an underlying metastasis (mICH) or brain tumor (tICH) lesion. METHODS: We conducted a retrospective, single-center study, evaluating patients presenting with occult ICH on initial CT imaging, classified as tICH or mICH on follow-up MRI imaging according to the H-Atomic classification. Demographic, clinical and radiological data were reviewed. RESULTS: We included 116 patients (tICH: 20/116, 17.24%; mICH: 96/116, 82.76%). The most common malignancies causing ICH were lung cancer (27.59%), malignant melanoma (18.10%) and glioblastoma (10.34%). The three most common stroke-like symptoms observed were focal deficit (62/116, 53.45%), dizziness (42/116, 36.21%) and cognitive impairment (27/116, 23.28%). Highest mICH prevalence was seen in the occipital lobe (mICH: 28.13%, tICH: 0.00%; p = 0.004) with tICH more in the corpus callosum (tICH: 10.00%, mICH: 0.00%; p = 0.029). Anticoagulation therapy was only frequent in mICH patients (tICH: 0.00%, mICH: 5.21%; p = 0.586). Hemorrhage (tICH: 12682 mm3, mICH: 5708 mm3, p = 0.020) and edema volumes (tICH: 49389 mm3, mICH: 20972 mm3, p = 0.035) were significantly larger within tICH patients. CONCLUSION: More than half of the patients with neoplastic ICH exhibited stroke-like symptoms. Lung cancer was most common in mICH, glioblastoma in tICH. While clinical presentations were similar, significant differences in tumor location and treatments were discernible.

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.

Predictors and Prognostic Impact of Hematoma Expansion in Infratentorial Cerebral Hemorrhage.

BACKGROUND: Hematoma expansion (HE) is common and predicts poor outcome in patients with supratentorial intracerebral hemorrhage (ICH). We investigated the predictors and prognostic impact of HE in infratentorial ICH. METHODS: We conducted a retrospective analysis of patients with brainstem and cerebellar ICH admitted at seven sites. Noncontrast computed tomography images were analyzed for the presence of hypodensities according to validated criteria, defined as any hypodense region strictly encapsulated within the hemorrhage with any shape, size, and density. Occurrence of HE (defined as > 33% and/or > 6-mL growth) and mortality at 90 days were the outcomes of interest. Their predictors were investigated using logistic regression with backward elimination at p < 0.1. Logistic regression models for HE were adjusted for baseline ICH volume, antiplatelet and anticoagulant treatment, onset to computed tomography time, and presence of hypodensities. The logistic regression model for mortality accounted for the ICH score and HE. RESULTS: A total of 175 patients were included (median age 75 years, 40.0% male), of whom 38 (21.7%) had HE and 43 (24.6%) died within 90 days. Study participants with HE had a higher frequency of hypodensities (44.7 vs. 24.1%, p = 0.013), presentation within 3 h from onset (39.5 vs. 24.8%, p = 0.029), and 90-day mortality (44.7 vs. 19.0%, p = 0.001). Hypodensities remained independently associated with HE after adjustment for confounders (odds ratio 2.44, 95% confidence interval 1.13-5.25, p = 0.023). The association between HE and mortality remained significant in logistic regression (odds ratio 3.68, 95% confidence interval 1.65-8.23, p = 0.001). CONCLUSION: Early presentation and presence of noncontrast computed tomography hypodensities were independent predictors of HE in infratentorial ICH, and the occurrence of HE had an independent prognostic impact in this population.

Differences in Trunk Acceleration-Derived Gait Indexes in Stroke Subjects with and without Stroke-Induced Immunosuppression.

Background: Stroke-induced immunosuppression (SII) represents a negative rehabilitative prognostic factor associated with poor motor performance at discharge from a neurorehabilitation unit (NRB). This study aims to evaluate the association between SII and gait impairment at NRB admission. Methods: Forty-six stroke patients (65.4 ± 15.8 years, 28 males) and 42 healthy subjects (HS), matched for age, sex, and gait speed, underwent gait analysis using an inertial measurement unit at the lumbar level. Stroke patients were divided into two groups: (i) the SII group was defined using a neutrophil-to-lymphocyte ratio ≥ 5, and (ii) the immunocompetent (IC) group. Harmonic ratio (HR) and short-term largest Lyapunov's exponent (sLLE) were calculated as measures of gait symmetry and stability, respectively. Results: Out of 46 patients, 14 (30.4%) had SII. HR was higher in HS when compared to SII and IC groups (p < 0.01). HR values were lower in SII when compared to IC subjects (p < 0.01). sLLE was lower in HS when compared to SII and IC groups in the vertical and medio-lateral planes (p ≤ 0.01 for all comparisons). sLLE in the medio-lateral plane was higher in SII when compared to IC subjects (p = 0.04). Conclusions: SII individuals are characterized by a pronounced asymmetric gait and a more impaired dynamic gait stability. Our findings underline the importance of devising tailored rehabilitation programs in patients with SII. Further studies are needed to assess the long-term outcomes and the role of other clinical features on gait pattern.

Using Noncontrast Computed Tomography to Improve Prediction of Intracerebral Hemorrhage Expansion.

BACKGROUND: Noncontrast computed tomography hypodensities are a validated predictor of hematoma expansion (HE) in intracerebral hemorrhage and a possible alternative to the computed tomography angiography (CTA) spot sign but their added value to available prediction models remains unclear. We investigated whether the inclusion of hypodensities improves prediction of HE and compared their added value over the spot sign. METHODS: Retrospective analysis of patients admitted for primary spontaneous intracerebral hemorrhage at the following 8 university hospitals in Boston, US (1994-2015, prospective), Hamilton, Canada (2010-2016, retrospective), Berlin, Germany (2014-2019, retrospective), Chongqing, China (2011-2015, retrospective), Pavia, Italy (2017-2019, prospective), Ferrara, Italy (2010-2019, retrospective), Brescia, Italy (2020-2021, retrospective), and Bologna, Italy (2015-2019, retrospective). Predictors of HE (hematoma growth >6 mL and/or >33% from baseline to follow-up imaging) were explored with logistic regression. We compared the discrimination of a simple prediction model for HE based on 4 predictors (antitplatelet and anticoagulant treatment, baseline intracerebral hemorrhage volume, and onset-to-imaging time) before and after the inclusion of noncontrast computed tomography hypodensities, using receiver operating characteristic curve and De Long test for area under the curve comparison. RESULTS: A total of 2465 subjects were included, of whom 664 (26.9%) had HE and 1085 (44.0%) had hypodensities. Hypodensities were independently associated with HE after adjustment for confounders in logistic regression (odds ratio, 3.11 [95% CI, 2.55-3.80]; P<0.001). The inclusion of noncontrast computed tomography hypodensities improved the discrimination of the 4 predictors model (area under the curve, 0.67 [95% CI, 0.64-0.69] versus 0.71 [95% CI, 0.69-0.74]; P=0.025). In the subgroup of patients with a CTA available (n=895, 36.3%), the added value of hypodensities remained statistically significant (area under the curve, 0.68 [95% CI, 0.64-0.73] versus 0.74 [95% CI, 0.70-0.78]; P=0.041) whereas the addition of the CTA spot sign did not provide significant discrimination improvement (area under the curve, 0.74 [95% CI, 0.70-0.78]). CONCLUSIONS: Noncontrast computed tomography hypodensities provided a significant added value in the prediction of HE and appear a valuable alternative to the CTA spot sign. Our findings might inform future studies and suggest the possibility to stratify the risk of HE with good discrimination without CTA.

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 (Tmax )-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 Tmax thresholds >9.5 seconds and >16 seconds, respectively. The difference between Tmax > 9.5 seconds and Tmax > 16 seconds volumes and the ratio between Tmax > 9.5 seconds and Tmax > 16 seconds volumes were considered ischemic penumbra and Tmax 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 Tmax 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 Tmax parameters were independent predictors of FIV and outcome. Tmax  > 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). Tmax  > 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 Tmax  > 16 seconds volume of ≤67 ml best identified subjects with favorable outcome (sensitivity = 0.91 and specificity = 0.73). INTERPRETATION: Tmax 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.

Secondary prevention after intracerebral haemorrhage.

BACKGROUND: Intracerebral haemorrhage (ICH) has high mortality in the acute phase and poor functional outcome in the majority of survivors. ICH recurrence is a major determinant of long-term prognosis and is the most feared complication of antithrombotic treatment. On the other hand, ICH patients are at high risk of future ischaemic vascular events. METHODS: This narrative review provides a critical analysis of the current knowledge on the topic. We performed a Pubmed search with the following terms 'intracerebral haemorrhage', 'stroke', 'outcome', 'secondary prevention', 'anticoagulation' and 'atrial fibrillation', including only English written studies with no time restrictions. RESULTS: Blood pressure management is the cornerstone of secondary ICH prevention, regardless of ICH location or underlying cerebral small vessel disease. Resumption of antiplatelet and anticoagulation therapy is often challenging, with limited evidence from randomized trials. Clinical and imaging predictors can inform the stratification of ICH recurrence risk and might identify patients at very high probability of future haemorrhagic events. This narrative review provides a summary of the main diagnostic tools and therapeutic strategies available for secondary prevention in ICH survivors. CONCLUSION: Appropriate recognition and treatment of modifiable risk factors for ICH recurrence might improve outcomes in ICH survivors. Ongoing randomized trials might provide novel insights and improve long-term management.

Added value of non-contrast CT and CT perfusion markers for prediction of intracerebral hemorrhage expansion and outcome.

OBJECTIVES: To test the hypothesis that the combined analysis of non-contrast CT (NCCT) and CT perfusion (CTP) imaging markers improves prediction of hematoma expansion (HE) and outcome in intracerebral hemorrhage (ICH). METHODS: Retrospective, single-center analysis of patients with primary ICH undergoing NCCT and CTP within 6 h from onset. NCCT images were assessed for the presence of intrahematomal hypodensity and shape irregularity. Perihematomal cerebral blood volume and spot sign were assessed on CTP. The main outcomes of the analysis were HE (growth > 6 mL and/or > 33%) and poor functional prognosis (90 days modified Rankin Scale 3-6). Predictors of HE and outcome were explored with logistic regression. RESULTS: A total of 150 subjects were included (median age 68, 47.1% males) of whom 54 (36%) had HE and 52 (34.7%) had poor outcome. The number of imaging markers on baseline imaging was independently associated with HE (odds ratio 2.66, 95% confidence interval 1.70-4.17, p < 0.001) and outcome (odds ratio 1.64, 95% CI 1.06-2.56, p = 0.027). Patients with the simultaneous presence of all the four markers had the highest risk of HE and unfavorable prognosis (mean predicted probability of 91% and 79% respectively). The combined-markers analysis outperformed the sensitivity of the single markers analyzed separately. In particular, the presence of at least one marker identified patients with HE and poor outcome with 91% and 87% sensitivity respectively. CONCLUSION: NCCT and CTP markers provide additional yield in the prediction of HE and ICH outcome. KEY POINTS: • Perihematomal hypoperfusion is associated with hematoma expansion and poor outcome in acute intracerebral hemorrhage. • Non-contrast CT and CT perfusion markers improve prediction of hematoma expansion and unfavorable prognosis. • A multimodal CT protocol including CT perfusion will help the identification of patients at high risk of clinical deterioration and poor outcome.

Non-contrast computed tomography features predict intraventricular hemorrhage growth.

OBJECTIVES: Non-contrast computed tomography (NCCT) markers are robust predictors of parenchymal hematoma expansion in intracerebral hemorrhage (ICH). We investigated whether NCCT features can also identify ICH patients at risk of intraventricular hemorrhage (IVH) growth. METHODS: Patients with acute spontaneous ICH admitted at four tertiary centers in Germany and Italy were retrospectively included from January 2017 to June 2020. NCCT markers were rated by two investigators for heterogeneous density, hypodensity, black hole sign, swirl sign, blend sign, fluid level, island sign, satellite sign, and irregular shape. ICH and IVH volumes were semi-manually segmented. IVH growth was defined as IVH expansion > 1 mL (eIVH) or any delayed IVH (dIVH) on follow-up imaging. Predictors of eIVH and dIVH were explored with multivariable logistic regression. Hypothesized moderators and mediators were independently assessed in PROCESS macro models. RESULTS: A total of 731 patients were included, of whom 185 (25.31%) suffered from IVH growth, 130 (17.78%) had eIVH, and 55 (7.52%) had dIVH. Irregular shape was significantly associated with IVH growth (OR 1.68; 95%CI [1.16-2.44]; p = 0.006). In the subgroup analysis stratified by the IVH growth type, hypodensities were significantly associated with eIVH (OR 2.06; 95%CI [1.48-2.64]; p = 0.015), whereas irregular shape (OR 2.72; 95%CI [1.91-3.53]; p = 0.016) in dIVH. The association between NCCT markers and IVH growth was not mediated by parenchymal hematoma expansion. CONCLUSIONS: NCCT features identified ICH patients at a high risk of IVH growth. Our findings suggest the possibility to stratify the risk of IVH growth with baseline NCCT and might inform ongoing and future studies. CLINICAL RELEVANCE STATEMENT: Non-contrast CT features identified ICH patients at a high risk of intraventricular hemorrhage growth with subtype-specific differences. Our findings may assist in the risk stratification of intraventricular hemorrhage growth with baseline CT and might inform ongoing and future clinical studies. KEY POINTS: • NCCT features identified ICH patients at a high risk of IVH growth with subtype-specific differences. • The effect of NCCT features was not moderated by time and location or indirectly mediated by hematoma expansion. • Our findings may assist in the risk stratification of IVH growth with baseline NCCT and might inform ongoing and future studies.

Intracranial carotid artery calcification morphology differs in patients with lacunar and nonlacunar acute ischemic strokes.

BACKGROUND AND PURPOSE: Intracranial carotid artery calcifications (ICACs) are a common finding on noncontrast computed tomography (NCCT) and have been associated with an increased risk of ischemic stroke. However, no data are available about the association between ICAC patterns and stroke etiology. We investigated the association between ICAC patterns and etiological subtypes of ischemic stroke. METHODS: We retrospectively analyzed a single center cohort of patients admitted for ischemic stroke with known etiology. Each carotid artery was evaluated separately on NCCT scans to define the ICAC pattern (intimal, medial, mixed). The association between ICAC patterns and stroke etiology was investigated using logistic regression models adjusting for relevant confounders. RESULTS: A total of 485 patients were included (median age = 78 [interquartile range (IQR) = 70-85] years, 243 [50%] female, median National Institutes of Health Stroke Scale = 6 [IQR = 3-12]). Frequencies of ICAC patterns were: intimal, n = 96 (20%); medial, n = 273 (56%); mixed, n = 51 (11%), indistinct/absent, n = 65 (13%) patients. Intimal pattern was more frequent in lacunar compared with nonlacunar (33% vs. 16%, p < 0.001) stroke etiology, whereas medial pattern was less frequent in lacunar compared with nonlacunar stroke (36% vs. 62%, p < 0.001). After adjustment for confounders, intimal ICAC predominant pattern remained associated with lacunar stroke etiology in two multivariate models (Model 1: adjusted odds ratio [aOR] = 2.08, 95% confidence interval [CI] = 1.20-3.56; Model 2: aOR = 2.01, 95% CI = 1.16-3.46). CONCLUSIONS: Our study suggests that intimal ICAC pattern is associated with lacunar stroke and may serve as a marker for lacunar stroke etiology, possibly strengthening the relation between endothelial dysfunction and lacunar stroke.

Pivotal role of multiphase computed tomography angiography for collateral assessment in patients with acute ischemic stroke.

The cerebral collateral circulation is the main compensatory mechanism that maintains the ischemic penumbra viable, the tissue at risk for infarction that can be saved if blood flow is restored by reperfusion therapies. In clinical practice, the extent of collateral vessels recruited after vessel occlusion can be easily assessed with computed tomography angiography (CTA) using two different techniques: single-phase CTA (sCTA) and multi-phase CTA (mCTA). Both these methodologies have demonstrated a high prognostic predictive value for prognosis due to the strong association between the presence of good collaterals and favorable radiological and clinical outcomes in patients with acute ischemic stroke (AIS). However, mCTA seems to be superior to sCTA in the evaluation of collaterals and a promising tool for identifying AIS patients who can benefit from reperfusion therapies. In particular, it has recently been proposed the use of mCTA eligibility criteria has been recently proposed for the selection of AIS patients suitable for endovascular treatment instead of the current accepted criteria based on CT perfusion. In this review, we analyzed the characteristics, advantages and disadvantages of sCTA and mCTA to better understand their fields of application and the potential of mCTA in becoming the method of choice to assess collateral extent in AIS patients.

Clinical Features, Non-Contrast CT Radiomic and Radiological Signs in Models for the Prediction of Hematoma Expansion in Intracerebral Hemorrhage.

PURPOSE: Rapid identification of hematoma expansion (HE) risk at baseline is a priority in intracerebral hemorrhage (ICH) patients and may impact clinical decision making. Predictive scores using clinical features and Non-Contract Computed Tomography (NCCT)-based features exist, however, the extent to which each feature set contributes to identification is limited. This paper aims to investigate the relative value of clinical, radiological, and radiomics features in HE prediction. METHODS: Original data was retrospectively obtained from three major prospective clinical trials ["Spot Sign" Selection of Intracerebral Hemorrhage to Guide Hemostatic Therapy (SPOTLIGHT)NCT01359202; The Spot Sign for Predicting and Treating ICH Growth Study (STOP-IT)NCT00810888] Patients baseline and follow-up scans following ICH were included. Clinical, NCCT radiological, and radiomics features were extracted, and multivariate modeling was conducted on each feature set. RESULTS: 317 patients from 38 sites met inclusion criteria. Warfarin use (p=0.001) and GCS score (p=0.046) were significant clinical predictors of HE. The best performing model for HE prediction included clinical, radiological, and radiomic features with an area under the curve (AUC) of 87.7%. NCCT radiological features improved upon clinical benchmark model AUC by 6.5% and a clinical & radiomic combination model by 6.4%. Addition of radiomics features improved goodness of fit of both clinical (p=0.012) and clinical & NCCT radiological (p=0.007) models, with marginal improvements on AUC. Inclusion of NCCT radiological signs was best for ruling out HE whereas the radiomic features were best for ruling in HE. CONCLUSION: NCCT-based radiological and radiomics features can improve HE prediction when added to clinical features.

Subclinical Vascular Brain Lesions in Young Adults With Acute Ischemic Stroke.

BACKGROUND: Subclinical vascular brain lesions are highly prevalent in elderly patients with stroke. Little is known about predisposing factors and their impact on long-term outcome of patients with stroke at a young age. METHODS: We quantified magnetic resonance-defined subclinical vascular brain lesions, including lacunes and white matter hyperintensities, perivascular spaces and cerebral microbleeds, and assessed total small-vessel disease (SVD) score in patients with first-ever acute ischemic stroke aged 18 to 45 years, and followed them up, as part of the multicentre Italian Project on Stroke in Young Adults. The primary end point was a composite of ischemic stroke, transient ischemic attack, myocardial infarction, or other arterial events. We assessed the predictive accuracy of magnetic resonance features and whether the addition of these markers improves outcome prediction over a validated clinical tool, such as the Italian Project on Stroke in Young Adults score. RESULTS: Among 591 patients (males, 53.8%; mean age, 37.5±6.4 years), 117 (19.8%) had subclinical vascular brain lesions. Family history of stroke was associated with lacunes (odds ratio, 2.24 [95% CI, 1.30-3.84]) and total SVD score (odds ratio, 2.06 [95% CI, 1.20-3.53] for score≥1), hypertension with white matter hyperintensities (odds ratio, 2.29 [95% CI, 1.22-4.32]). After a median follow-up of 36.0 months (25th-75th percentile, 38.0), lacunes and total SVD score were associated with primary end point (hazard ratio, 2.13 [95% CI, 1.17-3.90] for lacunes; hazard ratio, 2.17 [95% CI, 1.20-3.90] for total SVD score ≥1), and the secondary end point brain ischemia (hazard ratio, 2.55 [95% CI, 1.36-4.75] for lacunes; hazard ratio, 2.61 [95% CI, 1.42-4.80] for total SVD score ≥1). The predictive performances of the models, including magnetic resonance features were comparable to those of the random model. Adding individual magnetic resonance features to the Italian Project on Stroke in Young Adults score did not improve model prediction. CONCLUSIONS: Subclinical vascular brain lesions affect ≈2 in 10 young adults with ischemic stroke. Although lacunes and total SVD score are associated with thrombotic recurrence, they do not improve accuracy of outcome prediction over validated clinical predictors.

Delayed perihematomal hypoperfusion is associated with poor outcome in intracerebral haemorrhage.

BACKGROUND: The aim of this study was to characterize the temporal evolution and prognostic significance of perihematomal perfusion in acute intracerebral haemorrhage (ICH). METHODS: A single-centre prospective cohort of patients with primary spontaneous ICH receives computed tomography perfusion (CTP) within 6 h from onset (T0) and at 7 days (T7). Cerebral blood flow (CBF), cerebral blood volume (CBV) and mean transit time (MTT) were measured in the manually outlined perihematomal low-density area. Poor functional prognosis (modified Rankin Scale 3-6) at 90 days was the outcome of interest, and predictors were explored with multivariable logistic regression. RESULTS: A total of 150 patients were studied, of whom 52 (34.7%) had a mRS 3-6 at 90 days. Perihematomal perfusion decreased from T0 to T7 in all patients, but the magnitude of CBF and CBV reduction was larger in patients with unfavourable outcome (median CBF change -7.8 vs. -6.0 ml/100 g/min, p < .001, and median CBV change -0.5 vs. -0.4 ml/100 g, p = .010, respectively). This finding remained significant after adjustment for confounders (odds ratio [OR] for 1 ml/100 g/min CBF reduction: 1.33, 95% confidence interval [CI] (1.15-1.55), p < .001; OR for 0.1 ml/100 g CBV reduction: 1.67, 95% CI 1.18-2.35, p = .004). The presence of CBF < 20 ml/100 g/min at T7 was then demonstrated as an independent predictor of poor functional outcome (adjusted OR: 2.45, 95% CI 1.08-5-54, p = .032). CONCLUSION: Perihaemorrhagic hypoperfusion becomes more severe in the days following acute ICH and is independently associated with poorer outcome. Understanding the underlying biological mechanisms responsible for delayed decrease in perihematomal perfusion is a necessary step towards outcome improvement in patients with ICH.

Antithrombotic therapy in the postacute phase of cervical artery dissection: the Italian Project on Stroke in Young Adults Cervical Artery Dissection.

OBJECTIVE: To explore the impact of antithrombotic therapy discontinuation in the postacute phase of cervical artery dissection (CeAD) on the mid-term outcome of these patients. METHODS: In a cohort of consecutive patients with first-ever CeAD, enrolled in the setting of the multicentre Italian Project on Stroke in Young Adults Cervical Artery Dissection, we compared postacute (beyond 6 months since the index CeAD) outcomes between patients who discontinued antithrombotic therapy and patients who continued taking antithrombotic agents during follow-up. Primary outcome was a composite of ischaemic stroke and transient ischaemic attack. Secondary outcomes were (1) Brain ischaemia ipsilateral to the dissected vessel and (2) Recurrent CeAD. Associations with the outcome of interest were assessed by the propensity score (PS) method. RESULTS: Of the 1390 patients whose data were available for the outcome analysis (median follow-up time in patients who did not experience outcome events, 36.0 months (25th-75th percentile, 62.0)), 201 (14.4%) discontinued antithrombotic treatment. Primary outcome occurred in 48 patients in the postacute phase of CeAD. In PS-matched samples (201 vs 201), the incidence of primary outcomes among patients taking antithrombotics was comparable with that among patients who discontinued antithrombotics during follow-up (5.0% vs 4.5%; p(log rank test)=0.526), and so was the incidence of the secondary outcomes ipsilateral brain ischaemia (4.5% vs 2.5%; p(log rank test)=0.132) and recurrent CeAD (1.0% vs 1.5%; p(log rank test)=0.798). CONCLUSIONS: Discontinuation of antithrombotic therapy in the postacute phase of CeAD does not appear to increase the risk of brain ischaemia during follow-up.

Vessel wall magnetic resonance imaging in COVID-19-associated cryptogenic ischemic stroke.

BACKGROUND AND PURPOSE: Acute ischemic stroke (AIS) is a common complication of coronavirus disease 2019 (COVID-19), but the underlying biological mechanisms remain unclear. We aimed to describe the prevalence of vessel wall alterations in patients with cryptogenic stroke through vessel wall magnetic resonance imaging (vwMRI). METHODS: All consecutive patients admitted for AIS and COVID-19 to a single neuro-COVID unit from 10 November to 31 December 2020 were prospectively evaluated and underwent a complete etiologic workup for AIS. In patients with cryptogenic stroke, the diagnostic workup was completed with vwMRI study. RESULTS: After the exclusion of four patients ineligible for MRI, a total of 10 patients were included (median age = 78 years, 50% males), of whom four (40%) had a cryptogenic stroke. vwMRI showed vascular changes consistent with inflammation of intracranial artery walls in three subjects (75%). Two patients had focal and one multifocal involvement. CONCLUSIONS: vwMRI detected signs of vascular inflammation in the majority of patients with cryptogenic AIS, leading to an etiologic definition with potential therapeutical implications. Our findings are best interpreted as hypothesis-generating, suggesting the possibility of expanding the diagnostic workup of cryptogenic stroke with vessel wall imaging.