Two-stage convolutional neural network for segmentation and detection of carotid web on CT angiography.

BACKGROUND: Carotid web (CaW) is a risk factor for ischemic stroke, mainly in young patients with stroke of undetermined etiology. Its detection is challenging, especially among non-experienced physicians. METHODS: We included patients with CaW from six international trials and registries of patients with acute ischemic stroke. Identification and manual segmentations of CaW were performed by three trained radiologists. We designed a two-stage segmentation strategy based on a convolutional neural network (CNN). At the first stage, the two carotid arteries were segmented using a U-shaped CNN. At the second stage, the segmentation of the CaW was first confined to the vicinity of the carotid arteries. Then, the carotid bifurcation region was localized by the proposed carotid bifurcation localization algorithm followed by another U-shaped CNN. A volume threshold based on the derived CaW manual segmentation statistics was then used to determine whether or not CaW was present. RESULTS: We included 58 patients (median (IQR) age 59 (50-75) years, 60% women). The Dice similarity coefficient and 95th percentile Hausdorff distance between manually segmented CaW and the algorithm segmented CaW were 63.20±19.03% and 1.19±0.9 mm, respectively. Using a volume threshold of 5 mm3, binary classification detection metrics for CaW on a single artery were as follows: accuracy: 92.2% (95% CI 87.93% to 96.55%), precision: 94.83% (95% CI 88.68% to 100.00%), sensitivity: 90.16% (95% CI 82.16% to 96.97%), specificity: 94.55% (95% CI 88.0% to 100.0%), F1 measure: 0.9244 (95% CI 0.8679 to 0.9692), area under the curve: 0.9235 (95%CI 0.8726 to 0.9688). CONCLUSIONS: The proposed two-stage method enables reliable segmentation and detection of CaW from head and neck CT angiography.

Endovascular Treatment for Cerebral Venous Thrombosis: Applying Lessons Learned from Clinical Trials of Endovascular Treatment in Acute Arterial Ischemic Stroke.

BACKGROUND: Cerebral venous thrombosis (CVT) is a rare but severely disabling form of stroke. Acute treatment mainly consists of medical management, since there is no robust evidence suggesting the benefit of endovascular treatment for CVT. Given the relative lack of data to guide acute treatment decision-making, CVT treatment decisions are mostly made on a case-by-case basis. In some ways, the current status quo of endovascular treatment for CVT resembles the state of endovascular treatment for acute ischemic stroke before the wave of major positive large vessel occlusion endovascular treatment trials in 2015. SUMMARY: The current state of evidence with regard to endovascular CVT treatment is summarized, parallels to acute ischemic stroke are drawn, and it is discussed how the lessons learned from the evolution of acute ischemic stroke endovascular treatment (EVT) trials could be applied to designing a trial of endovascular treatment for CVT. The review ends by outlining possible scenarios for the future of endovascular CVT treatment. KEY MESSAGES: CVT is a serious disease, affecting young patients and their families, and harbors a considerable social and economic burden. Working toward high-level evidence for the best possible treatment strategy and exploring a possible role for EVT to improve outcomes in CVT needs to remain a high priority in stroke research.

Relationship Between Carotid Web Morphology on CT Angiography and Stroke: A Pooled Multicenter Analysis.

BACKGROUND: The Carotid web (CaW) is a cause of stroke particularly in younger individuals. However it's frequency, and the radiological features of the web's morphology associated with stroke risk are uncertain. We determined the CaW radiological features on CT angiography associated with ipsilateral stroke. MATERIAL AND METHODS: Data from six studies of patients with acute ischemic stroke were pooled. Identification and measurement of CaWs were performed by experienced readers on baseline neck CT angiography. We assessed six 2D CaW radiological features on sagittal oblique images, namely, main axis length, thickness, height, base width, distance to wall, and angle between web main axis and carotid wall, and CaW volume on 3D images. CaWs were divided into symptomatic if acute ischemic stroke was in the ipsilateral internal carotid artery territory and its etiology was undetermined and asymptomatic if one condition was unmet. Univariable and multivariable analyses were conducted to assess the association between each radiological CaW feature and symptomatic CaW. RESULTS: Of the 3442 patients in the pooled data with assessable CTAs, 60 (1.7%) had CaW. In patients with CaW, median age was 59 (IQR 50-68) years, 60% were women, and 3 patients had bilateral CaWs. There were 39 (62%) symptomatic and 24 (38%) asymptomatic CaWs. Patients with symptomatic CaW were younger (55 [IQR 49-61] years versus 69 [IQR 52-75] years), had lower rates of hypertension (9 [25.0%] versus 12 [57.1%]) and more intracranial large vessel occlusions compared to patients with asymptomatic CaWs. After adjusting for age, hypertension and occlusion location, CaW length (adjusted odds ratio [aOR] 1.84 [95%CI 1.03-3.28]), thickness (aOR 2.31 [95%CI 1.08-4.97]), volume (aOR 1.07 per 1 mm3 increment [95%CI 1.01-1.12]), and angle relative to the carotid wall (aOR 0.95 [95%CI 0.91-0.99]) were associated with symptomatic CaW. CONCLUSION: Radiological assessment of CaW morphology may determine its potential causal role in ischemic stroke etiology. Symptomatic CaWs tend to be longer, larger and oriented at more acute angles relative to the carotid wall as compared to asymptomatic CaWs.

Tenecteplase Versus Alteplase in Medium Vessel Occlusion Ischemic Stroke: A Secondary Analysis of the Alteplase Compared to Tenecteplase Randomized Trial.

BACKGROUND AND PURPOSE: The safety and efficacy of tenecteplase in patients with ischemic stroke due to medium vessel occlusion (MeVO) are not well studied. We aimed to compare tenecteplase with alteplase in stroke due to MeVO. METHODS: Patients with baseline M2-middle cerebral artery (MCA), M3/M4-MCA, P2/P3/P4-posterior cerebral artery (PCA), A2/A3/A4-anterior cerebral artery (ACA) occlusions from the Alteplase Compared to Tenecteplase (AcT) trial were included. Primary outcome was the proportion of 90-day modified Rankin Scale (mRS) 0-1. Secondary outcomes were 90-day mRS 0-2, ordinal mRS, mortality, quality of life measures (EuroQol 5-Dimension 5-Level, EuroQol visual analog scale), and symptomatic intracerebral hemorrhage (sICH). Initial and final successful reperfusion were reported in patients undergoing endovascular thrombectomy (EVT). RESULTS: Among 1,558 patients with available baseline computed tomography angiography; 455 (29.2%) had MeVO of which 27.5% (125/455) were proximal M2; 16.3% (74/455) were distal M2; 35.2% (160/455) were M3/M4; 7.5% (34/455) were A2/A3/A4; and 13.6% (62/455) were P2/P3/P4 occlusions. EVT was performed in 87/455 (19.1%) patients. mRS 0-1 at 90 days was achieved in 37.9% in the tenecteplase versus 34.7% in the alteplase group (adjusted risk ratio [aRR] 1.07; 95% confidence interval [CI] 0.91-1.25). Rates of 90-day mRS 0-2, sICH, and mortality were similar in both groups. No statistical difference was noted in initial successful reperfusion rates (13.0% vs. 7.5%) among the 87 patients who underwent endovascular thrombectomy. However, final successful reperfusion was higher in the tenecteplase group (71.7% vs. 60.0%, aRR 1.29, 95% CI 1.04-1.61). CONCLUSION: Intravenous tenecteplase had comparable safety, functional outcomes and quality of life compared to intravenous alteplase among patients with MeVO. Among those treated with EVT, tenecteplase was associated with higher successful reperfusion rates than alteplase.

Worldwide Survey on Approach to Thrombolysis in Acute Ischemic Stroke With Large Vessel Occlusion.

Background and Objectives: With recent trials suggesting that endovascular thrombectomy (EVT) alone may be noninferior to combined intravenous thrombolysis (IVT) with alteplase and EVT and that tenecteplase is non-inferior to alteplase in treating acute ischemic stroke, we sought to understand current practices around the world for treating acute ischemic stroke with large vessel occlusion (LVO) depending on the center of practice (IVT-capable vs IVT and EVT-capable stroke center). Methods: The electronic survey launched by the Practice Current section of Neurology: Clinical Practice included 6 clinical and 8 demographic questions. A single-case scenario was presented of a 65-year-old man presenting with right hemiplegia with aphasia with a duration of 1 hour. Imaging showed left M1-MCA occlusion with no early ischemic changes. The respondents were asked about their treatment approach in 2 settings: the patient presented to (1) the IVT-only capable center and (2) the IVT and EVT-capable center. They were also asked about the thrombolytic agent of choice in current and ideal circumstances for these settings. Results: A total of 203 physicians (42.9% vascular neurologists) from 44 countries completed the survey. Most participants (55.2%) spent ≥50% of their time delivering stroke care. The survey results showed that in current practice, more than 90% of respondents would offer IVT + EVT to patients with LVO stroke presenting to either an EVT-capable (91.1%) or IVT-only-capable center (93.6%). Although nearly 80% currently use alteplase for thrombolysis, around 60% would ideally like to switch to tenecteplase independent of the practice setting. These results were similar between stroke and non-stroke neurologists. Discussion: Most physicians prefer IVT before EVT in patients with acute ischemic stroke attributable to large vessel occlusion independent of the practice setting.

Safety of acute internal carotid artery stenting during endovascular thrombectomy in patients with acute ischemic stroke: a retrospective analysis of the OPTIMISE registry.

BACKGROUND: The optimal management of tandem carotid lesions during endovascular thrombectomy (EVT) remains uncertain. The safety and efficacy of acute carotid artery stenting (aCAS) are debated, including safety concerns such as procedural complications and symptomatic intracerebral hemorrhage (sICH). We aimed to assess aCAS safety among EVT-treated patients using a large Canadian registry. METHODS: We retrospectively analyzed the OPTIMISE registry and compared adult patients undergoing EVT and aCAS versus EVT only. The primary outcome was a composite of in-hospital death, long-term care facility destination at discharge, sICH, or any EVT-related procedural complications. Secondary outcomes included individual components of the primary outcome, EVT workflow times, final modified Thrombolysis in Cerebral Ischemia score and 90-day modified Rankin Scale score. Statistical significance was evaluated by a multivariate logistic regression model. RESULTS: 4205 patients were included (330 with EVT-aCAS and 3875 with EVT-only). Both groups were similar with regard to baseline National Institutes of Health Stroke Scale score, Alberta Stroke Program Early CT Score and use of IV thrombolysis, but differed in age (EVT-aCAS group 67.2±12.1 years vs EVT-only group 71.3±14.1 years, P<0.001), proportion of women (28.2% vs 53.3%, P<0.001), and occlusion location (internal carotid artery terminus 44% vs 16%, P<0.001). The EVT-aCAS group showed a non-significant increase in odds of composite safety outcomes (adjusted OR 1.35 (95% CI 0.97 to 1.84), P=0.06) with a significantly higher proportion of procedural complications (10.0% vs 6.2%, P=0.002). CONCLUSION: In a large national registry, EVT-aCAS was associated with a higher proportion of unfavorable safety outcomes, driven by more frequent procedural complications. Further research is needed to clarify the role of aCAS in tandem occlusion stroke.

Timing of Spot Sign Appearance, Spot Sign Volume, and Leakage Rate among Phases of Multiphase CTA Predict Intracerebral Hemorrhage Growth.

BACKGROUND AND PURPOSE: The presence of spot sign is associated with a high risk of hematoma growth. Our aim was to investigate the timing of the appearance, volume, and leakage rate of the spot sign for predicting hematoma growth in acute intracerebral hemorrhage using multiphase CTA. MATERIALS AND METHODS: In this single-center retrospective study, multiphase CTA in 3 phases was performed in acute intracerebral hemorrhage (defined as intraparenchymal ± intraventricular hemorrhages). Phases of the spot sign first appearance, spot sign volumes (microliter), and leakage rates among phases (microliter/second) were measured. Associations between baseline clinical and imaging variables including spot sign volume parameters (volume and leakage rate divided by median) and hematoma growth (>6 mL) were investigated using regression models. Receiver operating characteristic analysis was used as appropriate. RESULTS: Two hundred seventeen patients (131 men; median age, 70 years) were included. The spot sign was detected in 21.7%, 30.0%, and 29.0% in the first, second, and third phases, respectively, with median volumes of 19.7, 31.4, and 34.8 µl in these phases. Hematoma growth was seen in 44 patients (20.3%). By means of modeling, the following variables, namely the spot sign appearing in the first phase, first phase spot sign volume, spot sign appearing in the second or third phase, and spot sign positive and negative leakage rates, were associated with hematoma growth. Among patients with a spot sign, the absolute leakage rate accounting for both positive and negative leakage rates was also associated with hematoma growth (per 1-µl/s increase; OR, 1.26; 95% CI, 1.04-1.52). Other hematoma growth predictors were stroke history, baseline NIHSS score, onset-to-imaging time, and baseline hematoma volume (all P values < .05). CONCLUSIONS: The timing of the appearance of the spot sign, volume, and leakage rate were all associated with hematoma growth. Development of automated software to generate these spot sign volumetric parameters would be an important next step to maximize the potential of temporal intracerebral hemorrhage imaging such as multiphase CTA for identifying those most at risk of hematoma growth.

The independence of impairments in proprioception and visuomotor adaptation after stroke.

BACKGROUND: Proprioceptive impairments are common after stroke and are associated with worse motor recovery and poor rehabilitation outcomes. Motor learning may also be an important factor in motor recovery, and some evidence in healthy adults suggests that reduced proprioceptive function is associated with reductions in motor learning. It is unclear how impairments in proprioception and motor learning relate after stroke. Here we used robotics and a traditional clinical assessment to examine the link between impairments in proprioception after stroke and a type of motor learning known as visuomotor adaptation. METHODS: We recruited participants with first-time unilateral stroke and controls matched for overall age and sex. Proprioceptive impairments in the more affected arm were assessed using robotic arm position- (APM) and movement-matching (AMM) tasks. We also assessed proprioceptive impairments using a clinical scale (Thumb Localization Test; TLT). Visuomotor adaptation was assessed using a task that systematically rotated hand cursor feedback during reaching movements (VMR). We quantified how much participants adapted to the disturbance and how many trials they took to adapt to the same levels as controls. Spearman's rho was used to examine the relationship between proprioception, assessed using robotics and the TLT, and visuomotor adaptation. Data from healthy adults were used to identify participants with stroke who were impaired in proprioception and visuomotor adaptation. The independence of impairments in proprioception and adaptation were examined using Fisher's exact tests. RESULTS: Impairments in proprioception (58.3%) and adaptation (52.1%) were common in participants with stroke (n = 48; 2.10% acute, 70.8% subacute, 27.1% chronic stroke). Performance on the APM task, AMM task, and TLT scores correlated weakly with measures of visuomotor adaptation. Fisher's exact tests demonstrated that impairments in proprioception, assessed using robotics and the TLT, were independent from impairments in visuomotor adaptation in our sample. CONCLUSION: Our results suggest impairments in proprioception may be independent from impairments in visuomotor adaptation after stroke. Further studies are needed to understand factors that influence the relationship between motor learning, proprioception and other rehabilitation outcomes throughout stroke recovery.

Combining Early Ischemic Change and Collateral Extent for Functional Outcomes After Endovascular Therapy: An Analysis From AcT Trial.

BACKGROUND: Early ischemic change and collateral extent are colinear with ischemic core volume (ICV). We investigated the relationship between a combined score using the Alberta Stroke Program Early Computed Tomography Score and multiphase computed tomography angiography (mCTA) collateral extent, named mCTA-ACE score, on functional outcomes in endovascular therapy-treated patients. METHODS: We performed a post hoc analysis of a subset of endovascular therapy-treated patients from the Alteplase Compared to Tenecteplase trial which was conducted between December 2019 and January 2022 at 22 centers across Canada. Ten-point mCTA collateral corresponding to M2 to M6 regions of the Alberta Stroke Program Early Computed Tomography Score grid was evaluated as 0 (poor), 1 (moderate), or 2 (normal) and additively combined with the 10-point Alberta Stroke Program Early Computed Tomography Score to produce a 20-point mCTA-ACE score. We investigated the association of mCTA-ACE score with modified Rankin Scale score ≤2 and return to prestroke level of function at 90 to 120 days using mixed-effects logistic regression. In the subset of patients who underwent baseline computed tomography perfusion imaging, we compared the mCTA-ACE score and ICV for outcome prediction. RESULTS: Among 1577 intention-to-treat population in the trial, 368 (23%; 179 men; median age, 73 years) were included, with Alberta Stroke Program Early Computed Tomography Score, mCTA collateral, and combination of both (mCTA-ACE score: median [interquartile range], 8 [7-10], 9 [8-10], and 17 [16-19], respectively). The probability of modified Rankin Scale score ≤2 and return to prestroke level of function increased for each 1-point increase in mCTA-ACE score (odds ratio, 1.16 [95% CI, 1.06-1.28] and 1.22 [95% CI, 1.06-1.40], respectively). Among 173 patients in whom computed tomography perfusion data was assessable, the mCTA-ACE score was inversely correlated with ICV (ρ=-0.46; P<0.01). The mCTA-ACE score was comparable to ICV to predict a modified Rankin Scale score ≤2 and return to prestroke level of function (C statistics 0.71 versus 0.69 and 0.68 versus 0.64, respectively). CONCLUSIONS: The mCTA-ACE score had a significant positive association with functional outcomes after endovascular therapy and had a similar predictive performance as ICV.

Prevalence of depression and anxiety symptoms after stroke in young adults: A systematic review and meta-analysis.

BACKGROUND: Young adults with stroke have distinct professional and social roles making them vulnerable to symptoms of post-stroke depression (PSD) and post-stroke anxiety (PSA). Prior reviews have examined the prevalence of anxiety and depression in stroke populations. However, there are a lack of studies that have focused on these conditions in young adults. OBJECTIVE: We performed a systematic review and meta-analysis of observational studies that reported on symptoms of PSD, PSA and comorbid PSD/PSA in young adults aged 18 to 55 years of age. METHODS: MEDLINE, EMBASE, SCOPUS and PsycINFO were searched for studies reporting the prevalence of symptoms of PSD and/or PSA in young adults with stroke from inception until June 23, 2023. We included studies that evaluated depression and/or anxiety symptoms with screening tools or interviews following ischemic or hemorrhagic stroke. Validated methods were employed to evaluate risk of bias. RESULTS: 4748 patients from twenty eligible studies were included. Among them, 2420 were also evaluated for symptoms of PSA while 847 participants were evaluated for both PSD and PSA symptoms. Sixteen studies were included in the random effects meta-analysis for PSD symptoms, with a pooled prevalence of 31 % (95 % CI 24-38 %). Pooled PSA symptom prevalence was 39 % (95 % CI 30-48 %) and comorbid PSD with PSA symptom prevalence was 25 % (95 % CI 12-39 %). Varying definitions of 'young adult', combinations of stroke subtypes, and methods to assess PSD and PSA contributed to high heterogeneity amongst studies. CONCLUSIONS: We identified high heterogeneity in studies investigating the prevalence of symptoms of PSD and PSA in young adults, emphasizing the importance of standardized approaches in future research to gain insight into the outcomes and prognosis of PSD and PSA symptoms following stroke in young adults. Larger longitudinal epidemiological studies as well as studies on tailored interventions are required to address the mental health needs of this important population. FUNDING: None.

A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke with Proven Occlusion (TEMPO-2): Rational and design of a multicenter, randomized open-label clinical trial.

BACKGROUND: Almost half of acute ischemic stroke patients present with mild symptoms and there are large practice variations in their treatment globally. Individuals with an intracranial occlusion who present with minor stroke are at an increased risk of early neurological deterioration and poor outcomes. Individual patient data meta-analysis in the subgroup of patients with minor deficits showed benefit of alteplase in improving outcomes; however, this benefit has not been seen with intravenous alteplase in published randomized trials. DESIGN: TEMPO-2 (A Randomized Controlled Trial of Tenecteplase Versus Standard of Care for Minor Ischemic Stroke With Proven Occlusion) is a prospective, open label with blinded outcome assessment, randomized controlled trial, designed to test the superiority of intravenous tenecteplase (0.25 mg/kg) over nonthrombolytic standard of care, with an estimated sample size of 1274 patients. Adult patients presenting with acute ischemic stroke with the National Institutes of Health Stroke Scale (NIHSS) ⩽ 5 and visible arterial occlusion or perfusion deficit within 12 h of onset are randomized to receive either tenecteplase (0.25 mg/kg) or standard of care. The primary outcome is return to baseline neurological functioning, measured by the modified Rankin scale (mRS) at 90 days. Safety outcomes include death and symptomatic hemorrhage (intra or extra-cranial). Other secondary outcomes include mRS 0-1, mRS 0-2, ordinal shift analysis of the mRS, partial, and full recanalization on follow-up computed tomography angiogram. CONCLUSION: Results of this trial will aid in determining whether there is benefit of using tenecteplase (0.25 mg/kg) in treating patients presenting with minor stroke who are at high risk of developing poor outcomes due to presence of an intracranial occlusion. DATA ACCESS STATEMENT: Data will be available upon reasonable request.

Magnetic Resonance Imaging Assists With Determining Etiology After Transient Ischemic Attack or Minor Stroke.

BACKGROUND: Magnetic resonance imaging infarct topography may assist with determining stroke etiology. The influence of diffusion-weighted imaging (DWI)-positive lesions on etiology determination in patients with transient ischemic attack or minor stroke is not well studied. METHODS AND RESULTS: We prospectively enrolled patients between 2010 and 2017 in 2 studies; participants with a final diagnosis of probable or definite transient ischemic attack or stroke were pooled for analysis. The primary outcome was the adjudicated ischemic etiology. We compared proportion of each etiology (cardioembolic, large-vessel, small-vessel disease, other) in patients who had DWI positivity compared with DWI negativity. We used logistic regression to determine the adjusted odds ratio (OR) for each etiology compared with undetermined by DWI positivity. The final analysis included 1498 patients: 832 (55.5%) were DWI-positive. DWI-positive patients were more likely to be diagnosed with small-vessel disease (19.1% versus 5.3%) and less likely with undetermined etiology (36.9% versus 53.0%; P<0.001). After adjustment, the presence of any DWI lesion was associated with increased odds of assigning any etiology (OR, 1.8 [95% CI, 1.3-2.5]). A single DWI lesion was associated with increased odds of small-vessel disease diagnosis (OR, 9.5 [95% CI, 6.4-14.0]), and multiple DWI lesions with reduced odds of small-vessel disease (OR, 0.2 [95% CI, 0.1-0.4]) but increased odds of all other etiologies compared with undetermined etiology. CONCLUSIONS: Any DWI-positive lesion after suspected transient ischemic attack or minor stroke was associated with increased odds of assigning a etiology. Presence and topography of DWI lesions on magnetic resonance imaging may assist with etiology determination and may impact stroke prevention therapies.

Clinical uncertainty in large vessel occlusion ischemic stroke: does automated perfusion imaging make a difference? An intra-rater and inter-rater agreement study.

BACKGROUND: Limited research exists regarding the impact of neuroimaging on endovascular thrombectomy (EVT) decisions for late-window cases of large vessel occlusion (LVO) stroke. OBJECTIVE: T0 assess whether perfusion CT imaging: (1) alters the proportion of recommendations for EVT, and (2) enhances the reliability of EVT decision-making compared with non-contrast CT and CT angiography. METHODS: We conducted a survey using 30 patients drawn from an institutional database of 3144 acute stroke cases. These were presented to 29 Canadian physicians with and without perfusion imaging. We used non-overlapping 95% confidence intervals and difference in agreement classification as criteria to suggest a difference between the Gwet AC1 statistics (κG). RESULTS: The percentage of EVT recommendations differed by 1.1% with or without perfusion imaging. Individual decisions changed in 21.4% of cases (11.3% against EVT and 10.1% in favor). Inter-rater agreement (κG) among the 29 raters was similar between non-perfusion and perfusion CT neuroimaging (κG=0.487; 95% CI 0.327 to 0.647 and κG=0.552; 95% CI 0.430 to 0.675). The 95% CIs overlapped with moderate agreement in both. Intra-rater agreement exhibited overlapping 95% CIs for all 28 raters. κG was either substantial or excellent (0.81-1) for 71.4% (20/28) of raters in both groups. CONCLUSIONS: Despite the minimal difference in overall EVT recommendations with either neuroimaging protocol one in five decisions changed with perfusion imaging. Regarding agreement we found that the use of automated CT perfusion images does not significantly impact the reliability of EVT decisions for patients with late-window LVO.

Emerging Concept of Intracranial Arterial Diseases: The Role of High Resolution Vessel Wall MRI.

Intracranial arterial disease (ICAD) is a heterogeneous condition characterized by distinct pathologies, including atherosclerosis. Advances in magnetic resonance technology have enabled the visualization of intracranial arteries using high-resolution vessel wall imaging (HR-VWI). This review summarizes the anatomical, embryological, and histological differences between the intracranial and extracranial arteries. Next, we review the heterogeneous pathophysiology of ICAD, including atherosclerosis, moyamoya or RNF213 spectrum disease, intracranial dissection, and vasculitis. We also discuss how advances in HR-VWI can be used to differentiate ICAD etiologies. We emphasize that one should consider clinical presentation and timing of imaging in the absence of pathology-radiology correlation data. Future research should focus on understanding the temporal profile of HR-VWI findings and developing quantitative interpretative approaches to improve the decision-making and management of ICAD.

Mediation of Age and Thrombectomy Outcome by Neuroimaging Markers of Frailty in Patients With Stroke.

Importance: Age is a leading predictor of poor outcomes after brain injuries like stroke. The extent to which age is associated with preexisting burdens of brain changes, visible on neuroimaging but rarely considered in acute decision-making or trials, is unknown. Objectives: To explore the mediation of age on functional outcome by neuroimaging markers of frailty (hereinafter neuroimaging frailty) in patients with acute ischemic stroke receiving endovascular thrombectomy (EVT). Design, Setting, and Participants: This cohort study was a post hoc analysis of the Safety and Efficacy of Nerinetide (NA-1) in Subjects Undergoing Endovascular Thrombectomy for Stroke (ESCAPE-NA1) randomized clinical trial, which investigated intravenous (IV) nerinetide in patients who underwent EVT within a 12-hour treatment window. Patients from 48 acute care hospitals in 8 countries (Canada, US, Germany, Korea, Australia, Ireland, UK, and Sweden) were enrolled between March 1, 2017, and August 12, 2019. Markers of brain frailty (brain atrophy [subcortical or cortical], white matter disease [periventricular or deep], and the number of lacunes and chronic infarctions) were retrospectively assessed while reviewers were blinded to other imaging (eg, computed tomography angiography, computed tomography perfusion) or outcome variables. All analyses were done between December 1, 2022, and January 31, 2023. Exposures: All patients received EVT and were randomized to IV nerinetide (2.6 mg/kg of body weight) and alteplase (if indicated) treatment vs best medical management. Main Outcome and Measures: The primary outcome was the proportion of the total effect of age on 90-day outcome, mediated by neuroimaging frailty. A combined mediation was also examined by clinical features associated with frailty and neuroimaging markers (total frailty). Structural equation modeling was used to create latent variables as potential mediators, adjusting for baseline, early ischemic changes; stroke severity; onset-to-puncture time; nerinetide treatment; and alteplase treatment. Results: Among a total of 1105 patients enrolled in the study, 1102 (median age, 71 years [IQR, 61-80 years]; 554 [50.3%] male) had interpretable imaging at baseline. Of these participants, 549 (49.8%) were treated with IV nerinetide. The indirect effect of age on 90-day outcome, mediated by neuroimaging frailty, was associated with 85.1% of the total effect (ß coefficient, 0.04 per year [95% CI, 0.02-0.06 per year]; P < .001). When including both frailty constructs, the indirect pathway was associated with essentially 100% of the total effect (ß coefficient, 0.07 per year [95% CI, 0.03-0.10 per year]; P = .001). Conclusions and Relevance: In this cohort study, a secondary analysis of the ESCAPE-NA1 trial, most of the association between age and 90-day outcome was mediated by neuroimaging frailty, underscoring the importance of features like brain atrophy and small vessel disease, as opposed to chronological age alone, in predicting poststroke outcomes. Future trials could include such frailty features to stratify randomization or improve adjustment in outcome analyses.

Sex-Based Analysis of Workflow and Outcomes in Acute Ischemic Stroke Patients Treated With Alteplase Versus Tenecteplase.

BACKGROUND: Understanding sex differences in stroke care is important in reducing potential disparities. Our objective was to explore sex differences in workflow efficiency, treatment efficacy, and safety in the AcT trial (Alteplase Compared to Tenecteplase). METHODS: AcT was a multicenter, registry-linked randomized noninferiority trial comparing tenecteplase (0.25 mg/kg) with alteplase (0.9 mg/kg) in acute ischemic stroke within 4.5 hours of onset. In this post hoc analysis, baseline characteristics, workflow times, successful reperfusion (extended Thrombolysis in Cerebral Infarction score ≥2b), symptomatic intracerebral hemorrhage, 90-day functional independence (modified Rankin Scale score, 0-1), and 90-day mortality were compared by sex. Mixed-effects regression analysis was used adjusting for age, stroke severity, and occlusion site for outcomes. RESULTS: Of 1577 patients treated with intravenous thrombolysis (2019-2022), 755 (47.9%) were women. Women were older (median, 77 [68-86] years in women versus 70 [59-79] years in men) and had a higher proportion of severe strokes (National Institutes of Health Stroke Scale score >15; 32.4% versus 24.9%) and large vessel occlusions (28.7% versus 21.5%) compared with men. All workflow times were comparable between sexes. Women were less likely to achieve functional independence (31.7% versus 39.8%; unadjusted relative risk, 0.80 [95% CI, 0.70-0.91]) and had higher mortality (17.7% versus 13.3%; unadjusted relative risk, 1.33 [95% CI, 1.06-1.69]). Adjusted analysis showed no difference in outcomes between sexes. CONCLUSIONS: Differences in prognostic factors of age, stroke severity, and occlusion site largely accounted for higher functional dependence and mortality in women. No sex disparities were apparent in workflow quality indicators. Given the integration of the AcT trial into clinical practice, these results provide reassurance that no major sex biases are apparent in acute stroke management throughout participating Canadian centers. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Presenting Symptoms and Diffusion-Weighted MRI Positivity by Time After Transient Neurologic Events: A Pooled Analysis of 3 Cohort Studies

BACKGROUND AND OBJECTIVE: The association between focal vs nonfocal presenting symptom and diffusion-weighted imaging (DWI) positivity in relation to onset-to-imaging time in patients with transient neurologic events remains unclear. We hypothesize that episodes consisting of focal symptoms would have proportionally higher DWI-positive imaging at later onset-to-imaging times. METHODS: Patients with transient neurologic symptoms and a normal neurologic examination who had DWI in the combined data set of 3 cohort studies were included. We used logistic regression models to evaluate the association between each type of presenting symptom (motor weakness, speech impairment, sensory symptoms, vision loss, diplopia, gait instability, dizziness, headache, presyncope, and amnesia) and DWI positivity after adjusting for clinical variables (age, sex, history of stroke, dyslipidemia, coronary artery disease, atrial fibrillation, symptoms duration [<10, 10-59, ≥60 minutes, or unclear], and study source). We stratified the results by onset-to-imaging time categories (<6 hours, 6-23 hours, and ≥24 hours). RESULTS: Of the total 2,411 patients (1,345 male, median age 68 years), DWI-positive lesions were detected in 598 patients (24.8%). The prevalence of DWI positivity was highest in those with motor weakness (34.7%), followed by speech impairment (33.5%). In a multivariable analysis, the presence of motor weakness, speech impairment, and sensory symptoms was associated with DWI positivity, while vision loss and headache were associated with lower odds of DWI positivity, but nevertheless had 13.6% and 15.3% frequency of DWI positive. The odds of being DWI positive varied by onset-to-imaging time categories for motor weakness, with greater odds of being DWI positive at later imaging time (<6 hours: odds ratio [OR] 1.25, 95% confidence interval [CI] 0.84-1.87; 6-23 hours: OR 2.24, 95% CI 1.47-3.42; and ≥24 hours: OR 2.42, 95% CI 1.74-3.36; interaction p = 0.033). Associations of other symptoms with DWI positivity did not vary significantly by time categories. DISCUSSION: We found that onset-to-imaging time influences the relationship between motor weakness and DWI positivity in patients with transient neurologic events. Compared with motor, speech, and sensory symptoms, visual or nonfocal symptoms carry a lower but still a substantive association with DWI positivity.

Quality of Life After Intravenous Thrombolysis for Acute Ischemic Stroke: Results From the AcT Randomized Controlled Trial.

BACKGROUND: Recent evidence from thrombolysis trials indicates the noninferiority of intravenous tenecteplase to intravenous alteplase with respect to good functional outcomes in patients with acute stroke. We examined whether the health-related quality of life (HRQOL) of patients with acute stroke differs by the type of thrombolysis treatment received. In addition, we examined the association between the modified Rankin Scale score 0 to 1 and HRQOL and patient-reported return to prebaseline stroke functioning at 90 days. METHODS: Data were from all patients included in the AcT trial (Alteplase Compared to Tenecteplase), a pragmatic, registry-linked randomized trial comparing tenecteplase with alteplase. HRQOL at 90-day post-randomization was assessed using the 5-item EuroQOL questionnaire (EQ5D), which consists of 5 items and a visual analog scale (VAS). EQ5D index values were estimated from the EQ5D items using the time tradeoff approach based on Canadian norms. Tobit regression and quantile regression models were used to evaluate the adjusted effect of tenecteplase versus alteplase treatment on the EQ5D index values and VAS score, respectively. The association between return to prebaseline stroke functioning and the modified Rankin Scale score 0 to 1 and HRQOL was quantified using correlation coefficient (r) with 95% CI. RESULTS: Of 1577 included in the intention-to-treat analysis patients, 1503 (95.3%) had complete data on the EQ5D. Of this, 769 (51.2%) were administered tenecteplase and 717 (47.7%) were female. The mean EQ5D VAS score and EQ5D index values were not significantly higher for those who received intravenous tenecteplase compared with those who received intravenous alteplase (P=0.10). Older age (P<0.01), more severe stroke assessed using the National Institutes of Health Stroke Scale (P<0.01), and longer stroke onset-to-needle time (P=0.004) were associated with lower EQ5D index and VAS scores. There was a strong association (r, 0.85 [95% CI, 0.81-0.89]) between patient-reported return to prebaseline functioning and modified Rankin Scale score 0 to 1 Similarly, there was a moderate association between return to prebaseline functioning and EQ5D index (r, 0.45 [95% CI, 0.40-0.49]) and EQ5D VAS scores (r, 0.42 [95% CI, 0.37-0.46]). CONCLUSIONS: Although there is no differential effect of thrombolysis type on patient-reported global HRQOL and EQ 5D-5L index values in patients with acute stroke, sex- and age-related differences in HRQOL were noted in this study. REGISTRATION: URL: https://www.clinicaltrials.gov; Unique identifier: NCT03889249.

Intravenous tenecteplase compared with alteplase for minor ischaemic stroke: a secondary analysis of the AcT randomised clinical trial.

BACKGROUND: In ischaemic stroke, minor deficits (National Institutes of Health Stroke Scale (NIHSS) ≤5) at presentation are common but often progress, leaving patients with significant disability. We compared the efficacy and safety of intravenous thrombolysis with tenecteplase versus alteplase in patients who had a minor stroke enrolled in the Alteplase Compared to Tenecteplase in Patients With Acute Ischemic Stroke (AcT) trial. METHODS: The AcT trial included individuals with ischaemic stroke, aged >18 years, who were eligible for standard-of-care intravenous thrombolysis. Participants were randomly assigned 1:1 to intravenous tenecteplase (0.25 mg/kg) or alteplase (0.9 mg/kg). Patients with minor deficits pre-thrombolysis were included in this post-hoc exploratory analysis. The primary efficacy outcome was the proportion of patients with a modified Rankin Score (mRS) of 0-1 at 90-120 days. Safety outcomes included mortality and symptomatic intracranial haemorrhage (sICH). RESULTS: Of the 378 patients enrolled in AcT with an NIHSS of ≤5, the median age was 71 years, 39.7% were women; 194 (51.3%) received tenecteplase and 184 (48.7%) alteplase. The primary outcome (mRS score 0-1) occurred in 100 participants (51.8%) in the tenecteplase group and 86 (47.5 %) in the alteplase group (adjusted risk ratio (RR) 1.14 (95% CI 0.92 to 1.40)). There were no significant differences in the rates of sICH (2.9% in tenecteplase vs 3.3% in alteplase group, unadjusted RR 0.79 (0.24 to 2.54)) and death within 90 days (5.5% in tenecteplase vs 11% in alteplase group, adjusted HR 0.99 (95% CI 0.96 to 1.02)). CONCLUSION: In this post-hoc analysis of patients with minor stroke enrolled in the AcT trial, safety and efficacy outcomes with tenecteplase 0.25 mg/kg were not different from alteplase 0.9 mg/kg.