The Toxoplasma oxygen-sensing protein, TgPhyA, is required for resistance to interferon gamma-mediated nutritional immunity in mice.

As Toxoplasma gondii disseminates through its host, the parasite must sense and adapt to its environment and scavenge nutrients. Oxygen (O2) is one such environmental factor and cytoplasmic prolyl 4-hydroxylases (PHDs) are evolutionarily conserved O2 cellular sensing proteins that regulate responses to changes in O2 availability. Toxoplasma expresses 2 PHDs. One of them, TgPHYa hydroxylates SKP1, a subunit of the SCF-E3 ubiquitin ligase complex. In vitro, TgPHYa is important for growth at low O2 levels. However, studies have yet to examine the role that TgPHYa or any other pathogen-encoded PHD plays in virulence and disease. Using a type II ME49 Toxoplasma TgPHYa knockout, we report that TgPHYa is important for Toxoplasma virulence and brain cyst formation in mice. We further find that while TgPHYa mutant parasites can establish an infection in the gut, they are unable to efficiently disseminate to peripheral tissues because the mutant parasites are unable to survive within recruited immune cells. Since this phenotype was abrogated in IFNγ knockout mice, we studied how TgPHYa mediates survival in IFNγ-treated cells. We find that TgPHYa is not required for release of parasite-encoded effectors into host cells that neutralize anti-parasitic processes induced by IFNγ. In contrast, we find that TgPHYa is required for the parasite to scavenge tryptophan, which is an amino acid whose levels are decreased after IFNγ up-regulates the tryptophan-catabolizing enzyme, indoleamine dioxygenase (IDO). We further find, relative to wild-type mice, that IDO knockout mice display increased morbidity when infected with TgPHYa knockout parasites. Together, these data identify the first parasite mechanism for evading IFNγ-induced nutritional immunity and highlight a novel role that oxygen-sensing proteins play in pathogen growth and virulence.

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.

Long-Term Outcomes in Patients With Spontaneous Cerebellar Hemorrhage: An International Cohort Study.

BACKGROUND: Spontaneous intracerebral hemorrhage (ICH) in the cerebellum has a poor short-term prognosis, whereas data on the long-term case fatality and recurrent vascular events are sparse. Herewith, we aimed to assess the long-term case fatality and recurrence rate of vascular events after a first cerebellar ICH. METHODS: In this international cohort study, we included patients from 10 hospitals (the United States and Europe from 1997 to 2017) aged ≥18 years with a first spontaneous cerebellar ICH who were discharged alive. Data on long-term case fatality and recurrence of vascular events (recurrent ICH [supratentoria or infratentorial], ischemic stroke, myocardial infarction, or major vascular surgery) were collected for survival analysis and absolute event rate calculation. RESULTS: We included 405 patients with cerebellar ICH (mean age [SD], 72 [13] years, 49% female). The median survival time was 67 months (interquartile range, 23-100 months), with a cumulative survival rate of 34% at 10-year follow-up (median follow-up time per center ranged: 15-80 months). In the 347 patients with data on vascular events 92 events occurred in 78 patients, after initial cerebellar ICH: 31 (8.9%) patients had a recurrent ICH (absolute event rate, 1.8 per 100 patient-years [95% CI, 1.2-2.6]), 39 (11%) had an ischemic stroke (absolute event rate, 2.3 [95% CI, 1.6-3.2]), 13 (3.7%) had a myocardial infarction (absolute event rate, 0.8 [95% CI, 0.4-1.3]), and 5 (1.4%) underwent major vascular surgery (absolute event rate, 0.3 [95% CI, 0.1-0.7]). The median time to a first vascular event during follow-up was 27 months (interquartile range, 8.7-50 months), with a cumulative hazard of 47% at 10 years. CONCLUSIONS: The long-term prognosis of patients who survive a first spontaneous cerebellar ICH is poor and comparable to that of patients who survive a first supratentorial ICH. Further identification of patients at high risk of vascular events following the initial cerebellar ICH is needed. Including patients with cerebellar ICH in randomized controlled trials on secondary prevention of patients with ICH is warranted.

A Causal Classification System for Intracerebral Hemorrhage Subtypes.

OBJECTIVE: Determining the underlying causes of intracerebral hemorrhage (ICH) is of major importance, because risk factors, prognosis, and management differ by ICH subtype. We developed a new causal CLASsification system for ICH Subtypes, termed CLAS-ICH, based on recent advances in neuroimaging. METHODS: CLAS-ICH defines 5 ICH subtypes: arteriolosclerosis, cerebral amyloid angiopathy, mixed small vessel disease (SVD), other rare forms of SVD (genetic SVD and others), and secondary causes (macrovascular causes, tumor, and other rare causes). Every patient is scored in each category according to the level of diagnostic evidence: (1) well-defined ICH subtype; (2) possible underlying disease; and (0) no evidence of the disease. We evaluated CLAS-ICH in a derivation cohort of 113 patients with ICH from Massachusetts General Hospital, Boston, USA, and in a derivation cohort of 203 patients from Inselspital, Bern, Switzerland. RESULTS: In the derivation cohort, a well-defined ICH subtype could be identified in 74 (65.5%) patients, including 24 (21.2%) with arteriolosclerosis, 23 (20.4%) with cerebral amyloid angiopathy, 18 (15.9%) with mixed SVD, and 9 (8.0%) with a secondary cause. One or more possible causes were identified in 42 (37.2%) patients. Interobserver agreement was excellent for each category (kappa value ranging from 0.86 to 1.00). Despite substantial differences in imaging modalities, we obtained similar results in the validation cohort. INTERPRETATION: CLAS-ICH is a simple and reliable classification system for ICH subtyping, that captures overlap between causes and the level of diagnostic evidence. CLAS-ICH may guide clinicians to identify ICH causes, and improve ICH classification in multicenter studies. ANN NEUROL 2023;93:16-28.

Intravenous Thrombolysis 4.5-9 Hours After Stroke Onset: A Cohort Study from the TRISP Collaboration.

OBJECTIVE: To investigate the safety and effectiveness of intravenous thrombolysis (IVT) >4.5-9 hours after stroke onset, and the relevance of advanced neuroimaging for patient selection. METHODS: Prospective multicenter cohort study from the ThRombolysis in Ischemic Stroke Patients (TRISP) collaboration. Outcomes were symptomatic intracranial hemorrhage, poor 3-month functional outcome (modified Rankin scale 3-6) and mortality. We compared: (i) IVT >4.5-9 hours versus 0-4.5 hours after stroke onset and (ii) within the >4.5-9 hours group baseline advanced neuroimaging (computed tomography perfusion, magnetic resonance perfusion or magnetic resonance diffusion-weighted imaging fluid-attenuated inversion recovery) versus non-advanced neuroimaging. RESULTS: Of 15,827 patients, 663 (4.2%) received IVT >4.5-9 hours and 15,164 (95.8%) within 4.5 hours after stroke onset. The main baseline characteristics were evenly distributed between both groups. Time of stroke onset was known in 74.9% of patients treated between >4.5 and 9 hours. Using propensity score weighted binary logistic regression analysis (onset-to-treatment time >4.5-9 hours vs onset-to-treatment time 0-4.5 hours), the probability of symptomatic intracranial hemorrhage (ORadjusted 0.80, 95% CI 0.53-1.17), poor functional outcome (ORadjusted 1.01, 95% CI 0.83-1.22), and mortality (ORadjusted 0.80, 95% CI 0.61-1.04) did not differ significantly between both groups. In patients treated between >4.5 and 9 hours, the use of advanced neuroimaging was associated with a 50% lower mortality compared with non-advanced imaging only (9.9% vs 19.7%; ORadjusted 0.51, 95% CI 0.33-0.79). INTERPRETATION: This study showed no evidence in difference of symptomatic intracranial hemorrhage, poor outcome, and mortality in selected stroke patients treated with IVT between >4.5 and 9 hours after stroke onset compared with those treated within 4.5 hours. Advanced neuroimaging for patient selection was associated with lower mortality. ANN NEUROL 2023;94:309-320.

Advances in Recurrent Stroke Prevention: Focus on Antithrombotic Therapies.

The past decade has seen significant advances in stroke prevention. These advances include new antithrombotic agents, new options for dyslipidemia treatment, and novel techniques for surgical stroke prevention. In addition, there is greater recognition of the benefits of multifaceted interventions, including the role of physical activity and dietary modification. Despite these advances, the aging of the population and the high prevalence of key vascular risk factors pose challenges to reducing the burden of stroke. Using a cause-based framework, current approaches to prevention of cardioembolic, cryptogenic, atherosclerotic, and small vessel disease stroke are outlined in this paper. Special emphasis is given to recent trials of antithrombotic agents, including studies that have tested combination treatments and responses according to genetic factors.

Long-term headache after spontaneous intracerebral haemorrhage.

BACKGROUND: Though headache is commonly observed after stroke and may affect survivors' quality of life, it has rarely been studied after spontaneous intracerebral haemorrhage (ICH). In a cohort of ICH survivors, we assessed the long-term prevalence and determinants of headache. METHODS: We screened consecutive ICH survivors enrolled in the prospective, single-centre Prognosis of Intracerebral Haemorrhage study for headache 1, 3, and 6 years after ICH, according to the International Headache Society's criteria. Depressive and anxiety symptoms severity was measured at 1-year follow-up. Variables associated with the presence of headache 1 year after ICH were analyzed using univariate and multivariable models. RESULTS: Among the 146 patients included in this study, 31 (21%), 25 (19%), and 14 (20%) patients reported headache at 1-, 3-, and 6-year follow-up, respectively. In an age-adjusted model, patients with headache at ICH onset (adjusted odds ratio [aOR] 2.75; 95% CI 1.02-7.42) and previous history of headache (aOR 4.60; 95% CI 1.74-12.1) were associated with headache at 1-year follow-up. Patients with headache were more likely to report depressive and anxiety symptoms at 1-year follow-up (both p < 0.02). CONCLUSIONS: One in five ICH survivors suffered from headache and patients who reported headache at ICH onset were especially at risk.

Fatigue after spontaneous intracerebral haemorrhage: prevalence and associated factors.

BACKGROUND: Fatigue is a major complaint in stroke survivors, but data focusing on intracerebral haemorrhage (ICH) survivors are scarce. In a cohort of spontaneous ICH survivors, we assessed the long-term prevalence of fatigue and its associated factors. METHODS: We included consecutive 1-year ICH survivors from the prospective, observational, single-centre Prognosis of Intracerebral Haemorrhage (PITCH) study. We evaluated fatigue (defined as a score ≥ 4 in Chalder Fatigue Scale); the severity of neurological, depressive, and anxiety symptoms; and functional disability 1, 3, and 6 years after ICH. We performed univariable and multivariable models to evaluate clinical factors and brain magnetic resonance imaging (MRI) small vessel disease (SVD) markers associated with fatigue. RESULTS: Of 255 1-year ICH survivors, 153 (60%) underwent fatigue screening and were included in this study. Seventy-eight patients (51%) reported fatigue at 1-year, 56/110 (51%) at 3-year, and 27/67 (40%) at 6-year follow-up. Patients with fatigue exhibited more severe concomitant depressive/anxiety symptoms, but the severity of depressive symptoms was the only clinical factor significantly associated with 1-year fatigue in multivariable analysis (adjusted odds ratio 1.4 for one-point increase; 95% confidence interval 1.2-1.6). Patients with severe cortical atrophy at baseline had increased risk of fatigue at 1-year follow-up compared to patients with mild/no cortical atrophy (adjusted odds ratio 2.5; 95% confidence interval 1.1-5.8). CONCLUSIONS: Fatigue after ICH is frequent and long-lasting, and it is associated with cortical atrophy (but not with other MRI markers of cerebral SVD). The link between fatigue and depressive symptoms may represent a potential therapeutic target.

Cerebral Microbleeds During Transcatheter Aortic Valve Replacement: A Prospective Magnetic Resonance Imaging Cohort.

BACKGROUND: Cerebral microbleeds (CMBs) have been observed in healthy elderly people undergoing systematic brain magnetic resonance imaging. The potential role of acute triggers on the appearance of CMBs remains unknown. We aimed to describe the incidence of new CMBs after transcatheter aortic valve replacement (TAVR) and to identify clinical and procedural factors associated with new CMBs including hemostatic measures and anticoagulation management. METHODS: We evaluated a prospective cohort of patients with symptomatic aortic stenosis referred for TAVR for CMBs (METHYSTROKE [Identification of Epigenetic Risk Factors for Ischemic Complication During the TAVR Procedure in the Elderly]). Standardized neurologic assessment, brain magnetic resonance imaging, and analysis of hemostatic measures including von Willebrand factor were performed before and after TAVR. Numbers and location of microbleeds on preprocedural magnetic resonance imaging and of new microbleeds on postprocedural magnetic resonance imaging were reported by 2 independent neuroradiologists blinded to clinical data. Measures associated with new microbleeds and postprocedural outcome including neurologic functional outcome at 6 months were also examined. RESULTS: A total of 84 patients (47% men, 80.9±5.7 years of age) were included. On preprocedural magnetic resonance imaging, 22 patients (26% [95% CI, 17%-37%]) had at least 1 microbleed. After TAVR, new microbleeds were observed in 19 (23% [95% CI, 14%-33%]) patients. The occurrence of new microbleeds was independent of the presence of microbleeds at baseline and of diffusion-weighted imaging hypersignals. In univariable analysis, a previous history of bleeding (P=0.01), a higher total dose of heparin (P=0.02), a prolonged procedure (P=0.03), absence of protamine reversion (P=0.04), higher final activated partial thromboplastin time (P=0.05), lower final von Willebrand factor high-molecular-weight:multimer ratio (P=0.007), and lower final closure time with adenosine-diphosphate (P=0.02) were associated with the occurrence of new postprocedural microbleeds. In multivariable analysis, a prolonged procedure (odds ratio, 1.22 [95% CI, 1.03-1.73] for every 5 minutes of fluoroscopy time; P=0.02) and postprocedural acquired von Willebrand factor defect (odds ratio, 1.42 [95% CI, 1.08-1.89] for every lower 0.1 unit of high-molecular-weight:multimer ratio; P=0.004) were independently associated with the occurrence of new postprocedural microbleeds. New CMBs were not associated with changes in neurologic functional outcome or quality of life at 6 months. CONCLUSIONS: One out of 4 patients undergoing TAVR has CMBs before the procedure and 1 out of 4 patients develops new CMBs. Procedural or antithrombotic management and persistence of acquired von Willebrand factor defect were associated with the occurrence of new CMBs. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT02972008.

Acute Microbleeds and Microinfarcts Within the Perihematomal Area After Intracerebral Hemorrhage.

BACKGROUND: To further our understanding of the pathophysiology of spontaneous intracerebral hemorrhage (ICH) and related injury, we provided a postmortem neuropathological examination of acute microvascular lesions (microbleeds and microinfarcts) within the perihematomal area. METHODS: We included all consecutive cases (2005-2019) from the Lille University Hospital brain bank of ICH patients who died within the first month. Paraffin-embedded tissue sections from the perihematomal area were processed for several stainings and immunolabelings to investigate the presence of acute microbleeds and microinfarcts in the perihematomal area and to characterize surrounding neuronal and systemic inflammatory reaction (macrophages and neutrophils). RESULTS: We included 14 ICH cases (median age, 78 years; 10 females). Acute microbleeds were observed in the perihematomal area in 12/14 patients (86%, ranging from 1 through >10) and microinfarcts in 5/14 (36%, ranging from 1 through 4). Microbleeds were observed whatever the delay from ICH onset to death was, while most cases with acute microinfarcts were observed between day 3 and day 7 (n=3/5). Both lesions were characterized by an abundant accumulation of systemic inflammatory cells and necrotic areas. CONCLUSIONS: Acute microbleeds and microinfarcts might contribute to the propagation of secondary brain tissue damages after ICH. Our examinations also question the potential role of massive systemic inflammatory cells recruitment in the genesis of these microvascular injuries.

Clinical, Neuroimaging, and Genetic Markers in Cerebral Amyloid Angiopathy-Related Inflammation: A Systematic Review and Meta-Analysis.

BACKGROUND: There are limited data regarding the prevalence of distinct clinical, neuroimaging and genetic markers among patients diagnosed with cerebral amyloid angiopathy-related inflammation (CAA-ri). We sought to determine the prevalence of clinical, radiological, genetic and cerebrospinal fluid biomarker findings in patients with CAA-ri. METHODS: A systematic review and meta-analysis of published studies including patients with CAA-ri was conducted to determine the prevalence of clinical, neuroimaging, genetic and cerebrospinal fluid biomarker findings. Subgroup analyses were performed based on (1) prospective or retrospective study design and (2) CAA-ri diagnosis with or without available biopsy. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using Cochran-Q and I2-statistics. RESULTS: We identified 4 prospective and 17 retrospective cohort studies comprising 378 patients with CAA-ri (mean age, 71.5 years; women, 52%). The pooled prevalence rates were as follows: cognitive decline at presentation 70% ([95% CI, 54%-84%]; I2=82%), focal neurological deficits 55% ([95% CI, 40%-70%]; I2=82%), encephalopathy 54% ([95% CI, 39%-68%]; I2=43%), seizures 37% ([95% CI, 27%-49%]; I2=65%), headache 31% ([95% CI, 22%-42%]; I2=58%), T2/fluid-attenuated inversion recovery-hyperintense white matter lesions 98% ([95% CI, 93%-100%]; I2=44%), lobar cerebral microbleeds 96% ([95% CI, 92%-99%]; I2=25%), gadolinium enhancing lesions 54% ([95% CI, 42%-66%]; I2=62%), cortical superficial siderosis 51% ([95% CI, 34%-68%]; I2=77%) and lobar macrohemorrhage 40% ([95% CI, 11%-73%]; I2=88%). The prevalence rate of the ApoE (Apolipoprotein E) ε4/ε4 genotype was 34% ([95% CI, 17%-53%]; I2=76%). Subgroup analyses demonstrated no differences in these prevalence rates based on study design and diagnostic strategy. CONCLUSIONS: Cognitive decline was the most common clinical feature. Hyperintense T2/fluid-attenuated inversion recovery white matter lesions and lobar cerebral microbleeds were by far the most prevalent neuroimaging findings. Thirty-four percent of patients with CAA-ri have homozygous ApoE ε4/ε4 genotype and scarce data exist regarding the cerebrospinal fluid biomarkers and its significance in these patients.

Diffusion-Weighted Imaging Lesion Reversal in Older Patients With Stroke Treated With Mechanical Thrombectomy.

BACKGROUND: Diffusion-weighted imaging lesion reversal (DWIR) is frequently observed after mechanical thrombectomy for acute ischemic stroke, but little is known about age-related differences and impact on outcome. We aimed to compare, in patients <80 versus ≥80 years old, (1) the effect of successful recanalization on DWIR and (2) the impact of DWIR on functional outcome. METHODS: We retrospectively analyzed data of patients treated for an anterior circulation acute ischemic stroke with large vessel occlusion in 2 French hospitals, who underwent baseline and 24-hour follow-up magnetic resonance imaging, with baseline DWI lesion volume ≥10 cc. The percentage of DWIR (DWIR%), was calculated as follows: DWIR%=(DWIR volume/baseline DWI volume)×100. Data on demographics, medical history, and baseline clinical and radiological characteristics were collected. RESULTS: Among 433 included patients (median age, 68 years), median DWIR% after mechanical thrombectomy was 22% (6-35) in patients ≥80, and 19% (interquartile range, 10-34) in patients <80 (P=0.948). In multivariable analyses, successful recanalization after mechanical thrombectomy was associated with higher median DWIR% in both ≥80 (P=0.004) and <80 (P=0.002) patients. In subgroup analyses performed on a minority of subjects, collateral vessels status score (n=87) and white matter hyperintensity volume (n=131) were not associated with DWIR% (P>0.2). In multivariable analyses, DWIR% was associated with increased rates of favorable 3-month outcomes in both ≥80 (P=0.003) and <80 (P=0.013) patients; the effect of DWIR% on outcome was not influenced by the age group (P interaction=0.185) Conclusions: DWIR might be an important and nonage-dependent effect of arterial recanalization, as it seems to beneficially impact 3-month outcomes of both younger and older subjects treated with mechanical thrombectomy for acute ischemic stroke and large vessel occlusion.

Decompressive surgery in cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia.

BACKGROUND AND PURPOSE: Cerebral venous sinus thrombosis due to vaccine-induced immune thrombotic thrombocytopenia (CVST-VITT) is an adverse drug reaction occurring after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccination. CVST-VITT patients often present with large intracerebral haemorrhages and a high proportion undergoes decompressive surgery. Clinical characteristics, therapeutic management and outcomes of CVST-VITT patients who underwent decompressive surgery are described and predictors of in-hospital mortality in these patients are explored. METHODS: Data from an ongoing international registry of patients who developed CVST within 28 days of SARS-CoV-2 vaccination, reported between 29 March 2021 and 10 May 2022, were used. Definite, probable and possible VITT cases, as defined by Pavord et al. (N Engl J Med 2021; 385: 1680-1689), were included. RESULTS: Decompressive surgery was performed in 34/128 (27%) patients with CVST-VITT. In-hospital mortality was 22/34 (65%) in the surgical and 27/94 (29%) in the non-surgical group (p < 0.001). In all surgical cases, the cause of death was brain herniation. The highest mortality rates were found amongst patients with preoperative coma (17/18, 94% vs. 4/14, 29% in the non-comatose; p < 0.001) and bilaterally absent pupillary reflexes (7/7, 100% vs. 6/9, 67% with unilaterally reactive pupil, and 4/11, 36% with bilaterally reactive pupils; p = 0.023). Postoperative imaging revealed worsening of index haemorrhagic lesion in 19 (70%) patients and new haemorrhagic lesions in 16 (59%) patients. At a median follow-up of 6 months, 8/10 of surgical CVST-VITT who survived admission were functionally independent. CONCLUSIONS: Almost two-thirds of surgical CVST-VITT patients died during hospital admission. Preoperative coma and bilateral absence of pupillary responses were associated with higher mortality rates. Survivors often achieved functional independence.

Protecting the Brain, From the Heart: Safely Mitigating the Consequences of Thrombosis in Intracerebral Hemorrhage Survivors With Atrial Fibrillation.

Optimal antithrombotic management after intracerebral hemorrhage remains one of the central unresolved issues for patients who survive, especially for those patients with atrial fibrillation. Given the observational nature of the studies regarding anticoagulation resumption after intracerebral hemorrhage, there is uncertainty regarding resumption of oral anticoagulation therapy and its timing. There is limited high-quality evidence to guide clinical practice, leading to significant practice variation and uncertainty for patients and providers. Here, we aim to provide the key elements to guide clinicians in their individual decision: whether or not to start or resume anticoagulation in patients with a history of intracerebral hemorrhage.

Brain Peri-Hematomal Area, a Strategic Interface for Blood Clearance: A Human Neuropathological and Transcriptomic Study.

BACKGROUND: Enhancing the blood clearance process is a promising therapeutic strategy for intracerebral hemorrhage (ICH). We aimed to investigate the kinetic of this process after ICH in human brain tissue through the monocyte-macrophage scavenger receptor (CD163)/HO-1 (hemoxygenase-1) pathway. METHODS: We led a cross-sectional post-mortem study including 22 consecutive ICH cases (2005-2019) from the Lille Neurobank. Cases were grouped according to the time of death: ≤72 hours, 4 to 7 days, 8 to 15 days, 16 to 90 days, and >90 days after ICH onset. Paraffin-embedded tissue was extracted from 4 strategic areas, including hematoma core and peri-hematomal area to perform histological investigations. Additionally, we extracted RNA from the peri-hematomal area of 6 cases to perform transcriptomic analysis. RESULTS: We included 19 ICH cases (median age: 79 [71-89] years; median delay ICH-death: 13 [5-41] days). The peri-hematomal area concentrated most of reactive microglia, CD163/HO-1 and iron deposits as compared with other brain areas. We found a surge in the blood clearance process from day 8 to day 15 after ICH onset. Transcriptomic analysis showed that HO-1 was the most upregulated gene (2.81±0.39, adjusted P=1.11×10-10) and CD163 the sixth (1.49±0.29, adjusted P=1.68×10-5). We also identified several upregulated genes that exert a beneficial role in terminating inflammation and enhancing tissue repair. CONCLUSIONS: We provide histological and transcriptomic-based evidence in humans for the key role of peri-hematomal area in endogenous blood clearance process through the CD163/HO-1 pathway, especially from day 8 after ICH and favored by an anti-inflammatory environment. Our findings contribute to identify innovative therapeutic strategies for ICH.

Prevalence of Clinical and Neuroimaging Markers in Cerebral Amyloid Angiopathy: A Systematic Review and Meta-Analysis.

BACKGROUND: Limited data exist regarding the prevalence of clinical and neuroimaging manifestations among patients diagnosed with cerebral amyloid angiopathy (CAA). We sought to determine the prevalence of clinical phenotypes and radiological markers in patients with CAA. METHODS: Systematic review and meta-analysis of studies including patients with CAA was conducted to primarily assess the prevalence of clinical phenotypes and neuroimaging markers as available in the included studies. Sensitivity analyses were performed based on the (1) retrospective or prospective study design and (2) probable or unspecified CAA status. We pooled the prevalence rates using random-effects models and assessed the heterogeneity using the Cochran Q and I2 statistics. RESULTS: We identified 12 prospective and 34 retrospective studies including 7159 patients with CAA. The pooled prevalence rates were cerebral microbleeds (52% [95% CI, 43%-60%]; I2=93%), cortical superficial siderosis (49% [95% CI, 38%-59%]; I2=95%), dementia or mild cognitive impairment (50% [95% CI, 35%-65%]; I2=97%), intracerebral hemorrhage (ICH; 44% [95% CI, 27%-61%]; I2=98%), transient focal neurological episodes (48%; 10 studies [95% CI, 29%-67%]; I2=97%), lacunar infarcts (30% [95% CI, 25%-36%]; I2=78%), high grades of perivascular spaces located in centrum semiovale (56% [95% CI, 44%-67%]; I2=88%) and basal ganglia (21% [95% CI, 2%-51%]; I2=98%), and white matter hyperintensities with moderate or severe Fazekas score (53% [95% CI, 40%-65%]; I2=91%). The only neuroimaging marker that was associated with higher odds of recurrent ICH was cortical superficial siderosis (odds ratio, 1.57 [95% CI, 1.01-2.46]; I2=47%). Sensitivity analyses demonstrated a higher prevalence of ICH (53% versus 16%; P=0.03) and transient focal neurological episodes (57% versus 17%; P=0.03) among retrospective studies compared with prospective studies. No difference was documented between the prevalence rates based on the CAA status. CONCLUSIONS: Approximately one-half of hospital-based cohort of CAA patients was observed to have cerebral microbleeds, cortical superficial siderosis, mild cognitive impairment, dementia, ICH, or transient focal neurological episodes. Cortical superficial siderosis was the only neuroimaging marker that was associated with higher odds of ICH recurrence. Future population-based studies among well-defined CAA cohorts are warranted to corroborate our findings.

Reperfusion Without Functional Independence in Late Presentation of Stroke With Large Vessel Occlusion.

BACKGROUND: Reperfusion without functional independence (RFI) is an undesired outcome following thrombectomy in acute ischemic stroke. The primary objective was to evaluate, in patients presenting with proximal anterior circulation occlusion stroke in the extended time window, whether selection with computed tomography (CT) perfusion or magnetic resonance imaging is associated with RFI, mortality, or symptomatic intracranial hemorrhage (sICH) compared with noncontrast CT selected patients. METHODS: The CLEAR study (CT for Late Endovascular Reperfusion) was a multicenter, retrospective cohort study of stroke patients undergoing thrombectomy in the extended time window. Inclusion criteria for this analysis were baseline National Institutes of Health Stroke Scale score ≥6, internal carotid artery, M1 or M2 segment occlusion, prestroke modified Rankin Scale score of 0 to 2, time-last-seen-well to treatment 6 to 24 hours, and successful reperfusion (modified Thrombolysis in Cerebral Infarction 2c-3). RESULTS: Of 2304 patients in the CLEAR study, 715 patients met inclusion criteria. Of these, 364 patients (50.9%) showed RFI (ie, mRS score of 3-6 at 90 days despite successful reperfusion), 37 patients (5.2%) suffered sICH, and 127 patients (17.8%) died within 90 days. Neither imaging selection modality for thrombectomy candidacy (noncontrast CT versus CT perfusion versus magnetic resonance imaging) was associated with RFI, sICH, or mortality. Older age, higher baseline National Institutes of Health Stroke Scale, higher prestroke disability, transfer to a comprehensive stroke center, and a longer interval to puncture were associated with RFI. The presence of M2 occlusion and higher baseline Alberta Stroke Program Early CT Score were inversely associated with RFI. Hypertension was associated with sICH. CONCLUSIONS: RFI is a frequent phenomenon in the extended time window. Neither magnetic resonance imaging nor CT perfusion selection for mechanical thrombectomy was associated with RFI, sICH, and mortality compared to noncontrast CT selection alone. REGISTRATION: URL: https://www. CLINICALTRIALS: gov; Unique identifier: NCT04096248.

Intravenous Thrombolysis in Patients With Ischemic Stroke Aged ≥90 Years: A Cohort Study From the TRISP Collaboration.

BACKGROUND: The probability to receive intravenous thrombolysis (IVT) for treatment of acute ischemic stroke declines with increasing age and is consequently the lowest in very elderly patients. Safety concerns likely influence individual IVT treatment decisions. Using data from a large IVT registry, we aimed to provide more evidence on safety of IVT in the very elderly. METHODS: In this prospective multicenter study from the TRISP (Thrombolysis in Ischemic Stroke Patients) registry, we compared patients ≥90 years with those <90 years using symptomatic intracranial hemorrhage (ECASS [European Cooperative Acute Stroke Study]-II criteria), death, and poor functional outcome in survivors (modified Rankin Scale score 3-5 for patients with prestroke modified Rankin Scale score ≤2 and modified Rankin Scale score 4-5 for patients prestroke modified Rankin Scale ≥3) at 3 months as outcomes. We calculated adjusted odds ratio with 95% CI using logistic regression models. RESULTS: Of 16 974 eligible patients, 976 (5.7%) were ≥90 years. Patients ≥90 years had higher median National Institutes of Health Stroke Scale on admission (12 versus 8) and were more often dependent prior to the index stroke (prestroke modified Rankin Scale score of ≥3; 45.2% versus 7.4%). Occurrence of symptomatic intracranial hemorrhage (5.7% versus 4.4%, odds ratioadjusted 1.14 [0.83-1.57]) did not differ significantly between both groups. However, the probability of death (odds ratioadjusted 3.77 [3.14-4.53]) and poor functional outcome (odds ratioadjusted 2.63 [2.13-3.25]) was higher in patients aged ≥90 years. Results for the sample of centenarians (n=21) were similar. CONCLUSIONS: The probability of symptomatic intracranial hemorrhage after IVT in very elderly patients with stroke did not exceed that of their younger counterparts. The higher probability of death and poor functional outcome during follow-up in the very elderly seems not to be related to IVT treatment. Very high age itself should not be a reason to withhold IVT.

Outcomes of Cerebral Venous Thrombosis due to Vaccine-Induced Immune Thrombotic Thrombocytopenia After the Acute Phase.

BACKGROUND: Cerebral venous thrombosis (CVT) due to vaccine-induced immune thrombotic thrombocytopenia (VITT) is a severe condition, with high in-hospital mortality rates. Here, we report clinical outcomes of patients with CVT-VITT after SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) vaccination who survived initial hospitalization. METHODS: We used data from an international registry of patients who developed CVT within 28 days of SARS-CoV-2 vaccination, collected until February 10, 2022. VITT diagnosis was classified based on the Pavord criteria. Outcomes were mortality, functional independence (modified Rankin Scale score 0-2), VITT relapse, new thrombosis, and bleeding events (all after discharge from initial hospitalization). RESULTS: Of 107 CVT-VITT cases, 43 (40%) died during initial hospitalization. Of the remaining 64 patients, follow-up data were available for 60 (94%) patients (37 definite VITT, 9 probable VITT, and 14 possible VITT). Median age was 40 years and 45/60 (75%) patients were women. Median follow-up time was 150 days (interquartile range, 94-194). Two patients died during follow-up (3% [95% CI, 1%-11%). Functional independence was achieved by 53/60 (88% [95% CI, 78%-94%]) patients. No new venous or arterial thrombotic events were reported. One patient developed a major bleeding during follow-up (fatal intracerebral bleed). CONCLUSIONS: In contrast to the high mortality of CVT-VITT in the acute phase, mortality among patients who survived the initial hospitalization was low, new thrombotic events did not occur, and bleeding events were rare. Approximately 9 out of 10 CVT-VITT patients who survived the acute phase were functionally independent at follow-up.

The deglycosylated form of 1E12 inhibits platelet activation and prothrombotic effects induced by VITT antibodies.

In order to improve the safety of COVID-19 vaccines, there is an urgent need to unravel the pathogenesis of vaccineinduced immune thrombotic thrombocytopenia (VITT), a severe complication of recombinant adenoviral vector vaccines used to prevent COVID-19, and likely due to anti-platelet factor 4 (PF4) IgG antibodies. In this study, we demonstrated that 1E12, a chimeric anti-PF4 antibody with a human Fc fragment, fully mimics the effects of human VITT antibodies, as it activates platelets to a similar level in the presence of platelet factor 4 (PF4). Incubated with neutrophils, platelets and PF4, 1E12 also strongly induces NETosis, and in a microfluidic model of whole blood thrombosis, it triggers the formation of large platelet/leukocyte thrombi containing fibrin(ogen). In addition, a deglycosylated form of 1E12 (DG-1E12), which still binds PF4 but no longer interacts with Fcγ receptors, inhibits platelet, granulocyte and clotting activation induced by human anti-PF4 VITT antibodies. This strongly supports that 1E12 and VITT antibodies recognize overlapping epitopes on PF4. In conclusion, 1E12 is a potentially important tool to study the pathophysiology of VITT, and for establishing mouse models. On the other hand, DG-1E12 may help the development of a new drug that specifically neutralizes the pathogenic effect of autoimmune anti-PF4 antibodies, such as those associated with VITT.