bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3440: A Mouse Model of Germinal Matrix Hemorrhage based on Interactions between Vascular Endothelial Growth Factor (VEGF) and Pericellular Proteases
Authors: Yang Dianer , Kuan Chia-Yi , Baumann Jessica , Liang Hung-Chi
Published: March 2022

A Mouse Model of Germinal Matrix Hemorrhage based on Interactions between Vascular Endothelial Growth Factor (VEGF) and Pericellular Proteases Dianer Yang, Jessica Baumann, Hung-Chi Liang, Chia-Yi Kuan Division of Developmental Biology and Neurology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH, USA.

Introduction:
Germinal Matrix-Intraventricular Hemorrhaging (GMH-IVH) is a major threat to premature infants with a high incidence of neonatal mortality and life-long neurological deficits. The etiology of GMH-IVH is complex and involves both vascular and extravascular factors . However, there are few animal models of GMH-IVH and none addresses the interaction between vasculature and endogenous proteases in pathogenesis.

Hypothesis:
We hypothesize that over-expression of the vascular endothelial growth factor (VEGF) in the germinal matrix is able to induce pericellular proteases (tissue-type plasminogen activator, matrix metalloproteinse, or cathepsins) leading to hemorrhage in mouse embryos.

Methods:
We used a tetracycline-controlled transcriptional activator (tTA) system (bi-transgenic GFAP-tTA: TetO-VEGF165 embryos/mice) to over-express VEGF in the cortical ventricular zone from mid-gestation, when no doxycycline was administered. In the first set of investigation, we examined the cortical vasculature in E15-18 bi-transgenic embryos and sibling controls. The focus is to evaluate the density of blood vessels and the distribution of CD31+ endothelial cells and NG2+ pericytes. Microarray and in-situ hybridization were used to explore the downstream mediators of VEGF. Biochemical assays were used to compare the activity of various proteases. In the second set of study, doxycycline was administered to bi-transgenic embryos from E8 to E18 to adjust the timing of VEGF-induced angiogenesis.

Results:
The majority of bi-transgenic GFAP-tTA: TetO-VEGF165 embryos die before birth. In situ hybridization confirmed increased expression of VEGF in the cortical ventricular zone in bi-transgenic embryos, which exhibited overgrowth of blood vessels, CD31+ endothelial cells, and NG2+ pericytes at E16. The abnormal vessels showed glomeruloid microvascular proliferation-like morphology. Biochemical analysis revealed significantly increased Cathepsin B activity in the cortex of E16 embryos. Microarray and in-situ hybridization confirmed elevated expression of multiple Cathepsins. By E18, the bi-transgenic embryos exhibited spontaneous hemorrhage into the dilated ventricular space.

Conclusions:
High expression of VEGF in the ventricular zone of developing cerebral cortex is sufficient to induce vascular overgrowth and pericellular protease activity, leading to GMH-IVH-like outcomes. These results suggest that anti-VEGF or anti-Cathepsin treatment may interrupt this pathological process.
Abstract 3453: Eliminating Care Disparities: Does Evidence Based Practice Really Work?
Authors: Censullo Joan , Volpi John , Chiu David
Published: March 2022

Background:
Disparities in stroke care have been documented throughout the U.S. Major metropolitans, rural, and academic centers alike have uncovered and experienced care disparities. Interventions that may mitigate disparities have been referenced by the Institutes of Medicine and are readily available. Yet, care inequities continue. The question remains: to what extent does evidence-based practice (EBP) eliminate care disparities.

Methods:
The medical records of 1100 cases from 2010 were reviewed. Mortality, thrombolytic administration, and length of stay (los) were regressed against SES, controlling for EBP and stroke type.

Results:
Typically reported disparities in mortality, thrombolytic administration, los, and stroke core measures were not found for patients whose care was governed by EBP. The sole exception was a slight increase in los for African Americans, which may not be indicative of care inequities but other conditions such as severity or social support. . Core measures compliance was significantly related to MD specialty, for non-stroke physicians (p> 0.002, coef= -0.04). This is consistent with evidence- based practice literature and literature documenting cohorting of patients to practitioners who have greater disease specific experience.

Conclusions:
Outcomes differences did not exist across differing socio-economic strata, when use of evidence based practice was controlled for
Abstract 3559: Differential Effect of High Cholesterol by Intracerebral Hemorrhage Location
Authors: Martini Sharyl R , Brown W. Mark , Comeau Mary E , Flaherty Matthew , Haverbusch Mary , Moomaw Charles , Adeoye Opeolu , Kleindorfer Dawn , Kissela Brett , Broderick Joseph , Langefeld Carl D , Woo Daniel
Published: March 2022

Background:
High cholesterol has been associated with a reduced likelihood of intracerebral hemorrhage (ICH). Lobar ICHs that arise from brain parenchyma near the cortex are predominantly related to amyloid angiopathy and thus have a different risk factor profile than non-lobar ICHs for which the main risk factor is hypertension. We were interested in whether high cholesterol was associated with reduced likelihood of all ICH, or whether there was a differential effect by hemorrhage location.

Methods:
The Genetic and Environmental Risk Factors for Hemorrhagic Stroke Study is a prospective case-control study of hemorrhagic strokes in the Greater Cincinnati/Northern Kentucky region. Charts are abstracted by nurses and verified by physician review to identify cases. Controls selected by random-digit dialing are matched to each case by age (±5 years), race, and sex. Data is collected through structured interview by study nurses within 90 days of onset; history of high cholesterol is determined by self-report. Hemorrhage location is classified by physician review as either lobar or non-lobar (deep gray matter, brainstem, cerebellum, or pure intraventricular hemorrhage).

Results:
Of the 2,850 ICH cases identified from 5/98 to 11/06, 995 died prior to nurse contact, 396 declined interview, and 784 were not contacted within 90 days. To restrict the analysis to spontaneous, first-ever ICH cases among whites and blacks, 78 subjects were excluded due to prior ICH, structural cause of ICH, or “other” race. The remaining 597 subjects underwent direct interview and were matched to 1-3 controls base on ethnicity, age and gender. Frequency of high cholesterol history was 34% for all ICH cases vs. 43% in controls; 40% for lobar cases vs. 43% in their controls; and 31% in non-lobar cases vs. 42% in their controls. Multivariable logistic regression, controlling for hypertension, warfarin use, first-degree relative with ICH, education level, prior ischemic stroke, and Apolipoprotein E genotype, revealed odds ratios and 95% confidence intervals for high cholesterol of 0.57 (0.45-0.72) for all ICH, 0.45 (0.34-0.61) for non-lobar ICH, and 0.85 (0.57-1.26) for lobar ICH.

Conclusions:
High cholesterol is associated with a lower risk of ICH, and this appears to be driven primarily by its association with non-lobar ICHs. This novel finding suggests that hypercholesterolemia may be associated with reduced risk of hypertensive ICH.
Abstract 3565: Nox4 Overexpression is Associated with Thin Fibrous Cap in a Swine Model of Carotid Atherosclerosis
Authors: Shi Zhong-Song , Wang Jin-Shan , Jiang Xiao-Bing , Yuan Wei-Si , Liu Dong-Hong
Published: March 2022

Purpose:
The NADPH oxidases (Nox) are a family of reactive oxygen species generating enzymes, which play an important role in the pathophysiology of atherosclerosis. The relationship of Nox expression with carotid plaque vulnerability has not well been described. Vulnerable plaque with thin fibrous cap may be associated with the feature of distal emboli in a swine model of carotid atherosclerosis. The purpose of this study is to assess the association of Nox4 expression in vulnerable carotid plaque with thin fibrous cap in a swine model. Materials and

Methods:
Carotid atherosclerosis was induced in miniswines using the combination of partial ligation and high cholesterol diet, and a minimum 70% stenosis was confirmed by Doppler ultrasonography immediately post-ligation. Carotid artery sections were obtained for histopathological examination and immunohistochemical study for Nox4 at three months. Distal embolism was determined by the presence of atheroemboli in the ipsilateral rete mirabile. The atherosclerotic lesions of AHA stage type IV to VI were defined as vulnerable plaques. The association of distal embolism in the rete mirabile with vulnerable carotid plaque was analyzed. The association of Nox4 expression in the plaque with the morphological features of plaque vulnerability was analyzed.

Results:
One hundred ninety-one carotid segments from ten carotid artery models were assessed. One hundred two segments had vulnerable plaque. Vulnerable atherosclerotic plaques were found more frequently in the vessel wall proximal to the partial ligation than distal. Distal embolism was found in all 10 rete mirabilis, and deemed to be from the ipsilateral vulnerable carotid plaques. Areas positive for Nox4 tended to be greater in the plaques with the vulnerability features, including necrosis core, marked foam cells, plaque rupture, intraplaque hemorrhage and surface thrombus. The positive expression of Nox4 was associated with the feature of a large lipid core (p=0.035). Forty-eight segments were considered as thin fibrous cap plaques with the minimal thickness of fibrous cap less than 200 μ m. Areas positive for Nox4 were significantly greater in the plaque with thin fibrous cap than in the plaque with thick fibrous cap (p=0.005). On multivariate analysis, positive expression of Nox4 was an independent predictor of thin fibrous cap.

Conclusion:
Vulnerable carotid plaques with distal embolism were created in a swine model of carotid atherosclerosis. Increased expression of Nox 4 is associated with the feature of thin fibrous cap in vulnerable carotid plaques and may be used as a target for reducing the risk of distal embolism.
Abstract 3576: Selective Inhibition Of Rho-kinase Type 2 In Ischemic Stroke
Authors: Lee Jeong Hyun , Yi Zheng , Tong Warwick , Schueller Olivier , Sweetnam Paul , Ayata Cenk
Published: March 2022

Background and aims:
Rho/Rho-associated protein kinase (ROCK) pathway plays a pivotal role in the pathogenesis of vascular diseases including stroke. Indeed, ROCK inhibitors improve cerebral blood flow in ischemic brain, and are neuroprotective in a variety of experimental ischemia models. Evidence suggests that ROCK type 2 (ROCK2) is more relevant in acute stroke treatment. We tested the neuroprotective efficacy and safety of a novel selective small-molecule ROCK2 inhibitor, SLx-2119, in ischemic stroke, and characterized the dose-response and therapeutic window.

Methods and results:
All experiments were conducted by a blinded investigator. Mice were anesthetized with isoflurane (2.5% induction, 1.2% maintenance, in 70% N2O/30% O2), and subjected to 1h transient middle cerebral artery occlusion (MCAO) using an intraluminal filament inserted via the external carotid artery. Regional CBF was monitored using a laser Doppler probed placed over the core MCA territory. Neurological deficits were assessed before sacrifice at 48h, using five-point grading. Indirect infarct volumes were calculated using 1mm-thick TTC-stained coronal sections. SLx-2119 (50-300 mg/kg) or vehicle was administered via orogastric gavage (in 0.4% methylcellulose) every 12h until 48h after reperfusion. When started 24h before MCAO (pre-ischemic treatment), SLx-2119 produced a dose-dependent decrease in infarct volume (37% decrease at 200 mg/kg and 26% decrease at 100 mg/kg) compared to vehicle treated group. Post-ischemic treatment with SLx-2119 (200 mg/kg) remained efficacious when initiated 1h (34% decrease in infarct volume) or 3h (21% decrease in infarct volume), but not 6h after MCAO, suggesting a therapeutic window between 3-6h after stroke onset in mice. SLx-2119 also improved neurological deficits, but did not alter CBF reduction in the ischemic core, systemic arterial pressure, pH or blood gas values, or mortality.

Conclusions:
These data suggest that selective ROCK2 inhibition improves tissue and neurological outcome in acute stroke, with an efficacy comparable to that previously reported for non-selective ROCK inhibitors. Unlike non-selective ROCK inhibitors, ROCK2 inhibition does not precipitate hypotension, an important dose-limiting side effect in acute stroke.
Abstract 3585: Improved Fall Prevention Outcomes Utilizing a Fall Kit, New Products, and Standardized Process on a Neurology Stroke Unit
Authors: Peppa Royce S
Published: March 2022

Background:
Nurses are responsible for identification of patients who are at fall risk, and development of a plan of care to minimize risk in the hospital setting. Therefore, fall rate indicators can be positively influenced by nursing driven safety interventions using an interdisciplinary approach. Barriers to fall prevention and increased fall rates were validated through an assessment of unit nursing practice. Detailed assessment revealed: 1) an inconsistent fall prevention process, 2) lack of fall prevention products and alarm devices, and 3) increased time needed gather fall prevention forms/equipment. This resulted in increased potential risk for harm to patients, and reduced staff compliance.

Purpose:
The purpose was to implement a comprehensive fall prevention program with goals of 1) reduction in patient fall rate and 2) improvement in nursing compliance through use of fall prevention kits, and access to products/alarm devices. We also want to estimate the effect for a larger study and implementation on other nursing units.

Methods:
Methodology included the development of: 1 an interdisciplinary team, 2) the contents of a “fall prevention kit” which contained all necessary products and forms (i.e. room/hall signs, patient color-coded socks, patient and family contract/agreement, fall prevention checklist, and patient fall risk identification band) and 3) a standardized fall prevention process including education for all caregivers, patients and families, and 4) a process to improve access to fall prevention items and purchase of new prevention products. The pre- and post-implementation analyses included monthly fall rates, compliance of fall prevention, improved access and use of products, and staff satisfaction with fall prevention processes.

Results:
Fall Rate with injury pre-implementation defined as # of falls/bed-day x1000 was 1.16 and showed overall improvement post-implementation at a rate of 0.77 (≤.39). Improvement was also shown in compliance of caregivers with the standardized process (100%), reduction in time to access to products/devices reduced by 10 minutes per daily fall assessment episode (avg.10 pts/day= 100 minutes) and staff satisfaction with the new process (95.5%).

Conclusion:
Prevention in patient falls is critical to reduce risk of injury, cost of hospitalization, prolonged length of stay, disability, and/or death. A collaborative team approach utilizing a standardized process and improved access to products/devices was imperative to improve fall prevention strategies, diminish risk for injury, as well as improve nursing compliance on the stroke unit.
Abstract 3595: Perfusion imaging predicts Outcome in TIA and Minor Stroke. A Prospective Derivation-Validation Study
Authors: Asdaghi Negar , Coulter Jonathan I , Modi Jayish , Qazi Abdul , Goyal Mayank , Butcher Ken S , Demchuk Andrew , Hill Michael , Coutts Shelagh B
Published: March 2022

Background:
Patients presenting with transient or minor ischemic symptoms (TIA/MIS) are at risk for early deterioration. Identification of those at highest risk for progression may justify more aggressive acute reperfusion treatments. We tested the hypothesis that baseline perfusion (PWI)- diffusion (DWI) mismatch predicts clinical deterioration and infarct growth on follow-up imaging in this population.

Methods:
Patients with TIA/MIS (NIH Stroke Scale ≤ 3) were prospectively enrolled and imaged within 24 hours of symptom onset as part of two sequential prospective imaging studies. All patients had clinical follow-up. Baseline DWI and PWI (tmax+4s delay) and follow-up FLAIR infarct volumes (day 30 (derivation), day 90 (validation) cohort) were measured. Mismatch volumes were calculated as (Tmax+4s delay) - DWI lesion volume. Primary outcome was infarct growth on FLAIR imaging which was defined a priori as growth of at least 2.5 ml. Secondary outcome was clinical progression.

Results:
137 patients were included in the derivation and 281 patients in the validation cohorts. The rates of DWI (54% vs 56%, p= 0.67) and PWI lesions (42% vs 34.5%, p=0.16) at baseline were similar between the cohorts. The median time between symptom onset and baseline imaging was significantly shorter in the derivation (9.2 h, IQR=9.4) relative to the validation sets (15.1h, IQR=12.5 p<0.001). More patients had follow-up imaging in the derivation (87%) compared to the validation (76%) cohort (p=0.021). Primary and secondary outcome occurred in 18.5% and 9.5% in the derivation and 5.5% and 4.6% in the validation cohort. In the derivation cohort, baseline mismatch volumes adjusting for age, sex and time from symptom onset to MRI significantly predicted radiographic progression (OR=1.06 [1.03-1.09], p<0.001). The optimal threshold for maximizing sensitivity (Sen) and specificity (Spec) in predicting infarct growth occurred at a mismatch volume of 10ml; which correctly predicted infarct expansion with 82% (Sen) and 91%(Spec) (Area under the curve (AUC)= 0.89 [0.80-0.98]). In the validation cohort, this threshold was highly predictive of radiological progression (p=0.011, McNemars test). Linear regression showed that for every 10ml of mismatch, there would be 2.5ml infarct growth on day 30 FLAIR [R=0.80, p<0.001] (derivation set) and 1.1 ml of growth on day 90 FLAIR (R=0.22, p<0.001) (validation set). Baseline mismatch showed a high discriminative value in predicting clinical deterioration in the derivation (AUC =0.81 [0.67-0.96]) and moderate value in the validation cohort (AUC=0.66 [0.46, 0.85]).

Conclusion:
In a population of patients with minor stroke and TIA, early MR perfusion-diffusion mismatch predicts infarct growth and clinical progression. These findings suggest that there may be a group of patients with minor symptoms in whom reperfusion strategies may be beneficial.
Abstract 3603: Emergency Pre-hospital Stroke Triage In Washington State, Understood Through A Cohort
Authors: Sultan-Qurraie Ali , Tirschwell David L , Longstreth W. T , Becker Kyra J , Kay Marlan
Published: March 2022

BACKGROUND:
Washington State (WA) has legislated an emergency pre-hospital stroke triage system, with 3 levels of self-identified stroke centers. Our objective is to describe the new system using an existing cohort of pre-hospital patients and to extrapolate our findings to all of WA.

METHODS:
The cohort consisted of a population-based sample of patients whom emergency medical service (EMS) personnel treated over a 30-month period. All patients whose Seattle Fire Department records suggested a possible pre-hospital stroke diagnosis had hospital records reviewed for final diagnosis: TIA, ischemic stroke, intracerebral hemorrhage (ICH), subarachnoid hemorrhage (SAH), or “not a stroke.” These patients were also classified according to the FAST (Face, Arm, Speech, Time last normal) stroke screen. The WA pre-hospital stroke triage tool divides patients into 4 groups: FAST-, FAST+/>6h (arrived at hospital > 6 or unknown hours after last known normal), FAST+/>3.5-6h (arrived in window for intra-arterial (IA) therapies) and FAST+/<=3.5h (arrived in window for IV tPA).

RESULTS:
The cohort included 1,682 possible stroke patients, mean age 76 years, 60% women. We applied the stroke triage tool to our cohort with results shown in the
Table
. Assuming similar stroke presentations and given the population of WA is ∼11 times that of Seattle, we estimate that ∼2500 patients/yr would be triaged as possible IV tPA candidates; ∼450 patients/yr would be triaged as possible IA candidates with possibly longer transport to a Level 1 stroke center. There was significant heterogeneity in final diagnoses by triage tool categorization (
Table
, P < 0.0005). The triage tool identified combined IV or IA candidates with a sensitivity of 90% (95% CI 83-94%), specificity 91% (90-93%) and C statistic of .90 (.88-.93). Of the 10% of IV or IA candidates missed, 81% had initial NIHSSs < 3.

CONCLUSION:
These are the first estimates of how the WA pre-hospital stroke triage tool will parse patients. Discrimination of acute ischemic stroke patients eligible for time dependent interventions was excellent; the low NIHSS scores in 81% of those missed suggests an even higher clinically relevant sensitivity. A small proportion (2.4%) of the possible stroke patients presenting to EMS will meet criteria for transport to Level 1 stroke centers, suggesting the additional burden on EMS should be minimal.
Abstract 3655: Development of a Large Scale Predictive Atlas of Clinical Outcome in Acute Ischemic Stroke
Authors: Kidwell Chelsea , Szpakowski Natalie , Stidd Reva , Alger Jeffry R
Published: March 2022

Background:
Neuroimaging studies including diffusion and perfusion-weighted imaging identify the location and neuroanatomic extent of brain ischemia in the acute phase of infarction. Although there has been substantial progress in using early neuroimaging studies to predict whether localized regions of brain tissue will proceed to infarction or recover, there has been little effort to define imaging parameters that predict which of the patient’s acute functional deficits will remain or resolve with potential recanalization/reperfusion treatments. This information may be particularly important in late time windows when the number of patients with salvageable penumbral tissue progressively declines. We previously reported development of a proof of concept acute stroke imaging atlas correlating DWI lesions and NIHSS items in a relatively small number of subjects. The goal of the current analysis was to expand this atlas to include a much larger number of cases.

Methods:
As part of a global project aimed at creating a large scale stroke-specific predictive brain atlas, we correlated acute DWI lesion location with the presence of individual sub-item scores from the NIHSS. Inclusion criteria were: acute ischemic stroke; brain MRI (including DWI) performed within 24 hours of symptom onset; and baseline NIHSS score available. Intramural NINDS provided the imaging and clinical data. Acute DWI images from all subjects were aligned to a common neuroanatomic coordinate system. Chi square images were calculated on a voxel-by-voxel basis.

Results:
A total of 400 patients were included in the analysis. Mean age was 69, range 21-98. Baseline NIHSS was median 5, mean 7, range 0-32. The
figure
shows representative axial slices from the atlas, including color-coded chi square values, using a false discovery rate of 5%, for anatomic regions in which there was a significant correlation between NIHSS sub-item symptom presence and DWI hyperintensity.

Conclusions:
Employing a large dataset including 400 acute stroke patients, we have developed a large scale voxel-based stroke atlas correlating NIHSS sub-items employing acute DWI lesion data. The maps illustrate the neuroanatomic representation of the NIHSS sub-items in standardized space. An important next step will incorporate acute diffusion and perfusion MR imaging to predict long-term outcome for two scenarios: untreated vs. treated with recanalization therapy. This information may then assist in guiding treatment decisions for late recanalization therapies.
Abstract 3703: Utility of Cardiac MRI in Evaluation of Stroke Subtypes
Authors: Mowla Ashkan , Baher Alex A. , Shah Dipan J. , Volpi John J.
Published: March 2022

Introduction
: Cardiac magnetic resonance imaging (CMR) is a novel imaging modality that may aid in identifying potential cardiac etiology of ischemic stroke. We assessed the prevalence of cardiac abnormalities by the CMR in a population of patients with acute stroke.

Patients and Methods
: We performed CMR on 89 patients who were admitted to our stroke service between August 2009 and June 2011. None of these patients had MRI contraindication. Of those, 13 patients were excluded due to negative diffusion weighted MRI, one was excluded for having intracranial bleeding, and one for having vertebral artery dissection as the source of stroke. The remaining 74 patients with DWI positive or CT positive acute stroke were analyzed for abnormalities on cardiac MRI. CMR along with other routine stroke work up including MRI of the brain and MRA of head and neck were done for these patients within the first 48 hours of their admission. We consider cardioembolic etiology as definite, probable, or possible based on the presence of an abnormality on the CMR. We consider atherothrombotic etiology as definite, probable, or possible if there was a 50% or greater arterial stenosis identified in the territory of the infarct.

Results
: In our 74 patients, we found definite cardioembolic source in 21 patients (28.3%), definite atherothrombotic source in 14 patients (18.9%) and no definite etiology in 12 patients (16.2%).In the other patients (36.4%), there was at least one abnormality in CMR or MRA head /neck which could be considered as the probable or possible etiology of acute stroke. In the patients with definite cardioembolic source (21 patients), enlargement of left atrium were found in 9 (43%), systolic dysfunction in 6 (29%), mural thrombus in 5 (24%), mural scar in 4 (19%), myocardial infarction in 2 (9%) and cardiac mass in 1 (5%).

Conclusion:
CMR is an effective non-invasive modality in diagnosing cardioembolic etiologies in patients with stroke. Further studies to compare the effectiveness of CMR with other modalities such as transesophageal echocardiography are recommended.
Abstract 3744: Brain's High Constitutive Background Autophagy Level Is Disrupted by Stroke Injury and Post-stroke Pharmacological Induction of Autophagy Reduces Lesion Size
Authors: Buckley Kathleen M , Herberg Samuel , Hoda Nasrul , Ahmed Ajmal , Periyasamy-Thandavan Sudharsan , Hess Daniel , Barrett John , Kondrikova Galina , Hess David C , Schoenlein Patricia , Hill William D
Published: March 2022

Background:
Autophagy is a highly regulated and dynamic process that allows cells to recycle aging organelles, bulk proteins and lipids for nutritional reuse. Autophagy occurs in all cell types and body tissues and is induced by oxidative stress or lack of nutrients to promote survival. Excessive autophagy, however, can lead to cell death, including apoptotic (PCD type I) and autophagic cell death (PCD Type II). Recent literature reports that autophagy is disregulated during stroke and other brain injuries. We hypothesized that the normally high innate level of autophagy in the brain undergoes aberrant regulation during stroke injury and this aberrant regulation correlates to changes in stroke lesion size.

Methods:
We induced ischemia in C57BL/6J mice using a permanent MCA ligation model, with sacrifice 48 hours after stroke. For time course analysis mice were sacrificed at 3, 6, 12, 24, 48, or 72 hours after stroke. Mice were treated i.p. with chloroquine (30, 60, or 90 mg/K/d for 2 days), an autophagy inhibitor, rapamycin (1.25 or 2.5 mg/K/d for 2 days), an autophagy activator via inhibition of mTOR, or treated with vehicle (saline or 10% DMSO in 100 ul). The autophagy markers LC3, p62 and Beclin-1 were analyzed by Western blot and immunohistochemistry and infarct size was measured by TTC staining.

Results:
Brain showed consistently higher baseline levels of LC3II than other tissues. Chloroquine and rapamycin both reduced lesion size, the former between 28 & 34% and the later, in a dose dependent fashion, between 60 and 65%. Beclin-1 is decreased in the infarct side of the brain and treatment with rapamycin enhanced this depletion while treatment with chloroquine increased Beclin-1 levels. LC3II is decreased in the infarct side and does not increase with chloroquine treatment on the infarct side, suggesting that stroke injury may inhibit the high innate baseline level of autophagy in the brain. Rapamycin led to increased LC3II and p62, consistent with increased induction of autophagy. Time course analysis of stroked brains showed that LC3II and Beclin-1 are initially decreased at 3 to 6 hours post injury, then increased above non-injured between 12 and 24 hours before it falls below baseline at 48 to 72 hours.

Conclusions:
1) Stroke appears to inhibit the high innate baseline levels of autophagy in the brain after the injury. 2) Since chloroquine and rapamycin both decreased lesion size, this suggests cross-talk between autophagy and other programmed cell death pathways and/or direct effects of the drugs on these and other pathways. 3) The rapid decrease in autophagy markers post injury indicates that modulation of autophagy may offer a new therapeutic avenue for stroke.
Abstract 3758: Long-term Recurrence of Venous Thrombotic Events After Cerebral Vein Thrombosis
Authors: Cantu Brito Carlos , Arauz Antonio , Merlos Benitez Marlon , CHIQUETE ERWIN
Published: March 2022

Background.
It is assumed that cerebral venous thrombosis (CVT) implies a lower risk of death and recurrence at short- and mid-term follow-up; however, few information exist on risk factors and outcome of thrombotic venous recurrence after CVT in the long run. We aimed to describe the 20-year recurrence of intra and extracranial venous thrombotic events after an index CVT in a large cohort.

Methods.
Among 412 consecutive patients, we analyzed 336 (81.6%) cases (82,7% women, mean age: 30.9 years, range: 14 to 83 years) registered from 1986 to 2010 in a third-level referral center of Mexico City, for whom complete information of recurrent events was available and who survived the acute phase of CVT.

Results.
In a median follow-up of 28 months (range 2 to 288 months), the recurrence rate of either systemic or intracranial venous thrombotic events was 6.8% (n=23): 2.7% of recurrent CVT, 3% lower-limb thrombosis and 1.1% pulmonary embolism). Recurrent venous events occurred by a median of 5 months (range: 1 to 113 months), with 78% cases recurring in the following year after index CVT. Nonetheless, recurrent CVT occurred within 5 months in 78% cases. None of the recurrent CVT events caused death, but 50% of pulmonary embolisms were mortal. In a Cox proportional hazards model adjusted for multiple confounders, baseline factors associated with an increased risk of recurrent intra or extracranial venous thrombosis were thrombosis of jugular veins [hazard ratio (HR): 5.13, 95% confidence interval (CI): 1.39-18.9], diagnosis of anti-phospholipid syndrome (HR: 2.67, 95% CI: 1.01-7.07), mechanical ventilation (HR: 2.07, 95% CI: 1.08-3.93), and alcoholism (HR: 3.44, 95% CI: 1.12-10.58).

Conclusion.
Most venous recurrent events occur in the following year after index CVT. Recurrent CVT is not associated with a high mortality, but extracranial venous thromboembolisms can be fatal. This study is the largest to date on this topic.
Abstract 3774: Clinical Nurse Specialists, Nurse Practitioners&Physician Assistants Roles in the care of Stroke Patients
Authors: Kiernan Terri E
Published: March 2022

Background:
The promotion of acute stroke care is stronger now than it has ever been with hospitals being encouraged to become primary and comprehensive stroke centers (PSC & CSC). This is a hardship for some institutions due to the national shortage of American Board of Psychiatry and Neurology certified Vascular Neurologists and Emergency Medicine Physicians’ concern over independent decision making regarding thrombolysis eligibility without neurology collaboration. Hospitals and private physician practices are turning to Clinical Nurse Specialists (CNS), Nurse Practitioners (NP) and Physician Assistants (PA) to provide a continuum and maintain coordination of care in concurrence with vascular neurologists. The aim of this presentation is to identify the CNS-NP-PA roles and responsibilities.

Method:
An eight question, multiple choice with 3 multiple answer survey, which addressed certification, duration of stroke experience, role with CT reviewing, thrombolysis administration, and duties was sent to community and academic PSC and CSC CNS-NP-PAs from Neurovascular Education and Training in Stroke Management and Acute Reperfusion Therapy (NET SMART) program by means of a URL.

Results:
There were 44 respondents, NPs 65.9%, PAs 4.9% and CNS 29.2% with experience in stroke care totaling 1 to 2.9 years in 20.5%, 3 to 4.9 years in 15.9% and ≥ 5 years in 63.6%. Acute CT evaluation was completed autonomously by 10%, with radiology collaboration in 47.5%, and with neurology collaboration in 37.5%, with 5% responding “do not review”. Multiple choice with multiple answers pertaining to thrombolysis decision making; 7.3% reported working autonomously, 29.3% with physician collaboration by telephone, 63.4% with physician at bedside, and 17.1% reported no involvement with thrombolysis decisions. Delineation of responsibilities, also completed with multiple answers included acute inpatient stroke care for 95.2%, out patient stroke care for 23.8%, discharge planning 45.2%, stroke coordinator role 71.4%, core measure database extraction for 50.0% with input of database completed by 47.6%. Education conducted for patients at 81%, for nursing was 90.5%, for peers at 57.1%, for medical residents 40.5%, for neurology residents 16.7% and for community education 73.8% of responders.

Conclusion:
Although individual responsibilities may vary, the survey illustrates the CNS-NP-PA are valuable roles in the assessment, diagnosis, management, coordination and continuum of stroke care. More research is warranted to further evaluate these roles and quality stroke patient outcomes.
Abstract 3778: Trends in the Incidence, Types and Outcomes of Intracerebral Hemorrhage in Ontario from 1990 - 2010
Authors: Stamplecoski Melissa , Fang Jiming , Kapral Moira K , Silver Frank L
Published: March 2022

Background:
Intracerebral hemorrhage (ICH) accounts for approximately 15% of all acute strokes and is associated with the highest stroke mortality. The purpose of this study was to examine the incidence of ICH in Ontario over the last 20 years and investigate whether there have been changes in patient characteristics and treatment interventions over time.

Methods:
We analyzed data from a provincial administrative database to determine the rates of ICH in Ontario from 1990 to 2010. Data from the Registry of the Canadian Stroke Network (RCSN) from 2003 to 2008 were then used to investigate potential changes in demographic variables (age, gender), stroke severity (Canadian Neurological Scale), comorbidities (hypertension, atrial fibrillation), preadmission medications (warfarin, antihypertensives), hemorrhage location (lobar vs. deep), initial glucose, initial INR and outcomes (modified Rankin Scale at discharge, hospital length of stay) in ICH patients over time.

Results:
There were 30,353 patients in the administrative database who were admitted with a final diagnosis of ICH between 1990 and 2010. The mean age of these patients was 70.3 years, 51.5% were male and the 30-day mortality rate was 40.6%. The age of patients with ICH increased over this time period (especially in the group >85 years of age), the length of hospital stay shortened and the 30-day mortality rate decreased slightly.
Figure 1
shows the sex/age standardized ICH rate per 100,000 by fiscal year, which shows a decline in the ICH rate since 1997. From the 2,466 patients with ICH in the RCSN database from 2003 to 2008, the statistically significant changes included an increase in the lobar hemorrhage rate (39.2% to 46.9%, p=0.0000), an increase in the use of statins at admission (19% to 24%, p=0.0350) and a decrease in the mean systolic blood pressure (173.8±37.5 to 166.4±35.07, p=0.0040). There were no changes over time in neurosurgical interventions (craniotomy or intracranial pressure monitoring).

Conclusions:
In Ontario, based on hospitalizations, the rate of ICH increased until 1997 and since then has steadily decreased. This decline in the ICH rate over the past 12 years may reflect better management of hypertension.
Abstract 3793: Wake-up Strokes Similar to Known-Onset Morning Strokes in Severity and Outcomes
Authors: Denny M. Carter , Albright Karen C , Boehme Amelia K , Martin-Schild Sheryl
Published: March 2022

Background:
Stroke symptoms first noticed upon waking (wake-up strokes) account for 15-30% of all acute ischemic strokes. Whether or not the onset of ischemic stroke wakes people from sleep is not known. We sought to compare patient demographics, stroke characteristics and outcomes among people with wake-up strokes to those with known-onset morning strokes.

Methods:
Using retrospective chart review, we identified patients with wake-up strokes (WUS). WUS was defined as asleep for >3 hours and symptoms noted on wakening from 01:00-11:00. We then identified patients with known-onset morning stroke, defined as symptoms noted when patient already awake, during same time interval. We compared WUS to known-onset morning strokes with respect to patient demographics, stroke severity, etiology and outcomes.

Results:
112 patients with documented time of 01:00-11:00 when symptoms were first noted were included in the analysis; 33 (29.5%) wake-up strokes and 79 (70.5%) known-onset morning strokes. Patients with WUS were significantly more likely to be female (p=0.009). WUS patients demonstrated a trend toward lower IV tPA treatment rate (p=0.079), higher atherosclerotic burden with greater proportion having carotid artery stenosis (p=0.109), and large vessel mechanism (40.6% vs. 24%). A higher proportion of cortical involvement was also observed among wake-up strokes (p=0.07). Wake-up stroke and known-onset morning strokes were similar with respect to stroke severity (as measured by NIHSS score) at presentation, 24 hours and discharge. WUS was not an independent significant predictor of favorable functional status (mRS 0-2, p=0.371), good disposition (home or inpatient rehab, p=0.909) or mortality (p=0.303). Discussion: While wake-up strokes were similar to known-onset strokes that occurred in the same time interval in stroke severity, functional outcomes, disposition and mortality, WUS patients tended to be older, to be female, and to have large vessel disease. A larger sample size is needed to discern whether large artery atherosclerosis is more likely to cause ischemic stroke while a patient in sleeping and if IV tPA alters the natural history of wake-up strokes.
Abstract 3797: Patients with Diabetes and Previous Ischemic Strokes in the National Institute of NINDS trial
Authors: Sangha Navdeep S , Huang Jing , Grotta James C , Savitz Sean
Published: March 2022

Background and Purpose
Ischemic stroke is the leading cause of morbidity in the United States. Intravenous recombinant tissue plasminogen activator (rt-PA) given within 4.5 hours from symptom onset has shown to improve outcomes. The ECASS III trial, which helped to extend the time window for thrombolysis, had specific exclusion criteria. One of these exclusions was patients who had a past medical history of both previous diabetes (DM) and an ischemic stroke. This retrospective study aims to evaluate the impact of a previous history of both DM and an ischemic stroke on outcome in patients in the NINDS trial.

Methods
A retrospective review was conducted of the NINDS database. Subjects with a previous history of both DM and an ischemic stroke were identified. Baseline characteristics were analyzed for any difference between the two groups. The outcome measures included symptomatic intracerebral hemorrhage (sICH) as defined by NINDS criteria, and 90 day NIHSS, mRS and death. The statistical analysis was performed using a two sample median test and a Fisher’s exact test.

Results:
Thirty four individuals were identified with a previous history of DM and ischemic stroke. Fifteen (4.8%) were in the treatment group and 19 (6.1%) were in the placebo group. The median age in those treated with rt-PA was 74.6 years compared to 61.9 years in those who received placebo (p=0.02). The median systolic blood pressure was 178mmHg in the treated group versus 150mmHg in the placebo group (p=0.02). There was no difference between the baseline NIHSS. The rt-PA treated patients had a sICH rate of 6.67% compared to 5.26% in the placebo group (p=0.70). The median NIHSS at 90 days was 5 in the treated group and 3.5 in the placebo group (p=0.26). The median 90 day mRS was 4 in the rt-PA group and 2 in the placebo group (p=0.29). Four (26.7%) of treated patients died compared to 3(15.8%) of patients in the placebo group (p=0.67).

Conclusion:
Subjects in the NINDS trial who had the past medical history of both DM and an ischemic stroke were older and had a higher blood pressure in the treatment arm. There was no difference in the sICH rate between both groups. There was no difference in the outcomes of both groups. This study is limited by its retrospective nature and the small sample size of the sub-group.
Abstract 3822: Neutrophils and Toll-like receptor 4 Contribute to Injury after Intracerebral Hemorhage
Authors: Sansing Lauren H , Harris Tajie H , Kasner Scott E , Hunter Christopher A , Kariko Katalin
Published: March 2022

Background:
Inflammation contributes to injury after intracerebral hemorrhage (ICH). We have previously demonstrated that activation of Toll-like receptor 4 (TLR4) on cells within the hemorrhage is a key initiator of the inflammatory response. TLR4-deficient mice had reduced infiltrating neutrophils, monocytes, inflammatory monocytes, and microglia. TLR4-deficient mice given an ICH comprised of blood from a WT donor had increased recruitment of these cell populations. Our current objective was to determine whether intrahematomal neutrophils contribute to the TLR4-dependent inflammatory response.

Methods:
WT (C3H/HeOuJ) mice were depleted using a neutrophil-selective antibody (anti-Ly6G, clone 1A8, 5 mg/kg) or control rat IgG the day prior to being used as blood donors for ICH in TLR4-deficient (C3H/HeJ) mice. ICH was created by stereotaxic injection of 15 μ L blood from a neutrophil-depleted or control donor into the right striatum. Mice were tested on the cylinder test for 3 days and then sacrificed for analysis of leukocyte populations in the brain by flow cytometry. Brains were mechanically and enzymatically digested and then cells harvested from a 30%-60% Percoll gradient. Cells were then stained with fluorophore-conjugated antibodies to CD45, CD3, CD11b, CD11c, Ly6G, and Gr1 and counted on a LSRII cytometer. Cells were identified as microglia (CD45lowCD11b+), leukocytes (CD45hi), neutrophils (CD45hiCD11b+Ly6G+), monocytes (CD45hiCD11b+Ly6G-CD11b-Gr1-), inflammatory monocytes (CD45hiCD11b+Ly6G-CD11b-Gr1+) or dendritic cells (CD45hiCD11b+CD11c+Ly6G-).

Results:
TLR4-deficient mice with a WT, neutrophil-depleted ICH showed reduced numbers of leukocytes (p<0.05), dendritic cells (p<0.01), and microglia (p<0.05) compared to the TLR4-deficient mice with a WT, control ICH. There was no difference in neutrophils, monocytes, or inflammatory monocytes. The TLR4-deficient mice with a neutrophil-depleted ICH had better functional outcomes throughout the first 3 days after ICH (p<0.05 each day).

Conclusions:
Neutrophils within the ICH contribute to increases in microglia and dendritic cells as well as the neurological deficit in the TLR4-deficient host. However, the specific populations of leukocytes reduced after neutrophil depletion did not mirror the findings in TLR4-deficient mice given an ICH using autologous blood, which had reduced neutrophils, monocytes, and inflammatory monocytes. This suggests that intrahematomal neutrophils have a role in initiating TLR4 signaling but other cells contribute to the recruitment of monocyte and neutrophil populations.
Abstract 3846: Contrast Permeation In Hyperdense Artery Sign: Evidence Of Freshly Forming Thrombus Accumulating Around The Initial Clot? Pilot Data From The Interrsect Multicentre Thrombus Imaging Study.
Authors: Menon Bijoy , Sohn Sung-Il , Calleja Ana , Dowlatshahi Dar , Puig Josep , Jin Albert , Poppe Alex , Moreau Francois , Boulanger Jean-Martin , Stewart Teri , Goyal Mayank , Hill Michael D , Demchuk Andrew M ,   INTERRSeCT Study Group
Published: March 2022

Introduction:
Previous work has examined the importance of thrombus density impacting recanalization with systemic thrombolysis. The mechanism underlying thrombus density however is not well understood. RBC content is known to be high in hyperdense thrombi. We evaluated the relationship between density of thrombi and flow characteristics within and adjacent to thrombi in iv tPA treated patients in the INTERRSeCT pilot study.

Methods:
The pilot data analysed includes any patient (age > 40) with evidence of a visible and symptomatic thrombi on baseline CTA treated with IV t-PA as standard of care. Each patient enrolled in the study had early recanalization assessed on repeat CTA within 3-5 hours of baseline imaging. Imaging data were analyzed in a core-imaging lab. Hyperdense sign on NCCT, length and presence of contrast permeation through thrombus on CTA were assessed on 5 mm image slices using OSIRiX, an image processing software.

Results:
Of 101 patients enrolled in INTERRSeCT, 35 patients with MCA or intracranial ICA thrombi (mean age 70+− 12.5 yrs, 53% male) treated with IV t-PA were included in this analysis. The hyperdense sign (HDS) was seen in 22/35 (62.8%) and contrast permeation through thrombus was seen in 19/35 (54.2%). Median clot length was significantly higher in patients with HDS when compared to those without (2.46 cm vs 1.33 cm, p=0.03). We noted increased probability of contrast permeation in the presence of HDS (68.1% in HDS+ vs 30.7% in HDS-, p=0.03). (
Table
and
Figure
) HDS was associated with significantly lower early recanalization rates (36.3% in HDS+ vs 84.6% in HDS-, p=0.01).

Conclusion:
The evidence of contrast permeation, increased density and longer length of occlusion support the hypothesis that hyperdense artery sign represents freshly forming thrombus accumulating around the initial clot. These composite clots recanalize less with IV t-PA when compared to native clots. A larger cohort of patients is required to confirm these results.