bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TMP80: Intraoperative Blood Flow Changes Predict Angiographic Outcomes After Direct Cerebral Revascularization For Moyamoya Disease
Authors: AHMED Syed Uzair , Lee Hubert , Steinberg Gary
Published: February 2022

Introduction:
Moyamoya Disease (MMD) is a progressive steno-occlusive vasculopathy of the large intracranial vessels precipitating ischemic and hemorrhagic events. Cerebral revascularization is the mainstay of treatment in MMD. Intraoperative measurements of cerebral blood flow following direct intracranial bypass may be performed to quantitatively assess the anastomosis.

Objectives:
To correlate intraoperative flow parameters in direct cerebral bypass for moyamoya disease to postoperative angiographic and clinical outcomes.

Methods:
Consecutive patients undergoing direct superficial temporal artery (STA) to middle cerebral artery (MCA) bypass were retrospectively analyzed. Preoperative and 6-month postoperative patient data was collected including presenting symptoms, MRI and angiographic findings, neurological complications, and functional outcome. Intraoperative cerebral blood flow was measured from the donor and recipient arteries using a micro flow probe pre- and post-anastomosis.

Results:
A total of 50 direct revascularization procedures in 39 patients were analyzed, of which 40 were in females (80%). The mean flow prior to anastomosis in the M4 MCA was +2.2 ± 6.1 ml/minute and +26.8 ± 19.0 ml/min in the STA. Post-anastomosis, the mean flow was -10.9 ± 14.8 ml/min (towards the Sylvian Fissure) in the proximal M4 and +7.9 ± 9.2 ml/min in the distal M4. At 6-month follow-up angiography, the graft was patent in all cases, with 98% demonstrating direct supply. A component of indirect supply was observed in 56% of grafts. Matsushima grade A, B, and C revascularization were obtained in 64%, 20%, and 16% of cases, respectively. Amongst Matsushima grade A patients, low flow was observed in the M4 (mean 1.7 ± 4.8 ml/min) prior to bypass, which became retrograde following bypass, measuring -13.5 ± 16.0 ml/min. Lower post bypass flow was observed in grade B and C patients, with -6.8 ± 13.1 ml/min and -5.6 ± 10.3 ml/min, respectively. Postoperative stroke occurred in one patient, who had a Matsushima grade C.

Conclusions:
Greater intraoperative retrograde flow in the recipient MCA immediately following anastomosis was observed in patients achieving a higher Matsushima grade.
Abstract TMP83: Comparison Of Clinical Features And Vessel Involvement In Isolated Reversible Cerebral Vasoconstriction Syndrome And Associated Posterior Reversible Encephalopathy Syndrome
Authors: Scarsella Monica , Amin Moein , Toljan Karlo , Uchino Ken
Published: February 2022

Introduction:
Reversible cerebral vasoconstriction syndrome (RCVS) may co-occur with brain MRI T2/FLAIR sequence changes, and posterior reversible encephalopathy syndrome (PRES) may be associated with cerebral vasoconstriction. Both entities with overlapping features may be considered as a single group. We compared the isolated RCVS group to the overlapping group to investigate clinical and radiological features, with a focus on vessel involvement.

Methods:
We performed a retrospective study of adult patients admitted to a tertiary medical center from February 2008 until February 2018 and who were diagnosed with PRES or RCVS. Overlap cases consisting of PRES with vasoconstriction and RCVS with reversible MRI T2/FLAIR changes were compared to isolated RCVS cases. Clinical and radiological features of both groups were compared with each other. Involved vessel segments were classified as internal carotid artery, M1 and M2 middle cerebral artery, A1 and A2 anterior cerebral artery, P1 and P2 posterior cerebral artery, vertebral artery, and basilar artery. Severity was also graded (1-49% or >49%). Appropriate statistical tests were used to compare the variables and significant findings reported.

Results:
There were 86 cases with isolated RCVS and 44 cases of overlap. Seizures (19, 43%) and encephalopathy (13, 30%) were common in the overlap group, whereas headache was common in the isolated RCVS group (79, 92%). Immunosuppressant use was more often present in the overlap group (9, 20%), but there were no differences in antidepressant, cocaine, or marijuana use. Intracerebral hemorrhage was more common in the overlap group (12/44, p=0.003), but there were similar numbers of ischemic strokes and subarachnoid hemorrhages. There were no differences in the number or location of segments involved or stenosis severity between the groups. Home discharge was more frequent among pure RCVS (73, 85%) than among overlap patients (27, 61%, p=0.004).

Conclusion:
Clinical presentations and short-term prognosis differed among isolated RCVS and group with PRES-RCVS overlap characteristics. There was no difference in vascular involvement between the groups.
Abstract TMP90: Perioperative And Delayed Stroke After Surgical Revascularization In Pediatric Moyamoya Arteriopathy
Authors: Gatti John R , Gardner Sarah E , Sun Lisa R
Published: February 2022

Introduction:
Surgical revascularization is the mainstay of management in severe moyamoya arteriopathy (MMA). While perioperative stroke has been characterized, little is known about delayed postoperative stroke.

Methods:
We retrospectively identified patients diagnosed with MMA between 28 days and 18 years of age seen at our center between 1/2003 and 6/2021 using ICD codes. Those who underwent surgical revascularization either at our or another center were analyzed. Descriptive analysis of patients experiencing perioperative (defined as ≤7 days after surgery) versus delayed postoperative stroke (stroke occurring >7 days after surgery) was conducted.

Results:
53 unique patients underwent 68 revascularization surgeries of 95 hemispheres. Median age at time of surgery was 8.3 years. Median time from surgery to final follow-up was 6.6 years. Postoperative stroke occurred in 11 (16%) cases, including 7 (10%) in the perioperative period and 4 (6%) >7 days after surgery. Patients with delayed stroke had a median age of 5.1 years at surgery, and median time to stroke was 87 days. While MMA associated with Trisomy 21 represented only 15% of cases in our sample, these cases accounted for 36% of postoperative strokes. Delayed stroke occurred more frequently in patients with unilateral revascularization. These patients developed infarcts contralateral to the revascularized hemisphere.

Conclusions:
Delayed stroke following surgical revascularization in patients with MMA occurred less frequently than perioperative stroke in our cohort. Trisomy 21 may be a risk factor for postoperative stroke. Further study is needed to characterize and predict which patients are at risk for delayed stroke.
Abstract TMP94: Health Inequity And Time From Stroke Onset To Arrival Trends: A Single-centre Experience
Authors: Pai Akshat M , Nichol Daniel , To Teresa , Ertl-Wagner Birgit , Kassner Andrea , Deveber Gabrielle A , Dlamini Nomazulu
Published: February 2022

Introduction:
Clinical outcomes post childhood stroke have been shown to largely depend on age at the time of stroke, and the size and location of the infarct. However, the impact of health inequities on time to hospital arrival and outcomes remain inadequately addressed. This study examined trends in material deprivation and its impact on time from stroke onset to arrival in the ER for children with arterial ischemic stroke.

Methods:
A consecutive cohort of children >28 days-18 years of age diagnosed with arterial ischemic stroke between 2004 and 2019 at a comprehensive stroke centre were included. The Ontario Marginalization Index data for each child was derived from their residential postal code using validated mapping techniques. Within the index, material deprivation measures the income, education, single-parent families, and housing quality in a region. Patients were stratified into 3 cohorts by year of presentation; Cohort 1: 2004-2008, Cohort 2: 2009-2013, and Cohort 3: 2014-2019, while their postal codes were dichotomized into low or highly deprived neighbourhoods. The time from stroke onset to arrival was stratified into < 6 hours, 6 to 24 hours, and > 24 hours.

Results:
Amongst 285 children, more lived in a highly deprived neighbourhood in the later cohort (Cohort 3: 2014-2019) than the earlier cohort (Cohort 1: 2004-2008) (47.5% vs. 40.3%). Compared to Cohort 1, more patients in Cohort 3 arrived in the ER within 6 hours of stroke onset (28.3% vs 52.5%) while a similar trend was found in patients arriving 6 to 24 hours post onset of stroke (10.1% vs. 23.2%). From Cohorts 1 to 3, a significant increase in the proportion of patients arriving in the ER within 6 hours of stroke onset was found (χ
2
= 10.9,
p
= 0.027).

Conclusion:
Our study demonstrated an increasing trend toward more patients with stroke coming from highly deprived neighbourhoods. This is a cause for concern. However, whether this has an impact on stroke severity and outcomes is yet to be determined. Over the same period, more patients within the later cohort arrived in the ER within 6 hours of stroke onset. These findings may be attributed to sustained community-based education and primary-care initiatives that have led to increased awareness of childhood stroke symptoms over the past 15 years.
Abstract TMP96: Maladaptive Plasticity In Dystonia Following Pediatric Basal Ganglia Stroke: Associations Between Structural Connectivity And Cognitive Functioning
Authors: Ledochowski Justine , Feldman Samantha , Walker Kirstin , Domi Trish , Robertson Amanda , Jobst Cecilia , Cheyne Douglas , Westmacott Robyn , D Mary , Dlamini Nomazulu
Published: February 2022

Background:
Dystonia is one of the most common movement disorders after pediatric basal ganglia stroke, causing significant disability. It presents several months post stroke suggesting a role of maladaptive neuroplasticity in its manifestation. Children with dystonia show additional difficulties in intelligence (IQ), academics, and cognitive inhibition, beyond those associated with stroke.

Objective:
To examine structural connectivity in children with post-stroke dystonia and its relationship with cognitive outcomes.

Method:
A prospective study of children with unilateral basal ganglia stroke and dystonia and healthy controls. Diffusion tensor imaging was used to assess white matter integrity in the cingulum and superior longitudinal fasciculus (SLF) using fractional anisotropy (FA) and mean diffusivity (MD). Participants completed measures of IQ and cognitive inhibition and flexibility.

Results:
Six children with basal ganglia stroke and dystonia (6 female; Median age= 15.98, IQR= 4.32) and 6 neurotypical controls (3 male; Median age= 18.01, IQR= 5.13) were included. Participants were age-matched within 1-3 years. Hemispheres were matched by dominance such that if the stroke was in the dominant hemisphere the control’s dominant hemisphere was matched to the ipsilateral side and vice versa. Mann Whitney-U tests showed children with dystonia had poorer performance on measures of IQ (U= 0, p=. 002, η
2
= .69) and inhibition (U= 4.5, p= .026, η
2
= .39). FA was lower in the ipsilateral cingulum (U= 5, p= .041, η
2
= .36) and MD was higher in the ipsilateral SLF (U= 32, p= .026, η
2
= .42) in the dystonia participants. Significant associations (p< .05) were found between ipsilateral cingulum FA and IQ (r= .56), inhibition (r= .76), and flexibility (r= .60); contralateral cingulum FA and inhibition (p= .59); ipsilateral SLF FA and inhibition (r= .51) and flexibility (r= .58); and ipsilateral SLF MD and inhibition (r= -.54) and flexibility (r= -.55). Associations between the contralateral cingulum FA and IQ (r= .47, p= .060) and flexibility (r= .50, p= .051) trended to significance.

Conclusion:
Findings support the hypothesis that post-stroke dystonia reflects maladaptive reorganization after injury that is associated with motor and cognitive outcome.
Abstract TMP98: Insights From Meta-analysis Of Studies With Models Predicting Stroke Or Composite Outcomes: A 2021 Study Update
Authors: Saxena Anshul , Zhang Zhenwei , Ahmed Md Ashfaq , McGranaghan Peter , Rubens Muni , Veledar Emir
Published: February 2022

Objective:
There are several challenges in implementing models for predicting stroke or stroke related outcomes. Most of these models have average concordance, and several of the important variables cannot be modified. In this study, we updated and performed a meta-analysis of commonly utilized models to predict stroke related outcomes. Our primary aim was to evaluate the discriminative ability of the concordance statistic by adding additional studies.

Methods:
Studies reporting c-index and SE (or 95% CI) for predicting stroke or related outcomes were included in our analysis. In addition to the c-index, total participants, year of publication, type of analytical method (survival, logistic regression, neural network, etc.) and type of outcome (predicting stroke or composite outcome) were utilized. Combined effect sizes with the random model, test for heterogeneity, and publication bias were considered. Egger’s test was used to assess funnel asymmetry.

Results:
Twenty-seven models were included (patients= 1762461; c-index=14, Harrell’s c-index= 13; only stroke =21, composite=6) in the analysis. Combined mean c-index was 0.76 (95% CI: 0.71, 0.81; 95% predictive interval: 0.59, 0.93). Combined mean Harrell’s c-index was 0.65 (95% CI: 0.61, 0.69; 95% predictive interval: 0.56, 0.74). Test of heterogeneity showed high variation between studies reporting c-index and Harrell’s c-index (I2=97.49% and 80.0% respectively). Egger’s test intercept was -2.1 (95% CI: -7.2, 3.0, P > .40) for c-statistic and 1.2 (95% CI: -1.2, 3.5, P > .32) for Harrell’s c-index studies.

Conclusion:
Current studies have not improved the prediction interval significantly as compared to our previous meta-analysis for predictive or explanatory model available for stroke risk. However, recent studies were found to be more inclusive of non-traditional biomarkers (e.g., genetic, or polygenic scores) and utilized various machine learning methods that were not used before.
Abstract TP1: Chlorpromazine And Promethazine Inhibits Oxidative Stress After Ischemic Stroke
Authors: Guo Sichao , Geng Xiaokun , Ding Yuchuan
Published: February 2022

Background:
Excess reactive oxygen species (ROS) generated by nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) promotes apoptotic cell death following ischemic/reperfusion injury. Effect of chlorpromazine and promethazine (C+P) on brain activity was reported to induce neuroprotection. The current study was designed to evaluate the inhibitory function of C+P on oxidative injury after stroke.

Methods:
Adult male Sprague-Dawley rats were subjected to 2 h middle cerebral artery occlusion (MCAO) followed by 6 or 24 h of reperfusion. At the onset of reperfusion, rats received C+P, or apocynin (NOX inhibitor), or rottlerin [protein kinase C (PKC) δ inhibitor]. Brain damage was evaluated using infarct volumes and neurological deficits as well as apoptotic cell death (TUNEL). The enzymatic activity of NOX and ROS production as well as protein expressions of NOX subunits (gp91
phox
, p67
phox
, p47
phox
, and p22
phox
), phosphorylation of PKC δ (p-PKC δ)/PKC δ and manganese superoxide dismutase (MnSOD) was examined. Neural SHSY5Y cells were used under 2 h of oxygen-glucose deprivation (OGD) followed by reoxygenation for 6 and 24 h with or without C+P treatment. ROS and protein levels of NOX subunits, p-PKC δ/PKC δ and MnSOD were detected. Moreover, measurement of PKC δ membrane translocation and detection of the interaction of p47
phox
and PKC δ through co-immunoprecipitation were performed.

Results:
C+P reduced cerebral infarct volumes, neurological deficits, and apoptotic cell death in the ischemic rats, as well observed in the presence of NOX and PKC δ inhibitors. ROS production, NOX activity, expression of NOX subunits, p-PKC δ/PKC δ and MnSOD were significantly reduced by C+P. In ischemic rats administered with NOX and PKC δ inhibitors, ROS, activity of NOX and the NOX subunits protein levels were all decreased. In the OGD/R model, C+P decreased ROS and protein levels of NOX subunits, p-PKC δ/PKC δ and MnSOD. Furthermore, C+P reduced the PKC δ membrane translocation and the interaction of p47
phox
and PKC δ.

Conclusion:
C+P treatments confers neuroprotection in severe stroke by suppressing oxidative stress and ROS production. PKC δ/NOX/MnSOD may be the vital regulators and the potential targets for an efficacious therapy following ischemic stroke.
Abstract TP10: Inflammatory And Neurodegenerative Gene Expression Changes Occur Long-term After ICH
Authors: Hooper Destiny , Howard Timothy D , Williamson Brady J , BEHYMER Tyler P , Comeau Mary E , Zimmerman Kip , Khandwala Vivek , Gilkerson Lee A , Kittner Steven J , Roh David J , James Michael L , Testai Fernando D , Vahidy Farhaan S , Bagga Ranjit S , Thornton James B , Maloney Thomas , Sawyer Russell P. P , Shatz Rhonna S , Boyne Pierce , Dunning Kari , Vagal Achala , Langefeld Carl D. D , Woo Daniel
Published: February 2022

Objective:
There is a high prevalence of progressive cognitive impairment in intracerebral hemorrhage (ICH) survivors. We sought to identify gene expression changes, in association with long-term neurodegeneration, among patients 12-24 months post-ICH.

Methods:
The
Recovery and Outcomes from StrokE (ROSE)
study prospectively recruits patients with spontaneous, supratentorial ICH, collecting baseline peripheral blood samples and MRI with diffusion tract imaging (DTI). The
Recovery of StrokE-Longitudinal Assessment with Neuroimaging (ROSE-LAWN)
study performs long term follow-up at 12-24 months on cases enrolled in ROSE. We report on the first five cases enrolled in the ROSE-LAWN study from December 2020 to March 2021. Controls were matched to an overall ICH population by age, sex, and race. RNA-sequencing, aligned to human genome assembly GRCh38, was tested for differential gene expression. Canonical pathway enrichment and network analyses were computed for differentially expressed genes using Ingenuity Pathway Analysis, STRING and MCODE.

Results:
RNA-seq analysis of 5 ICH cases [male, 80%; median age, 61 (45 - 73); black, 40%; ICH volume, 14.88cc ± 13.07] and 13 controls [male, 54%; median age, 74 (69 - 79); black, 15%] identified 554 differentially expressed genes (genomic control adjusted p < 0.01), of which 24 met the false discovery rate correction for multiple comparisons (FDR < 0.05). The most significant difference was observed in hypoxia up-regulated 1 (
HYOU1),
a heat shock protein related gene (p = 2.64E-11). Pathway analysis identified enrichment of dopamine and serotonin receptor signaling (p = 8.74E-03, 2.23E-02), cell cycle regulation (p = 1.75E-02) and agranulocyte adhesion pathways (p = 2.18E-02). Comparison of baseline and follow-up MRI DTI demonstrated extensive cortical tract degeneration, beyond the initial injury.

Conclusion:
These results provide novel evidence of significant gene expression changes occurring years after the initial ICH. Despite resolution of the ICH, persistent inflammation may correlate with progressive neurodegeneration and subsequent cognitive impairment in ICH survivors. Future studies with greater sample sizes are supported by this work.
Abstract TP103: Vertebral Artery Tortuosity And Morphometric Characteristics In Recurrent Cervical Artery Dissection
Authors: Narrett Jackson A , Aldridge Chad M , Garrett John , Abdalla Basil , Donahue Joseph , Worrall Bradford B , Southerland Andrew M
Published: February 2022

Background:
Cervical Artery Dissection (CeAD) is an important cause of stroke in the young. Data on incidence and associations of recurrent CeAD are lacking. Increased Vertebral Artery Tortuosity Index (VTI) has been reported in patients with CeAD and associated with earlier age of arterial dissection in patients with connective tissue disease. We hypothesized that VTI may be associated with recurrent CeAD.

Methods:
We reviewed data from a large single-center registry of CeAD patients enrolled between 2011-2021. CT angiography (CTA) was reviewed for neck length, vertebral artery length (VAL), linear distance from the vertebral artery origin to the vertebrobasilar junction (VOBJ), and VTI [((VAL/VOBJ)–1)*100]. Recurrence was defined as radiographic diagnosis of a new dissection during a follow-up period between initial CTA imaging and July 1, 2021. Incidence rate of recurrent dissection was calculated using Poisson regression. Differences between groups were analyzed using the Kruskal-Wallis rank sum test and Fisher’s exact test.

Results:
The cohort included 155 patients: women (56%), mean (SD) age 42 (±10) years, and 116 single (carotid or vertebral) and 39 multiple artery dissections. Eight (5%) had a recurrence with a 10 year incidence rate (95% CI) of 1.23 events (0.53, 2.38) per 100 person-years. The recurrent group had a lower mean VTI than the nonrecurrent group (39.2 vs. 45.8; p = 0.024) and trended towards a lower mean age (34.6 vs. 42.3; p = 0.058). Participants with vertebral artery dissection were younger than those with carotid artery dissection with mean ages of 38.5 and 45.1 respectively (p < 0.001) and did not differ in mean VTI (46.0 vs. 44.9; p = 0.747). Morphometric characteristics of height, neck length, and BMI were not associated with recurrence.

Conclusion:
In this single center cohort of patients with CeAD, greater VTI was associated with a decreased risk of recurrent dissection. This finding is hypothesis generating as adults with recurrent dissections may have distinct mechanistic or genetic factors contributing to their risk of dissection. This study is limited by relatively small sample size and the retrospective analysis. Further study of VTI and risk of incident CeAD in larger independent cohorts is warranted.
Abstract TP107: Sex-differences In Intracranial Atherosclerosis Among Hypertensive Patients With Ischemic Stroke
Authors: Song Jae W , Xiao Jiayu , liu xiao , Wu Fang , Schlick Konrad , Yang Qi , Song Shlee S , Fan Zhaoyang
Published: February 2022

Introduction:
We hypothesized sex-differences in the prevalence of intracranial atherosclerosis (ICAS) among hypertensive patients with ischemic stroke due to ICAS.

Methods:
Subjects with ischemic stroke secondary to ICAS underwent MR vessel wall imaging (VWI) within 8 weeks of symptom onset. Demographic data, cardiovascular risk factors, and medication history were recorded. A neuroradiologist blinded to clinical history scored proximal (A1/M1/P1) and distal (A2/M2-3/P2) plaques involving the anterior/middle/posterior cerebral arteries. The most stenotic vessel lesion with wall thickening/enhancement and supplying the ischemic territory was defined as a culprit plaque. Continuous variables are summarized by medians and interquartile ranges. Chi square and Mann Whitney U-tests compared categorical and continuous variables, respectively.

Results:
Sixty-one subjects (male, N=42) with a diagnosis of hypertension and ischemic stroke due to ICAS were included. There were no significant sex-differences in demographic or cardiovascular risk factors except for smoking history (p=0.002). Hypertensive males with ischemic stroke due to ICAS had a significantly higher number of proximal plaques than females [males=8 (4, 10) vs females=5 (3, 7); p=0.03; Figure] but not distal plaques [males=3 (1, 5) vs females=2 (0, 5); p=0.33]. Among subjects on an anti-hypertensive prior to admission (N=35), males with ischemic stroke had a significantly higher proximal plaque burden than females [males=8 (4, 10) vs females=4 (3, 6); p=0.05]. The culprit plaque was proximal in 95% and 92% of cases in males and females treated for hypertension and with ischemic stroke, respectively.

Conclusions:
Attention to differential management of hypertension for males versus females may be warranted to reduce ischemic stroke risk given significantly higher proximal ICAS burden in hypertensive males than females despite medical treatment.
Abstract TP108: Intracranial Artery Calcification: Frequency, Determinants, And Modification Of Outcomes From Endovascular Thrombectomy
Authors: Phan Allan , Yoo Bryan , Liebeskind David S , Sharma Latisha K , Bahr Hosseini Mersedeh , Jahan Reza , Duckwiler Gary , Tateshima Satoshi , Nour May , Szeder Viktor , Colby Geoffrey , Saver Jeffrey L
Published: February 2022

Introduction:
Intracranial artery calcification (ICAC) is a common finding on CTA in patients presenting with LVO acute ischemic stroke and could potentially serve as a useful biomarker of intracranial atherosclerosis and altered intracranial vessel pliability in patients undergoing endovascular thrombectomy (EVT). However, ICAC frequency, determinants, and outcome associations have not been well delineated.

Methods:
In a prospectively maintained database, we analyzed consecutive patients undergoing CTA immediately prior to EVT from Mar 2016 - Aug 2020. Extent of ICAC in the intracranial ICA or VA proximal to the target vessel was scored using a validated grading scale (Babiarz et al, AJNR 2003: 5 levels for greatest calcific thickness and 5 levels for greatest circumferential extent). Example cases in Figure 1. Patients were stratified into low (0-2), medium (3-4), and high (5-6) ICAC groups.

Results:
Among 91 patients, mean age was 73, 54% female, and mean NIHSS 17. Median ICAC score was 3 [IQR 0-4]. Baseline characteristics associated with higher ICAC scores were: CAD (3.8 vs. 2.4,
p
= 0.02), HTN (3.1 vs. 2.1,
p
= 0.07), and age (
r
= 0.50, p < 0.001). There was a U-shaped association between ICAC score and successful reperfusion (mTICI 2b-3): 90.9%, 65.7%, and 95.0% in low, medium, and high ICAC score groups, respectively (
p
= 0.006). Need for rescue intervention (angioplasty/stenting, IA thrombolysis, or GpIIb/IIIa inhibitor) was higher in the high ICAC group: 5.9% vs. 5.6% vs. 28.6% (
p
= 0.01). Functional independence (mRS 0-2) at discharge (29.4% vs. 22.2% vs. 19.0%,
p
= 0.64) or 90 days (40.0% vs. 30.0% vs. 21.4%,
p
= 0.22) did not differ, nor did symptomatic intracranial hemorrhage (
p
= 0.96).

Conclusions:
Calcification of intracranial vessels is frequently seen on CTA in LVO patients and is associated with age and vascular risk factors. Degree of calcification has important associations with rates of successful reperfusion and need for rescue intervention during EVT.
Abstract TP110: Clinical Risk Factors For Stroke And Associations With Microembolic Signals On Transcranial Doppler
Authors: Adil Abdullah , Mitchell Carol , Cook Thomas , Bock Jenna , Meshram Nirvedh , Steffel Catherine , Varghese Tomy , Wilbrand Stephanie , Dempsey Robert J
Published: February 2022

Introduction:
Transcranial Doppler (TCD) has been used to identify microembolic signals (MES) in individuals with carotid atherosclerosis. MES are hypothesized to originate from unstable carotid plaque and have been identified in both symptomatic and asymptomatic individuals with cerebrovascular disease. The purpose of this study was to examine the relationship of clinical risk factors (CRF) for stroke and the presence of MES to further understand how clinical risk factors are associated with MES.

Method:
Participants (n=89) scheduled for clinically indicated CEA (>60% stenosis NASCET and ACAS Criteria) were evaluated preoperatively for CRF for stroke and the presence MES with TCD. TCD was performed for 60 minutes examining both the right and left middle cerebral arteries. Kendall’s tau correlation coefficients were used to examine the relationship between MES and continuous CRFs. Pearson χ2 test was used to examine the relationship between MES and categorical CRFs. Logistic regression analysis with backward selection was used to examine the relationship between MES presence and CRFs (symptomatic status, age, sex, BMI, heart rate, blood pressure, hypertension, hyperlipidemia, diabetes, peripheral vascular disease, previous stroke, tobacco use, cardiac risk for MES, cancer, and taking aspirin).

Results:
Participants had a median (interquartile range [IQR]) age of 71(13) years, 30(33.7%) female, and 53(59.6%) were symptomatic. MES were detected in 32 (36%) participants. There was significant evidence of association between MES with older age (p =0.026) and male sex (p =0.007). No other clinical variables showed significant association with MES (all p-values>0.05). Logistic regression (with p output 0.10) demonstrated that a model including age(p=0.018), sex(p=0.013) and hyperlipidemia(p=0.083) was significantly associated with the presence of MES(p=0.001).

Conclusion:
MES were associated with age and sex in a cohort with advanced carotid atherosclerosis. Symptomatic status was not a predictor for MES in this cohort, suggesting that plaques in both symptomatic and asymptomatic individuals have the ability to release microemboli, highlighting the need for further work to be done to identify unstable plaques.
Abstract TP111: Pterygopalatine Fossa Blockade As Novel, Narcotic-sparing Treatment For Headache In Patients With Spontaneous Subarachnoid Hemorrhage - A Case Series
Authors: J.P. Teixeira Fernanda , Smith Cameron R , Garvan Cynthia , Spana Jessica C , Maciel Carolina , Busl Katharina M
Published: February 2022

Background & Purpose:
Severe headache is a hallmark of spontaneous subarachnoid hemorrhage (SAH), affecting nearly 90% of patients during index hospitalization. In addition, up to 25% of SAH-survivors experience chronic headaches. Despite its high prevalence, means of management of headaches are limited, largely reliant on opioids, and often ineffective. Urgent efforts to reduce opioid use require innovative treatment strategies for the management of post-SAH headaches.

Methods:
This is a retrospective cohort comprising 12 adults who received bilateral pterygopalatine fossa (PPF) blockade from 9/2018 to 3/2021 for refractory headaches after spontaneous SAH. We examined pain scores, analgesic requirements and transcranial doppler ultrasound (TCD) parameters before and after the block placement. Descriptive statistics were calculated for all variables.

Results:
Twelve patients (mean age 54 years, 66% females, nine aneurysmal and three non-aneurysmal SAH) received PPF-block on post-bleed day 2 to 11 (median 6.5) during hospitalization in the neurointensive care unit. Hunt and Hess scores ranged from 1-3. Pain scale scores from 24-hour period before the block (8.8 ±1.4; mean, SD) decreased significantly to a mean of 5.1 (SD ± 3.0) until 20 hours post-block (p = 0.0156). Opioid use also decreased significantly from median (range) oral morphine equivalent dose (mg) administered in the 24h before the block of 22.5 (0-75) vs. 7.5 (0-45) after PPF-block (p=0.0391). Five (41%) patients had radiographic (but not clinical) vasospasm by TCD criteria before PPF-block; in four of these patients, TCD velocities improved on the day after PPF-block, in one patient velocities were increased on the day after PPF-block. The block was well tolerated with no adverse events of bleeding, infection, pain, or numbness at the injection site.

Conclusion:
These results demonstrate that PPF-blockade might be a promising alternative for managing post-SAH headaches. Further prospective controlled randomized powered to address the safety and efficacy of the PPF-block are warranted.
Abstract TP122: Comparison Of Pharmacologic And Physical Venous Thromboembolism Prophylaxis: A Single Center Descriptive Analysis
Authors: Sandhu Sukhmani
Published: February 2022

Introduction:
Recent American Heart Association/American Stroke Association guidelines suggest that physical venous thromboembolism (VTE) prophylaxis modalities are effective at preventing VTE events.

Objective:
To compare the incidence of VTE events among AIS patients receiving either pharmacologic prophylaxis or physical prophylaxis during hospitalization.

Methods:
Single center data was retrospectively analyzed among AIS patients who developed DVT or PE during their hospitalization. Patients were selected from January 1, 2016 - December 31, 2020. Inclusion criteria included age 18 and above, AIS patients, diagnosis of acute or chronic VTE events, and exclusive use of physical or pharmacologic VTE prophylaxis modality. We excluded patients who received combined SCD and pharmacologic prophylaxis during hospitalization.

Results:
Of 5104 patients diagnosed with AIS, 40 patients (0.8%) developed VTE events during their hospitalization. Of these, 29/40 (73%) received pharmacologic VTE prophylaxis and 11/40 (27%) received physical VTE prophylaxis. Of the 3488 patients receiving pharmacologic VTE prophylaxis, 29 (0.8%) developed VTE. Of the 1616 that received physical VTE prophylaxis, 11 (0.7%) developed VTE.

Conclusions:
Our single center study observed higher rates of VTE events among AIS patients receiving pharmacologic VTE prophylaxis in comparison to physical VTE prophylaxis.
Abstract TP124: Early Neurological Improvement Can Reduce Intensive Care Unit Length Of Stay In Aneurysmal Subarachnoid Hemorrhage
Authors: Snow Ryan , Shamshad Alizeh , Helliwell Alexandra , Stretz Christoph , Potter Nicholas S , Wendell Linda C , Thompson Bradford , Furie Karen L , Reznik Michael , Mahta Ali
Published: February 2022

Introduction:
Aneurysmal Subarachnoid Hemorrhage (aSAH) is often accompanied by an extended length of stay (LOS) in the intensive care unit (ICU), at tremendous cost to both the hospital system and the patient. We sought to determine predictors for ICU LOS in these patients.

Methods:
We performed a retrospective study of a cohort of consecutive patients with aSAH admitted to an academic referral center from 2016 to 2021. Multiple linear regression was performed in survivors to identify predictors for ICU LOS among factors present on admission and those related to hospital course.

Results:
In a cohort of 306 patients with confirmed aSAH, mean age was 57 years (SD 13.7), 61% were female and 70% were white. ICU LOS was longer for survivors (median 19 days, IQR 14-25) than for non-survivors (median 5 days, IQR 2-8; p<0.001). For survivors (n=210), admission-related factors including Hunt and Hess grades 4 or 5 (4 additional days, 95% CI 0.5-7.5; p=0.027), hydrocephalus with external ventricular drain (EVD) requirement (9.2 additional days, 95% CI 5.7-12.8; p<0.001), and coagulopathy (3.2 additional days, 95% CI 0.9-6.2; p=0.03) were associated with longer ICU LOS; however, early neurological improvement (defined as decrease in Hunt and Hess grades within first 3 days of admission) was associated with shorter ICU LOS (5.4 fewer days, 95% CI 2.7-8.5; p=0.001). Among hospital-related factors, symptomatic vasospasm (3.2 additional days, 95% CI 1.9-6.5; p=0.016), pneumonia (5.7 additional days, 95% CI 3.5-9.4; p= 0.001), and laryngeal edema requiring intubation or reintubation (4.3 additional days, 95% CI 0.7-7.8; p<0.001) were associated with prolonged ICU LOS. Laboratory values from the emergency department and past medical history were not predictive for ICU LOS.

Conclusion:
Admission-related factors and in-hospital complications were more predictive for prolonged ICU LOS than past medical history or any laboratory values on admission. Early neurological improvement was associated with shorter ICU LOS which underscores the importance of early aggressive treatment measures in patients with aSAH.
Abstract TP139: Therapeutic Value Of Antifibrinolytic Medication In Acute Ischemic Stroke Patients With Alteplase-associated Intracerebral Hemorrhage
Authors: Bains Navpreet K , bhatia kunal , Akhtar Iqra , French Brandi R , Chandrasekaran Premkumar N , Siddiq Farhan , Gomez Camilo R , Qureshi Adnan I
Published: February 2022

Background and Purpose:
Intracerebral hemorrhage can occur in acute ischemic stroke patients receiving alteplase (recombinant tissue plasminogen activator). Antifibrinolytic medications such as the synthetic lysine analogs tranexamic acid and ε;-aminocaproic acid that inhibit fibrinolysis by attaching to the lysine-binding site of the plasminogen molecule have been utilized. However, the efficacy of antifibrinolytic medication in prevention of hematoma expansion is not known.

Methods:
We analyzed the effect of antifibrinolytic medication in acute ischemic stroke patients with intracerebral hemorrhage associated with Alteplase from 2012 to 2017. The Region-of-Interest method on a Horos Open Source Medical Image Viewer (Version 3.3.6) was utilized for volume measurement. We compared the change in hemorrhage volume in patients who did and did not receive antifibrinolytic medication.

Results:
A total of 36 patients (mean age 72.7±11.5, 56% were men) who received intravenous alteplase with subsequent intracerebral hemorrhage were identified. Fourteen patients received antifibrinolytic treatment; five patients had reduction or stabilization in hematoma volume (overall pre-treatment volume 13.87±15.74 cm
3
and post-treatment volume 16.74±29.67 cm
3
). Mean fibrinogen level in the antifibrinolytic medication group was 297 mg/dL; two patients had levels < 200 mg/dL. In the cohort of patients did not receive antifibrinolytics, 15 out of 22 patients had reduction or stabilization in hematoma volume (overall pre-treatment volume 19.25±33.33 cm
3
and post-treatment volume 17.41±26.56 cm
3
). Mean volume difference in the group that received antifibrinolytic medication was 36% and 9% in the group that did not receive antifibrinolytic medication. [Figure 1]

Conclusion:
We did not identify any advantage of antifibrinolytic treatment in reduction or stabilization in hematoma volume in patients with Alteplase-associated intracerebral hemorrhages.
Abstract TP144: Extracellular Vesicles Derived From Stroke Patient Clots Impair Cerebral Endothelial Cell Function
Authors: Li Chao , Chebl Alex B , Khadem Alsrouji Owais K , Marin Horia , Kole max , Zhang Yi , Chopp Michael , Zhang Zheng Gang
Published: February 2022

Introduction:
Most patients undergoing thrombectomy fail for full reperfusion. The present study tested whether small extracellular vesicles (sEVs) from stroke patient clots impair cerebral endothelial cell (CEC) function, which may contribute to dysfunction of downstream CECs, leading to reduction of cerebral tissue perfusion.

Methods:
Per IRB-approved protocol, clots were collected from 60 patients (30 males) with acute ischemic stroke subjected to thrombectomy. Red and white clots were determined by immunochemistry. Clot-sEVs were isolated and characterized using ultracentrifugation, size distribution, and Western blot. The effects of clot-sEVs on human CEC (hCEC) permeability and proteins were measured using trans-endothelial assay and trans-endothelial electrical resistance (TEER) and Western blot, respectively. Nystatin, an inhibitor of caveolin-dependent endocytosis, was employed to study hCEC uptake of clot-sEVs.

Results:
Clot-sEVs had a mean size of 73±2nm. Cellular source analysis of clot-sEVs revealed that 22%, 30%, and 44% of sEVs from red clots and 28%, 28%, and 52% of sEVs from white clots were from neutrophils, endothelial cells, and platelets, respectively. Compared to sEVs derived from donor plasma (plasma-sEVs), treatment of hCECs with clot-sEVs significantly increased cell permeability (227% vs 100% of plasma-sEVs) and reduced TEER (66.6ω.cm
2
vs 87.3ω.cm
2
). Clot-sEVs significantly increased pro-inflammatory and pro-coagulation proteins in the hCECs including ICAM1, VCAM1, TNF-a, HMBG1, tissue factor, and significantly reduced tight junction proteins ZO-1 and Claudin-5. The effects of white clot-sEVs on hCEC dysfunction were greater than red clot-sEVs. Nystatin significantly reduced hCEC uptake of clot-sEV from 232% to 142% and the clot-sEV-increased permeability. Moreover, Pearson correlation showed that the severity of clot-sEV impaired hCEC function was significantly correlated with final TICI scores of the individual patients (permeability vs TICI, r=-0.3348, p=0.02; TEER vs TICI, r=0,3666, p=0.01).

Conclusion:
Clot-sEVs contribute to hCEC dysfunction by augmenting pro-inflammatory and pro-coagulation proteins. Blocking uptake of clot-sEVs by recipient cells may improve patient outcomes.
Abstract TP145: Effects Of Collateral Compensation On Endovascular Treatment In Basilar Artery Occlusion
Authors: huang jia cheng , Qiu Zhongming , Zi Wenjie , Yang Qingwu
Published: February 2022

Background:
We evaluated the prognostic value of collateral compensation on endovascular treatment (EVT) in patients with basilar artery occlusion (BAO).

Methods:
Eligible participants from the Endovascular treatment for Acute Basilar Artery Occlusion Study with collected composite collateral score were included. The effects of standard medical treatment (SMT) alone versus EVT plus SMT for patients based on both categorical (0-1 vs 2-3 vs 4-5) and continuous composite collateral score were evaluated. The primary outcome was defined as a modified Rankin Scale score 0-3 at 90 days and safety outcomes included symptomatic intracerebral hemorrhage and mortality at 90 days.

Results:
In total, 828 patients were included: 108 patients with composite collateral score 0-1 (SMT: 11; EVT: 97), 495 with composite collateral score 2-3 (SMT: 101; EVT: 394), and 225 with composite collateral score 4-5 (SMT: 70; EVT: 155). EVT was associated with favorable outcome (adjusted OR with 95% CI, 3.86 [0.32-46.24], 6.92 [2.95-16.23], 6.98 [2.83-17.21], respectively). Multivariable logistic analysis revealed that patients with the anastomosis between the posterior cerebellar artery and the superior cerebellar artery (PICA-SCA anastomosis,
P
= 0.007) and composite collateral score ≥2 (
P
= 0.027) were significantly correlated with better outcomes after EVT. Furthermore, onset-to-puncture time (OPT) within 4 hours was a prognostic factor in the poor collateral subpopulation (
P
= 0.049).

Conclusions:
PICA-SCA anastomosis is a strong prognostic factor in patients with BAO after EVT. Patients of BAO with composite collateral score ≥2 favored EVT and patients with poor collateral status could profit from EVT with OPT ≤4 hours.
Abstract TP146: The Effect Of Statins On Thrombus Composition Retrieved By Mechanical Thrombectomy In Acute Ischemic Stroke
Authors: Arturo Larco jorge , Abbasi Mehdi , Mereuta Oana M , Dai Daying , KADIRVEL Ram , Savastano Luis , Kallmes David F , Brinjikji Waleed
Published: February 2022

Introduction:
Ample evidence exists in support of the anti-inflammatory properties of statins which in turn could affect arterial thrombosis. Compositional analysis of thrombi retrieved by MT may provide us with knowledge useful for evaluating the effect of current Statin therapy on thrombus composition.

Methods:
Consecutive AIS-LVO patients were included. Histopathological evaluation of thrombi retrieved during MT was performed using Martius Scarlet Blue staining (MSB) and immunohistochemistry for von Willebrand Factor (vWF) and anti-citrulinated H3 (CitH3; NETs marker) and the composition of thrombi was determined using image analysis software. Thrombus was considered rich in a given composition if that composition was higher than its overall mean. We reviewed patient’s medication records and cataloged any statin therapy prior to MT.

Results:
117 patients were included in this study. The mean density of red blood cells (RBCs), white blood cells (WBCs), platelets (PLT), fibrin (FIB), vWF and NETs (CitH3) in thrombi was 43.4%, 3.7%, 23.6%, 29.3%, 14.3% and 21.1% respectively. Twenty-seven patients were taking Statins at the time of MT. Statins were not associated with pre-thrombectomy IV-tPA, and stroke etiology (p values: >0.05). There was no association between Statins and thrombi composition and type (p values: >0.05 for all thrombus components and type). Additionally, Statins were not associated with MT outcomes including number of device passes and final mTICI score.

Conclusion:
Pre-stroke Statin therapy was not associated with differences in thrombus composition.
Abstract TP148: An Alternative Reduced Dose Regimen Of Ticagrelor For Neuroendovascular Patients
Authors: Thind Sonam , Tangonan Ruth , Kass-hout Tareq , Kass-hout Omar
Published: February 2022

Background:
There is a growing use of Ticagrelor in patients undergoing neuroendovascular procedures, especially those who demonstrate Clopidogrel resistance. While multiple dosages are studied in the cardiology literature, the optimal dose for patients with neurological pathology has yet to be established. Here we describe a single center experience involving 39 patients who underwent neuroendovascular procedures that then received an adjusted lower dose of Ticagrelor

Methods:
A retrospective chart review was performed between 2013 and 2017 for patients on dual antiplatelet therapy (DAPT) for either cervical or intracranial vascular pathologies, as well as stenting of the neurovasculature, including carotid arteries. Patients were placed on Ticagrelor if their measured PRU responses to Clopidogrel were outside the expected range in our center using the P2Y12 test. All patients were maintained on a dose of 45mg BID except for one patient who received 22.5 mg BID. Responsiveness to Ticagrelor were measured utilizing the P2Y12 test

Results:
The mean number of days for follow up post treatment initiation was 532 days. A total of 39 patients were included in the analysis. Of these, 8 patients (21%) received implantation of intracranial stents (5 patients received pipeline embolization devices, 1 patient received stent assisted coiling, and 2 patients received intra-cranial stents for atherosclerotic disease). Fourteen patients (35%) received carotid angioplasty and stenting. Seventeen patients (44%) did not receive permanent implantation of a stent. All patients on the lower dose Ticagrelor of mg BID achieved responsiveness per the P2Y12 test. Hemorrhagic transformation of ischemic stroke occurred in one patient (2.5%). No other hemorrhagic complications were encountered. No thromboembolic events were recorded aside from one patient (2.5%) with intracranial atherosclerotic disease who had an ischemic event

Conclusion:
A lower dose of Ticagrelor (45 mg BID) appears to be a safe and effective in this small cohort of patients who are resistant to Clopidogrel per P2Y12 testing and who have increased risk of ischemic or hemorrhagic strokes due to neurovascular pathologies and implants. Further randomized studies are required to confirm these findings