bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WMP112: Internal Carotid Artery Stenosis and Flow Diversion: Relationship With Headache
Authors: Herial Nabeel A , Miran Muhammad Shah , Saleem Muhammad A , Qureshai Ihtesham A , Qureshi Adnan I
Published: July 2021

Background:
The phenomenon of flow diversion in high grade internal carotid artery (ICA) stenosis and secondary head and facial pain from increased regional flow in the external carotid artery (ECA) system remains under-recognized and unreported. We examine this phenomenon in a large study population of Asymptomatic Carotid Atherosclerosis Study

Methods:
We utilized the Asymptomatic Carotid Atherosclerosis Study (ACAS) data to explore the relationship between ICA stenosis and headache. In ACAS, eligible patients with carotid stenosis ≥ 60 % were randomized to endarterectomy or medical management and risk of stroke or stroke & death over 5 years was observed. Information on headache and its characteristics was collected at the baseline visit and comprised questions inquiring self-reported history of headache, including characteristics of migraine, and physician diagnosis of headache. Carotid stenosis was evaluated by doppler ultrasound (as <60%, 60-80%, 81-99%, and 100%) and catheter angiography (as percent stenosis). All analyses were performed using IBM SPSS (version 20) software.

Results:
In this study (n= 1662), patients with stenosis (measured by Doppler) of 60% or higher in the right ICA or left ICA, self-reported headache within the past year was reported in 424, and physician diagnosed headache in only 68 patients. Significant relationship was noted between physician diagnosis of headache and right ICA (χ2=10.3, df=4, p 0.036), and left ICA (χ2=15.6, df=4, p=0.004) stenosis categories. Self-reported history was associated with left ICA stenosis (χ2=26.6, df=4, p<0.001). Average stenosis measured by angiogram was 57% in the right ICA and 56% in the left ICA in this study population. No relationship with self-reported or physician diagnosed headache was noted with percent stenosis measured by catheter angiogram.

Conclusion:
Recognition of flow-diversion into the ECA as a possible mechanism for headaches may help in further understanding of ICA disease, its progression, and the effects of carotid revascularization on quality of life. Headache as a likely surrogate marker of carotid stenosis with flow-diversion warrants more research, and may be critical in the early identification of significant ICA stenosis and prevention of TIA or stroke.
Abstract WMP20: Validation of an Efficient Machine-learning Approach to Quantify CSF Volume Changes Using Multicenter CT Scans
Authors: Chen Yasheng , Dhar Raj , Kulik Tobias , Yuan Kristy , Heitsch Laura , Ford Andria , Lin Weili , Shen Dinggang , An Hongyu , Lee Jin-Moo
Published: July 2021

Introduction:
CSF volumetric change within the first 24hrs after ischemic stroke (ΔCSF) may be an early imaging biomarker of cerebral edema. The ability to accurately and rapidly quantify ΔCSF in large multicenter stroke populations will facilitate large-scale studies to understand complex dynamics and genetic influences of cerebral edema.

Hypothesis:
An automated machine-learning approach to CSF segmentation utilizing random forest will be superior to standard Hounsfield unit thresholding for measuring ΔCSF using CT scans from different medical centers.

Methods:
Manual CSF delineation on both the baseline (within 6hrs) and 24hr follow-up head CT scans from 26 ischemic stroke patients acquired at center A were used as the training samples for random forest classifiers to segment CSF. The trained classifiers were then employed to segment baseline and 24-hr scans from 12 new patients from center B. Correlations of random forest detected CSF volumes to manual segmentation (including correlation coefficient and pvalue) were then compared to those from a thresholding approach, applying the optimal CT threshold derived from the training scans to the validation cohort from center B.

Results:
Random forest segmentation was very efficient (run time: 23 min/scan) and was able to accurately quantify CSF volumes and volumetric changes in the validation cohort. As shown in the table, random forest outperformed thresholding in the correlations between automated quantification and manual delineation.

Conclusion:
We have developed a robust, efficient and accurate automated approach to quantify both absolute and relative CSF volume changes from multicenter head CT images. This approach is ready to be employed in multicenter large data analysis of the genetic influence on edema formation following acute ischemic stroke.
Abstract WMP30: Quantitative Aneurysm Flow Evaluation of Combined FD and Coil Treatment Shows Higher Flow Reduction During the Healing Process Based on 2D DSA Images
Authors: Chien Aichi , Yu Qianyi , Gao Xu , Vinuela Fernando
Published: July 2021

Purpose:
This pilot study demonstrates an approach to quantitatively evaluate the effectiveness of flow diverter (FD) stents and coil treatments based on follow-up images.

Method:
2D digital subtraction angiography (DSA) images from 18 aneurysm patients were analyzed using IS FlowMap flow analysis software. Each patient had DSA images (3 frames/sec) acquired before, after the FD treatment and during follow-up examinations. 11 patients received FD treatment, and 7 patients received FD and coil combined treatment. The percentage of blood flow redirected into the parent artery was calculated. The relative aneurysm blood flow reduction caused by the stent was obtained. Based on the inlet contrast (CA) concentration profile, the blood flow changes in aneurysm and vessel blood flow were obtained.

Result:
18 patients’ average aneurysm blood flow reduction was 52% after the treatment. All scaled aneurysm CA concentration profile slopes before and after the treatment showed a clear difference (p=0.003). Post-treatment aneurysm CA slopes decreased 36% in average compared to pre-treatment, indicating a lower inflow rate of blood entering the aneurysm after the treatment. 7 patients with FD and coil combined treatment showed an average of 54% aneurysm blood flow reduction right after the treatment. FD and coil combined treatment had an average of 73% aneurysm blood flow reduction in patients’ first DSA follow up (8±3 months post treatment). Representative cases of FD and Coil combined treatment (flow reduction 53% right after the treatment; 89% at the 8 month follow-up) and FD only (flow reduction 48% right after the treatment; 75% at the 6 month follow-up) are shown in the figure.

Conclusion:
IS FlowMap quantitatively measures the effectiveness of treatment in patients with brain aneurysms using only 2D DSA. The result suggests that FD and coil combined treatment is more effective in preventing aneurysm blood inflow during the healing process.
Abstract WMP38: ABCA1/HDL Pathway Mediates GW3965 Induced Neurorestoration and White Matter Remodeling After Stroke
Authors: Cui Xu , Chen Jieli , Zacharek Alex , Cui Yisheng , Roberts Cynthia , Chopp Michael
Published: July 2021

ATP-binding cassette transporter A1 (ABCA1), a major cholesterol transporter in the central nervous system, plays an important role in the formation of brain HDL-cholesterol. ABCA1 is up-regulated by the transcription factors, liver X receptors (LXRs). Our previous study using brain-specific ABCA1 deficient (floxed, nestin-Cre positive, ABCA1-B/-B) and ABCA1 floxed-control (ABCA1fl/fl) mice showed that ABCA1 has anti-inflammatory effects and reduces white matter (WM) damage in ischemic stroke models. Here, we further test whether GW3965, a synthetic LXR agonist treatment of stroke increases ABCA1 and HDL, and thereby improves WM-remodeling and functional outcome. Adult male ABCA1fl/fl and ABCA1-B/-B mice were subjected to permanent extraluminal distal middle cerebral artery occlusion (dMCAo) by transcranial ligation method. Animals were gavaged with saline or GW3965 (10 mg/kg) starting 24h after dMCAo and daily till sacrificed 14 days after dMCAo. There were no differences in the lesion volume and blood levels of total cholesterol and triglyceride before and after dMCAo between ABCA1-B/-B and ABCA1fl/fl mice. However, GW3965 treatment significantly increased blood HDL levels in ABCA1fl/fl mice, but not in ABCA1-B/-B mice 14 days after dMCAo. GW3965 treatment of ABCA1fl/fl stroke mice, but not in ABCA1-B/-B stroke mice, also increased: 1) WM-density identified by Luxol Fast Blue (myelin marker), Bielshowsky silver (axon marker), and SMI31 (phosphorylated neurofilament marker) staining; 2) the number of platelet-derived growth factor receptor alpha positive oligodendrocyte progenitor cells; 3) ABCA1, synaptophysin and myelin basic protein expression in the ischemic brain; 4) functional outcome 7 and 14 days after dMCAo, compared with non-treatment ABCA1fl/fl stroke mice (p<0.05, n=9/group). GW3965 and HDL treatment significantly increase axonal/neurite outgrowth in cultured primary cortical neurons derived from ABCA1fl/fl embryos, but not in neurons derived from ABCA1-B/-B embryos. Treatment of stroke with GW3965 significantly increased blood level of HDL, increased ABCA1 expression and WM-remodeling in the ischemic brain. Increasing ABCA1 may contribute to GW3965 induced neurorestoration and WM remodeling after stroke.
Abstract WMP5: Endovascular Therapy Stroke Outcome in Very Elderly: Meta-analysis
Authors: Lin Michelle P , Liebeskind David S , Cen Steven , Mack William J , Amar Arun P , Tenser Matthew , Towfighi Amytis , Sanossian Nerses
Published: July 2021

Introduction:
Very elderly (age ≥80yo) individuals account for about one-third of all stroke admissions with mixed literature demonstrating relative poor stroke outcomes. With overwhelming recent evidence supporting the use of intra-arterial thrombectomy in addition to IV thrombolysis for large-vessel occlusive stroke, we conducted a metaanalysis to assess long-term functional outcome following mechanical thrombectomy in very elderly.

Hypothesis:
Very elderly patients with acute ischemic stroke treated with thrombectomy have equally favorable long-term functional outcomes to their younger counterparts

Methods:
Stroke endovascular trials published in New England Journal of Medicine 2014-2015 were included if they reported odds ratio of good functional outcome (improvement in modified Rankin score, mRS) comparing thrombectomy vs IV-tPA dichotomized by age groups (age ≤ 80yo vs >80yo, 2 studies dichotomized age at 70yo). Multivariate adjusted odds ratios and the corresponding standard errors were used for the metaanalysis. Pooled odds ratio estimates across trials were synthesized by using a random-effects model based on Mantel-Haenszel methods. The pooled estimates with 95% confidence interval were compared between elderly and younger age groups. Forest plots constructed.

Results:
Of the 5 recent intraartrial thrombectomy trials, 4 studies reported subgroup analysis by age with 1,206 participants, 28% (N=334) were above the age of 80yo, 72% (N=872) were ≤80yo. Among very elderly patients undergoing thrombectomy, the pooled odds ratio of good functional outcome at 3 months was 1.91 (1.13-3.24), in the younger group the pooled odds ratio was 1.95 (1.50-2.53).

Conclusions:
Endovascular therapy was an effective therapy for very elderly individuals presenting with acute ischemic stroke caused by large vessel occlusive disease. Future studies are needed to further assess the safety and effectiveness of thrombectomy in this growing population.
Abstract WMP52: Shake, Rattle & Roll Trial - Effects on Blood Pressure Control and Therapy
Authors: Nguyen-Huynh Mai N , Young Joseph D , Chin Terrence A , Sorel Mike , Quesenberry Charles , Alexeeff Stacey , Sidney Stephen
Published: July 2021

Background:
In Kaiser Permanente Northern California (KPNC), a setting where all members have similar access to healthcare and a very high overall rate of HTN control, blacks still had poorer BP control than whites. It has been suggested that greater difficulty in controlling BP and lifestyle differences may account for this difference. The “Shake, Rattle and Roll” (SRR) trial is named for: 1) “shake” the salt habit; 2) “rattle” the intensity of current BP management; and 3) adapt and “roll” out the interventions to other communities.

Methods:
SRR is a pragmatic clustered randomized controlled trial. All PCPs at Kaiser Oakland and their panels of black patients were randomized, stratified by panel size, to one of 3 arms: 1) usual care (UC); or 2) enhanced monitoring (EM) of current KPNC BP management protocol; or 3) culturally tailored diet and lifestyle (LS) coaching focused on the DASH eating plan. Black patients from KPNC HTN registry with an identifying high BP reading ≥ 140/90 qualified to be recruited into SRR. The intervention period lasted 12 months. We assessed rates of BP control using the latest follow-up BP measurements between enrollment and 15 months post-enrollment. Data on demographics and anti-hypertensives were collected from participants’ EMRs.

Results:
We cluster randomized 107 PCPs to one of 3 arms. There were 1185 enrolled in UC, and 318 in EM and 259 in LS. Median ages ranged from 63-65 years [Table]. Among those enrolled, BP control rates were higher in EM and LS than in UC (53% in UC, 69% in EM, and 71% in LS, p<0.001). However, a significant proportion of UC did not have a follow-up BP measurement during the trial period. There were also significant differences in anti-hypertensive usage across the 3 arms [Table].

Conclusions:
Preliminarily, among those enrolled in SRR, EM and LS arms had better BP control than UC and there were differences in the types of anti-hypertensive therapy used. Further analyses of all aspects of BP management in SRR are under way.
Abstract WMP65: A Dichotomized Cincinnati Prehospital Stroke Score is Correlated With Revascularization Therapy in Acute Stroke
Authors: Richards Christopher T , Markul Eddie , Stein-Spencer Leslee , Prabhakaran Shyam
Published: July 2021

Introduction:
Early revascularization improves outcomes in patients with acute stroke, and prehospital identification of patients with large vessel occlusions can result in preferential transport to centers with endovascular capability. Several stroke severity scales have been developed to assist with prehospital triage, but emergency medical services (EMS) provider training on new assessment scales presents challenges.

Hypothesis:
A dichotomized Cincinnati Prehospital Stroke Scale (CPSS) with a cut-off of 2 correlates with acute stroke revascularization in a large US city.

Methods:
Patients with confirmed stroke arriving via EMS between August 2012 and April 2014 at a high-volume stroke center in a large urban city with a single municipal EMS provider were identified. Demographics, prehospital CPSS, initial NIH stroke scale score (NIHSS) at hospital arrival, and type of revascularization (intravenous tissue plasminogen activator [IVtPA] or endovascular) were captured. Spearman’s rank correlation and Mann-Whitney U Test were performed after applying skewness/kurtosis tests. The Youden index was used to identify the optimal cut-off for the dichotomized CPSS. Multivariate logistic regression controlling for age, sex, and race determined the odds ratio (OR) for revascularization.

Results:
A total of 144 patients were included; 51% were male, 57% were white, and 33% were black. The mean age was 68.8 years (SD 16.1). A total of 31 patients (21.5%) underwent revascularization, most often with IVtPA alone (n=30). CPSS was ≥2 in 42% of patients, and the median NIHSS in patients with CPSS <2 vs CPSS ≥2 was 2 vs 8 (p<0.0001). CPSS and NIHSS in patients presenting within 4.5 hours were strongly correlated (Spearman's rho = 0.57, p<0.0001). The optimum CPSS cut-off that predicted revascularization was 2, with a sensitivity of 0.79, specificity of 0.81, and a Youden index of 0.61. CPSS ≥2 was strongly associated with revascularization (adjusted OR 14.5, 95% CI 5.0-42.4).

Conclusions:
Prehospital dichotomized CPSS with a cut-off of 2 is well correlated with acute stroke revascularization in a large US city. Further studies should investigate how the dichotomized CPSS performs in the prehospital identification of stroke patients with large vessel occlusions.
Abstract WMP66: Minnesota Prehospital Stroke Scale For Prediction of Emergent Large Vessel Occlusion
Authors: Higashimori Takamasa , Anderson David
Published: July 2021

Intro:
Recent randomized clinical trials have demonstrated the benefit of endovascular mechanical thrombectomy in acute ischemic stroke patients with Emergent Large Vessel Occlusion (ELVO). Cincinnati Prehospital Stroke Scale is widely used tool by EMS but not specifically designed to predict ELVO. Previously reported prehospital stroke scales for ELVO have been limited, and not widely used. It is imperative to establish a simple and accurate tool for EMS to predict ELVO facilitating rapid patient transport to hospitals capable of endovascular intervention.

Hypothesis:
Minnesota Prehospital Stroke Scale (MPSS) can predict the presence of ELVO with high accuracy comparable to NIHSS.

Methods:
The MPSS assesses five parameters: Facial weakness, Arm weakness, Leg weakness, Speech difficulty and Eye deviation, with total score ranging 0-10 (See Table). We set MPSS 6 or above and NIHSS 7 or above as a cutoff for ELVO. We retrospectively analyzed all the stroke code patients seen in ED between January 2015 and April 2015 at a primary stroke center (n=120). We selected patients arriving in less than 6 hours with prehospital stroke alert activated by EMS. Hemorrhagic stroke patients were excluded. The following data were collected: 1) Presence of ELVO, 2) Initial NIHSS in ED, and 3) MPSS abstracted from initial ER NIHSS, then assessed the results using 2x2 table for ELVO and MPSS vs. NIHSS.

Results:
Of 28 patients meeting criteria, 6 (21%) had ELVO (ICA, M1/M2): Mean MPSS was 7.5, whereas mean NIHSS was 15 for ELVO patients. Mean HPSS was 1.6, whereas mean NIHSS was 5.1 for non-ELVO patients. Sensitivity 83%, specificity 100%, PPV 100%, NPV 96%, and accuracy 96% for HPSS; sensitivity 83%, specificity 77%, PPV 50%, NPV 94% and accuracy 79% for NIHSS.

Conclusion:
MPSS may be a useful tool for predicting ELVO. Further studies are necessary to validate the efficacy of the scale.
Abstract WMP68: Smartphone Support System for Mobile Imaging Display and Management of Acute Stroke
Authors: Shkirkova Kristina , Akam Eftitan Y , Huang Josephine F , Sheth Sunil A , Nour May , Liang Conrad , McManus Michael H , Trinh Van D , Duckwiler Gary , Tarpley Jason , Vinuela F , Saver Jeffrey L ,   UCLA Stroke Systems of Care Study Group
Published: July 2021

Introduction:
Rapid dissemination and coordination of clinical and imaging data among multidisciplinary team members is essential for optimal acute stroke care. Standard desktop EMRs are ill-suited for this purpose, but mobile smartphone and tablet applications are highly promising platforms for accelerated, data-driven patient diagnosis and treatment. This study tested an advanced mobile integrated system for distribution of patient clinical and imaging information.

Methods:
We tested the iStroke/Synapse ERm system (Figure) for smartphone and tablet display and integration of clinical data, CT, MR, and catheter angiographic imaging, and real-time stroke team communications, in consecutive acute neurovascular patients at a Comprehensive Stroke Center.

Results:
From 5/2014 to 10/2014, the Synapse ERm application was installed and used by 33 stroke team members, in 84 Code Stroke ED patients. Patient age was 69.1 (±17.5), with 40.5% female. Final diagnosis was: ischemic stroke 66%, TIA 7%, ICH 6%, and CV mimic 21%. Each patient record was viewed on average 13 times by at least 3 team members. The most used feature was CT, MR and cath angio image display, viewed on average 4 times per patient by at least 2 users. In-app tweet team communications were sent by average 2 users per case and viewed by average 6 team members. Use of the system was associated with treatment times that exceeded national guideline targets for thrombolysis and endovascular thrombectomy, including door-to-needle 50 min (IQR 24-60) and door-to-groin 92 min (IQR 65-128). In user surveys, the mobile information platform was judged easy to employ in 91% of uses and of added help in stroke management in a substantial majority of cases.

Conclusion:
The Synapse ERm system, a smartphone/tablet platform for stroke team communication and distribution and integration of clinical and imaging data, showed high ease of use, substantial added management value, and association with rapid processes of care.
Abstract WP112: Trans-arterial Regional Hypothermia Provides Robust Neuroprotection in Rat Permanent Middle Cerebral Artery Occlusion Model
Authors: Kurisu Kota , Abumiya Takeo , Ito Masaki , Shichinohe Hideo , Nakayama Naoki , Kazumata Ken , Osanai Toshiya , Houkin Kiyohiro
Published: July 2021

Background and Purpose:
We previously reported the neuroprotective effects of trans-arterial regional hypothermia in rat transient middle cerebral artery occlusion (tMCAO) model (ISC 2014, ISC 2015). The tMCAO model is representative of the clinical setting of successful recanalization in acute ischemic stroke. However, it is not always possible to achieve successful recanalization. Herein, we investigated the neuroprotective effects of trans-arterial regional hypothermia in permanent MCAO (pMCAO) model as well.

Methods:
Three groups were provided to investigate the neuroprotective effects. Regional hypothermia group had a single infusion of 20ml/kg 10°C cold saline via the ipsilateral internal carotid artery for 15 min at 0 hr or 1 hr after the onset of pMCAO. Vehicle group had a 37°C warm saline infusion in the same manner. Control group had no infusion after pMCAO. The rats were tested for neurological score after 48-hour pMCAO and then sacrificed to evaluate infarction size and pathological condition. Immunohistochemical analysis was performed to investigate the neuronal apoptosis (NeuN, cleaved caspase 3), glial reaction (GFAP), and microglial activation (Iba-1).

Results:
The regional hypothermia group showed significantly better neurological score compared with the other groups (p<0.01). Infarct volume was significantly smaller in the regional hypothermia group (8.1±4.7% at 0 hr and 15.7±5.9% at 1 hr) than in the vehicle group (35.8±5.6% at 0 hr and 34.0±3.6% at 1 hr) and also in the control group (35.1±8.9%) (p<0.01). Neuronal apoptosis (p<0.01), reactive gliosis (p<0.01), and microglial activation (p<0.05) in the peri-infarct area were significantly inhibited in the regional hypothermia group compared with the other groups. The degree of the inhibition was somewhat more evident at 0 hr than at 1 hr.

Conclusions:
Our result demonstrated that trans-arterial regional hypothermia provided robust neuroprotection in pMCAO model as well as tMCAO model, suggesting that this therapy may have a wide clinical application in ischemic stroke treatment.
Abstract WP114: Retrograde Labeling, FACS Isolation, and Transcriptional Profiling of Layer 5 Cortical Neurons After White Matter Stroke Reveals Unique Pathways of Degeneration and Regeneration
Authors: Nunez Stefanie , Joy Mary Teena , Hinman Jason D
Published: July 2021

Introduction:
Small vessel ischemic strokes account for 25% of strokes in the US. They often occur silently, increasing the prevalence 5-10 fold and are progressive with new strokes occurring adjacent to prior strokes. In this common form of stroke, there is a local injury damaging axons and white matter, and a distant injury damaging the neurons with axons affected by the stroke, leading to cortical thinning in the connected cortex. This selective neuronal loss contributes to minor stroke related cognitive dysfunction and disability yet the molecular response of neurons with stroke-injured axons remains challenging to study.

Hypothesis:
White matter stroke injures cortical projection neurons and triggers a unique molecular program that contributes to selective neuronal loss.

Methods:
To determine the neuronal effects of a white matter stroke, we produced a subcortical white matter stroke below the forelimb motor cortex in adult male C57/Bl6 mice resulting in a focal white matter lesion. Retrograde neuronal tracing identifies individual neurons damaged by the white matter stroke. Layer 5 cortical neurons were isolated by magnetic microbead separation of non-neuronal cells, followed by fluorescent-activated cell sorting (FACS) isolation of retrogradely-labeled cells.

Results:
Stereologic measurement of the neurons with stroke-injured axons co-labeled with the Layer 5 neuronal marker CTIP-2 reveals that focal white matter stroke selectively identifies between 15-25% of the Layer 5 cortical neurons in both sensory and motor cortex with spanning the cortical regions of interest, compared to only ∼3% in sham injured animals. Using FACS isolation, we compared the transcriptional profile of white matter stroke injured cortical projection neurons to uninjured Layer 5 neurons at one week after stroke. An average of 6,297 cells were collected per isolation, RNA isolated and analyzed by qPCR and RNA-seq.

Conclusions:
Bioinformatic analysis of differentially expressed genes indicates that white matter stroke activates both degenerative and regenerative pathways in stroke-induced axonally-injured neurons. These data can be harnessed to prevent selective neuronal loss after white matter stroke and induce neural repair after stroke.
Abstract WP120: Measuring Carotid Stenosis With a Novel Non-contrast Enhanced MR Angiography Technique (SNAP): Comparison With Contrast-enhanced MR Angiography
Authors: Shu Hongge , Sun Jie , Balu Niranjan , Liu Haining , Hippe Daniel S , Hatsukami Thomas S , Yuan Chun
Published: July 2021

Introduction:
Contrast-enhanced MR angiography (CE-MRA) provides highly accurate measurement of carotid stenosis. But non-contrast techniques are desired as contrast agents may lead to anaphylaxis or nephrogenic system fibrosis. Recently, an inversion-recovery gradient echo sequence with phase-sensitive reconstruction was developed for assessment of lumen and intraplaque hemorrhage in one sequence - Simultaneous Noncontrast Angiography and intraPlaque hemorrhage (SNAP).

Hypothesis:
We tested the hypothesis that SNAP provides an accurate and reproducible assessment of carotid stenosis compared to CE-MRA.

Methods:
Fifty-eight subjects with 16-79% stenosis on ultrasound were scanned using a large-coverage (16 cm), isotropic-resolution (0.8 mm) SNAP sequence. Minimum intensity projections were generated at ten degrees increments to get 3D views of carotid arteries. Carotid stenosis was measured bilaterally according to the NASCET criteria by independent readers to estimate inter-reader reproducibility. To assess agreement between SNAP and CE-MRA, 24 subjects also underwent CE-MRA with same resolution (0.8 mm isotropic) after injection of gadolinium contrast (Magnevist). Maximum intensity projections were generated for CE-MRA and analyzed while blinded to SNAP data.

Results:
Of 116 carotid arteries imaged by SNAP, 10 (8.6%) were excluded by at least one reader due to poor image quality or insufficient coverage. Inter-reader reproducibility was high, yielding an intra-class correlation coefficient (ICC) of 0.95 (95% CI: 0.93, 0.96). When stenosis measurements were categorized as no/mild (0-29%), moderate (30-69%) and severe (70-99%), weighted kappa was 0.77 (95% CI: 0.66, 0.88). In the 48 arteries with CE-MRA images, agreement between SNAP and CE-MRA was excellent (ICC: 0.96, 95% CI: 0.92, 0.98; weighted kappa: 0.90, 95% CI: 0.79, 1.00).

Conclusions:
SNAP can be used to obtain accurate and reproducible measurement of extracranial carotid artery stenosis without gadolinium contrast. The ability of SNAP to assess both traditional (stenosis) and emerging (intraplaque hemorrhage) risk factors may promote its use in clinical workup of carotid stenosis.
Abstract WP121: An Evaluation of Hemodynamics Across Intracranial Steno-occlusive Lesions by Computational Fluid Dynamics
Authors: Fan Florence SY , Ip Vincent HL , Lau Alexander YL , Chan Anne YY , Au Lisa WC , Ma SH , Soo Yannie OY , Leung Thomas WH , Liebeskind David Sigmund , Wong Lawrence KS
Published: July 2021

Introduction:
Intracranial atherosclerotic steno-occlusive disease (ICAS) is a major cause of stroke worldwide and portends a high risk of recurrence. Computational fluid dynamics (CFD) is a novel technique developed to solve and analyze the dynamic effects of fluid flow. We aimed to analyse hemodynamics across ICAS using CFD on processed CTA images and explore the correlation between the degree of arterial stenosis and hemodynamic flow status.

Methods:
We recruited patients with symptomatic ICAS from Acute Stroke Unit, Prince of Wales Hospital. All patients received CTA and DSA as vascular workup. Using CFD analysis of processed CTA images, we first defined the hemodynamic parameters, including pressure difference, pressure ratio, pressure gradient, shear strain rate ratio (SSR), wall shear stress (WSS) ratio and velocity ratio, across the stenosed vessels, and then we correlated the severity of stenosis as defined by DSA, with these parameters.

Results:
Among the 53 recruited patients (mean age 62.9 years, 69.8% males), 45 (85%) had lesions in the anterior circulation. The severity of stenosis showed a weak-to-moderate correlation with pressure difference (rs=0.392, p=0.004), pressure ratio (rs=-0.429, p=0.001) and pressure gradient (rs=0.419, p=0.002). There was no significant correlation between the severity of stenosis with SSR ratio, WSS ratio and velocity ratio. Among patients with anterior circulation stroke or TIA, the severity of stenosis showed a weak to moderate correlation with pressure difference (rs=0.381, p=0.01), pressure ratio (rs=-0.426, p=0.004) and pressure gradient (rs=0.407, p=0.005). For patients with posterior circulation stroke or TIA, the severity of stenosis was strongly correlated with pressure difference (rs=0.714, p=0.047) and pressure ratio (rs=-0.714, p=0.047); and very strongly correlated with velocity ratio (rs=0.833, p=0.01).

Conclusions:
The severity of ICAS showed only weak-to-moderate correlation with hemodynamic parameters across the culprit lesion. Thus, risk stratification and treatment based solely on stenotic severity may be inadequate. Our findings may guide further research in estimating stroke risks and selection of high-risk patients who may benefit from adjunctive treatments.
Abstract WP136: Clinical, Laboratory, and Imaging Characteristics Oof Transient Ischemic Attack Caused by Large Artery Lesion: A Comparison Between Carotid and Intracranial Artery
Authors: Uehara Toshiyuki , Ohara Tomoyuki , Nagatsuka Kazuyuki , Toyoda Kazunori , Minematsu Kazuo
Published: July 2021

Background:
The purpose of this study was to determine the differences in clinical characteristics and the risk of ischemic stroke between patients with transient ischemic attack (TIA) attributable to extracranial carotid and intracranial artery occlusive lesions.

Methods:
Among 445 patients admitted to our stroke care unit within 48 hours of TIA onset between April 2008 and December 2013, 85 patients (63 men, 69.4 years) with large artery occlusive lesions relevant to symptoms were included in this study. The primary endpoints were ischemic stroke at 2 days and 90 days after TIA onset.

Results:
Twenty-eight patients had carotid artery occlusive lesions (extracranial group), and 57 patients had intracranial artery occlusive lesions (intracranial group). Patients in the intracranial group were significantly younger, had lower levels of fibrinogen, and were less likely to have occlusion when compared to those in the extracranial group. Eleven patients in the extracranial group and no patient in the intracranial group underwent revascularization procedures within 90 days of TIA onset. The 2-day risk (14.2% vs. 0%, p = 0.044) and 90-day risk (17.1% vs. 0%, p = 0.020) of ischemic stroke after TIA onset were significantly higher in the intracranial group than in the extracranial group.

Conclusions:
Patients with intracranial artery occlusive lesions were more frequent and were at higher risk of early ischemic stroke than those with extracranial carotid artery occlusive lesions among our patients with TIA caused by large artery disease. These data highlight the importance of prompt assessment of intracranial artery lesions in patients with TIA.
Abstract WP137: Validation of a New Diagnostic Scoring System of Transcranial Doppler for Middle Cerebral Artery Stenosis
Authors: Hao Qing , Levine Steven R , Balucani Clotilde , Feldmann Edward
Published: July 2021

Introduction:
Large vessel intracranial stenosis (LVIS) is the most common stroke subtype worldwide and is associated with high risk of stroke recurrence. Current transcranial Doppler (TCD) diagnostic criteria for LVIS mainly rely on velocity measurement with unsatisfactory accuracy.

Hypothesis:
A new scoring system that integrated several features of the cerebral blood flow velocity from TCD is able to offer more reliable identification of significant (≥ 50%) LVIS.

Methods:
Using the TCD-Digital Subtraction Angiography (DSA) database from a previous NIH-funded trial - Stroke Outcomes and Neuroimaging of Intracranial Atherosclerosis (SONIA), the hard copy TCDs from SONIA trial were reviewed blinded to the results of DSA. A summed score was calculated for each middle cerebral artery (MCA) based on the four parameters: mean velocity (MV) (score 0: MV<80 cm/s, 1: MV=80-99 cm/s, 2: MV=100-119 cm/s, 3: MV≥120 cm/s); stenotic/pre-stenoic ratio (score 0: ratio<2, 1: ratio≥2); stenotic/contralateral MCA ratio (score 0: ratio<1.50, 1: ratio=1.50-1.99, 2: ratio ≥ 2.00); spectrum pattern (score 0: normal spectrum, 1: any pattern of turbulence). DSA results (presence of ≥ 50% stenosis) from SONIA were used as the gold standard. To define the optimal score that predict significant stenosis on DSA, predictive values (positive predictive value [PPV] and negative predictive values [NPV], and overall accuracy) with 95% CI were calculated.

Results:
110 MCAs with both TCD and DSA were available in 72 patients (50.7 % of total patients with TCD). The mean score was 1.8 (SEM 0.21), the optimal cutoff score with balanced PPV and NPV for identifying ≥50% stenosis was >4 with the PPV 76% (53-92), NPV = 84% (75-91) and overall accuracy 83% (76-90).The PPV of the new scoring system (76%) was higher than velocity-only criteria in SONIA (i.e. previously validated cutpoints from SONIA of MV=80 cm/s [32%] or 100 cm/s [37%]), while NPV remained similar between the two methods (84% for new scoring vs 86% or 85%).

Conclusions:
The new TCD scoring system suggested higher diagnostic accuracy compared to the velocity-only method in diagnosis of ≥50% MCA stenosis using digital subtraction angiography as the confirmative method. Further validation is required.
Abstract WP163: One in Three Stroke Survivors has Uncontrolled Blood Pressure 90 Days After Stroke
Authors: Levine Deborah , Morgenstern Lewis B , Langa Kenneth M , Brook Robert D , Brown Devin , Zahuranec Darin Z , Meurer William J , Case Erin , Sanchez Brisa , Lisabeth Lynda D
Published: July 2021

Background and Objectives:
High blood pressure (BP) is a major modifiable cause of recurrent stroke. The prevalence of uncontrolled BP 90 days after stroke in contemporary populations of unselected stroke patients is unclear. We measured the prevalence and predictors of uncontrolled BP 90 days after stroke in a population-based stroke surveillance project.

Methods:
Prospective cohort study of 214 Mexican American or non-Hispanic white adults aged ≥45 years with ischemic or hemorrhagic stroke and completed outcome assessments 90 day after stroke in the Brain Attack Surveillance in Corpus Christi (BASIC) project from March 2011 through June 2012. Trained personnel conducted in-home examinations following a standardized protocol to measure BP 90 days after stroke using an automated arm monitor (OmROn model 700 series). BP was measured in triplicate and the third BP reading was used. BP control was defined as BP<140/90 mm Hg. We investigated risk factors for uncontrolled BP 90 days after stroke using logistic regression and adjusting for ethnicity, age, sex, education, and insurance status as well as variables that were associated with uncontrolled BP.

Results:
Median age was 66 years (interquartile range [IQR], 58-77 years), and 93% of strokes were ischemic. Median systolic BP was 128.5 mm Hg (IQR, 114-145) and diastolic BP was 76 mm Hg (IQR, 68 to 84). Overall, BP was uncontrolled in 35.1% (95% CI, 29.9% to 41.7%) of stroke survivors 90 days after stroke, and this did not differ by ethnicity (Mexican American, 34.3% [95% CI, 26.8% to 42.7%] vs. non-Hispanic white, 36.3%; [95% CI, 26.6% to 47.2%]; Wald P=0.58). Uncontrolled BP 90 days after stroke was more likely in stroke survivors with older age (adjusted odds ratio [aOR], 1.03 per 1 year increase; 95% CI, 1.00 to 1.06; P=0.03), no health insurance (aOR, 3.08; 95% CI, 1.19 to 7.96; P=0.02, and hypertension (aOR, 2.24; 95% CI, 0.96 to 5.26; P=0.06).

Conclusion:
More than one third of stroke survivors has uncontrolled BP 90 days after stroke in this population-based study. Interventions designed to improve BP control and targeting older and uninsured stroke survivors are needed.
Abstract WP164: An Assessment of Stroke Knowledge in the Coulee Region Community
Authors: Kabbani Mouhammed , Riley Katherine , Smith Angela L , Borgert Andrew , Gabbert John , Schossow Andrea
Published: July 2021

Introduction:
Delayed presentation to the hospital persists as a significant barrier to early intervention of stroke with tPA treatment. Community knowledge about stroke symptoms is moderate at best and not parallel with behavior.

Objective:
To assess our community’s level of knowledge about stroke to direct the development of targeted educational efforts.

Methods:
Members of communities in our regional stroke alert locations were asked to complete a 15-item survey that included questions about basic demographics, stroke symptoms, behavior actions and interest in and barriers to attending stroke education. Surveys were collected from local businesses, online and in public venues. Overall scores were calculated by summing the number of correct responses and, with the exception of questions pertaining to the BEFAST mnemonic, subtracting the number of incorrect or unmarked responses. Reported metrics include overall survey scores and demographics of survey respondents. Total scores were compared between demographic groups via the Wilcoxon Rank Sum, while question level comparisons utilized the χ2 or Fisher’s exact test. GIS technology was applied to identify geographic clusters of different knowledge levels.

Results:
Among 1118 participants, 86% had low levels of stroke knowledge as defined by a survey score of ≤ 70% accuracy (medium = 71-89%; high ≥ 90-100%). Knowledge was low throughout most of our community with isolated pockets of higher knowledge in outlying areas. Awareness was highest (though still low) among females, middle-aged adults (36-55 yo), those with post-high school degrees, and those with previous formal stroke education. In case of stroke, older adults (55+ yo) were least likely to call 9-1-1. Only 21.6% of participants were likely or highly likely to attend stroke education.

Conclusions:
The level of stroke knowledge in our community is low. People tend to not be interested in attending formal stroke education outside of their regular day. Efforts must be made to raise awareness about stroke symptoms and treatment in order to increase more positive outcomes following stroke. Incorporating stroke education into work and school curriculums will be our targeted approach.
Abstract WP175: Stroke Prevalence Among US- and Foreign-born Adults in the United States
Authors: Fang Jing , Yuan Keming , Ayala Carma , Gindi Renee , Ward Brian
Published: July 2021

Introduction:
The proportion of US adults who are foreign-born has almost tripled since 1970. While foreign-born adults have lower cardiovascular disease mortality and risk factors (e.g., hypertension) than US-born adults, less is known about the morbidity of stroke in this population.

Objective:
To compare the prevalence of stroke among US adults by birthplace.

Methods:
We used data on 223,842 non-institutionalized adults from the 2006-2013 National Health Interview Survey. Birthplace was categorized as US- and foreign-born, and foreign-born was then grouped into 7 regions. Data on years of living in the US was included. Self-reported stroke was defined as ever being told by doctor or other health professional that s/he had a stroke. Select descriptive (age, sex, race/ethnicity, education, health insurance, language of interview, use of interpreter) and health characteristics (hypertension, diabetes, body mass index, alcohol use, smoking status) were used in analysis. Age-standardized prevalence of stroke was compared between US- and foreign-born and then by birthplace regions among foreign-born. Adjusted odd ratios (AORs) were used to assess stroke risk between US- and foreign-born after adjusting for demographic and health characteristics.

Results:
Sixteen percent of US adults were classified as foreign-born. Age-standardized prevalence of stroke was higher among US- than foreign-born adults overall (2.7% vs 2.0%, p<0.0001) and by race/ethnicity: non-Hispanic blacks (4.1% (US) vs 2.2% (foreign-born), p<0.0001), Hispanics (2.8% vs 2.2%, p=0.03) and non-Hispanic whites (2.5% vs 1.7%, p<0.0001). Compared to US-born men, AORs of stroke for foreign-born men by region of birth, ranged from 0.24 (95% confidence interval 0.08-0.69) for Africa to 1.05 (0.74-1.51) for Europe. Among foreign-born women, AORs ranged from 0.07 (0.01-0.43) for the Middle East to 1.13 (0.54-2.34) for Africa, after adjustment for selected characteristics. Among foreign-born adults, there was no association between age-standardized stroke prevalence and the number of years living in the US.

Conclusion:
Overall, foreign-born US adults had a lower prevalence of stroke than US-born adults. However, considerable heterogeneity of stroke risk was noted by region of birth.
Abstract WP190: Clinical Features of Sarcoid Patients With Ischemic Stroke
Authors: Obeidat Ahmed Z , Sucharew Heidi , Moomaw Charles J , Kleindorfer Dawn O , Kissela Brett M , Alwell Kathleen , Flaherty Matthew , Broderick Joseph P , Woo Daniel
Published: July 2021

Background:
Current knowledge on ischemic stroke in sarcoid patients stems from sporadic case reports. The mechanism is thought to be related to granulomatous involvement of brain vasculature. However, clinical, demographic, and radiographic features of sarcoid patients with ischemic stroke are lacking. If sarcoid patients are at higher risk for ischemic stroke event, we hypothesized that the risk factors for ischemic stroke and stroke subtype distribution would differ between sarcoid and non-sarcoid ischemic stroke patients.

Methods:
Cases of ischemic stroke were identified for the years 2005 and 2010 from the population-based Greater Cincinnati/Northern Kentucky Stroke Study (population 1.3 million). Ischemic stroke cases were physician study confirmed and patients with a history of sarcoid were identified through medical chart review. Clinical variables were compared between stroke patients with history of sarcoid and those with no prior sarcoid history.

Results:
A total of 4258 cases of ischemic stroke were identified; of them, only 18 had prior diagnosis of sarcoid (0.04%). Brain MRI showed diffusion restriction in 14 out of 15 (93%) MRIs performed in sarcoid patients. The table presents risk factor and subtype data on sarcoid patients compared with non-sarcoid patients.

Conclusions:
We identified only a few cases of prior sarcoid history in our two-year ascertainment of ischemic stroke patients in our population. In comparison with stroke patients with no prior history of sarcoid, the sarcoid patients tended to be of younger age at presentation, female, have a history of diabetes and hyperlipidemia, and more likely of African descent, perhaps related to the diagnosis of sarcoid itself. We were unable to detect differences in stroke subtype distributions between sarcoid and non-sarcoid ischemic stroke patients.
Abstract WP206: A Tale of Blacks With Stroke on Two Continents and in Two Eras: Comparison of Baseline Risk Profiles in Black Africans and Black Americans
Authors: Owolabi Mayowa O , Lackland Daniel T , Gebregziabher Mulugeta , Armstrong Kevin S , Sarfo Fred S , Akinyemi Rufus , Owolabi Lukman , Obiako Reginald , Akpalu Albert , Boan Andrea D , Melikam Sylvia , Saulson Raelle , Bruce Ovbiagele Bruce Ovbiagele ,   SIREN Investigators
Published: July 2021

Background:
It is projected that Sub-Saharan Africa (SSA) will experience a rising epidemic of cardiovascular diseases (CVD) driven by a surge in rates of major CVD risk factors; while it has been well established for several decades that African Americans have a much higher stroke incidence and mortality than their non-Hispanic White Counterparts.

Objective:
To compare baseline characteristics of current Black stroke survivors in SSA with Black stroke survivors encountered during a roughly similar epidemiologic stage (i.e. earlier aspects of the
“Age of Degenerative and Man-Made Diseases”
) in the United States (US).

Methods:
We compared baseline data obtained in 1960 from stroke cases within the historical Black Pooling Project (BPP) comprising the Charleston Heart Study and Evans County Heart Study cohorts with baseline data from stroke cases encountered within the ongoing Stroke Investigative Research and Education Network (SIREN) Project taking place at several sites in Nigeria and Ghana.

Results:
There were 188 stroke cases in the BPP cohort and 422 in the SIREN cohort. We found a similar pattern of events by age (figure 1) between the two study populations with the majority of the strokes occurring before 65 years of age (BPP 67%;SIREN 65%). However, SIREN cases were more common at the age extremes, and BPP cases more common in the middle-age range. Modifiable risk factors were comparable between the groups: hypertension (BPP 89%; SIREN 90%) and diabetes (BPP 3%; SIREN 20%).

Conclusion:
While baseline hypertension rates of Black American stroke survivors in the 1960s and Black Africans in the 2010s are similar, the former experienced stroke more frequently in mid-life and lower rates of diabetes. Further phenotypic and genotypic comparisons of both these cohorts could provide novel insights into stroke risk among people of African ancestry.
Abstract WP211: The Association Between Arterial Stiffness and Perivascular Space Topography in Stroke Patients
Authors: Bae Jae-Han , Park Kwang-Yeol , Kim Jeong-Min , Park Moo-Suk
Published: July 2021

Background:
Arterial stiffness aggravation is known to increase cerebral small vessel disease burden. We investigated the association between brachial-ankle pulse wave velocity (baPWV) and the topography of MRI visible perivascular space in acute stroke population.

Method:
We analyzed clinical and laboratory data of acute ischemic stroke or transient ischemic attack patients who had been admitted to Chung-Ang University Hospital within 7 days after symptom onset between January 1st 2014 and May 31th 2015. We included those patients who underwent both brain MR imaging including T2 weighted sequence and baPWV. The topography of perivascular space was examined in basal ganglia and centrum semiovale level with validating scale (score 0-4), and dichotomized as low (score3).

Result:
A total of 481 patients were included (mean age 68.2±12.3, 44.7% male). When the distribution of baPWV were divided into quartile, the proportions of high PVS in basal ganglia was 10%, 20%, 40% and 40%, respectively. The proportion of high PVS in centrum semiovale was 20%, 40%, 36%, and 49%, respectively. Multivariate logistic regression analysis revealed that the high degree of basal ganglia PVS was associated with baPWV>2255cm/s (odds ratio 1.7, confidence interval 1.0-2.7, p=0.048) after adjusting age>70 years, hypertension, current smoking status and previous stroke history. The high degree of centrum semiovale PVS showed marginal association with baPWV>2255cm/s (odds ratio=1.4, confidence interval 0.9-2.3, p=0.137) after adjusting age>70 years and hypertension.

Conclusion:
Our pilot study suggests potential pathophysiological association between arterial stiffness and PVS topography.