bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP144: Overexpression of tPA in the Spinal Cord Promotes Corticospinal Axonal Remodeling and Motor Behavioral Recovery in Mice After Stroke
Authors: Liu Zhongwu , Xin Hongqi , Gan Xinling , Shang Xia , Wang Fengjie , Lu Mei , Chopp Michael
Published: January 2019

Our previous studies demonstrated that axonal remodeling of the corticospinal tract (CST) in the spinal cord contributes to neurological recovery after stroke in rodents. In the present study, we designed a novel non-invasive peripheral approach, to over-express tPA in the denervated gray matter of the spinal cord mediated via recombinant adeno-associated virus (AAV) intramuscular injection. Here, tPA is not used as a fibrinolytic agent in the circulation system, but as a neurorestorative agent in the central nervous system. The study was performed in transgenic mice subjected to permanent middle cerebral artery occlusion (MCAo) or sham-MCAo, in which the CST axons are specifically and completely labeled with yellow fluorescent protein (YFP). One day after surgery, mice were randomly selected to receive AAV serotype 5 encoding RFP or tPA under neuron specific Synapsin promoter injected into the stroke-impaired forelimb wrist extensor and flexor muscles at a dose of 1x10
10
viral particles in 5 μl total volume (n=10/group). The functional deficits and recovery were monitored with a series of foot-fault test and single pellet reaching performed prior to and on day 3 after stroke, and weekly thereafter. Mice were euthanized at day 28 after MCAo. The cervical enlargements were processed for vibratome traverse section to examine YFP labeling with a laser scanning confocal imaging system. Single layer confocal images were used to measure axonal densities in the central area of the gray matter on 30 consecutive sections. The ratio of axonal densities in the stroke-affected side and intact side on same sections was used as an index to evaluate axonal remodeling. Compared with AAV-RFP treated mice, intramuscular injection of AAV-tPA significantly enhanced behavioral recovery measured in both functional tests (p<0.01), as well as the index of CST axonal remodeling (p<0.001). Our results provided a fundamental basis for further development of therapeutic approaches aimed on promoting corticospinal innervation in the denervated spinal gray matter to enhance neurological recovery after stroke. If successful, this would greatly impact a large population of stroke patients with a significant unmet medical need of efficacious stroke treatment beyond the acute stage.
Abstract WP146: DHC Enhances the Hypothermia-induced Neuroprotection Following Ischemic Stroke in Rat Over a Long-term Period
Authors: Wu Di , Duan Yunxia , Ding Yuchuan , Ji Xunming
Published: January 2019

Introduction:
The combination of pharmacological hypothermia and intra-arterial selective cold infusions (SCI) was found to enhance the efficiency of hypothermia and efficacy of hypothermia-induced neuroprotection in acute ischemic stroke of rats. The aim of this study was to explore whether the combination could induce a long-term neuroprotective effects, as well as the underlying mechanism.

Methods:
Sprague-Dawley rats were subjected to right middle cerebral artery occlusion (MCAO) for 2 h using intraluminal hollow filament. The ischemic rats were randomized to receive: 1) pharmacological hypothermia by intraperitoneal (i.p.) injection of dihydrocapsaicin (DHC); 2) physical hypothermia by SCI for 10 min; or 3) the combined treatments. Extent of brain injury was determined by neurological deficit, infarct volume over a 21-day observation period. BBB permeability was assessed by detecting EB contents in ischemic hemispheric tissue at 2 h. Cytokine factors were determined in both infarct and penumbra areas in a quantitative way at 24 h after the onset of ischemia.

Results:
MRI-based infarct size analysis indicated that the combination of DHC and SCI resulted in a further reduction in infarct volume at both 48 h and 21 day following the onset of ischemia than either alone (P<0.05). Furthermore, the combination treatment favorably improved neurologic deficit scores over the 21-day observation period (P<0.01 or 0.05). This neuroprotective effects could partially be ascribed to decreased blood brain barrier injury, reduced pro-inflammatory cytokines (TNF-α, IL-2, and IFN-γ) in the infarct areas and/or penumbra areas, and increased protective cytokines (IL-4 and IL-10) in the infarct and/or penumbra regions.

Conclusions:
The combination approach was able to enhance the efficacy of hypothermia-induced neuroprotection following ischemic stroke in a long-term. The findings here provide a hint to translate the combination method from bench to bedside.
Abstract WP149: Post-stroke Vascular Remodeling and the Role of Neural Precursor Cells
Authors: Williamson Michael R , Dunn Andrew K , Drew Michael R , Jones Theresa A
Published: January 2019

The time course, mode, regulation, and relevance to functional recovery of post-stroke vascular remodeling are poorly defined. We tracked peri-infarct vascular remodeling in mice with repeated
in vivo
two-photon imaging of vascular structure (labeled with transgenic expression of green fluorescent protein) and multi-exposure speckle imaging of cortical blood flow over months after photothrombotic cortical lesions. Vascular structure in the intact brain is remarkably stable. In contrast, we found that peri-infarct vasculature (micro- and macrovessels) underwent long-term structural changes, including formation and elimination of vessel segments, beginning within days of infarction. Remodeling continued after peri-infarct blood flow was restored and was most pronounced in superficial vessels. Histological methods indicated that vascular density was rapidly (within days of ischemia) and persistently (at least one month) increased surrounding the infarct. Past findings suggest that neural precursor cells (NPCs) originating in the subventricular zone associate closely with remodeling blood vessels in peri-infarct cortex. To evaluate the role of NPCs in vascular remodeling, we used a pharmacogenetic method to ablate NPCs. NPC ablation prior to infarct altered the pattern of vascular remodeling: the neovascularization response was exaggerated and the orientation of peri-infarct vessels was disordered compared to the normal pattern of vessels oriented towards the lesion. As well, NPC ablation worsened recovery of behavioral function after ischemia. Collectively, these results suggest that vascular remodeling is a chronic process instigated by stroke and that proper vascular patterning is directed by NPCs. NPCs likely contribute to behavioral recovery after brain injury at least in part through their influence on neovascularization.
Abstract WP153: Prenatal Alcohol Exposure Induces Glucose Intolerance and Exacerbates Stroke Severity in Middle-Aged Rats
Authors: Bake Shameena , Miranda Rajesh , Sohrabji Farida
Published: January 2019

Background and Purpose:
Metabolic disorders and cardiovascular diseases in post-natal life have been linked to adverse prenatal environment. There is very little information on the developmental origin of adult diseases, particularly fetal alcohol exposure and stroke outcomes. The present study tested the hypothesis that fetal alcohol exposure induces glucose intolerance and leads to greater stroke severity in middle-aged rats.

Methods:
Timed-pregnant Sprague Dawley rats (GD12) purchased from Envigo laboratories were intragastrically gavaged with ethanol (3g/kg/bwt) or water twice per day from GD12 through 15. Fetal alcohol exposed (FAE) progeny (10 mo. old) were injected with glucose (1g/kg.bwt) and tested for glucose intolerance (glucose clearance rate at 15, 30 and 60 min.) Animals were subjected to endothelin-1 induced MCAo and outcomes evaluated after 2 and 5 days. Stroke induced disabilities were assessed from behavioral assays (adhesive removal, Vibrissae evoked fore-limb placement and circling) and infarct volume.

Results:
Glucose tolerance test showed elevated blood glucose levels in both control and FAE group at 15 and 30 min but FAE animals exhibited prolonged elevation of blood glucose (60 min., p< 0.017) compared to control animals. At 2 day post-stroke, FAE animals exhibited greater neurological deficit as determined by their higher score on circling behavior (lack of muscle control, p<0.031) compared to controls. No mortality was seen in the control group while MCAo resulted in 25% mortality in the FAE group. Among the survivors, brain damage assessed by infarct volume at post-stroke 5 day was not significantly different between the two groups.

Conclusions:
The present findings support the hypothesis that prenatal exposure to alcohol contributes to long-lasting adverse effects on adult health as indicated by poor glucose tolerance and worse neurological outcomes during the acute stage of stroke.
Abstract WP154: Estrogen Modulates Serotonin-induced Vasoconstriction Through Tyrisine Kinase Inhibition
Authors: Kim Sung Hun , Cho Hana , Bae Young Min
Published: January 2019

Earlier onset of menopause may influence the risk of stroke. However, hormone therapy, estrogen, alone or with a progestogen, increases stroke risk. Thus, it is needed to clarify whether estrogens prevent or promote vasomotor symptoms, as well as the mechanism(s) involved. Recent study showed that serotonin enhancing drugs, including antidepressants, migraine therapies and diet pills, can trigger a stroke via vasoconstriction. In this study, we examined the modulatory mechanisms of estrogen in
serotonin
-induced vasoconstriction by using a combinatory approach of isometric tension measurements, molecular biology, and patch-clamp techniques. 17β-estradiol (E2) elicited a significant and concentration-dependent relaxation of serotonin-induced contraction in deendothelialized aorta strips isolated from male rats. E2 triggered a relaxation of serotonin-induced contraction even in the presence of tamoxifen, an estrogen receptor antagonist, suggesting that E2-induced changes were not mediated by estrogen receptor. Patch clamp studies in rat arterial myocytes showed that E2 prevented Kv channel inhibition induced by serotonin. Serotonin increased Src activation in arterial smooth muscle required for contraction, which is significantly inhibited by E2. The estrogen receptor-independent inhibition of Src by E2 was confirmed in HEK239T cells that do not express estrogen receptor. Taken together, these results suggest that estrogen exerted vasodilatory effects on serotonin-precontracted artery via Src, implying a critical role of estrogen in prevention of vascular hyperreactivity to serotonin.
Abstract WP156: Poly-arginine Peptides R18 and R18D Improve Functional Outcomes After Endothelin-1-induced Stroke in the Sprague Dawley Rat
Authors: Blacker David J , Meloni Bruno P , South Samantha M , Gill Daphne A , Marriott Amber L , Deziel Robert A , Jacques Angela , Knuckey Neville W
Published: January 2019

Aims:
We have previously demonstrated that the poly-arginine peptides R18 and R18D are neuroprotective at 24 hours following intraluminal middle cerebral artery occlusion (MCAO) in the rat. Therefore, using an independent laboratory we examined the ability of R18 and R18D to improve functional outcomes after endothelin-1 (ET-1) induced MCAO in rats over 56 days post-stroke.

Methods:
Peptides were administered intravenously at 100, 300 or 1000 nmol/kg, 60 minutes after ET-1 induced MCAO. Multiple forelimb placing tests and horizontal ladder tests were performed post-stroke, and the neuroprotective peptide NA-1 (TAT-NR2Bpc), which is being assessed in Phase 3 clinical stroke trials, was used as a benchmark.

Results:
R18 (300 and 1000nmol/kg, respectively) was the most effective peptide to improve functional outcomes, followed by R18D (300 and 1000 nmol/kg, respectively), and NA-1 (300 and 100 nmol/kg, respectively). Furthermore, R18 at 300 and 1000 nmol/kg was the most effective treatment to restore pre-stroke animal body weight (post-stroke day 4 versus day 7 for saline, and days 5-7 for all other treatments), while R18 and R18D at 300 and 1000 nmol/kg, but not NA-1 also significantly reduced the number of animals requiring special care (hand feeding) 48 hours after stroke.

Conclusion:
In conclusion, this study confirms that R18 and R18D can improve long-term functional outcomes after stroke, and given the superior effectiveness of R18 over NA-1 in the present, as well as in our previous studies, justifies further evaluation in a non-human primate stroke model and in a clinical stroke trial.
Abstract WP16: Symptomatic Retinal Artery Occlusion After Carotid Artery Angioplasty and Stent: Incidence and Related Risk Factors
Authors: Cho Young Dae
Published: January 2019

Background:
Retinal arterial occlusion (RAO) is one of the rare complications developed after carotid artery angioplasty and stenting (CAS). Therefore, RAO after CAS has not well been documented yet. The aim of this study is to investigate the incidence and risk factor of symptomatic RAO after CAS, focusing on comparing the difference depending on whether ophthalmic artery (OA) before CAS was supplied from external or internal carotid artery (ECA or ICA)

Method:
A total of 342 patients with carotid stenosis were retrospectively reviewed, each subjected to CAS for severe and/or symptomatic stenosis from January 2009 to December 2017. Cumulative medical records and radiologic data were assessed. RAO was confirmed by fundus photography and fluorescent angiography performed by ophthalmologist. All patients were grouped by supply of OA from which artery, either ICA or ECA dominant. In all patients, distal filter systems with various types were applied as cerebral protection device (CPD) during procedure. Univariate and multivariate analyses were conducted to identify risk factors for RAO after CAS.

Result:
Symptomatic RAO was observed in 6 patients (1.4%), whom 5 (6.8%) were in ECA dominant group (n=74). In binary logistic regression analysis, OA supplied from ECA (OR, 15.345; 95% CI, 1.061-147.112) and older age (OR, 1.245; 95% CI, 1.035-1.498) were the significant factors related to RAO after CAS. OA supplied from ECA was associated with severity of ipsilateral ICA stenosis (p<0.001), decreased vascular reservoir (p=0.029), common carotid artery involvement (p=0.024), and ulcerative plaque (p=0.006).

Conclusion:
Under usage of distal filtering system on ICA as CPD, CRO after CAS for severe stenosis was related to OA supplied from ECA. In those patients with old-age, simultaneous ICA-ECA protective CPD might be helpful to prevent RAO after CAS.
Abstract WP163: From Static Imaging to Hemodynamic Modelling: Automated Nascet Grading Using Computational Fluid Dynamics
Authors: Yeo Leonard L , Tu Tian Ming , Boopathy Sethu Raman , Mohammadzadeh Milad , Monajemi Sadaf , Tan Benjamin , Sharma Vijay
Published: January 2019

Aim:
Duplex ultrasound is used for non-invasive assessment of internal carotid artery (ICA) disease and stenosis grading based on The North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria. Computational fluid dynamics (CFD) can be used to model blood flow based on static scans (like CT or MR angiograms), but such models are rarely validated in real clinical settings. We evaluated the accuracy of an automated vascular analysis software that simulates blood flow given a CT or MR angiogram (See-Mode Technologies, Singapore) against NASCET grading done by duplex ultrasound.

Methods:
20 carotid arteries from patients with ICA disease were retrospectively analyzed using an automated vascular analysis software according to a blinded protocol. Three-dimensional models of the carotid arteries were reconstructed from MR or CT angiogram DICOM images, and CFD was used for patient-specific modelling of blood flow in the vasculature. Blood flow velocities, specifically ICA peak systolic velocity (PSV) and PSV ratio between the ICA and the common carotid artery (CCA) were obtained from the software and used for stenosis grading based on the NASCET criteria. Bland-Altman analysis was used to assess the agreement between the software and duplex ultrasound.

Results:
The blood flow simulations were in excellent agreement with duplex ultrasound for both metrics, i.e. ICA PSV (r
2
= 0.936, P < 0.001) and ICA/CCA PSV ratio (r
2
= 0.932, P < 0.001). There was no significant over or under estimation of ICA PSV, but there was a slight over estimation of the ICA/CCA PSV ratio with the software (ICA PSV: bias = 5 cm/s, lower limit of agreement (LOA) = -43 cm/s, upper LOA = 52 cm/s; ICA/CCA PSV ratio: bias = 0.16, lower LOA = -0.54, upper LOA = 0.86). All carotid arteries were correctly classified with the software compared against the NASCET grading done with duplex ultrasound.

Conclusion:
While CFD is commonly used for modelling blood flow, its accuracy is rarely assessed in real clinical settings. This is the first validated comparison of carotid artery stenosis grading using blood flow simulations against duplex ultrasound. When the data was categorized according to NASCET criteria, all cases were correctly classified with the software compared against duplex ultrasound.
Abstract WP164: Validation of Noninvasive Methods of Intracranial Stenosis Measurement Against Conventional Angiography
Authors: Alexander Matthew D , De Havenon Adam , McNally J Scott
Published: January 2019

Introduction:
Stenosis caused by intracranial atherosclerotic plaques has long driven treatment algorithms. Conventional digital subtraction angiography (DSA) is considered the gold standard for measuring such stenosis, but fewer patients are evaluated with this modality as utilization of endovascular treatment has decreased. Vessel wall MRI (VWMRI) offers improved characterization by allowing inspection of the vessel wall and disease itself rather than narrowing of the lumen. This study compares measurements of stenosis in VWMRI against those made on conventional angiography or older noninvasive imaging techniques.

Methods:
VWMRI studies performed for patients with plaques that had caused a stroke were retrospectively analyzed. Stenoses were measured according to the WASID technique on DSA, post-contrast T1 DANTE, non-contrast time of flight (TOF), post-contrast TOF, and CTA images. Intraclass correlation coefficient (ICC), weighted kappa, and Cohen’s kappa were calculated as appropriate to assess agreement among stenosis measurements on these techniques.

Results:
Studies from 54 patients met inclusion criteria. Mean stenosis as measured by post-contrast T1 DANTE was 53.8% (±23.2%). 13 (24.1%) had stenosis ≥70%. ICC analysis of agreement between stenosis measurements on DSA demonstrated highest agreement with post-contrast T1 DANTE (ρ=0.927) and CTA (ρ=0.935), with excellent agreement also seen with post-contrast (ρ=0.915) and non-contrast TOF (ρ=0.8110). When separating measurements into ≥70% or <70%, agreement was highest for CTA (κ=1.0) and post-contrast T1 DANTE (κ=0.857), and post-contrast TOF (κ=0.857), while non-contrast TOF agreement was much lower (κ=0.400). Classifying stenosis ordinally by quartiles, greatest agreement with DSA as identified by weighted kappa analysis was seen with post-contrast T1 DANTE (wκ=0.331), followed by post-contrast TOF (wκ=0.268), CTA (wκ=0.253), and non-contrast TOF (wκ=0.222).

Conclusion:
Contrast-enhanced noninvasive angiographic techniques had greatest agreement with DSA when measuring plaque stenosis, with best agreement seen with post-contrast T1 DANTE and CTA. Non-contrast TOF agreement was inferior. The majority (75.9%) of symptomatic lesions had stenosis <70%.
Abstract WP165: Contrast Enhanced MR Angiography Overestimates Carotid Stenosis Compared With Time-of-Flight MR Angiography and Digital Subtraction Angiography
Authors: Kim Yong Bum
Published: January 2019

Background:
Contrast-enhanced magnetic resonance angiography (CEMRA) has begun to replace time-of-flight magnetic resonance angiography (TOFMRA), because it reduces imaging time and improves signal-to-noise ratio. However CEMRA might overestimate the degree of arterial stenosis.

Objectives:
With digital subtraction angiography (DSA) as reference standard, we tried to find out if CEMRA overestimates carotid artery stenosis more than TOFMRA.

Methods:
From April, 2013 to August, 2015, fifty six consecutive patients underwent TOFMRA, CEMRA and DSA. The degree of stenosis was measured using NASCET (North American Symptomatic Carotid Endarterectomy Trial) method and classified as mild (1~49%), moderate (50~69%), and severe (70~99%).

Results:
Six patients were excluded because of the poor quality of images. In 100 carotid arteries of 50 patients, 23 arteries had various degree of stenosis, 8 were occluded, and 69 were normal. CEMRA overestimated the severity of carotid stenosis in 8 out of 92 but TOFMRA did in 3 out of 92. We calculated the agreement by κ in CEMRA vs. DSA (κ = 0.79,
p
< 0.05) and TOFMRA vs. DSA (κ= 0.92,
p
< 0.05). For detection of severe stenosis, CEMRA had the sensitivity of 100% and the specificity of 90% while TOFMRA had 100% and 97.5% respectively. The rate of misclassification of patients as an appropriate candidate for carotid endarterectomy (CEA) was 40.4% in CEMRA and 14.8% in TOFMRA.

Conclusion:
CEMRA has some advantages over TOFMRA but it tends to overestimate the severity of carotid stenosis. The results of CEMRA should be compared with those of TOFMRA or DSA when surgical intervention is considered.
Abstract WP166: The Correlation of Proximal Complex Aortic Plaque and Possible Symptomatic Cervicocephalic Atherosclerotic Stenosis
Authors: Ma Xin , Kong Qi , Wang Chen , Xue Sufang , Zhang Yuren , Du Xiangying
Published: January 2019

Background and Purpose:
Complex aortic plaque (CAP) in the proximal thoracic aorta can be an embolic source for acute ischemic cerebrovascular disease (AICVD), while culprit cervicocephalic atherosclerotic stenosis may coexist. However, the associations between proximal CAP and possible symptomatic cervicocephalic atherosclerotic stenosis (PS-CAS) remain unclear. We aimed at testing whether CAP tended to distribute in the proximal thoracic aorta in AICVD patients with PS-CAS, offering potential risk of aortogenic cerebral embolism.

Methods:
Patients ≥45 years old with AICVD were consecutively enrolled and underwent CT angiography of cervicocephalic arteries and thoracic aorta. Thoracic aorta was divided into proximal and distal parts by the ostium of the left subclavian. Plaques with thickness ≥4 mm, associated ulcer or mural thrombus were considered to be CAP. Distributing patterns of CAP in the thoracic aorta included proximal only (PO), distal only (DO) and proximal + distal (PD). Extracranial and intracranial atherosclerotic stenosis which could be the potential cause of the cerebral ischemia with luminal stenosis ≥50% was defined as PS-CAS.

Results:
Within 285 patients with AICVD, 55 had CAP-PO (19.3%), 37 had CAP-DO (13.0%), 72 had CAP-PD (25.3%). Extracranial and intracranial PS-CAS were detected in 62 and 143 patients (21.8% and 50.2%) respectively. AICVD patients with PS-CAS were more likely to have CAP-PO and CAP-PD than those without (51.9% vs. 35.2%, p=0.005). Regardless of age, sex and vascular risk factors, CAP-PO was associated with extracranial PS-CAS (adjusted OR=5.39, 95%CI: 2.18-13.36) and intracranial PS-CAS (adjusted OR=2.59, 95%CI: 1.25-5.38), whereas CAP-DO bored no relationship with them. CAP-PD was independently related to extracranial PS-CAS (adjusted OR=6.59, 95%CI: 2.53-17.15) but not intracranial PS-CAS.

Conclusions:
AICVD patients with PS-CAS were more likely to have CAP in the proximal thoracic aorta. The risk of potential aortogenic cerebral embolism might be higher when PS-CAS, especially the extracranial ones, was identified in patients with AICVD.
Abstract WP167: Is There a Distinct Phenotype for Non-Asian Moyamoya Patients?
Authors: Gatollari Hajere J , Miller Eliza C , Boehme Amelia K , Connolly E. Sander , Elkind Mitchell S , Willey Joshua Z
Published: January 2019

Background and Purpose:
Idiopathic moyamoya syndrome (IMMS) is a progressive narrowing of the anterior circulation arteries resulting in the development of a tenuous collateral blood supply which is prone to rupture or thrombosis. IMMS has mostly been studied in East Asian populations where it was first described, with limited data describing this syndrome in non-Asians. We aimed to describe IMMS patients in New York and identify differences between Asians and non-Asians in this population.

Methods:
Using the New York State Department of Health Statewide Planning and Research Cooperative System database from 2000-2014 we identified all newly diagnosed cases of IMMS (ICD-9 437.5) in adults aged 18 and older. We excluded patients with down syndrome, neurofibromatosis type 1 and sickle cell disease. We compared patient demographics, comorbidities and extracranial-intracranial revascularization (ECIC) rates for IMMS patients that self-identified with Asian race/ethnicity vs those who did not.

Results:
All IMMS diagnoses occurred in urban hospitals. There were 554 IMMS patients in total; 89.4% (n=495) were non-Asian while only 10.6% (n=59) were Asian. A smaller proportion of non-Asian IMMS patients were diagnosed in smaller, non-academic hospitals compared to Asians (3.8% vs 10.2%, p=0.03) (Table). Both groups showed comparable rates of characteristics and comorbidities. Stroke risks following IMMS diagnosis were similar for both Asians and non-Asians (13.6% vs 22.4%, p=0.1); strokes occurred later for non-Asian patients with ECIC than in those without (2.1
+
2.8 vs 1.4
+
2.1 years, p=0.04). No subsequent strokes occurred in Asians after ECIC.

Conclusion:
Individuals of non-Asian origin account for almost 90% of IMMS diagnoses in New York State, but they are infrequently diagnosed in small, non-academic hospitals. Further research is needed to identify a distinctive phenotype and genotypic profile of IMMS in non-Asians.
Abstract WP168: Cerebrovascular Reactivity Predicts Surgical Decisions in Moyamoya Patients
Authors: Liu Peiying , Welch Babu G , Thomas Binu P , Li Yang , Pinho Marco C , Huang Judy , Lu Hanzhang
Published: January 2019

Introduction:
Moyamoya disease (MMD) is characterized by chronic occlusion of the distal intracranial internal carotid arteries and can be treated by revascularization surgery. At present, surgical decisions are primarily based on symptomatology and imaging studies using DSA and SPECT, which are are costly, invasive, time consuming and qualitative. Here we applied a novel iVas-MRI technique that provides quantitative assessment of multiple hemodynamic parameters in a 9-minute scan in MMD patients, and evaluated the ability of iVas parametric maps to predict surgical decisions in such patients.

Methods:
Sixteen MMD patients were scanned on 3T MRI. Each patient had at least one hemisphere pending decision regarding surgery at the time of MRI. During iVas-MRI, a concomitant CO2/O2 breathing challenge was performed while BOLD images were continuously collected. BOLD images and end-tidal (Et) CO2 and O2 traces were used to calculate maps of cerebrovascular reactivity (CVR, based on BOLD signal change to EtCO2 change), cerebral blood volume (CBV, based on BOLD signal change to EtO2 change), and bolus arrival time (BAT, based on the time lag between EtCO2/O2 and BOLD signal). Parametric values from the ICA perfusion territory were compared between two groups, surgical and medical, with decision made by the treating neurosurgeons blinded to research data. The area-under-the-ROC-curve (AUC) was calculated to evaluate the performance of the MRI indices in predicting surgical decisions.

Results:
Out of the 23 hemispheres under consideration, 9 were diagnosed as surgical and 14 considered medical. CVR, CO2-BAT and O2-BAT values showed significant differences between the two groups (p=0.0002, 0.005 and 0.001, respectively), while CBV values showed no difference (p=0.45). Brain hemispheres that required revascularization surgeries had lower CVR and longer BAT, compared to medically-managed hemispheres. ROC analyses revealed an AUC of 0.89, 0.84 and 0.95 for CVR, O2-BAT, and CO2-BAT respectively.

Conclusion:
Our results showed that CVR and BAT had a great accuracy in predicting surgical decisions. Therefore, iVas-MRI may be a cost-effective and reliable method to select between medical and surgical treatments for MMD patients.
Abstract WP169: Coated-platelets and Tumor Necrosis Factor Alpha Predict TIA/stroke at Twenty-one Months in Asymptomatic Carotid Stenosis
Authors: Kirkpatrick Angelia , Prodan Calin , Vincent Andrea , Khattab Mohamad , Arif Mohammad , Ijaz Sardar , Bajwa Muhammad , Dale George
Published: January 2019

Background:
The clinical spectrum of carotid atherosclerosis is well characterized, but the events leading to plaque instability and stroke are less understood. Evidence suggests that platelets serve as an interface among hemostasis, inflammation, and atherosclerosis. Coated-platelets, a subset of platelets with high procoagulant potential, are increased in asymptomatic carotid stenosis patients at high risk for stroke or TIA. We now examine the impact of other soluble mediators of inflammation, cell adhesion, angiogenesis and coagulation on the association between coated-platelets and TIA/stroke in asymptomatic carotid stenosis.

Methods:
Consecutive asymptomatic patients with ≥50% carotid stenosis were enrolled. Coated-platelet levels were assayed and plasma was obtained for measurement of 58 biomarkers. Patients were followed at 6-month intervals for intensive vascular risk reduction. Those with signs or symptoms of TIA/stroke underwent either brain CT or MRI. Rank order correlations between inflammatory marker concentrations, coated-platelet levels and TIA/stroke were determined using the Spearman correlation coefficient. Variables associated with TIA/stroke (p<0.15) were included in multivariate analysis.

Results:
We enrolled 117 patients (97% male, average age 71, 94% on statins, 96% on antiplatelets, and 33% currently smoking, average HgA1c 6.6% and average LDL 86 mg/dL). There were 6 strokes and 2 TIA’s ipsilateral to carotid stenosis during a mean 21.3 ± 6.7 months of follow-up (incidence of 3.89/100 person-years). Stepwise logistic regression identified TNF alpha (OR=11.1, p=0.0300) and coated-platelet group (OR=14.1, p=0.0167) as predictors of TIA/stroke ipsilateral to stenosis. Cox Proportional Hazard analysis yielded a TIA/stroke HR of 11.8 for the high coated-platelet group (95% CI 1.4, 96.1, p=0.0215) and 8.0 (95% CI 0.97, 66.3, p=0.0529) for the high TNF alpha group.

Discussion:
Coated-platelets and TNF alpha predict TIA/stroke in asymptomatic carotid stenosis at 21 months. These findings expand on our previous work in coated-platelets and asymptomatic carotid stenosis and suggest that coated-platelets may represent a common link between hemostatic and inflammatory mechanisms of plaque instability.
Abstract WP170: Selective Surgical Treatment for Internal Carotid Artery Near Occlusion
Authors: Yasuda Takaya , Kurosaki Yoshitaka , Chin Masaki , Yamagata Sen
Published: January 2019

Introduction:
From the results of NASCET and ECST, surgical treatment for carotid artery near occlusion (NO) has not been as effective as of that for severe stenosis. A meta-analysis published in 2015 supported surgical treatment for NO, but this is still controversial because recent large prospective studies such as CREST or ICSS exclude NO.

Method:
We conducted a retrospective single center case-controlled study in Japan. Among all NO cases from May 2006 to May 2017, we selected those who had internal carotid artery (ICA) without collapse, with collapse but with detection of vascular lumen from neck to intracranium by angiography and MRI, and without mechanical changes of vessel wall. We excluded patients who had ICA with full collapse and without the possibility for expansion. The carotid artery endarterectomy (CEA) or carotid artery stenting (CAS) was performed according to plaque character, position, and expectancy of expansion. The primary outcome was ipsilateral stroke within 90 days after surgery. Secondary outcomes included restenosis of more than 50%, and perioperative complications (postoperative procedural DWI positive, myocardial infarction, death).

Result:
In the eligible 60 patients, 56 were male, and the median age was 73±6.3. The number of symptomatic lesions and string signs were 27 and 5, and the CEA and CAS groups consisted of 33 and 27 patients, respectively. There was no significant difference between each group in the patient backgrounds other than the age and follow-up period (71 and 76 [p = 0.0093], 63 and 39 months, respectively [p = 0.0185]). Ipsilateral stroke within 90 days after surgery occurred in 0 and 4 patients (p = 0.0328), and restenosis in 7 (3 needed additional CAS) and 3 patients (p = 0.490). The postoperative DWI positive was 7 and 11 (p = 0.095), and all of them were asymptomatic or transient. There were no cases of perioperative myocardial infarction, and perioperative death occurred in 1 patient.

Conclusion:
CEA group had the advantage of procedural safety but also the risk of restenosis. In CAS group, we can expect good expansions of ICA, but perioperative complications are relatively high. Our results suggest that there exist specific factors including surgical indication which lead to good outcome by surgical treatment.
Abstract WP176: Recanalization of Chronically Occluded Internal Carotid Artery
Authors: Hasan David M , Zanaty Mario , Starke Robert M , Chalouhi Nohra , Jabbour Pascal , Guerrero Waldo , Nakagawa Daichi , Samaniego Edgar A , Mbabuike Nnenna , Tawk Rabih , Siddiqui Adnan H , Levy Elad I , Novakovic Robin , White Jonathan , Shirmer Clemens M , Brott Thomas G , Shallwani Hussain , Hopkins L Nelson
Published: January 2019

Objective:
The overall risk of ischemic stroke from a chronically occluded internal carotid artery (COICA) is around 5%-7% per year despite receiving the best medical therapy. We propose a radiographic classification of COICA that can be used as a guide to determine the technical success and safety of endovascular recanalization for symptomatic COICA.

Methods:
The radiographic images of 100 consecutive subjects with COICA were analyzed. A new classification of COICA was proposed based on the morphology, location of occlusion, and presence or absence of reconstitution of the distal ICA. The classification was used to predict successful revascularization in 32 symptomatic COICAs in 31 patients. Patients were included in the study if they had a COICA with ischemic symptoms refractory to medical therapy.

Results:
Four types (A-D) of radiographic COICA were identified. Types A and B were more amenable to safe revascularization than types C and D. Recanalization was successful at a rate of 68.75% (22/32 COICAs; type A: 8/8; type B: 8/8; type C: 4/8; type D: 2/8). The perioperative complication rate was 18.75% (6/32; type A: 0/8 [0%]; type B: 1/8 [12.50%]; type C: 3/8 [37.50%], type D: 2/8 [25.00%]). None of these complications led to permanent morbidity or death. Twenty (64.52%) of 31 subjects had improvement in their symptoms at the 2-6 months' follow-up. A statistically significant decrease in systolic blood pressure (SBP) was noted in 17/21 (80.95%) patients who had successful revascularization, which persisted on follow-up (p = 0.0001). The remaining 10 subjects in whom revascularization failed had no significant changes in SBP (p = 0.73).

Conclusions:
The pilot study suggested that our proposed classification of COICA may be useful as an adjunctive guide to determine the technical feasibility and safety of revascularization for symptomatic COICA using endovascular techniques. Additionally, successful revascularization may lead to a significant decrease in SBP postprocedure. A Phase 2b trial in larger cohorts to assess the efficacy of endovascular revascularization using our COICA classification is warranted.
Abstract WP178: “CTA for All”: Emergency CT Angiography for All Stroke Patients Presenting Within 24 Hours of Onset Improves Outcome After Large Vessel Occlusion
Authors: Mayer Stephan , Viarasilpa Tanuwong , Panyavachiraporn Nicha , Griffith Brent , Miller Daniel , Brady Megan , Scozzari Dawn , Katramados Angelos , Hefzy Hebah , Malik Shaneela , Marin Horia , Kole Maximilian , Abou-Chebl Alex , Lewandowski Christopher , Mitsias Panayiotis
Published: January 2019

Introduction:
Computed tomographic angiography (CTA) is an important initial assessment for detecting large vessel occlusion (LVO) in acute ischemic stroke (AIS) and for selecting patients for mechanical thrombectomy (MT). This study is designed to evaluate the impact of an emergency CTA protocol on outcome of AIS patients with LVO.

Methods:
On July 1, 2017 we implemented the policy of performing CTA at the same time as non-contrast CT (NCCT) in all AIS patients presenting within 24 hours of symptom onset regardless of baseline NIHSS. Previously emergency CTA was reserved for patients presenting within 6 hours with an NIHSS ≥6. We compared treatment processes and outcomes between AIS patients admitted 1-year before (N=396) and 1-year after (N=494) protocol implementation.

Results:
After protocol implementation, more patients underwent CTA (90% vs 60%, P < 0.001) and had CTA performed at the time of the initial NCCT (77% vs 34%, P <0.001). Median time from last known well (LKW) to CTA was also shorter (2.4 [interquartile range, IQR 1.2-6.0] vs 2.9 [IQR 1.5-7.6] hours, P = 0.005). More cases of LVO were detected (162 vs 93; 33% vs 25% of all AIS, P = 0.007), and more MT cases were performed (110 vs 69; 22% vs 17% of all AIS, P=0.07). Among LVO patients who presented within 6 hours of onset, median time from symptom onset to MT was shorter (209 [IQR 166-289] vs 247 [IQR 195-338] minutes, P = 0.031), and more were discharged with a favorable outcome (GOS 4-5, 54% vs 36%, P = 0.015). Symptomatic intracerebral hemorrhage (1% vs 5%, P = 0.159) and mortality (13% vs 22%, P = 0.097) were also non-significantly lower among LVO patients who presented within 6 hours of symptom onset.

Conclusion:
Emergency CTA for all stroke patients presenting within 24 hours regardless of baseline NIHSS improves LVO detection, increases the MT treatment population, speeds intervention, and improves outcome after LVO. The benefit primarily affects patients who present within 6 hours of symptom onset.
Abstract WP179: A Korean Population-Based Data Indicates a Higher Mortality With Carotid Artery Stenting Compared to Endarterectomy in Patients With Carotid Artery Stenosis
Authors: Seo Kwonduk , Lee Kyung-Yul , Suh Sang Hyun
Published: January 2019

Introduction:
Carotid endarterectomy (CEA) is more recommended than carotid artery stenting (CAS) for the treatment of carotid stenosis. However, CAS has been favored more in Korea because of its non-invasiveness and the limited number of capable operators. The aim of this study was to assess long-term outcomes after CAS compared with CEA.

Methods:
We obtained all data from the nationwide database of Health Insurance Review & Assessment Service (HIRA) during the study period using several codes regarding to the procedure or operation. We included the data which fulfilled at least one-year follow-up after the procedures. International classification of disease-codes was utilized to identify underlying diseases associated with ischemic stroke.

Results:
A total of 16,990 eligible patients who were treated with CAS or CEA between 1 January 2007 and 31 December 2016 were analyzed. The number of patients with CAS and CEA was 12,974 (76.4%) and 4016 (23.6%), respectively. The proportion of males was 82.2% and the mean age was 69.7 years. During the follow-up period, 2945 patients with CAS (22.7%) and 675 patients with CEA (16.8%) died. The 30-day, 90-day and 1-year death frequency were 0.39%, 1.55% and 5.24%.

Conclusions:
In this nationwide data, the overall mortality rate was higher in patients with CAS over the long period. The results of our study are consistent with the outcomes from previous studies.
Abstract WP18: The Impact of Fast versus Slow Infarct Growth on Recanalization in Patients Presenting With Acute Ischemic Stroke
Authors: Shah Kavit , Desai Shashvat , Rocha Marcelo , Hawkes Christine , Tememe Danoushka , Jovin Tudor G , Jadhav Ashutosh P
Published: January 2019

Background:
Favorable clinical outcomes after acute ischemic stroke (AIS) in the setting of a symptomatic large vessel occlusion (LVO) are reliant upon fast and high quality recanalization. Recent data suggests that modified first pass effect mFPE (mTICI ≥ 2b after one attempt of thrombectomy) is a strong predictor of favorable outcome; however, the patient specific features that favor mFPE are poorly understood. In this study, we aim to understand the rate of mFPE in fast versus slow progressors of early infarct growth before recanalization.

Methods:
A retrospective review of all patients presenting with AIS due to LVO treated with endovascular thrombectomy (ET) at a single comprehensive stroke center between November 2014 and February 2017 was performed. The following data was collected: patient demographic features, imaging characteristics and procedural details (mTICI, thrombectomy attempts). Ischemic core volume before ET was analyzed using automated software (RAPID, IschemaView, Inc). Patients were stratified based on infarct growth and defined as follows: fast progressor (last known well-LKW <6 hours, core >50ml), slow progressors (LKW >6hours, core <30 ml), and intermediate progressor. Chi-square and student t-test were utilized to compare different groups.

Results:
Of 98 patients with available baseline core imaging, 8% (n=8) were fast progressors, 42% (n=41) were slow progressors, and the remaining 50% were intermediate progressors (n=49). mFPE rates were significantly higher in slow progressors compared to fast progressors (p = 0.02). Rates of successful recanalization (mTICI ≥ 2b) were lower in fast progressors compared to the slow and intermediate progressors (p = 0.073).

Conclusion:
Higher rates of successful recanalization and mFPE were observed in slow progressors of infarct growth. These results indicate that early recognition of LVO stroke phenotypes may aid in future device and technique selection for ET.
Abstract WP182: Machine Learning Models are More Accurate Than Regression-based Models for Predicting Functional Impairment Risk in Acute Ischemic Stroke
Authors: Alaka Shakiru A , Brobbey Anita , Menon Bijoy K , Williamson Tyler , Goyal Mayank , Demchuk Andrew M , Hill Michael D , Sajobi Tolulope
Published: January 2019

Background and Purpose:
The burden of stroke-related functional impairment remains high among stroke survivors. Clinical prediction models are commonly used to estimate patient functional impairment risk. However, these models have been principally developed based on regression models, which are sensitive to multicollinearity. This study investigates whether there is any advantage in using machine learning models to develop stroke-related functional impairment risk prediction tools.

Methods:
Using data from a multi-center hospital-based cohort study (n = 614). Modified Rankin Scale (mRS) score was used to assess 90-day functional impairment status. The accuracy of machine learning models was used to predict the risk of patient-specific risk of 90-day functional impairment. Area under the receiver operating characteristic curve (AUC) was used to assess the predictive accuracy of these models via internal cross-validation and external validation in the ESCAPE randomized controlled trial data.

Results:
Of the 614 patients included in the analyses, 348(56.7%) had some form of functional impairment (i.e., mRS > 1), 313 (50.9%) were males, while the median and interquartile range (IQR) of age and baseline NIHSS scores were 72 years (IQR = 63-80) and 12 (IQR = 6-19), respectively. Internal cross-validation shows that the AUC for regression models were 68.3% (95%CI = [63.9% - 76.5%]) and 70.1% (95%CI = [63.5% - 76.1%]) while the AUC for machine learning models ranged between 62.7% to 68.8%. But when these models were externally validated in the ESCAPE data, the AUC for regression models were 39.6% (95%CI = [36.1% - 47.5%]) and 35.8% (95%CI = [30.4% - 41.5%]) while the AUC for machine learning models ranged between 61.6% (95%CI = [58.2% - 67.3%]) and 66.7% (95%CI = [61.3% - 72.3%]).

Conclusions:
This study shows that while there were negligible differences between risk prediction models based on machine learning and regression-based models when internally validated, the former are more accurate than the latter in predicting stroke-related functional impairment in externally validated data. Future research will use Monte Carlo methods to develop recommendations for selecting machine learning models under a variety of data characteristics.
Abstract WP186: The Efficacy of a Patient-centered Self-management Empowerment Intervention Program (pcsmei) for First-time Stroke Survivors: A Randomized Controlled Trial
Authors: Chen Lu , Wang Fang , lv Lin , Zhang Yang , Shen Xiaofang
Published: January 2019

Keywords:
Patient-centered; Self-management; Empowerment; Stroke

Purpose:
To evaluate the efficacy of a patient-centered self-management empowerment intervention (PCSMEI) program for first-time stroke survivors on self-management behaviors, stroke related depression and quality of life.

Design:
A single-blinded parallel-group randomized controlled trial was designed. Patients were randomly allocated into control group (CG: n=72) or intervention group (IG: n=72) after baseline measurement. The intervention group received a patient-centered self-management empowerment intervention (PCSMEI) and the control group received a routine care. Please add the brief description of the intervention. The data of self-management behaviors, stroke related depression and quality of life were collected at baseline (T0), on discharge (T1), one month post-discharge (T2) and three months post-discharge (T3). Generalized Estimating Equations Modelling (GEE) analyses were conducted to estimate the intervention effect over time.

Findings:
One hundred and twenty-six participants finished the study (IG: n=64; CG: n=62). Significant improvement in self-management behaviors in the intervention group were observed in stretching or strengthening at T2 and T3; cognitive symptom management at T1, T2 and T3. The depression level was lower in IG than that in CG at T1, T2 and T3. Significant difference in quality of life between the two groups were shown in Physical Component Summary (PCS) at T3 and in Mental Component Summary (MCS) at T2 and T3.

Conclusions:
The patient-centered self-management empowerment intervention program appears to be an effective and well-received solution to improve first-time stroke patients’ self-management behaviors, stroke related depression and quality of life.(This study was funded by the National Natural Science Foundation of China : 7150030201 )