bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP43: Body Mass Index and Clinical Outcomes in Large Vessel Occlusion Acute Ischemic Stroke After Endovascular Therapy: The Obesity Paradox
Authors: Bouslama Mehdi , Perez Hilarie , Rebello Letícia C , Haussen Diogo C , Grossberg Jonathan A , Barreira Clara M , Schindler Kiva M , Belagaje Samir R , Bianchi Nicolas A , Frankel Michael R , Nogueira Raul G
Published: October 2018

Background:
Obesity has been associated with increased morbidity and mortality in the general population. However, several reports have described lower mortality rates in overweight or obese patients as compared to normal weight ones. Several studies have investigated the phenomenon, commonly known as the obesity paradox, with mixed results thus far. We sought to determine whether clinical outcomes differ between patients with acute ischemic stroke after endovascular therapy according to their body mass index (BMI).

Methods:
We reviewed our prospectively collected endovascular database at a tertiary care academic institution. All patients that underwent endovascular therapy for acute large vessel occlusion acute ischemic stroke were categorized according to their BMI into four groups (1) underweight (BMI<18.5), (2) normal weight (BMI=18.5-25), (3) overweight (BMI=25-30) and (4) obese (BMI>30). Baseline characteristics, procedural radiological as well as outcome parameters were compared.

Results:
A total of 926 patients qualified for the study of which 20 (2.2%) were underweight, 253 (27.3%) had a normal weight, 315 (34%) were overweight and 338 (36.5%) obese. When compared with normal weight (reference) overweight patients had higher rates of dyslipidemia as well as diabetes and higher glucose and HbA1c levels while obese patients were younger, less often smokers and had higher rates of hypertension as well as diabetes and higher glucose and HbA1c levels. Other baselines characteristics including NIHSS and ASPECT scores as procedural characteristics were comparable between groups. In terms of outcomes, rates of successful reperfusion (mTICI 2b-3), parenchymal hematomas, 90-Day good clinical outcomes (modified Rankin scale, mRS 0-2) and 90-day mortality were comparable between BMI groups. On multivariate analysis, BMI was not associated with good outcomes nor mortality whether as a continuous variables or a categorical variable comparing groups with normal weight patients (reference) two by two.

Conclusions:
In stroke patients treated with mechanical thrombectomy, BMI does not seem to be associated with outcomes. However, patients who are overweight or obese have more co-morbities and should strive for a normal weight.
Abstract WP45: Algorithm Enhanced Gray-White Matter Non-Contrast CT Improves Reliability of ASPECTS Scoring
Authors: Hafeez Moiz , Qiu Wu , Kuang Hulin , Najm Mohamed , Wilson Alexis T , Bobyn Amy , Dey Sadanand , Goyal Mayank , Hill Michael D , Demchuk Andrew , Menon Bijoy K
Published: October 2018

Objective:
The Alberta Stroke Program Early CT Score (ASPECTS) is widely used to assess and diagnose acute ischemic stroke (AIS) patients. However, reliability of ASPECTS scoring is poor among physicians with limited expertise. We hypothesize that reliability for ASPECTS scoring can be improved by using algorithm enhanced gray-white matter (AEGWM) NCCT.

Methods:
Inter-rater reliability for ASPECTS scoring was assessed between plain and AEGWM NCCT by an expert and a novice reader. 50 AIS patient NCCT images were acquired acutely. NCCT images were then enhanced by skull stripping, image smoothing, histogram equalization, and JET color mapping. ASPECTS scoring was done on AEGWM color mapped NCCT and on standard 5mm NCCT images by a novice reader. ASPECTS scoring was done two days apart on standard NCCT first, followed by AEGWM NCCT. Expert (neuro-radiologist) scores on standard NCCT were then compared with scores from the novice reader on both regular and AEGWM NCCT.

Results:
Agreement between novice and expert for trichotomized ASPECTS (0-4, 5-7, 8-10) was best when the novice was reading ASPECTS on AEGWM NCCT (kappa=0.7093) vs. when novice read ASPECTS on standard NCCT (kappa=0.2409). Difference in scoring the full 10-point ASPECTS score was least when the novice read ASPECTS on AEGWM NCCT (mean ASPECTS difference between novice and expert for algorithm-enhanced NCCT 0.68 ± 1.1 vs. 1.48 ± 1.8 for standard NCCT). A Bland Altman plot comparing the difference is attached and the coefficient of variation was found to be 0.14 for AEGWM NCCT scoring.

Conclusion:
Algorithm Enhanced Gray-White Matter NCCT allows more accurate/ reliable ASPECTS scoring. Further evaluation on a larger dataset with readers with different levels of expertise is ongoing.
Abstract WP46: Objective Collateral Assessment to Identify Patients Suffering From Distal Middle Cerebral Artery Occlusion Refractory to Intravenous Tissue Plasminogen Activator Therapy
Authors: Mori Takahisa , Tanno Yuhei , Kasakura Shigen , Yoshioka Kazuhiro , Nakai Noriyoshi
Published: October 2018

Introduction:
It remains unknown who requires endovascular therapy in case of distal middle cerebral artery (MCA) occlusion.

Hypothesis:
Objective collateral assessment can identify acute ischemic stroke (AIS) patients with distal MCA occlusion refractory to intravenous tissue plasminogen (iv-tPA) alone.

Methods:
We Included patients 1) who were admitted to our institution from July 2009 to March 2017 within 4.5 hours of onset and diagnosed as AIS in the territory of the MCA, and 2) who underwent iv-tPA alone (0.6mg/kg). We assessed collateral status with time-intensity curves (TIC) produced by intravenous administration of gadolinium in bilateral MCA territories. We excluded patients with proximal MCA occlusion within 5 mm in length from the origin. According to the time to peak (TP) and the peak value (PV) of TIC comparing the affected side (a) with the contralateral side (c), we defined collateral status as following; Poor was defined as TP(a) minus TP(c) (TP delay) of 2 seconds or more and PV(a) divided by PV(c) (PV ratio) of less than 0.25, Moderate as TP delay of 2 seconds or more and PV ratio of 0.25 or more and of less than 0.75, Good as TP delay of less than 2 seconds or PV ratio of 0.75 or more. We evaluated association of collateral status with modified Rankin scale (mRS) scores at 3 months. We defined mRS score of 0 to 2 as favorable.

Results:
Sixty-six patients matched our criteria. A median NIHSS score was 12.5. Two patients had Poor collateral, 36 patients had Moderate and 28 patients had Good. Clinical outcome was favorable in none (0%) with Poor, in 19 (52.8%) with Moderate and in 18 (64.3%) with Good. Clinical outcome of all 5 patients with occlusion of opercular or cortical branches was favorable. Except for the 5 patients, among 34 patients with Moderate, outcome was favorable in 1 (50%) of 2 with NIHSS score of less than 5 and in 16 (50%) of 32 with NIHSS score of 5 or more, and among 25 patients with Good, outcome was favorable in all (100%) of 4 with NIHSS of less than 5 and in 11 (52%) of 21 with NIHSS of 5 or more.

Conclusion:
All patients with Poor collateral, half of the patients with Moderate collateral, about half of the patients with Good collateral coupled with NIHSS score of 5 or more are refractory to iv-tPA alone for distal MCA occlusion except opercular or cortical branches.
Abstract WP47: Quantitative Analysis of Hemorrhage and Infarct Volume for Predicting Outcome in Cerebral Venous Sinus Thrombosis
Authors: Shaban Amir , Samaniego Edgar , Aksan Nazan , Dai Biyue , Ahmed Uzair , Granchi Julia , Zheng-Lin Binbin , Lazarre Lara , Adams Harold , Derdeyn Colin , Leira Enrique , Ortega-Gutierrez Santiago
Published: October 2018

Background and purpose:
Intracerebral hemorrhage (ICH) and venous infarction are known complications that independently predict poor outcome in patients with cerebral venous sinus thrombosis (CVST). We aimed to study the utility of precise quantification of volumes of venous infarction and ICH using digitalized images in refining our prediction of discharge outcome.

Methods:
We retrospectively reviewed all patients with CVST admitted to University of Iowa Health Care between 2004-2014. All patients received standard of care management per available AHA/ASA recommendations. Scans were analyzed using Carestream Vue PACS software. Gradient Echo (GRE) MRI sequence was used to calculate ICH volume. When MRI was not available CT was used. Diffusion Weighted Imaging (DWI) MRI sequence was used to calculate infarction volume. Volume scorer was blinded to the clinical outcomes. Univariate and multivariate analyses were conducted. A
p value ≤ 0.05
was set as statistically significant.

Results:
115 patients met inclusion criteria, 76 women, mean age 42. A total of 30 (26%) had venous infarction, 34 (30%) had ICH. The median volumes were 8 cc (SD=27) for ICH and 14 cc (SD= 35) for infarction. Both ICH and infarction volumes were significantly higher among those with a poor functional outcome (mRS=3-6) [Mdn=16 cc, SD=32 for ICH; Mdn=33 cc, SD=46 for infarction] than those with good outcome [Mdn=5 cc, SD=7 for ICH; Mdn=7 cc, SD=162 for infarction], p= .029 and p=.027 respectively. The correlation between ICH volume and mRS was r=.43, p=.012 and the corresponding correlation for infarction volume was r=.62, p=.002. Regressions testing the effects of ICH and infarction volumes on discharge mRS showed that both significantly contributed (p<.001 & p=.004 respectively). These effects remained significant when controlling for the effects of age, gender, presence of deep infarct, and altered mental status at presentation (p=.001 and p=.013 respectively).

Conclusion:
Quantitative measurement of Infarction and ICH volumes on admission leads to a more accurate prediction of outcome at discharge in CVST patients. Its combination with clinical variables might signify an additional prognostication tool for identification of high risk patients refractory to standard therapy.
Abstract WP51: Currency of Collaterals: Validation and Clinical Utility of a Novel Imaging Paradigm for Triage to Endovascular Therapy
Authors: Liebeskind David S , Leyhe Johanna , Scalzo Fabien , Tsogkas Ioannis , Behme Daniel , Psychogios Marios
Published: October 2018

Background:
The pivotal impact of collateral circulation on outcomes in endovascular therapy has fueled the development of numerous single and multiphase CTA collateral scales, yet synchronized validation with conventional angiography has never occurred. Multiphase flat detector CT angiography (mpFDCTA) enables direct patient transfer to the angiography suite and rapid collateral triage. We validated this novel collateral imaging paradigm and potential clinical utility for endovascular stroke treatment.

Methods:
Consecutive acute ischemic stroke patient data, including mpFDCTA followed within few minutes by digital subtraction angiography (DSA), in the setting of ICA or proximal MCA occlusions were analyzed. An independent core lab scored mpFDCTA with an established multiphase CTA collateral scale and separately graded ASITN collateral status on DSA, blind to all other data.

Results:
24 consecutive cases (age 76.7 ± 7.3 years; 58.3% women; baseline NIHSS median 17 (4-23)) of acute stroke due to ICA or proximal MCA occlusion were analyzed with simultaneous mpFDCTA and DSA. Arterial occlusion sites included 18 M1 MCA, 5 ICA, 1 M2 MCA. ASPECTS was median 8 (4-10). Time from first noncontrast FDCT to intracranial DSA was 23.04 ± 7.6 minutes with mTICI ≥ 2b reperfusion in 91.7% of cases. mpFDCTA collateral score was median 3 (0-5) and DSA ASITN was median 2 (0-3), including the full range of potential collateral grades. mpFDCTA and ASITN were highly correlated (r=0.86, p<0.001). mpFDCTA provided more complete collateral data compared to selective DSA injections in cases of ICAO. ROC analyses for prediction of clinical outcomes revealed an AUC of 0.76 for mpFDCTA collaterals and 0.70 for DSA ASITN collateral grades.

Conclusions:
Multiphase flat detector CT angiography (mpFDCTA) in the angiography suite provides a validated measure of collaterals, offering distinct advantages over conventional angiography. Direct patient transfer to the angiography suite and mpFDCTA collateral grading provides a novel and reliable triage paradigm for acute ischemic stroke.
Abstract WP52: ASPECTS and eASPECTS Correlation With Baseline and Final Infarct Volume in Acute Ischemic Stroke Thrombectomy Patients
Authors: Olive-Gadea Marta , Martins Nuno , Boned Sandra , Carvajal Jaime , Rios Miguel A , Muchada Marian , Molina Carlos A , Tomasello Alejandro , Ribo Marc , Rubiera Marta
Published: October 2018

Alberta Stroke Program Early CT score (ASPECTS) is widely used as cut-off point to indicate thrombolysis therapy in acute ischemic stroke. Its role in predicting patients likely to benefit from endovascular therapy has not been defined yet. ASPECTS presents a poor interrater reliability, and an automated software (eASPECTS) has been recently created to solve this limitation. Our aim was to evaluate correlation between ASPECTS measured by neurorradiologists, eASPECTS and cerebral blood volume (CBV) lesion, as well as to determine the impact of ASPECTS and eASPECTS on final infarct in thrombectomy patients.

Methods:
Consecutive patients with acute intracranial ICA and proximal MCA (M1) occlusion who underwent endovascular thrombectomy were included. ASPECTS and e-ASPECTS on basal non-contrast CT were evaluated. Admission infarct core was measured on CBV in CT perfusion. We assessed time from symptom onset to neuroimaging evaluation and recanalization (TICI 2b-3) after thrombectomy. Infarct volume was measured on 24-hour control CT.

Results:
We included 214 patients (88% with MCA occlusion). Median NIHSS was 18 (IQR 14-20) and mean time from symptom onset to CT was 194.11±154.34 min. Complete recanalization rate was 80.84%. Median ASPECTS was 9 (IQR 8-10) and median eASPECTS 9 (IQR 7.75-10), mean CBV infarct core was 55.29±90cc. Correlation (r
s
) between ASPECTS and eASPECTS was 0.44 (p<0.01). ASPECTS/eASPECTS and CBV presented a significant correlation only after 180 min of symptom onset (r
s
=-0.44, p<0.01 / r
s
=-0.26, p<0.05). Both ASPECTS and eASPECTS (r
s
=-0.40 and -0.43) correlated with 24h infarct volume in patients with complete recanalization (p<0.01). A logistic regression analysis showed that both ASPECTS (OR 0.56, p<0.01, CI 0.43-0.72) and eASPECTS (OR 0.57, p<0.01, CI 0.44-0.73) predicted independently low final infarct volume, together with recanalization (OR 4.6, p=0.03, CI 1.69-2.34).

Conclusions:
Correlation of ASPECTS and eASPECTS with CBV was time-dependent as both measurements correlated with CBV when time to CT was>180 min. Both ASPECTS and eASPECTS predicted infarct volume after thrombectomy.
Abstract WP55: Low Predictive Value of Multiphase CT Angiography for CT Perfusion Defined Ischemic Penumbra
Authors: Wannamaker Robert , Jayaprakash Harsha , Rempel Jeremy , Buck Brian , Kosior Jayme , Butcher Kenneth
Published: October 2018

Introduction:
Multiphase CT angiography (mCTA) has been proposed as an alternative to CT Perfusion (CTP) for identification of acute stroke patients with the potential for salvage after reperfusion therapy. We tested the hypothesis that poor collateral patterns on mCTA are predictive of large CTP defined ischemic cores.

Methods:
Multiphase CTA was generated from CTP source images (peak arterial, +8 and +16 s). Two expert raters assessed the collateral pattern on mCTA (absent/moderate/good). An Alberta Stroke Program Early CT (ASPECT) score was also assessed on the first and last phase of the mCTA as well as the non-contrast CT (NCCT). Hypoperfused regions were defined as those without vessel enhancement on the first phase. Core regions were defined as those without vessel enhancement on the final phase and/or NCCT changes. An ASPECTS mismatch score was calculated as a penumbral estimate. Penumbral tissue on CTP was defined as regions with a Delay Time (DT) >3 seconds, and ischemic core was defined as a combination of DT>3 seconds and relative CBF<40% of the contralateral hemisphere.

Results:
Of 141 patients, 79(56%) had penumbral patterns on CTP. Of these, 71(90%) had moderate/good collaterals. The mean penumbral volume in all patients was 20.8±26.6 ml and that in patients with large vessel occlusions (LVO; n=40) was 44.0±30.5 ml. At an ASPECTS mismatch score threshold of 2, mCTA predicted CTP defined penumbral patterns with a sensitivity of 77% and specificity of only 10%. The positive and negative predictive values were 57.7% and 61.5% respectively. In large vessel occlusion patients, mCTA predicted penumbra with 95.8% sensitivity and 43.8% specificity. The positive predictive value for penumbral patterns was 71.7%, and the negative predictive value was 87.5%. Eight patients were found to have a large core (>70 ml) on CTP, 3 of whom had moderate/good collaterals and 2 of whom also had a NCCT ASPECTS>5. Four large core patients had a mCTA penumbral score ≥ 2.

Discussion:
mCTA predicts penumbra with relatively high sensitivity, particularly in LVO patients. In some patients, however, mCTA can incorrectly classify penumbral patterns despite the presence of large cores on CTP. In non-LVO patients, mCTA is neither sensitive, nor specific for penumbral patterns.
Abstract WP56: Imaging Intra-Carotid Thrombosis Using Near InfraRed Fluorescent-NanoDiamond Particles Bio-engineered With the Disintegrin Bitistatin
Authors: Barone Frank C , Gerstenhaber Jonathan A , Marcinkiewicz Cezary , Li Jie , Lelkes Peter I , Sternberg Mark , Feuerstein Giora Z
Published: October 2018

Background:
Thromboembolism is a major cause of events in carotid artery (CA) disease and predisposes the dissemination of clots to upstream ischemic strokes. Although diagnostic methods are available to define thromboembolic strokes (CT, MRI, etc.), there is no technology to provide ambulatory assessment to ‘content image’ thrombi within the CA bifurcation free of the hospital setting. To address this unmet medical need we bioengineered the joining of the disintegrin bitistatin (Bit) to fluorescent NanoDiamond Particles (F-NDP) in order to bind to and non-invasively image vascular clots. F-NDP-Bit preferentially binds to the human platelet fibrinogen receptor (GPIIB/IIIA). F-NDP-Bit was systematically evaluated for NIR emission capacity in various tissues and demonstrated penetration of NIR fluorescence across distances similar to the distance from the human skin surface to the CA bifurcation.

Methods:
In vitro
studies were conducted to evaluate binding of F-NDP-Bit to purified human GPIIB/IIIA. Also, the ability of the F-NDP-Bit to bind to vascular clots
In Vivo
was investigated in rat FeCl3-induced internal CA coagulation.

Results:
Using the specific GPIIB/IIIA antagonist lotrafiban,
In Vitro
specific and concentration-related F-NDP-Bit binding was demonstrated.
In Vivo
, intravenous administration of F-NDP-Bit during the evolution of FeCl3-induced internal CA thrombosis resulted in the dose-related clot accumulation of F-NDP-Bit that was cross-validated by three independent methods (all measures were significant as described; p < 0.05): (
1
)
In Situ
whole rat imaging via
In Vivo
Imaging System (IVIS: using Ex 54 nm; Em 695-770 nm); (
2
)
Ex Vivo
whole vessel/clot imaging (Scanning Confocal Microscopy), and (
3
) Extract, isolate and quantitate F-NDP-Bit following internal CA clot dissolution (12N HNO3) and direct counting (hemocytometer).

Conclusions:
These data indicate that F-NDP-Bit might address the need for fast, safe and highly affordable ambulatory imaging of vascular clot burden. Functionalization of F-NDP with selective ligands that can be pathognomonic for many disease situations also could facilitate risk assessment, earlier intervention and preventative medicine.
Abstract WP57: Prevalence of CTA Spot Sign in Intraventricular Hemorrhage
Authors: Hussein Omar , Sawalha Khalid , Hamed Mohammad , Hinduja Archana
Published: October 2018

Background:
The presence of spot sign on computed tomography angiogram (CTA) source images is a sign of active bleeding and can predict hematoma expansion in intraparenchymal hemorrhage (IPH). The purpose of this study is to estimate the prevalence of spot sign in intraventricular hemorrhage (IVH), whether isolated or combined with IPH, and its prediction of hematoma expansion.

Methods:
We retrieved data of hemorrhagic stroke patients seen at our medical center from January 2015 to June 2017- total of 293 patients. We excluded 61 patients who did not have CTA. All medical records were reviewed to obtain the patients demographics and factors associated with hemorrhagic stroke. Patients were grouped into three groups based on the location of hemorrhage-based (IPH, isolated IVH or combined IPH and IVH), and the presence or absence of spot sign in each subgroup was evaluated. The prevalence and rates of hematoma expansion were compared between groups using Pearson chi-square test.

Results:
Among 232 subjects included in our analysis, 28 patients (12.1%) had a positive spot sign. A positive spot sign was identified in 11.8% of patients with IPH and 16.4% of patients with combined IPH and IVH. Only 7.8% of patients with isolated IVH had positive spot sign. A total of 68% of patients with a positive spot sign developed hematoma expansion. Among IPH, combined IPH and IVH and isolated IVH groups with a spot sign, 72%, 77% and 100% respectively demonstrated hematoma expansion. On the contrary, 35%, 44% and 31% of patient without a spot sign developed hematoma expansion (P value: <0.0001).

Conclusion:
Our study showed that the prevalence of spot sign in intraventricular hemorrhage is comparable to intraparenchymal hemorrhage despite its lower incidence in patients with isolated intraventricular hemorrhage. Nonetheless, spot sign in patients with IVH could be a good predictor of hematoma expansion.
Abstract WP61: Automated Large Artery Occlusion Detection IN Stroke Imaging - ALADIN Study
Authors: Barreira Clara M , Bouslama Mehdi , Haussen Diogo C , Grossberg Jonathan A , Baxter Blaise , Devlin Thomas , Frankel Michael , Nogueira Raul G
Published: October 2018

Introduction:
Acute ischemic stroke (AIS) treatment relies on prompt clinical suspicion, neuroimaging findings and stroke neurologists’ referrals, especially for Large Vessel Occlusion (LVO) patients. Recent advances in artificial intelligence have revolutionized the field of computer vision. We propose the use of artificial-intelligence based algorithm for detection of LVOs in AIS setting.

Methods:
We performed a multi-center retrospective analysis of CTAs, randomly picked from a prospective cohort of AIS adult patients, with and without LVOs, admitted at comprehensive stroke centers, from 2014 to 2016. An experienced stroke neurologist graded the CTAs for the presence of occlusion and occlusion sites. Concurrently, studies were analyzed by Viz-AI-Algorithm® v3.04 - a Convolutional Neural Network programed to detect MCA-M1 and/or ICA-T occlusions. The primary analysis included ICA-T and/or MCA-M1 LVOs versus more distal occlusions or no LVOs. The secondary analysis included any ICA and/or MCA-M1 and/or M2 LVOs versus more distal occlusions or no LVOs.

Results:
Analysis of 500 CTAs is ongoing and will be fully presented at the ISC. Interim results are available in 152 CTAs (Age, 64.1+/-15.7; bNIHSS 16 [IQR, 10-22]; bASPECTS 8 [IQR, 6-10]). Data was enriched for LVO (82.2%). For the primary analysis, the algorithm obtained sensitivity of 0.97 and specificity of 0.52, with a PPV of 0.74 and NPPV of 0.91, and overall accuracy of 0.78. For the secondary analysis (M2 and proximal ICA included), the algorithm obtained sensitivity of 0.92 and specificity of 0.75, with a PPV of 0.92 and NPPV of 0.75, and overall accuracy of 0.88. Maximal running time of the algorithm was under five minutes.

Conclusion:
The Viz-AI-Algorithm performs remarkably well for proximal intracranial LVOs. Endeavors on optimization of MCA-M2 LVO detection are being implemented. To the best of our knowledge, this is the first AI-algorithm for detecting intracranial LVOs.
Abstract WP63: Global Cerebral Edema is Associated With Worse Outcomes in Patients With Cerebral Venous Sinus Thrombosis
Authors: Shaban Amir , Samaniego Edgar , Aksan Nazan , Dai Biyue , Ahmed Uzair , Granchi Julia , Zheng-Lin Binbin , Lazarre Lara , Adams Harold , Derdeyn Colin , Leira Enrique , Ortega-Gutierrez Santiago
Published: October 2018

Background and Purpose:
Obstruction of venous drainage may lead to venous hypertension, edema, infarction or intracerebral hemorrhage (ICH) in patients with cerebral venous thrombosis (CVST). While the presence of ICH and infarction are associated with worse outcomes, the independent effect of edema remains unknown. We aimed to evaluate the impact of the characteristics of brain edema on functional outcomes as measured by the modified Rankin Scale (mRS) at discharge.

Methods:
We retrospectively reviewed all patients who presented to the University of Iowa Health Care with CVST between 2004-2014. All patients received standard of care management per available AHA/ASA recommendations. Edema was categorized as focal vasogenic, focal cytotoxic or global cerebral edema (GCE). Vasogenic edema was described as hyperintensity on FLAIR MRI sequences around the location of venous clot while cytotoxic edema was noted when hyperintensities were visualized around the location of ICH/ venous infarction on FLAIR or DWI respectively. GCE was scored when bilateral finger-like extensions into gray white junction and effacement of gyri/sulci were seen on CT scans as described by Claassen et al. Edema scorer was blinded to outcome measures. Multiple regressions were conducted on mRS outcome to test hypotheses of interest. A
p
value ≤ 0.05 was set as statistically significant.

Results:
115 patients met inclusion criteria, 76 women, mean age 42. A total of 30(26%) had venous infarction, 34(30%)ICH , 57(50%) had cerebral edema(20% vasogenic, 35% cytotoxic and 32% GCE). The three edema types together explained 22% variance in discharge mRS (p<.001). The effect of GCE remained significant (p=.001) when adjusting for age, presence/absence of ICH and infarct. The 95%CIs for discharge mRS among those with GCE [2.89-4.17] compared to those without GCE [1.44-2.12]. Vasogenic and cytotoxic edema did not contribute significantly to prediction in multivariate analyses.

Conclusions:
Characterization of early cerebral edema might contribute to a better prognostication of high risk patients after CVTS. GCE in particular forecast an unfavorable outcome. Further understanding of its pathogenesis may represent a new therapeutic window for refractory patients to standard therapies.
Abstract WP66: Anticoagulant Use is Not Associated With Higher Post tPA Hemorrhagic Conversion
Authors: Lunagariya Abhishek , Patel Achint , Dalal Shaman , Jani Vishal , Nagaraja Nandakumar , Huisa Branko , Hemmen Thomas
Published: October 2018

Introduction:
Even though tissue plasminogen activator (tPA) has unequivocally shown to improve outcomes in Acute Ischemic stroke (AIS), its utilization remains low due to various concerns/contraindications. Many clinicians are concerned about the risk of hemorrhage after tPA in patients on anti-coagulation (AC). With the rise of AC use, we aimed to explored the relationship between anticoagulation use and hemorrhagic conversions (HC) in patients treated with IV tPA in a large and representative national patient registry.

Method:
We analyzed Nationwide Inpatient Sample (NIS) and Healthcare Cost and Utilization Project (HCUP) data for years 2002-2014. We identified AIS with ICD-9-CM codes 433.xx-436, IV tPA with procedure code 99.10, and HC with ICD-9 431. Anticoagulation use was identified by previously validated ICD-9-CM codes. Parametric tests and survey logistic procedure were used to analyze group comparison and multivariate regression.

Results:
A total of 264,643 patients with AIS received IV tPA, of which 12,690 (4.8%) were on AC prior to admission. Unadjusted, the frequency of HC was higher among AC group (9.1% v 8.0%; p<0.001). However, after adjusting for confounders with multivariate analysis, there was no difference in HC between AC and ‘not on AC’ group [OR 0.87; 95% Confidence Interval(CI) 0.75-1.01; p=0.071]. Additionally, there was no difference in in-hospital mortality [OR 0.91; 95% CI 0.79-1.05; p=0.178] and discharge to home [OR 1.1; 95% CI 0.99-1.2; p=0.05] among AC and ‘not on AC’ group.

Conclusion:
Our study shows, AC use prior to AIS onset is not associated with higher HC with tPA use. Moreover, no significant differences in outcomes were observed in AC and ‘not on AC’ group. Being on AC should not be a prohibitive factor for tPA utilization in AIS patients. Further prospective studies, that includes precise anticoagulant measurements, are required to better understand the relationship between AC use and HC.
Abstract WP67: Outcomes in the Elderly Post-alteplase Treatment in a Community Setting
Authors: Nguyen Huynh Mai N , Hatfield Meghan , Klingman Jeffrey
Published: October 2018

Background:
Risks and benefits of acute thrombolysis in elderly stroke patients remained unclear, especially in those aged ≥90 years. We evaluated the safety of thrombolysis in the elderly in a large integrated healthcare system.

Methods:
In 2016, Kaiser Permanente Northern California (KPNC) launched a new standardized acute telestroke care workflow for all 21 stroke centers. It included immediate evaluation by a stroke neurologist via video, an expedited IV alteplase treatment program, rapid CT angiographic investigation, and expedited transfer and treatment for patients with large vessel occlusion (LVO). We compared patient characteristics, door-to-needle (DTN) times and symptomatic intracranial hemorrhage (sICH) rates between those treated with IV alteplase aged <80 to those 80-89 to those ≥90 years. Multivariable logistic regression model accounting for within hospital clustering was used to assess whether being ≥90 years was associated with a poorer outcome.

Results:
For 2016, our Telestroke program gave IV alteplase to 646 KP members [Table]. The oldest subgroup had a higher percentage of female and higher rates of vascular risk factors. They were more likely to arrive by EMS, to have a higher initial NIHSS and to have a LVO. Average DTN times were not different between the three age groups. There were no differences in the rates of sICH and length of stay. The in-hospital mortality rate was higher in the elderly, possibly due to higher rates of comorbidities. In multivariable model, after adjusting for demographics, co-morbidities, EMS arrival, sICH, NIHSS, and DTN, being elderly did not affect the likelihood of being discharged home post-thrombolysis (OR=0.56, 95% CI 0.29-1.07, p=0.08).

Conclusions:
In a large community setting with a standardized approach to acute stroke treatment, our data supported IV alteplase use in elderly patients. It is important to consider pre-stroke disability when deciding on thrombolysis in the elderly.
Abstract WP69: Guideline-Based Intravenous rPA for Central Retinal Artery Occlusion: A Case Series and Systematic Review
Authors: Alkuwaiti Mohammed , Bongiorno Connie , Engel Kevin , Male Shailesh , Logue Christopher , Miller Benjamin , Reshi Rwoof A , Anderson David , Urrutia Victor , Streib Christopher
Published: October 2018

Introduction:
Central retinal artery occlusion (CRAO) rapidly leads to irreversible retinal damage with spontaneous visual recovery in only 10-20%. IV tPA may improve visual outcomes in CRAO, but protocols are heterogeneous. Deviation from acute ischemic stroke guidelines (AISG) for IV tPA is associated with symptomatic intracranial hemorrhage (sICH). Our study characterizes outcomes for CRAO patients treated with IV tPA per AISG to better define the risk and benefit.

Methods:
We executed a systematic literature review (SLR) of IV tPA for CRAO in Cochrane, Embase, and Medline. Subsequently, we performed a retrospective chart review at two local academic hospitals. All CRAO patients identified locally or via SLR who were treated with IV tPA per AISG were included in our study. Primary outcomes included improvement in visual acuity (VA), defined as ≥0.3 logMAR, and safety, specifically sICH.

Results:
Our SLR yielded 136 articles of which 19 were eligible. 137 total CRAO patients were identified, 32 (23%) of whom received IV tPA per AISG. 13 additional CRAO patients treated per AISG were identified locally (Table 1A). Of these 45 cases, VA was reported in 39, with improvement in 64%, no change in 28%, and worsening in 8%. The risk of sICH was 2.2% (n=1) (Table 1B). The case of sICH occurred locally, with hemorrhage adjacent to 2 chronic appearing infarcts. Post-sICH it was impossible to determine radiographically whether a component of his infarct may have been subacute. Interestingly, in our local cases, clinically silent diffusion restriction was evident on MRI in 6 patients (46%).

Conclusion:
Our study suggests that IV tPA administered per AISG may improve visual outcomes in comparison to the natural history of CRAO, however, the rate of sICH was not inconsequential. Additionally, our case series includes the first reported sICH in a CRAO patient administered IV tPA per AISG. Randomized studies are warranted to assess the efficacy and safety of IV tPA administered per AISG in CRAO.
Abstract WP71: Efficacy and Safety of Intravenous Thrombolysis in Acute Ischemic Stroke Due to Small Vessel Occlusion: a Multicenter Retrospective Observational Study
Authors: Hong Keun-Sik , Choi Jay Chol , Lee Ji Sung , Paek Young Min , Bae Hee-Joon , Kim Beom Joon , Park Jong-Moo , Lee Soo Joo , Cha Jae Kwan , Park Tai Hwan , Lee Kyung Bok , Lee Jun , Lee Byung-Chul , Kim Joon-Tae , Kim Dong-Eog , Shin Dong-Ick , Kim Wook-Joo , Sohn Sung-Il , Oh Mi Sun
Published: October 2018

Backgrounds:
Small vessel occlusion (SVO) accounts for 15-20% of acute ischemic stroke (AIS). Given the mechanism of vessel occlusion, sharing pathophysiology with intracerebral hemorrhage (ICH), and minor symptom presentation, the efficacy and safety of intravenous tissue plasminogen activator (IV-TPA) in patients with AIS due to SVO remain unclear, particularly in Asian patients who are at a higher ICH risk than other populations.

Methods:
Using a multicenter stroke registry of 15 centers in South Korea, we identified patients with AIS due to SVO admitted within 24 h from onset. The other inclusion criteria were prestroke mRS score 0-1, initial NIHSS <11, and 3-month mRS score available. The IV-TPA group included patients who were treated with IV-TPA within 4.5 h from onset in the participating centers. The control group included patients who did not receive IV-TPA. The primary and secondary efficacy outcomes were 3-month mRS 0-1 and mRS distribution. Safety outcomes were symptomatic ICH and 3-month mortality. Multivariable analysis was used to adjust baseline imbalances.

Results:
Between FEB 1, 2011 and JAN 31, 2016, we identified 202 patients in the IV-TPA group and 2381 patients in the control group. The IV-TPA group versus the control group had higher median (IQR) NIHSS score (5 [4-6] vs 2 [1-4]) and shorter onset-to-arrival time (1 [1-2] vs 10 [4-16], h). In addition, the TPA group compared to the control group had more prestroke mRS 0, less prior stroke, more males, higher initial SBP, less prestroke antiplatelet, less prestroke statin, and less aspirin/clopidogrel dual therapy after admission. At 3 months, 116 (57.4%) in the IV-TPA group and 1589 (66.7%) in the control group had mRS 0-1. No patients in the IV-TPA group and 19 (0.8%) in the control group died. On multivariable analyses adjusting for covariates, adjusted OR (95% CI) with IV-TPA was 1.55 (1.06-2.27) (P=0.022) for 3-month mRS 0-1 outcome, 1.38 (1.02-1.86) (P=0.039) for 3-month mRS favorable shift, and 0.15 (0.01-2.18) (P=0.166) for 3-month mortality. Three (1.5%) in the IV-TPA group and one (0.04%) in the control group had symptomatic ICH.

Conclusion:
This observational study suggests that IV-TPA improves outcome in patients with AIS due to SVO with an acceptable risk of symptomatic ICH.
Abstract WP72: Why Are Acute Ischemic Stroke Patients Not Receiving IV tPA in Telestroke Network
Authors: Onteddu Sanjeeva Reddy , Kovvuru Sukanthi , Nalleballe Krishna , Brown Aliza , Kairamkonda Supriya , Culp William , Joiner Renee , Gundapaneni Sukumar
Published: October 2018

Background:
Reasons for non-lysis treatment are explored as telestroke networks have become more common. Telemedicine is increasingly becoming the first contact for evaluation and treatment of AIS patients.

Objective:
Determine reasons for not giving intravenous (IV) Activase to eligible patients with acute ischemic stroke (AIS).

Methods:
We performed a retrospective analysis of prospectively collected data of non-lytic patients who were seen as a telestroke consultation with Arkansas Stroke Assistance through Virtual Emergency Support (
AR SAVES
) for possible AIS for year 2015.

Results:
A total of 809 total patients who met criteria for telemedicine consults received neurology examination. A total of 238 patients received IV Activase treatment. Of the remaining 571 non-treated patients (no thrombolytics), 305 were thought to be AIS based on clinical evaluation. Of these patients data was available for 276. The most common reason non-treatment was: 1) minimal deficits at 44% (n=124), 2) falling out of the 4.5 hour time window 27% (n=76) and 3) next of kin refusal in 19% (n=53). Other less common causes for non-treatment were; 4) abnormal labs (n=15), 5) recent surgery (n=4), 6) neoplasms (n=2) and 7) determination of hemorrhagic stroke (n=2). Minimal deficits or rapidly improving symptoms was the most common reason for not being treated with IV Activase in our telestroke program. The 27% who fell out of the treatment sphere were due to excess time spent door to CT. The next of kin refusal for treatment at 19% is higher than the 6% reported for traditional practices.

Conclusion:
Minimal deficits was the most common reason for non-lytic treatment in our telestroke system and other hospitals. Next of kin refusal seems to be significantly higher than reported for traditional practices which are around 6% compared to 19% with our patient population. This might have been secondary to difficulty in explaining the risk vs benefits over a video conference. Other causes should also be explored as telestroke networks have become more common and are increasingly becoming first contact for evaluation and treatment of acute ischemic stroke patients.
Abstract WP74: Influence of Antiplatelet Pre-treatment on Platelet Function and Clinical Outcomes After Intravenous Trombolysis in Stroke Patients
Authors: yang jie , Hang Jing
Published: October 2018

Background and aims:
There May be a link between platelet function and clinical outcomes in acute stroke patients with intravenous thrombolysis. We aimed to compare dynamic change of maximum platelet aggregation (MPA) in 24 hours after thrombolysis and outcomes between patients naïve to antiplatelet therapy (AP) and those with prior AP.

Methods:
We conducted a prospective study on acute stroke patients who received intravenous recombinant tissue plasminogen activator (rt-PA). The patients were divided based on whether to have prior AP or not. Five venous blood samples were collected: on admission before thrombolysis (baseline); at 3h, 6h, 12h and 18h after thrombolysis. MPA was determined using light transmittance aggregometry (LPA), and agonists tested were arachidonic acid (AA) and adenosine diphosphate (ADP). The outcomes were NIHSS on 1 hour, 24 hours and 7 days after thrombolysis, symptomatic intracerebral hemorrhage (sICH) in 36 hours, mortality in 1 month, mRS in 1 month, 3 month, 6 month and 1 year.

Result:
Of a total of 58 patients, 23 were pretreated with AP. They achieved significant reduction of AA-induced aggregation on 3 hours, 6 hours, 12 hours, 18 hours after thrombolysis compared with those naïve to AP (P<0.05). There were not significant differences on sICH, mortality, good outcomes (mRS≤2) on 1 month and 3 months (P>0.05). A good long-term outcomes (mRS≤2) on 6 month and 1 year was detected in those naïve to AP (P<0.05).

Conclusion:
Prior AP may decrease MPA and have an impact on long-term functional outcomes, although it did not increase the risk of sICH and mortality.
Abstract WP76: Shear Stress Sensing on the Endothelium Initiates Chronic Inflammation of the Arterial Wall During Cerebral Aneurysm Formation: Potential Novel Therapy for Cerebral Aneurysms With Paroxetine
Authors: Fukuda Shunichi , Fukuda Miyuki , Ando Joji , Yamamoto Kimiko , Tsukahara Tetsuya , Hasegawa Koji
Published: October 2018

Background and purpose:
It is thought that the cerebral aneurysm is caused by chronic inflammation of the arterial wall. However, it is still not clear what triggers the inflammation. We hypothesize that shear stress-related hemodynamics initiates cerebral aneurysm formation, and have reported that disruption of the endothelial shear stress sensor, P2X4 purinoceptor, significantly reduces cerebral aneurysm formation using knockout mice of the sensor. We examined here whether inhibition of P2X4 purinoceptor has any influence on expressions of inflammatory contributors to aneurysm formation or not.

Methods:
Sprague-Dawley rats (n = 61) were subjected to cerebral aneurysm-generating surgery with ligation of unilateral common carotid artery and renal hypertension, and the P2X4 purinoceptor inhibitor, paroxetine (8 mg/kg/day) was administered after the surgery for 3 weeks. The incidence of aneurysm formation was examined with light microscopy and expressions of inflammatory contributors to aneurysm formation using a quantitative real-time PCR analysis.

Results:
Paroxetine significantly attenuated the incidence of induced aneurysms in rats after aneurysm-generating surgery (p = 0.031, Wilcoxon/Kruskal-Wallis test). Expression levels of known inflammatory contributors to aneurysm formation, COX-2, TNFα, MCP-1, IL1β, and iNOS, were significantly increased in rats after aneurysm-inducing surgery than control non-operated animals by a quantitative real-time PCR analysis. Paroxetine significantly reduced the expression levels of COX-2, TNFα, MCP-1, IL1β, and iNOS (p = 0.0019, 0.0101, 0.0019, 0.0239, 0.0101, respectively).

Conclusions:
These data suggest that shear sensing on the arterial endothelium initiates chronic inflammation in the arterial wall during cerebral aneurysm formation. Because paroxetine has been used for human as an antidepressant, clinical use of this P2X4 purinoceptor inhibitor is expected as a novel therapy for cerebral aneurysms.
Abstract WP78: Outcomes After Off-Label Use of the Pipeline Embolization Device for Intracranial Aneurysms: a Multicenter Cohort Study
Authors: Zammar Samer G , Buell Thomas J , Chen Ching-Jen , Crowley R W , Ding Dale , Griessenauer Christoph J , Hoh Brian L , Ogilvy Christopher S , Raper Dan , Singla Amit , Thomas Ajith J , Cockroft Kevin M , Simon Scott D
Published: October 2018

Objectives:
The aim of this retrospective multicenter cohort study is to examine the outcomes of the Pipeline embolization device (PED) for the treatment of intracranial aneurysms outside of United States Food and Drug Administration approved (off-label) indications.

Methods:
Data from aneurysm patients treated with the PED for off-label indications was pooled from four different centers. The primary endpoints were decline in modified Rankin Scale (mRS) by at least 1 point and angiographic aneurysm occlusion at follow-up.

Results:
The study cohort was comprised of 109 patients. The mean aneurysm size was , 20% were located in the posterior circulation, and 12% were ruptured. The most common reasons for off-label use were aneurysm size (57%), location (11%) or both (12%). The mean follow-up was 9 months. Complete occlusion was achieved in 82% of cases at last angiographic follow-up and mRS decline was found in 18.8% of the cases. In the univariate analysis, only ruptured aneurysm presentation was significantly associated with mRS decline (p=0.016) (Table 1). In the multivariate analysis, size as the indication for off-label use was associated with higher odds of complete aneurysm occlusion on final angiography (Table 2).

Conclusion:
The off-label use of the PED has a reasonable risk to benefit profile for appropriately selected aneurysms. Posterior circulation location and fusiform morphology do not appear to be associated with worse clinical or angiographic outcomes.
Abstract WP89: A Functional Outcome Model for a Telestroke-guided Tissue Plasminogen Activator Treatment of Stroke Patients
Authors: Gainey Jordan , Wormack Leah , Brechtel Leanne , Nathaniel Thomas I
Published: October 2018

Background:
The success of telestroke systems as a means to extend stroke-care expertise into rural and underserved areas has been reported. Evidence of clinical outcomes associated with the use of tissue-type plasminogen activator (rtPA) in community hospitals has been documented, but evidence of functional outcome studies in telestroke-guided rtPA treatment are lacking. This issue was investigated in this study.

Methods:
Data from a stroke registry of 307 acute ischemic patients treated with intravenous rtPA in a telestroke network was analyzed. A new functional outcome model was developed to asses rtPA treatment outcome using a combination of visual basic and multivariate logistic models. Differences in functional outcomes between patients that received rtPA and those did not receive rtPA were determined. A partial proportional-odds model was developed for common odd ratio based on cumulative logits for all functional outcome variables. The significance level of all analysis was set to a probability level of p<0.05.

Results:
In a telestroke-guided rtPA treatment of stroke patients, age was significantly (P<0.0001, OR 0.902) associated with improved functional outcome. Stroke patients with a medical history of obesity (P=0.002, OR 4.016), and a previous history of stroke (P=0.024, OR 2.765) were associated with improved functional outcomes. The odd of an improved functional outcome was higher for stroke patients with systolic blood pressure (P=0.012, OR 3.135) as the initial vital sign. Moreover, patients with initial lower NIH stroke scale scores (P<0.001, OR 0.911) were associated with improved functional outcome.

Conclusion:
Modified Rankin Scale distribution and other measures have been used to measure clinical outcomes in rtPA-treated patients. The development of a new functional outcome model provides a new approach to improve the efficiency of the telestroke and increase of rtPA for stroke patients.