bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract T P323: National Trends in Utilization and Outcomes of Intravenous Thrombolytic Treatment Among Pediatric Patients With Acute Ischemic Stroke in United States
Authors: Chaudhry Saqib A , Zafar Taqi T , Afzal Mohammad , Adil Malik M , Sachdeva? Gautam , Jani Vishal , Pawar Swaroop , Hussain Syed I , Qureshi Adnan I
Published: July 2021

Background:
Thrombolytic treatment has been used with varying frequency among pediatric ischemic stroke patients.

Objective:
To evaluate trends in utilization of IV recombinant tissue plasminogen activator (rt-PA) and associated rates of death and disability among acute ischemic stroke patients over a six year period.

Methods:
We obtained data for pediatric patients (aged ≤18 years) admitted to United States in 2003, 2006 and 2009 with a primary diagnosis of ischemic stroke using the Nationwide Inpatient Sample (NIS-KID). We determined the rate and pattern of utilization, and associated in-hospital outcomes of IV-rt-PA including post-thrombolytic intracerebral hemorrhage (ICH) and rates death among pediatric ischemic stroke patients.

Results:
Of the 5,137 pediatric patients admitted with ischemic stroke, 48 (0.93%) received IV rt-PA during the study period. There was a 2.5 fold increase in rates of patients who received the thrombolytic treatment (0.53% in 2003, 0.87% in 2006 and 1.35% in 2009). The rate of post-thrombolytic ICH was 9.6% with no change in frequency over the three periods. The overall rate of post-thrombolytic intracerebral hemorrhage (ICH) was 9.6% with a trend towards decrease in rates (41%, 9.8%, and 0%) in 2003, 2006, and 2009. The overall rate of in hospital mortality was 9.6% with some decrease in rates (17.2%, 13.0%, and 5.9%, p value for trend=0.7).

Conclusion:
There has been a significant increase in the proportion of pediatric acute ischemic stroke patients receiving IV rt-PA treatment with some evidence of decrease in adverse outcomes at discharge.
Abstract T P41: Determination of Collateral Supply Patterns Using MR or CT Perfusion Imaging
Authors: Eldeniz Cihat , Lee Yueh , Matheus Maria Gisele , Smith Jeffery Keith , Faber James , Solander Sten , An Hongyu
Published: July 2021

Introduction:
In this study, we sought to develop a collateral flow mapping method based on MR or CT perfusion imaging and compare this method with the digital subtraction angiography (DSA) method.

Methods:
Ischemic tissue supplied by collateral flow is likely to have delayed tracer arrival but relatively normal flow. In this study, abnormal Tmax (> 6 sec), MTT (4 sec or greater than unaffected hemisphere) and CBF (<40% of unaffected hemisphere) were labeled with green, red and blue, respectively (Fig. A). Any perfusion patterns can then be represented by a combination of this integrated RGB maps (Integrated Collateral flow Maps, iCMaps). 24 patients were included in this study. DSA images were obtained from all patients, whereas MR and CT perfusion images were acquired from 15 and 9 patients, respectively, within 30 hours after MCA occlusion. iCMaps collateral flow was scored independently as follows. iCMaps without any perfusion abnormality was assigned “1”. iCMaps with white as the dominant perfusion pattern was assigned a “5”; while those with a dominant green and yellow pattern were assigned a “2” or a “3”, depending on the relative green and yellow volume. Finally, iCMaps with a white region surrounded with yellow and green was assigned a “4”. Examples of iCMaps scoring are shown in Fig. B. Using a DSA scoring method in the literature5, a score of 1-5 was given independently based on the degree of retrograde collateralization (5: poor collateralization).

Results:
Good correlation was found between the MR perfusion iCMaps and DSA (DSA=0.70*MR iCMaps+0.54, R=0.75). Moderate correlation was obtained between the CT perfusion iCMaps and DSA (DSA=0.51*CT iCMaps+1.9, R=0.56).

Conclusions:
Based on the different characteristics of Tmax, MTT and CBF maps, the proposed MR or CT perfusion based iCMaps method can provide DSA comparable collateral flow information.
Abstract T P42: Patients With a Clinical Diagnosis of Non-disabling Stroke, and a Normal MRI are Clinically Indistinguishable From Patients With a MRI Lesion at 1 Year Post Stroke
Authors: Makin Stephen , Dennis Martin , Wardlaw Joanna M
Published: July 2021

Background:
Up to one third of patients with a clinically apparent mild stroke and no other apparent cause of their symptoms have a normal MRI. We examined disability, recurrent stroke, and cognitive impairment at one year compared to patient with an MRI-DWI lesion.

Methods:
We recruited consecutive patients with a non-disabling ischaemic stroke, and performed clinical assessment and MRI (with DWI) . An expert panel reviewed all cases, we included patients with a final diagnosis of stroke and excluded patients with another diagnosis.

At one year post stroke we recorded modified Rankin scale (mRs), stroke and TIA recurrence, Addenbrookes Cognitive Assessment Revised (ACE-R) and the Beck Depression index (BDI) and performed another MRI. Non-attenders were assessed by telephone or post. We defined cognitive impairment as ACE-R of <88, and depression as a BDI of >9.

Results:
Almost one third (75/264) (median NIHSS=2) of patients had a no relevant lesion on MRI DWI. There was no difference in age, sex, symptoms, or risk factors in patients with and without a lesion, 197 had MRI at 1 year (all had clinical follow-up). Of 75 with no lesion, 41% were mRs ≥2, 13% had recurrent stroke or TIA, 36% were cognitively impaired and 46% had depression. This was not significantly different from the patients with a lesion. Of the 197 who had a follow-up MRI 50 patients with no initial lesion had follow-up MRI and one had a new lesion, (versus 20/147 patients with a lesion) (p=0.016).

Conclusions:
Patients with a clinical stroke and no other obvious cause for their symptoms are clinically indistinguishable from patients with the same NIHSS who have a lesion on DWI-MRI, in terms of recurrence, disability, or cognitive impairment. Suggesting that these patients have had a stroke that does not appear on MRI. The presence of an initial lesion increases the liklihood of a lesion on 1 year MRI, however without a difference in clinical stroke this is of doubtful significance.
Abstract T P44: Relative Cerebral Blood Volume as a Marker of Durable Tissue-at-risk Viability in Hyperacute Ischemic Stroke
Authors: Calleja Ana I. , Cortijo Elisa , García-Bermejo Pablo , Martinez-Gáldamez Mario , Pérez-Fernández Santiago , Reyes Javier , Muñoz M. Fe , Arenillas Juan F.
Published: July 2021

Background:
Selection of best responders to endovascular reperfusion could be aided by predicting the expected duration of tissue-at-risk viability, which may be dependant on collateral circulation status. We aimed to identify the best predictor of good collateral circulation among perfusion computed tomography (PCT) parameters in middle cerebral artery (MCA) ischemic stroke, and to analyze how early MCA response to intravenous thrombolysis and PCT-derived markers of good collaterals interact to determine stroke outcome.

Methods:
We prospectively studied acute MCA ischemic stroke patients treated with intravenous thrombolysis who underwent PCT prior to treatment showing a target-mismatch profile. Collateral status was assessed using a PCT source-images based score. PCT maps were quantitatively analyzed. Cerebral blood volume (CBV), cerebral blood flow (CBF) and Tmax were calculated within the hypoperfused volume and in the equivalent region of unaffected hemisphere. Occluded MCAs were monitored by transcranial Duplex to assess early recanalization. Main outcome variables were final infarct volume and modified Rankin score at day 90.

Results:
One hundred MCA ischemic stroke patients imaged by PCT received intravenous thrombolysis, and 68 met all inclusion criteria. A relative CBV > 0.93 emerged as the most robust predictor of good collaterals [OR 12.6 (95% CI 2.9-55.9), p=0.001]. Early MCA recanalization was strongly associated with better long-term outcome and lower infarct volume in patients with rCBV <0.93, but not in patients with high rCBV. None of the patients with rCBV < 0.93 achieved good outcome in absence of early recanalization.

Conclusion:
rCBV was the strongest marker of collateral status and may help predict the duration of tissue-at-risk viability in hyperacute MCA ischemic stroke
Abstract T P53: Implementation and Outcome of Intravenous Recombinant Tissue Plasminogen Activator Administered 3-4.5 hour after Stroke in Korea
Authors: Park Tai Hwan , Hong Keun-Sik , Park Sang-Soon , Ko Youngchai , Lee Soo Joo , Kang Kyusik , Park Jong-Moo , Choi Jay Chol , Kim Dong-Eog , Cho Yong-Jin , Kim Joon-Tae , Kim Dae-Hyun , Cha Jae-Kwan , Han Moon-Ku , Yu Kyung-Ho , Lee Byung-Chul , Lee Ji Sung , Lee Juneyoung , Lee Kyung Bok , Lee Jun , Bae Hee-Joon , Yoon Byung-Woo
Published: July 2021

Background:
Although the benefit of intravenous recombinant tissue plasminogen activator (IV-TPA) has been proved in patients with 3-4.5 hour after stroke from a randomized trial and observational studies, in which most subjects were Western population. We aimed to determined the safety and efficacy of IV-TPA within the 3- to 4.5-hour window in Korean population.

Methods:
Using a prospective, web-based registry of consecutive patients with acute stroke or transient ischemic attack (TIA) admitted to 12 academic hospitals in Korea, we enrolled 616 patients receiving IV-TPA therapy within 3 hours and 107 within 3-4.5 hours after stroke onset for this study. Functional outcome measured by modified Rankin scale (mRS) at 3 months after stroke was compared between the two time window cohorts. Symptomatic intracranial hemorrhage (SICH) defined as any apparently extravascular blood in the brain or within the cranium associated with 4 points or more increase in the National Institutes of Health Stroke Scale (NIHSS) score or leading to death was evaluated for safety. Odds ratios (OR) and 95% confidence intervals (CI) was calculated to present the probability of achieving each outcome for patients treated within 3-4.5 hours compared to those treated within 3 hours.

Results:
The excellent outcome (mRS 0-1) was less often achieved in the 3-4.5 hours cohort than in the within 3 hours cohort (39.3% vs 42.9%), but the difference was not statistically significant after adjusting for age, sex, baseline NIHSS score, weight, glucose, center (adjusted OR [95% CI], 1.26 [0.60-2.65]). The proportion of mRS 0-2 at 3 months (48.6% vs55.7%) was not also different between two groups (adjusted OR [95% CI], 0.80 [0.41-1.54]). The rate of SICH was higher in the 3-4.5 hours cohort than in the within 3 hours cohort (4.7% vs 3.1%), but the difference was not statistically significant (adjusted OR [95% CI], 0.81 [0.20-3.35]).

Conclusion:
This study shows that IV-TPA therapy within the 3- to 4.5-hour window after ischemic stroke is safe and effective in Korean patients.
Abstract T P69: Stroke Induces HDAC4 Nuclear Shuttling in Neurons
Authors: Kassis Haifa , Chopp Michael , Shehadah Amjad , Liu Xian Shuang , Zhang Yi , Roberts Cynthia , Zhang Zheng Gang
Published: July 2021

Background:
Nuclear shuttling of class II histone deacetylases (HDACs) in neurons regulates apoptosis and facilitates neuronal recovery in response to injury. The present study examined the temporal profile of the subcellular localization of class II HDACs (4 and 5) in the peri-infarct cortex during brain recovery after stroke.

Methods:
Adult male Wistar rats were subjected to permanent middle cerebral artery occlusion (MCAo) and were sacrificed at 2, 7 and 14 days after MCAo. Sham operated rats were used as a control (n=6/group). To identify phenotypes of HDAC immunoreactive cells, double immunohistochemistry was performed with antibodies against each HDAC isoform (4 or 5) along with MAP-2 (a marker of dendrites), p-NFH (a marker of axons), APC (a marker of oligodendrocytes) or GFAP (a marker for astrocytes).

Results:
In cortical neurons of sham operated rats, HDACs 4 and 5 immunoreactivity was mainly localized to the cytoplasm and dendrites, but not axons. Stroke significantly (p<0.05) increased the percentage of neurons with nuclear HDAC4 immunoreactivity in the peri-infarct cortex at 2 (55 ± 2%), 7 (65 ± 5%) and 14 (76 ± 2%) days after MCAo compared to sham (27 ± 3%). Stroke-induced nuclear expression of HDAC4 was accompanied by a significant (p<0.05) decrease in HDAC4 staining in neuronal dendrites over the same period (7 ± 1% at 2d, 7 ± 2% at 7d, and 6 ± 1% at 14d vs. 19 ± 2% in sham). Neurons with nuclear HDAC4 were not TUNEL positive, indicating that these cells are not apoptotic. In parallel, augmentation of neurons expressing nuclear HDAC4 was significantly correlated to an increase in MAP-2 immunoreactive density after stroke (r=0.7, p<0.05). Stroke-induced nuclear shuttling of HDAC4 is specific to neurons, since HDAC4 was not detected in nuclei of GFAP+ astrocytes or APC+ oligodendrocytes. Neuronal nuclear HDAC4 localization was not associated with a change in Histone H3 lysine 9 acetylation or methylation levels. Unlike HDAC4, stroke did not alter nuclear localization of HDAC5 in neurons.

Conclusion:
Our data show that stroke induces HDAC4 nuclear shuttling in neurons with increased dendritic density in the peri-infarct cortex, suggesting a role for HDAC4 in promoting neuronal remodeling after stroke.
Abstract T P81: Long-Term Activity Levels Vary by Rat Strain Following Stroke: A Disruption of the Circadian Rhythm?
Authors: Kunze Allison , Zierath Dannielle , Drogomiretskiy Olga , Jaspers Brett , Barclay Tessa , Becker Kyra J
Published: July 2021

Background:
Assessment of long-term behavioral outcome after experimental cerebral ischemia is important for evaluating potential therapeutic interventions. In this study, we explored strain related differences in baseline behavior and in response to stroke.

Methods:
Spontaneous cage activity was monitored (cm moved per hr) and analyzed before and after 2 hour middle cerebral artery occlusion (MCAO) in male Lewis, Wistar, and Sprague Dawley (SD) rats using the Noldus PhenoTyper® cages and EthoVision® Software system. Stroke severity was assessed using the neuroscore, foot fault errors, and performance on the rotarod. Infarct volume at 24 hours was determined in a second cohort of animals. Animals were sacrificed 56 days after MCAO. Data are analyzed using non-parametric statistics.

Results:
Prior to stroke, the median distance moved per hour during the dark was similar among the 3 strains, but Lewis rats were more active during the light cycle (P=0.001). Neuroscores did not differ between strains at 3 hrs after MCAO nor did infarct volumes at 24 hours after MCAO. Lewis rats, however, performed worse on the rotarod in the month following MCAO (P<0.05 at each time point). Foot fault errors were similar throughout the study period. After stroke, Lewis rats became more active during the dark cycle while Wistar and SD rats became more active during the light cycle (Figure).

Summary:
The 3 strains of rats evaluated in this study had different patterns in the change in activity after MCAO. Lewis rats showed an increase in activity during the dark cycle while Wistar and SD rats showed an increase in activity during the light cycle. This observation suggests that there are genetic differences in the response to stroke that may alter the circadian rhythm after stroke.
Abstract T P88: Angiographic Steno-Occlusive Lesion and Collateral Circulation in Cerebral Vascular Reservoir in Acute Ischemic Stroke and Transent Ischemic Attack
Authors: Lee Si Baek , Won Yoo Dong , Yoo Do-Sung
Published: July 2021

Background:
: Atherosclerotic intra- or extra- cranial steno-occlusive disease is one of the risk factors of ischemic stroke. While best medial treatment, some patients with these lesions still have hypoperfusion and may need an intervention for proper perfusion. In the real world of clinical practice, it is difficult to perform all kinds of studies such as digital subtraction angiography (DSA), MR perfusion, SPECT with Diamox challenig for assessment of perfusion status and cerebral vascular reservoir (CVR). We selected patients who undergone those methods and evaluated the correlations beween the collateral pattern and perfusion status and clinical manifestation and short term outcome.

Methods:
From a cohort of patients consecutively admitted for stroke or transient ischemic attack (TIA), we selected patients with symptomatic large artery steno-occlusive lesion confirmed by DSA. Cerebral angiogram was graded systematically in a blinded fashion for collateral flow, using Theraupeutic Neuroradiology/Society of Interventional Radiology (ASITN/SIR) grading. We also evaluated diffusion-perfusion mismatch in MRI studies and CVR by Diamox SPECT. Demographic and clnical variables, initial NIHSS score and modified Rankin scale (mRS) scores at discharge were collcted. We divided thse patients in two groups according to cerebral vascalar reservoir pattern and compared clnical and imaging status.

Results:
A total of 21 patient were selected. Men was 14(67%) and mean age was 64.3(range of 40 to 84). Eleven patients had ICA steno-occlusive (7 with occlusion), 8 had MCA steno-occlusive lesions(4 with occlusion) and remaning 2 had tandem lesions. In Diamox SPECT, 6 patients showed preserved CVR. Patients with preserved CVR more had stenotic lesion while those with reduced CVR had occlusive lesion (p=0.001) and ASITN/SIR grading was differently distributed between two groups (p=0.046).

Conclusion:
DSA is still most important in evaluating steno-occlusive lesion and collateral status as shown previous studies. The status of the steno-occlusive lesion may have an effect on CVR. And the pattern of collateral flows may have a certain relation to vascular reserve capacity. But there are needed longer follow up in much larger populations.
Abstract W MP10: The Prognostic Value of Age and NIH Stroke Scale in Predicting the Outcomes of Endovascular Stroke Therapy in the STAR Registry; Validation of the SPAN-100 score
Authors: Almekhlafi Mohammed A , Davalos Antoni , Bonafe Alain , Chapot Rene , Gralla Jan , Pereira Vitor M , Goyal Mayank
Published: July 2021

Background:
Age and stroke severity are inversely correlated with the odds of favorable outcome after ischemic stroke. The Stroke Prognostication using Age and NIH Stroke Scale (SPAN) index identified that patients with a SPAN index 100 or more (SPAN-100 positive) did not benefit from IV tPA in the NINDS trial. The effect of successful reperfusion on the prognostic value of this score is not known.

Methods:
The SPAN index was calculated for patients in the prospective Solitaire FR Thrombectomy for Acute Revascularisation "STAR" study: an international single-arm multi center cohort for anterior circulation stroke. The proportion with favorable outcome (90-day mRS score ≤ 2) was compared between SPAN-100 positive vs. negative patients.

Results:
Of the 202 patients enrolled, 196 had non-missing baseline NIHSS. Fifteen (7.7%) patients were SPAN -100 positive. There was no difference in the rate of successful reperfusion (TICI2b or 3) between SPAN-100 positive vs. negative groups (93.3% vs. 82.8% respectively, p=0.3). SPAN-100 positive patients had a significantly lower proportion of favorable clinical outcome (26.7% vs. 60.8% in SPAN-100 negative, p=0.01) (Figure). In a univariable analysis, SPAN-100 positive status was associated with lower odds of favorable outcome (OR 0.23, CI95 0.07 to 0.77; p=0.02). In a multivariable logistic regression, only baseline ASPECTS and time from onset to revascularization were significant predictors of favorable outcome.

Conclusion:
A significantly lower proportion of patients with a positive SPAN-100 index achieved favorable outcome at 90 days. In our cohort, this effect was accounted for by delays in the time from onset to revascularization.
Abstract W MP14: Early Infarct Growth Predicts Long-term Clinical Outcome in Ischemic Stroke
Authors: Kim Seung Min , Lee Deok Hee , Kwon Sun U. , Kim Sang Joon , Kim Jong S. , Kang Dong-Wha
Published: July 2021

Background:
Ischemic lesion is dynamically evolving during acute phase of stroke. However, it is still controversial whether early changes in ischemic lesion have a prognostic information in addition to clinical variables. We hypothesized that early infarct growth on diffusion-weighted imaging (DWI) might be independently associated with long-term outcome.

Methods:
This was a prospective study of acute ischemic stroke patients who underwent DWI at baseline (within 24 hours) and at 5-day after stroke onset. Early infarct growth was defined as the difference between the final and the baseline infarct volume. Clinical outcomes were assessed using the modified Rankin Scale (mRS) at 3 months. Univariate and multivariate analyses were performed to assess the relationship between early infarct growth and clinical outcomes. The cut-off values of early infarct growth predicting long-term clinical outcomes were estimated using receiver operating characteristic analysis.

Results:
Of total 409 patients included, 345 (84.4%) showed any early infarct growth (median, 0.63cm
3
, interquartile range, 0.11-6.33cm
3
). After adjusting age, diabetes, baseline National Institutes of Health Stroke Scale, and baseline infarct volume by multiple logistic analysis, infarct growth was an independent predictor of poor clinical outcomes (for mRS 2-6, odds ratio [OR], 1.03, 95% confidence interval [CI], 1.002-1.06, p=0.04; and for mRS 3-6, OR, 1.03, 95% CI, 1.01-1.05, p=0.01). The cut-off values of early infarct growth discriminating between good and poor outcomes were 0.99cm
3
for mRS 0-1 vs. 2-6 (area under curve [AUC], 0.685, p<0.001) and 8.86cm
3
for mRS 0-2 vs. 3-6 (AUC, 0.736, p<0.001).

Conclusions:
Infarct growth within a week of symptom onset independently predicts 3-month clinical outcomes. This suggests that short-term changes in infarct volume may serve as a surrogate marker of long-term clinical outcomes after ischemic stroke.
Abstract W MP19: MRI Voxel-Based Profiling of Tissue Viability and Ischemia in Acute Ischemic Stroke: Elimination of Time as a Treatment Barrier?
Authors: Tansy Aaron P , Scalzo Fabien , Starkman Sidney , Ali Latisha K , Kim Doojin , Vespa Paul M , Rao Neal M , Yallapragada Anil , Alger Jeffrey R , Salamon Noriko , Saver Jeffrey L , Liebeskind David S ,   for the UCLA Stroke Investigators
Published: July 2021

BACKGROUND:
Despite its proven efficacy in acute ischemic stroke, thrombolytic treatment rates are exceedingly low. A common barrier is a prerequisite estimation of finite event duration. Whole-brain MR DWI-FLAIR comparative methods of hyperacute-acute ischemic match/mismatch are currently under investigation as a potential surrogate for unknown duration. Profiles that reflect field ischemia but not viability may not detect important voxel-level heterogeneity and, consequently, areas that may potentially benefit from revascularization. Voxel-based MR methods that assess viability (PWI) and ischemia (DWI-FLAIR) may afford a more informative measure to determine and expand treatment eligibility.

METHODS:
Consecutive, treated M1 ischemic stroke patients with serial MRI were analyzed with voxel-based, volumetric measures of DWI, FLAIR, and PWI for match/mismatch. Co-registration of Day 0 DWI, PWI, and FLAIR with Day 5/discharge FLAIR was then followed by ROI analysis of the affected MCA field. Day 0 DWI, PWI, FLAIR and Day 5/discharge FLAIR voxels were pooled into average populations according to positivity. Serial voxel-populations were then quantified at Day 0 and at Day 5/discharge individually and group-wise. Data processing and analysis were performed with MatLab, 3DSlicer, and Microsoft Excel.

RESULTS:
38 treated M1 occlusive patients (mean age 65 years, 25 female) underwent a voxel-based analysis of DWI, PWI, and FLAIR at day 0 and FLAIR at day5/discharge. At baseline, 93% of the affected MCA field was DWI-/PWI+/FLAIR-; 7% was DWI+/PWI+/FLAIR-; and ~3% was FLAIR+. At day 5/discharge, 36% of baseline at-risk field (DWI-/PWI+); >95% of baseline field undergoing ischemia (DWI+/PWI+); and 94% of baseline ischemic tissue (FLAIR+) were FLAIR+.

CONCLUSIONS:
Voxel-based analyses of DWI, PWI and FLAIR on serial MRI reveal heterogeneity of voxel status at baseline and in tissue fate, and provide a dynamic tissue profile in treated M1 ischemic stroke. Over 1/3 of baseline viable tissue became ischemic at day 5 suggesting nearly 2/3 of the field remained viable. Future evaluations of voxel-based approaches that profile viability and ischemia are warranted to validate this methodology and its potential to expand acute stroke treatment eligibility.
Abstract W MP61: Prevalence of Echocardiographic Abnormalities in Acute Ischemic Stroke
Authors: Eckerle Bryan , Sucharew Heidi , Alwell Kathleen , Moomaw Charles J , Flaherty Matthew , Martini Sharyl , Woo Daniel , Khatri Pooja , Adeoye Opeolu , Ferioli Simona , Kissela Brett M , Kleindorfer Dawn O
Published: July 2021

Introduction:
Non-invasive cardiac imaging is an important tool in evaluation of acute ischemic stroke, as a cardiac source can be implicated in approximately 20% of cases. However, the preferred imaging method is unclear due in part to the lack of consistent data regarding the yield of the two most commonly employed modalities, transthoracic and transesophageal echocardiography (TTE and TEE). Here we examine, in a large, biracial population, the prevalence of abnormalities detected by echocardiography during evaluation of acute ischemic stroke.

Methods:
Acute ischemic stroke cases were identified from a population of 1.3 million in the Greater Cincinnati area in 2005. Medical history and echocardiography results were determined by retrospective chart review. Echocardiographic abnormalities were pre-defined based on possibility of change in clinical decision making. All cases were abstracted by study nurses and subsequently verified by study physicians. Results were stratified by cardiac history and choice of echocardiographic technique; groups were compared using chi-square test or Fisher’s Exact test.

Results:
There were 2197 hospital-ascertained ischemic stroke cases in 2005. Median age was 73 (IQR 61-81), 22% were black, and 55% were female. TTE was performed in 68% of cases; TEE was performed in 7%. TEE revealed at least one abnormality in 55% of cases with cardiac history and 32% of cases without (Table). Yield of TTE was 20% in cases with cardiac history and 3% in cases without.

Discussion:
TEE is of considerable yield in selected patients, irrespective of cardiac history. This is in keeping with prior cost-effectiveness analyses recommending TEE alone for patients in whom suspicion of occult source of cardiac embolism is high. Prevalence of abnormalities on TTE in this population is similar to that of previously published series.
Abstract W MP67: Etiology-Specific Clinical and Imaging Features in Ischemic Stroke
Authors: Arsava Ethem Murat , Brown Robert D , Kittner Steven J , Meschia James F , Mitchell Braxton D , Rexrode Kathryn M , Rosand Jonathan , Rundek Tatjana , Woo Daniel , Worrall Bradford B , Ay Hakan
Published: July 2021

Background:
Identification of clinical and imaging characteristics of ischemic stroke that can predict the underlying etiology is critical for accurate stroke subtyping. We sought to investigate the relationship between stroke characteristics and stroke etiology in 7,591 patients in the NINDS Stroke Genetics Network Study.

Methods:
We determined the probability of having a major etiology in the presence of certain stroke characteristics that were previously linked to specific stroke mechanisms. We excluded patients with multiple competing major etiologies. All patients had brain imaging, intra- and extra-cranial vascular imaging, and complete cardiac assessment. We defined major etiologies according to the Causative Classification of Stroke System Criteria without reference to the stroke characteristics under study.

Results:
History of 1 ipsilateral ischemic events within the last month, the presence of internal watershed infarcts or multiple, ipsilateral, unilateral, and temporally separate infarcts were associated with large artery atherosclerosis (Table). Multiple acute infarcts in different cerebral circulations were more common in patients with major cardiac source of embolism as well as in those with uncommon/cryptogenic causes. Stereotypic lacunar TIAs within the last week and lacunar syndrome were associated with lacunar infarction

Discussion:
Clinical and imaging stroke characteristics appear to predict stroke etiologies. This information may find utility in developing algorithms for a guided stroke evaluation as well as help identify the most likely causative etiology in the presence of multiple competing etiologies.
Abstract W MP70: Characteristics of Patients With Microemboli Detected With Transcranial Doppler Monitoring
Authors: Koffman Lauren , Ahmed Zubair , Michael Rebecca , Baus Leasa , Raber Larry , Katzan Irene
Published: July 2021

Introduction:
TCD emboli monitoring (TCDe) is a non-invasive tool used to detect the presence of ongoing microembolic signals (MES) in the intracranial arterial vessels. The clinical utility of this test in the evaluation of acute stroke patients has been debated. Our goal was to evaluate clinical factors associated with MES in ischemic stroke patients who underwent TCDe to determine which patient population may benefit from TCDe.

Methods:
Retrospective cohort study of adult patients admitted to our tertiary care center for TIA or ischemic stroke from 2011 to 2012 who underwent TCDe. Monitoring was performed for 20 minutes using a standardized protocol. Inclusion criteria included insonatation of both middle cerebral arteries and completion of TCD bubble study (TCB). Repeat TCDe performed on the same patient were excluded from the analysis. Demographic, clinical and objective data were collected using our EMR system.

Results:
Of the 113 patients included in the final analysis, mean age was 57.9 years and 46.9% were female. MES occurred in 33.6% patients. Mean # of MES was 9.3 (SD 60.6). Patients with MES were significantly younger (51.8 years vs 61.0, p.006) and had fewer vascular risk factors: diabetes (10.5% vs 33.3%, p 0.006), hyperlipidemia (23.7% vs 49.3%, p 0.007), hypertension (47.4% vs 17.33%, p 0.067), atrial fibrillation (7.9% vs 17.33 %, p 0.16), congestive heart failure (5.3% vs 10.7%, p 0.32) and coronary artery disease (18.4 % vs 29.3%, p 0.2). Cryptogenic stroke and the presence of right to left shunt (RLS) was more frequent in patients with MES than those without. Mean WBC count and usCRP were both nonsignificantly higher in patients with MES.

Conclusions:
Clinical characteristics of patients with MES on TCDe differed from those without MES, which may have diagnostic and clinical implications. Patients with MES were younger and had fewer stroke risk factors. MES were seen more often in patients with RLS and in those with cryptogenic stroke, which raises the possibility of an association between these two factors. Interestingly, patients with MES also had higher usCRP and WBC values, suggesting a possible inflammatory component to the occurrence of MES. More research is needed with a larger sample size to better define the significance of the above findings.
Abstract W MP73: Protective Effect of Argatroban on Behavioral Outcome Following MCAo up to Four Hours
Authors: Zhao Lifu , Pereira Benedict , Lamb Jessica , Rajput Padmesh , Lyden Patrick
Published: July 2021

Background and Purpose:
We showed previously that thrombin enters brain and causes damage to the neurovascular unit (NVU) during ischemia. We hypothesized that the direct thrombin inhibitor argatroban after MCAo would ameliorate behavioral deficits. We explored the therapeutic time window with a standard bioassay following pre-clinical testing guidelines from RIGOR and STAIR.

Methods:
Male Sprague-Dawley rats underwent MCAo during which each received placebo, 18mg/kg Argatroban over 24 hours (hi dose), or 10mg/kg over 24 hours (lo dose). Blood flow was restored by removing the filament after variable times. At reflow and daily thereafter animals were rated using a modified Bederson scale. After 48 hours the animals were sacrificed and lesion volume measured with TTC imaging (planimetry; Image Pro Plus). Animals were assigned to treatment randomly and studies were triple blinded at surgery, at behavioral assessment, and during histology. We used the quantal bioassay (Exp Neurol 1997;147:346-352) to compute the ED
50
for each group, which measures the duration of ischemia in minutes needed to cause abnormal behavior in 50% of the group.

Results:
Both doses of argatroban were superior to saline when treatment was delayed as long as 3 hours. For example, after 1 hour delay, the ED
50
±SD for placebo (n=19) was 24.0±5.6, lo dose (n=19) 46.3±3.4, hi dose (n=19) 40.6±5.7 (p<0.05, t-test, Bonferroni). After 3 hours (Figure), placebo (n=25) was 15.5±3.3, lo dose (n=20) 30.1±5.6, and hi dose (n=20) 30.1±3.74 (P<0.05). After 4 hours delay, there were no beneficial effects. Lesion volumes measured by TTC confirmed the behavioral results.

Conclusion:
Argatroban after MCAo significantly ameliorated behavioral deficits and reduced lesion volume compared to saline. The effect was robust and seen with 2 doses. Protection was noted after a delay as long as 3 hours but not 4 hours. These data support earlier findings that thrombin inhibition shows promise for neuroprotection.
Abstract W MP86: Improving the Accuracy of the ABC/2 Estimation Technique in Spontaneous Supratentorial Intracerebral Hemorrhage
Authors: Ziai Wendy , Nekoovaght-Tak Saman , Betz Joshua F , Muschelli John , Fisico Ryan N , Li Ximin , Hanley Daniel F
Published: July 2021

Introduction:
The ABC/2 formula is the most common, rapid, and effective method to estimate intracerebral hemorrhage (ICH) volumes. However, ABC/2 overestimates clot volume with increasing error for larger hematomas. We used linear and nonlinear regressions to find if adjusting C, adjusting the denominator, or adjusting both would improve ICH volume estimation.

Materials and methods:
We assessed the diagnostic computed tomography (CT) scans of 373 patients enrolled in the MISTIE II (N=100) and CLEAR III (N=273) clinical trials using a standard central laboratory ABC/2 technique compared with planimetry volumetric calculations. Linear and nonlinear regressions were used to find optimal adjustments for C and the denominator, both individually and jointly. Results were stratified by study population to determine generality.

Results:
In MISTIE II (M2) patients, mean hematoma volume was 45.72 ± 27.1 (SD) cm
3
using ABC/2 vs. 39.48 ± 19.58 cm
3
using planimetry. In CLEAR III (C3) patients, mean hematoma volume was 11.11±8.30 (ABC/2) vs. 9.58±7.10 cm
3
(planimetry). The optimal denominator for the ABC approximation without adjusting C was 2.39 in M2 patients (95% CI 2.33, 2.46) and 2.37 in C3 patients (95% CI 2.31, 2.42). When these samples are combined, the optimal denominator was 2.39 (95% CI 2.35, 2.42). Without any correction to the denominator, the optimal adjustment for C was a decrease of 0.8352 in M2 patients (95% CI -0.976, -0.694) and a decrease of 0.5277 in C3 patients (95% CI -0.595, -0.46). In regression models adjusting C and the denominator, the optimal adjustment for C was an increase of 0.5707 in M2 patients (95% CI -0.215, 1.635), and an increase of 0.0485 in C3 patients (95% CI -0.383, 0.235). The optimal value of the denominator in these models was 2.64 in M2 patients (95% CI 2.29, 3.13) and 2.39 in C3 patients (95% CI 2.21, 2.62).

Conclusion:
Empirical evidence from a large international population of ICH patients suggests that ABC/2 consistently over-estimates ICH volumes. Shrinking the C-axis of the ellipse improves fit, but the optimal adjustment depends on ICH size. Using a denominator of 2.4 is a simple, objective way to improve rapid ICH assessment with the existing measurement paradigm, which is consistent in both large and small hematomas.
Abstract W MP89: Validation of Clinical-Radiological Criteria for the Diagnosis of Cerebral Amyloid Angiopathy-related Inflammation
Authors: Auriel Eitan , Gurol Mahmut Edip , Ni Jun , Van Etten Ellis , Martinez-Remirez Sergi , Piazza Fabrizio , DiFrancesco Jacopo , Frosch Matthew , Pontes-Neto Octavio , Vashkevich Anastasi , Ayers Alison , Shoamanesh Ashkan , Schwab Kristin , Viswanathan Anand , Greenberg Steven
Published: July 2021

Introduction:
Cerebral amyloid angiopathy-related inflammation (CAA-ri) is a disease subtype characterized by rapidly progressive cognitive decline, seizures, headaches, T2-hyperintense MRI lesions, and neuropathologic evidence of CAA-associated vascular inflammation. CAA-ri is an important diagnosis to reach in clinical practice, as many patients respond to immunosuppressive therapy. Definitive diagnosis of CAA-ri generally requires brain biopsy, however, highlighting the importance of developing noninvasive diagnostic criteria.

Objectives:
To test the sensitivity and specificity of modified criteria (Table 1) for possible and probable CAA-ri in groups of subjects with histologically proven CAA-ri and non-CAA-ri.

Methods:
After refining previously proposed clinical- radiological criteria we retrospectively analyzed clinical charts and MRI FLAIR and gradient-echo scans obtained from 17 subjects with pathologically confirmed CAA-ri and 37 control subjects with pathologic diagnosis of non-inflammatory CAA. The control group was further divided into those with past intracerebral hemorrhage (ICH) (n=21) and those with cerebral microbleeds (CMB) only and no history of ICH (n=16).

Results:
In the CAA-ri group 14/17 (82.4%) met criteria for both probable and possible CAA-ri. One (4.7%) of the subjects in the control CAA-ICH group (n=21) met the criteria for possible and none met criteria for probable CAA-ri. In the control CAA-no ICH group 1/16 (6.25%) and 11/16 (68.75%) met criteria for probable and possible CAA-ri respectively. This yields sensitivity and specificity of 82% and of 97.3% respectively for the probable criteria and sensitivity and specificity of 82% and 67.6% respectively for the possible criteria.

Conclusions:
Our data suggest that a reliable diagnosis of CAA-ri can be reached from basic clinical and radiographic information alone with good sensitivity and excellent specificity.
Abstract W MP93: The STICH II Prognostic Score Predicts Outcomes in the ERICH Study
Authors: Rasmussen Jennifer , Birnbaum Lee , Langefeld Carl D , Brown W. M , Moomaw Charles J , Nanez Esther , Vashkevich Anastasia , Rosand Jonathan , Kidwell Chelsea S , Osborne Jennifer , Woo Daniel
Published: July 2021

Introduction:
The Surgical Trial in Lobar Intracerebral Hemorrhage (STICH II) investigators developed a pre-trial prognostic score based on Glasgow Coma Scale (GCS), age, and intracerebral hemorrhage (ICH) volume at randomization: 10 х GCS - age - 0·64 х ICH volume. The STICH II results demonstrate that lobar ICH subjects with a good prognostic score are more likely to have a good to moderate recovery. Our study implements this prognostic score in both lobar and deep supratentorial ICH in the Ethnic/Racial Variations of Intracerebral Hemorrhage (ERICH) cohort.

Methods:
ERICH subjects with a supratentorial ICH, presenting GCS, ICH volume, and 6-month mRS are included in the analysis. Exclusion criteria are primary IVH cases and withdrawal of care patients at time of hospital discharge (comfort care or hospice). Based on STICH II, a good prognostic score is >27.672. We define a good outcome as 6-month mRS <=3. Prediction of outcome is analyzed using ordinal logistic regression with a cumulative logit link and positive and negative predictive values (PPV and NPV). An odds ratio (OR) is computed to estimate the effect size.

Results:
A total of 584 subjects were included (mean age 60 years +/- 14.7; black 42%, Hispanic 32%, white 25%; 41% women). There were 392 (67.1%) deep ICH. The average ICH volume was 19.6 cc +/-22.8, and average GCS was 12.6 +/- 3.5. The prognostic score was predictive of mRS in both lobar (OR=5.5, p<0.0001) and deep (OR=6.3, p<0.0001) ICH (Table 1). PPV’s are lobar 71.5% and deep 68.1%; NPV’s are lobar 68.8% and deep 75.0%.

Conclusions:
ERICH subjects with either lobar or deep ICH and a good prognostic score are more likely to have a good to moderate outcome, define in our study as a 6-month mRS <=3. In addition, the ICH subjects with a poor prognostic score are more likely have a poor outcome. Our findings suggest that the STICH II prognostic score may be applicable in other cohorts of both lobar and deep ICH.
Abstract W P106: A 3D Computational Model of the Hemodynamic Changes in EC-IC Bypass With Physiologic Boundary Conditions
Authors: Connolly Mark , Scalzo Fabien , Liebeskind David S , Gonzalez Nestor R
Published: July 2021

Introduction:
Intracranial arterial stenosis (IAS) accounts for 10% of ischemic strokes. EC-IC bypass trials have failed to show benefit of STA to MCA bypass over medical management, particularly for patients with severe stenosis rather than occlusion. These outcomes may be explained by retrograde flow from the bypass competing with flow through the stenosis, creating conditions at risk for thrombosis, such as stagnant or turbulent flow. We present a computational fluid dynamics model of EC-IC bypass extracted from patient images to demonstrate the hemodynamic effects of a bypass.

Methods:
A 2D-to-3D reconstruction algorithm was used to extract the vascular geometry from biplane angiograms of a patient with STA-MCA bypass. Additional details, such as the anterior temporal branch and lenticulostriates (LSAs) were added. The model was modified with varying degrees of stenosis. The boundary conditions of the outlets were adjusted to account for cerebrovascular autoregulation by finding the steady state of an autoregulatory model. The ANSYS: Simulation Technology package was used to evaluate hemodynamic parameters at 70% and 90% stenosis.

Results:
The 70% stenosis showed small pressure drop across the stenosis compared to the 90% stenosis (712Pa, 3618Pa). Flow velocity and wall shear stress (WSS) were substantially higher in the M1 segment distal to the lesion in the 70% stenosis model than in the 90% model (105cm/s, 27cm/s; 3.4Pa vs. 0.66Pa). Both models exhibited slow retrograde flow through the M2 segment (7cm/s, 10cm/s). Maximal turbulent kinetic energy (TKE) was higher in 70% stenosis model (0.00586m^2/s^2, 0.0012m^2/s^2).

Conclusions:
EC-IC bypass causes competitive flow within the M1 and M2 segments resulting in near complete stagnation of flow in regions of the MCA with high WSS and TKE, a set of conditions at high risk for intra-arterial thrombosis.
Abstract W P114: Assessment of Platelet Thrombus Formation in Patients with Carotid Disease Administered Clopidogrel
Authors: Yamazaki Masako , Ohnishi Tomoko , Hosokawa Kazuya , Okada Yoshikazu , Kawashima Akitsugu , Yoneyama Taku , Yamaguchi Kouji , Uchiyama Shinichiro
Published: July 2021

Background:
Many studies have demonstrated that high residual platelet function in patients administered clopidogrel is associated with cardiovascular events, although, the majority of those studies examined the patients with coronary artery disease. We studied platelet function in patients with ischemic stroke treated by clopidogrel, and compared residual platelet function according to the severity of carotid disease.

Methods:
We measured platelet aggregation induced by ADP, VerifyNow P2Y12 assay (PRU), phosphorylation of vasodilator-stimulated phosphoprotein (PRI), platelet-leukocyte complex (PLC), and platelet p-selectin expression (PS) in 30 patients with ischemic stroke administered clopidogrel (21 males and 9 females, mean age was 65 years). We also measured platelet thrombus formation under arterial flow conditions using newly developed microchip-based flow chamber system. In this system, platelet thrombus formation was analyzed by measuring flow pressure changes due to occlusion of microchip and was quantified by calculating area under the flow pressure curve (AUC). Each marker was compared between patients with severe carotid stenosis (15 cases) and those with mild to moderate carotid stenosis (15 cases).

Results:
Platelet function tests such as percentages of platelet aggregation induced by ADP, PRU, PRI, and PS was not significantly different between different severities of carotid stenosis. On the other hand, AUC values and PLC of patients with severe major carotid stenosis were significantly higher than those with mild to moderate stenosis.

Conclusions:
These results suggested that clopidogrel inhibits platelet aggregation irrespective of the severity of carotid stenosis. On the other hand, platelet thrombus formation under arterial flow conditions and platelet leukocyte interactions were higher in patients with severe carotid stenosis than those with mild to moderate stenosis.
Abstract W P12: Intra-procedural Hemodynamics in General Anesthesia versus Monitored Anesthesia Care During Endovascular Therapy for Acute Anterior Circulation Ischemic Stroke
Authors: John Seby , Thebo Umera , Saqqur Maher , Gomes Joao , Farag Ehab , Hussain Muhammad S
Published: July 2021

Background:
Recent studies have identified general anesthesia (GA) as a predictor of poor outcome compared to non-intubated sedation techniques during intra-arterial therapy (IAT) for acute ischemic stroke (AIS). Factors contributing to this difference are not well understood.

Objective:
Identify factors associated with poor outcome in patients receiving GA vs Monitored Anesthesia Care (MAC). We speculated that peri-procedural blood pressure (BP) may be influenced by anesthesia and could plausibly contribute to differences in outcome.

Methods:
190 patients who underwent IAT for anterior circulation AIS from 1/2008 to 12/2012 were included. Patients <18 years of age and posterior circulation AIS were excluded. Demographics, NIHSS, IV tPA use, use of GA/MAC, thrombus location, recanalization grade, post-procedure intracranial hemorrhage (ICH), and 30-day outcomes were collected. Intra-procedural hemodynamics including maximum/minimum heart rate and systolic/diastolic/mean BP were collected. Primary outcomes were in-hospital mortality and good outcome (mRS 0-2) at 30 days. Secondary outcomes were successful recanalization (TICI 2b-3) and ICH (PH1+2) based on ECASS definitions.

Results:
There were 91 and 99 patients in the GA and MAC groups respectively. Baseline characteristics including NIHSS scores were similar between both groups. The GA group had more ICA terminus occlusions (39.1% vs 18.2%, p = 0.043). There was significantly higher mortality (25.8% vs 13.3%, p = 0.040) and a trend towards poorer outcome (14.9% vs 22.8% with mRS 0-2, p = 0.239) in the GA group. Successful recanalization was higher in the GA group (57.1% vs 47.5%, p = 0.182), but the rate of PH1+2 ICH was significantly higher in the GA group (26.3% vs 10.1%, p = 0.003). There were no significant differences in intra-procedural hemodynamics, prior to or after recanalization. GA was an independent predictor of mortality and PH1+2 ICH.

Conclusions:
Patients placed under GA prior to IAT appear to have a higher probability of mortality and a trend towards poorer outcome. Outcome differences do not seem to be related to hemodynamic factors. There were significantly higher number of ICHs in the GA group and this could potentially be the factor driving the difference between outcomes.