bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2185: The Historical Stroke Severity Score Predicts Stroke Progression in TIA and Minor Stroke
Authors: Coutts Shelagh B , Demchuk Andrew M , Poppe Alexandre Y , Barber Philip A , Shobha Nan , Hill Michael D
Published: July 2021

TIA and minor stroke have a high risk of early neurological deterioration. Many of these early deteriorations are from progression of the presenting event. It has previously been shown that patients with large early neurological improvement are at high risk of subsequent deterioration. In this study we prospectively generated a scoring system for assessing the most severe historical deficit.

Methods:
Consecutive patients presenting with TIA or minor stroke (NIHSS<4) were prospectively enrolled in the prospective CATCH imaging study, if a stroke neurologist assessed them and they had a CT/CTA (Aortic arch to vertex) completed within 24 hours of symptom onset. The Historical Stroke Severity Score (HSSS) was developed in advance of the study to allow measurement of the severity of a patients’ worst deficits. The HSSS was scored based upon the clinical history and ranged from 0-11 points and included assessment of: a. Level of consciousness (alert (0), drowsy (1), Unconscious (2)); b. Speech disturbance (normal (0), dysarthria only (1), mild aphasia (2), severe aphasia or mute (3)); c. Arm motor power (normal (0), mild weakness or heaviness (1), moderate weakness (2), severe weakness (3)); d. Leg motor power (normal (0), mild weakness or heaviness (1), moderate weakness (2), severe weakness (3)); e. Sensory symptoms (normal (0), mild sensory (1), severe sensory (2)). The individual components of the score and the total score were assessed for their ability to predict symptom progression. Symptom progression was defined as a worsening of the presenting symptoms related to the initial event and not as a distinct second event.

Results:
510 patients were enrolled and 90-day follow up was available in 499 (98%). These patients were assessed early with a median time from symptom onset to CTA was 5.5 hours (IQR: 6.4 hours). The HSSS was rated immediately after patients were enrolled in the study - ie immediately after the CT/CTA. 19 (3.7% 95% CI 2.3-5.8) patients had symptom progression with a median time to event of one day. The progression rates for low (0-3), intermediate (4-7) and high (8-11) total scores were 2.7%, 6% and 14%. The total HSSS was associated with symptom progression (ROC 0.68 (0.56-0.79). Only the motor severity components of the HSSS were predictive of symptom progression (arm motor weakness (p=0.015) and leg motor weakness (p=0.006). Therefore the score could be simplified to include only motor historical severity of the arm and leg (ROC 0.68 (0.57-0.8) with a total score range of 0-6.

Conclusions:
The taking of a detailed history is highly relevant. A score based on the historical description of how severe the worst deficits were is able to predict symptom progression in a TIA and minor stroke population assessed early in the emergency department. Severity of motor symptoms appears to best predict symptom progression in TIA and minor stroke patients.
Abstract 2199: Ultra Rapid Brain Attack Team MRI Useful in Selecting Patients with Acute Stroke-like Symptoms for Intravenous Thrombolysis
Authors: Paolini Stephanie , Poole Roxanne D , Hawsey Kelly , Graham Blease C , Sen Souvik
Published: July 2021

Introduction:
In acute ischemic stroke (AIS), intravenous tissue plasminogen activator (IV TPA), if administered appropriately can be beneficial; however, with stroke misdiagnosis, it can expose patients to unnecessary bleeding risks. Thus, accurate diagnosis is critical. Brain Magnetic Resonance Imaging (MRI) is sensitive to detect AIS; however, a complete exam may consume 30-45 minutes. At the University of South Carolina Palmetto Health Richland Stroke Center, an ultra-rapid, 10 minute MRI called the Brain Attack Team MRI (BAT MRI) was designed to accurately and expeditiously diagnose AIS. Hypothesis: BAT MRI is a useful clinical tool to select or exclude patients for IV TPA who present acutely with stroke-like symptoms. Clinical correlates are not an effective substitution for BAT MRI to confirm AIS.

Methods:
In an ongoing study, conducted in 2010-11, 31 consecutive patients were identified who presented <4.5 hours from symptom onset and received a BAT MRI. They were 43-90 years in age; 48.4% White, 48.4% African American, and 3.2% unknown. BAT MRIs included diffusion weighted imaging, T2 gradient echo, T2 axial, and FLAIR sequences. The algorithm for BAT MRI use is shown in Figure 1. BAT MRIs were evaluated for ischemia, hemorrhage and other central nervous system (CNS) pathologies. Stroke risk factor correlates of abnormal BAT MRIs were assessed using t-test for continuous variables and Fisher's Exact Test for categorical variables.

Results:
Of the 31 BAT MRIs, 13 were read as abnormal (11-acute ischemia, 1-hemorrhage, 1-ischemia with hemorrhage). The hemorrhage was in the pons on BAT MRI and was not detected by CT. This finding excluded using IV TPA in this patient. Two cases where BAT MRI demonstrated AIS met NINDS/ECASS-III criteria and received IV TPA. Of the 18, in whom BAT MRI was read as normal, 9 had a discharge diagnosis of TIA, 2 MRI negative strokes, 3 conversion disorders, 1 CNS neoplasm, 1 respiratory failure and 1 peripheral vertigo. Stroke risk factor analysis yielded no significant correlation between BAT MRI findings and gender, race, prior stroke/TIA, coronary artery disease, diabetes, hyperlipidemia, hypertension, or smoking. Patients with AIS on BAT MRI were older (68.2 ± 17.5) than those without (58.6 ± 9.7); although, it bordered statistical significance (p=0.08). Atrial fibrillation correlated with AIS on BAT MRI (p=0.02).

Conclusion:
In patients with AIS-like symptoms, BAT MRI may be used to confirm AIS, exclude stroke mimics and assess candidacy for IV TPA. Atrial fibrillation correlated with AIS on BAT MRI; therefore, these patients may be more likely to be IV TPA candidates.
Abstract 2224: The Relationship Between Process and Outcomes for Stroke Post Prospective Payment in Inpatient Rehabilitation Facilities
Authors: O'Brien Suzanne R , Ingersoll Gail , Xue Ying , Kelly Adam , Chen Din
Published: July 2021

Background and Objective:
Previous studies have reported decreasing length of stay (LOS) for inpatient rehabilitation facilities (IRFs), with conflicting effects on discharge Functional Independence Measure (FIM) scores and discharge destination (DD). This study was the first to examine the post prospective payment system (PPS) period using Medicare data drawn from the national Inpatient Rehabilitation Facility Patient Assessment Instrument (IRF-PAI) database. The purposes were to examine trends over time for process and outcome factors, and to describe the relationships between process, LOS, and outcomes (discharge FIM scores and DD), for Medicare patients with stroke.

Methods:
The study included 371,211 Medicare Part A beneficiaries aged 65 and older with stroke, admitted to United States (US) IRFs between January 1, 2002 and June 30, 2007. Descriptive statistics and generalized estimating equations (GEE) modeling for clustered data were used for analysis. Continuous GEE evaluated LOS and discharge FIM scores, and binomial GEE evaluated LOS and DD (community verses institution). Covariates in models were: admission FIM scores, age, gender, race/ethnicity, comorbidities, complications, and stroke type. Time interactions with admission FIM scores, LOS, and discharge FIM scores (binomial model only) were examined.

Results:
During the study period, mean LOS decreased from 17.9 (SD=9.9) to 16.1(SD=8.3) days (p<. 0001), mean discharge FIM scores decreased from 80.1 (SD=24.5) to 76.5 (SD=24.5) points (p<. 0001), and rate of community discharge decreased from 66.6% to 61.2% (p<. 0001). LOS predicted discharge FIM scores (95% CI, .48, .52, p<.0001), but the relationship to community discharge was weak (OR .997, p=.007). Discharge FIM scores predicted discharge destination (OR 1.07, p<.0001). Covariates of admission FIM scores, age, gender, race/ethnicity, comorbidities, complications, and stroke type also predicted outcomes. Time interactions were present for LOS, admission FIM scores, and discharge FIM scores.

Conclusions:
During the first 5.5 years of PPS, declining trends were found for LOS, discharge FIM scores, and rate of community discharge for Medicare beneficiaries with stroke. LOS was a strong predictor for discharge FIM scores, but weak for DD. Discharge FIM scores were a better predictor of DD than LOS. Effects of covariates on discharge FIM scores and DD have clinical implications for IRF stroke rehabilitation in the US. Because of the reduced time for treatment, dose of IRF rehabilitation for Medicare beneficiaries may not be achieving expected results in the post-PPS period.
Abstract 2269: Leukoaraiosis Predicts 90-day Outcome After Intracranial Large Artery Occlusion
Authors: Henninger Nils , Lin Eugene , Baker Stephen P , Wakhloo Ajay K , Takhtani Deepak , Moonis Majaz
Published: July 2021

Background:
Intracranial large artery occlusion (ILAO) accounts for a significant number of ischemic strokes and predicts a poor outcome. However, factors modifying the outcome following ILAO remain incompletely characterized. Leukoaraiosis (LA), which is a frequent finding in stroke patients, has been associated with poor post-stroke outcomes. However, its contribution to patient outcome after ILAO remains to be clarified. We sought to determine the association between LA-severity and 90-day outcomes in patients following anterior circulation ILAO.

Methods:
We retrospectively analyzed 1153 consecutive patients with imaging confirmed ischemic stroke during a 4-year period (2007-2010). The final study cohort included 87 patients with acute ILAO subjected to multimodal CT-imaging within 24 hours of symptom onset. LA-severity was assessed using the van Swieten scale on non-contrast CT. Leptomeningeal collaterals were graded using CT-angiogram source images. Hemorrhagic infarction was determined on follow-up CT. Multivariate logistic regression controlling for hemorrhagic infarction, treatment modality, demographic, as well as baseline clinical and imaging characteristics was used to identify independent predictors for outcome.

Results:
Factors independently associated with poor outcome (90-day mRS≥3) were admission NIHSS (p=0.0001; OR 5.11; 95% CI, 2.07-14.49 for each 10-point increase) and severe LA (p=0.0056; OR 13.86; 95% CI, 1.94-∞;
Figure
). There was a trend for an association between presence of hemorrhagic conversion and poor outcome (p=0.0572; OR 4.82; CI 0.96-32.65). Compared to patients with none-to-moderate LA, patients with severe LA were more likely to have hypertension (p=0.027), coronary artery disease (p=0.008), poor collaterals (p<0.001), higher admission NIHSS (p=0.003), higher mRS at 90 days (p<0.001), and they were older (p=0.002). Patients with severe LA had a uniformly poor outcome (p<0.001).

Conclusion:
In addition to NIHSS, the severity of pre-existing LA has substantial impact on outcome in patients with acute ILAO and may prove to be an important factor to guide clinical decision making.

Figure:
Functional outcome by Leukoaraiosis grades Functional outcome at 90 days (modified Rankin Score, mRS) stratified by severity of Leukoaraiosis (LA) grades (van Swieten Score 0-2 vs. 3-4, P<0.001). Numbers indicate n per mRS-category.
Abstract 2281: Full Dose IV-tPA Followed By IA Therapy For Acute Ischemic Stroke Does Not Increase Morbidity Or Mortality
Authors: Katz Jeffrey M , Natanzon Calvin , Setton Avi , Libman Richard
Published: July 2021

Background and Purpose:
“Bridging Therapy” is well described in the literature. However the dose of bridging tissue plasminogen activator (tPA) is a matter of debate given the well-established guideline of 0.9 mg/kg as the standard intravenous dose. Previous and ongoing bridging trials use lower doses of IV-tPA (0.6 mg/kg) with a goal of maximizing safety. Our aim was to explore whether full bridging dose IV-tPA at 0.9 mg/kg can be given safely in combination with intra-arterial (IA)-tPA.

Methods:
Data were collected prospectively on 47 consecutive patients with acute ischemic stroke who were treated with endovascular stroke therapy (EST, that is IA-tPA +/- mechanical embolectomy (ME)). Patients who were candidates for IV-tPA, who did not clinically improve after receiving full dose IV-tPA (0.9mg/Kg), underwent EST (bridging group, n=23, 15/23 IA-tPA + ME). These patients were compared to patients treated with EST alone because they were not candidates for IV-tPA (control group, n=24, 14/24 IA-tPA + ME). Symptomatic intracranial hemorrhage (ICH) rates were recorded, as defined in the NINDS IV-tPA trial. Death rates were recorded at one month and modified Rankin score was used to measure functional outcome (6 month mean follow-up).

Results:
Mean age was 62 years in the bridging group and 63 years in the control group. Baseline mean National Institute of Health Stroke Scale was 20 in the bridging group and 21 in the control group (p = 0.188). The mean IA-tPA dose was 14.4 mg in the bridging group and 18.3 mg in the control group (p = 0.371). There was an 8% risk of symptomatic ICH in the control group and no symptomatic ICH in the bridging group (p = 0.155). At 30 days, mortality was 17% in the bridging group and 29% in the control group (p = 0.313). The mean follow-up modified Rankin score was 3 in the bridging group and 4 in the control group (p = 0.20).

Conclusion:
This non-randomized retrospective cohort study suggests that full dose IV-tPA combined with IA-tPA administered during EST is safe in patients with acute ischemic stroke. Given the possibility that full bridging dose tPA may be more effective than lower dose IV-tPA, a prospective, randomized bridging trial using full dose IV-tPA may be warranted.
Abstract 2323: Statin Use and Discharge Disposition After Ischemic Stroke Hospitalization
Authors: Flint Alexander , Kamel Hooman , Navi Babak , Rao Vivek , Faigeles Bonnie , Conell Carol , Klingman Jeff , Hills Nancy , Nguyen Mai , Johnston S. Claiborne
Published: July 2021

Objective:
To determine whether statin use is associated with improved discharge disposition after ischemic stroke.

Methods:
We analyzed 12,689 patients with ischemic stroke over a 7 year period at 17 hospitals in Kaiser Permanente Northern California. We used multivariable generalized ordinal logistic regression and instrumental variable analysis of treatment patterns by hospital to control for the possibility of confounding.

Results:
Statin users before and during stroke hospitalization were more likely to be discharged home (54.9% for statin users, 46.3% for statin non-users) and less likely to die in hospital (5.3% for statin users, 10.3% for statin non-users). Patients who underwent statin withdrawal in-hospital were less likely to be discharged home (39.1% for statin withdrawal, 54.9% for statin continuation) and more likely to die in hospital (22.3% for statin withdrawal, 5.3% for statin continuation). Users of higher statin doses (>60 mg / day) were even more likely to be discharged home (62.5% for high dose statin, 56.5% for usual dose statin, and 47.4% for no statin) and less likely to die in hospital in-hospital (3.5% for high dose statin, 5.6% for usual dose statin, and 10.6% for no statin). These results were confirmed by multivariable analysis. The association of statin use and improved outcomes was also confirmed by instrumental variable analysis of treatment patterns by hospital, and thus this association cannot be explained by confounding at the individual patient level.

Conclusions:
Statin use is associated with improved discharge disposition after ischemic stroke, particularly at higher doses.
Abstract 2327: Impact Of MRI Based Carotid Artery Plaque Evaluation On The Risks Of Thromboembolic Events During Carotid Artery Stenting.
Authors: ISHIBASHI TOSHIHIRO , Murayama Yuichi , Ebara Masaki , Arakawa Hideki , Irie Koreaki , Kato Masataka , Kobayashi Norikata , Takao Hiroyuki , Kajiwara Ikki , Nishimura Kengo , Saguchi Takayuki , Abe Toshiaki
Published: July 2021

Objective:
To evaluate if the MRI image findings of carotid arterial plaques using Magnetization-Prepared Rapid Acquisition with Gradient Echo (MPRAGE) is associated with the risk of thromboembolic event during carotid artery stenting (CAS).

Methods:
A total of 109 carotid stenting was performed on 99 patients. Correlation between the Pre-operative MRI findings of carotid arterial plaque using MPRAGE and the procedure related thromboembolic event was assessed. Distal protection devices were used in all cases including a balloon protection device (Guardwire) and filter devices (AngioguardXP, Filterwire EZ). All lesions were classified into three types according to the intensities on MPRAGE: high intensity (group A), intermediate intensity (group B) and iso-intensity groups (group B). Procedure related morbidity within 30days of procedure was evaluated using Modified Rankin Scale (MRS).

Results:
Neurological ischemic events associated with the carotid stenting occurred in 11 out of 109 procedures (10.1%). Two (1.8%) cases showed persistent neurological deficit and six (5.5%) showed transient neurological events. Ocular ischemia occurred in 3 cases (2.8%). Thromboembolic events in group A (n=40), group B (n=36) and group C (n=30) were 7 (23.3%), 4 (11.1%) and 0 (0%), respectively. The incidence of thromboembolic events was significantly higher in the combined group A and B as compared to that in group C (P=0.006). Thromboembolic events of CAS with use of Guardwire, Angioguard and Filterwire were 12.1%, 14.3% and 0%, respectively. In CAS for high intensity plaque (n=66), incidence of thromboembolic event with use of Angioguard (4 of 15, 26.7%) was higher than that of Guardwire (7 of 38, 18.4%). In group A, none of the cases (n=20) treated with filter wire showed procedure related ischemic event.

Conclusions:
High intensity plaque on MPRAGE can be related to high rate of thromboembolic events during CAS.
Abstract 2352: 18F-fluorodeoxyglucose PET Can Identify The Inflamed and Vulnerable Carotid Plaque - A Prospective Study in Japan
Authors: Kuroda Satoshi , Saito Hisayasu , Maruichi Katsuhiko , Nakayama Naoki , Hirata Kenji , Shiga Tohru , Houkin Kiyohiro , Tamaki Nagara
Published: July 2021

Objective -
There are few studies that denote the validity of 8F-fluorodeoxyglucose (FDG) PET to detect the inflammation of severe (>70%) carotid artery stenosis in Asian populations. This study was aimed to clarify whether 18F-FDG PET can identify inflamed and vulnerable plaque at higher risk for subsequent ischemic stroke in Japanese patients with severe carotid artery stenosis.

Methods -
This prospective study included 33 patients with severe carotid artery stenosis between 2006 and 2011. Of these, 12 patients were symptomatic and other 21 were asymptomatic. There were 28 males and 5 females. Their mean age was 71.1 ± 8.2 years, ranging from 48 to 85. Their clinical data were precisely collected. All 33 patients underwent 18F-FDG PET and ultrasound sonography (US) to evaluate the plaque composition prior to carotid endarterectomy (CEA). FDG uptake was quantified by maximum standardized uptake values (SUV). Following surgery, the specimens were stained with the antibodies against CD68 and MMP-9.

Results -
High FDG uptake (SUV>2.0) was observed in 15 (45%) of 33 operated plaques. High FDG uptake significantly correlated with the other vascular disorders (P=0.048), echolucent plaque (P=0.041), lipid-rich plaque (P<0.001), CD68 expression (P<0.001), and MMP-9 expression (P=0.002). 18F-FDG PET showed significantly higher sensitivity and specificity to identify lipid-rich and CD68-positive plaque than US. However, high FDG uptake was not related to patients’ gender, age, and the degree of stenosis. There was no significant correlation between FDG uptake and symptomatic or asymptomatic patients.

Conclusion -
These findings strongly suggest that 18F-FDG PET would provide more valuable information to identify the inflamed, vulnerable plaque than conventional ultrasound in Japanese patients with severe carotid artery stenosis.
Abstract 2360: Aortogenic Stoke: Comparative Analysis With Lacunar And Atherothrombotic Infarction
Authors: Fukushima Yoshihisa , Sugimori Hiroshi , Kuroda Junya , Fukuda Kenji , Ago Tetsuro , Kamouchi Masahiro , Kitazono Takanari
Published: July 2021

[Background & aims]
Detailed characteristics of aortogenic stroke (AO) have remained unclear so far. Our aim was to determine clinical characteristics of AO in Japanese stroke patients in comparison with lacunar infarction (LA) and atherothrombotic infarction (AT), two subtypes affected different sizes of cerebral vessels.

[Methods]
From June 2007 to October 2010, 3228 consecutive patients were hospitalized for acute ischemic stroke and were enrolled in the Fukuoka Stroke Registry. AO was defined as follows; embolic stroke of which source was complicated plaque lesion in the aortic arch depicted by transesophageal echocardiography or 3-dimension computed tomography and no other potential embolic sources existed. We collected the data regarding clinical background, risk factors, prescription, laboratory data, severity and outcome of AO patients, and compared with those of the patients with LA and AT.

[Results]
We identified 137 (4.2%) AO patients, 658 (20.4%) AT patients, and 753 (23.3%) LA patients. Among the three patient groups, AO patients were the oldest (74.5±0.93 y o, p<0.01) and had family history of stroke (45.1%, p<0.01) and past history of cardiovascular disease (33.1%, p<0.01) the most frequently. Both AO and AT patients were prescribed more with antiplatelet (40.9%, p<0.01) and lipid-lowering agent (24.8%, p= 0.045) than LA patients before stroke onset. In the acute phase, alteplase (5.1%, p<0.01) and unfractionated heparin (80.3%, p<0.01) were used more frequently in AO patients than in LA and AT patients. AO patients showed the highest in-hospital recurrence rate (6.6% in AO, 6.5% in AT and 0.8% in LA, respectively); however, the NIHSS score of AO patients was the lowest during the whole length of hospitalization (IQR 0-4 points on admission, p<0.01 and IQR 0-2 points on discharge, p<0.01). At discharge, warfarin (13.9%, p< 0.01) and aspirin (51.8%, p<0.01) were chosen for prevention of recurrence in AO patients. Stroke recurrence rates within first one year in AO, AT and LA were 2.2%, 4.7% and 1.9%, respectively. Frequency of good prognosis (modified Rankin scale 0-2) at discharge and at one year from onset was more than 80% in both AO and LA patients, whereas that in AT patients was significantly low (55.2% at discharge and 62.8% at one year).

[Conclusion]
AO patients were older and had more cardiovascular risk factors and were prescribed more medications than those with LA and AT. In spite of high in-hospital recurrence rate and large size of the affected vessels, AO patients showed few long-term recurrence and relatively favorable outcome.
Abstract 2367: Increased Density Of Neuroscience Providers Is Associated With Decreased Risk Of Death From Stroke In The United States
Authors: Desai Atman , Erkmen Kadir , Bekelis Kimon , Zhao Wenyan , Ball Perry A
Published: July 2021

Background.
Stroke is a leading cause of death and disability in the United States. Given that neurologists and neurosurgeons hold special expertise in this area relative to other healthcare providers, we hypothesized that the density of neuroscience providers would be associated with reduced mortality from stroke across US counties.

Methods.
The Area Resource File 2009-2010 was retrospectively analyzed. The primary outcome variable was the three-year (2004-2006) average in cerebrovascular disease deaths per million population for each county. The primary independent variable was the combined density of neurosurgeons and neurologists per million population in the year 2006. Multiple regression analysis was performed, adjusting for density of general practitioners, urbanicity of the county, and socioeconomic status of the county.

Results.
The median number of annual stroke deaths per million population, in the 3139 counties analyzed, was 586 (IQR 449-754). The median number of neuroscience providers (neurologist or neurosurgeon) per million population was 0 (IQR 0-26), while the median number of general practitioners per million population was 274 (IQR 175-410). Each increase of one neuroscience provider per million population was associated with 0.71 fewer deaths from stroke per million population (
p
< 0.001). On multivariate adjusted analysis, each increase of one neuroscience provider per million population was associated with 0.38 fewer stroke deaths per million population (
p
< 0.001). Rural location (p<0.001) and increased density of general practitioners (
p
< 0.001), were associated with significant increases in the rate of stroke deaths, while persistent poverty and low educational levels were not significant.

Conclusions.
Higher density of specialist neuroscience providers is associated with significant reduction in deaths from stroke, a major cause of mortality nationally. This suggests that the availability of specialists is an important factor in the overall likelihood of survival from stroke, and therefore underlines the importance of promoting specialist education and practice throughout the country.
Abstract 2389: The Utility of the Modified Early Warning Score in Acute Stroke Patients
Authors: Giltinane Mary , Boyle Karl , O'Kane Grainne , Harbison Joseph
Published: July 2021

Introduction.
The Modified Early Warning Score (MEWS) is a tool for estimating risk of death or poor outcome in the Emergency Department (ED). It is a 0-14 point score based on initial physiological observations including heart rate, respiratory rate, systolic blood pressure, temperature and level of consciousness. In Acute medical patients, a score > 4 has been found to be associated with increased risk of death. The score is being widely adopted for use as a risk stratification tool for patients admitted through EDs and in Acute Medical Assessment Units and has been used in stroke patients but has not been validated for acute stroke. We applied the score to a population of acute stroke patients admitted through ED to determine its utility.

Methods.
Records on consecutive patients admitted through ED to an acute stroke service of an inner city university teaching hospital over 8 months were identified and MEWS calculated for each. Patients dying within 6 months or with a prolonged hospital stay (>42 days) were identified.

Results.
132 subjects (Mean age 71, 59% male) were admitted to the service, 122 were admitted through ED. Median MEWS was 1 (range 0-4) and 18 (17%) died within 6 months. Subjects with a MEWS>2 were significantly more likely to die (10/91 vs 10/31 p=0.006 Chi square. O.R. 3.9 (1.4-10.5)) and those who survived more likely to have a prolonged length of stay (21/81 vs 11/21 p=0.02. Chi square. O.R 3.1 (1.2-8.5)). As a tool for identifying those with acute stroke risk of dying the MEWS performed only moderately well (PPV 0.5, NPV 0.68).

Conclusion.
As part of a screening test for stroke patients a MEWS>2 at ED admission is associated with worse outcome however it is neither sensitive or specific enough to be used in isolation as a means of triaging stroke patients into risk categories.
Abstract 2436: Acute Metformin Treatment Worsens Short-term Stroke Outcome: Comparison Of Underlying Mechanisms In Control And Type 2 Diabetic Rats
Authors: Li Weiguo , Chung Connie , Prakash Roshini , Chawla Dhruv , Johnson Maribeth , Fagan Susan , Ergul Adviye
Published: July 2021

Background:
Admission hyperglycemia aggravates neurovascular injury and worsens outcome in acute ischemic stroke (AIS). Current stroke guidelines recommend glycemic control as an important therapeutic strategy to prevent cerebrovascular complications. We have previously shown that chronic glucose control with metformin prior to AIS prevents cerebrovascular remodeling, reduces hemorrhagic transformation (HT), and improves neurological outcome. The goal of this study was to test the hypothesis that acute glucose control in diabetes prior to AIS will also provide neurovascular protection and improve functional outcome.

Methods:
Ten-week-old male control and type 2 diabetic Goto-Kakizaki (GK) rats (n=6-9 each group) were treated with or without metformin (300mg/kg/day in drinking water) for 3 days prior to stroke. Infarct size, edema ratio (% edema/infarct), and HT frequency and severity were evaluated in all groups after 3 hr middle cerebral artery occlusion (MCAO) and 21 hr reperfusion. AMPK activity and lactate levels--biomarkers of ischemic brain metabolism--were also measured.

Results:
Compared to controls, metformin treatment decreased blood glucose levels in diabetic animals (160.4±36.5 vs. 120.1±31.1 mg/dL, p<0.0001). Metformin treatment decreased edema ratio in GKs (0.90±0.71 vs. 1.55±0.70, p<0.05), but increased infarct size (23.3±17.5 vs. 12.5±9.5%, p<0.05). Untreated diabetic rats had lower composite scores for neurological tests (3.8±2.4 vs. 5.9±1.2, p<0.05), indicating worse outcome. Metformin treatment worsened this deficit in both diabetic and control animals (2.4±1.6 vs. 1.9±1.0, p=0.0008). AMPK activity was increased only in metformin-treated GK rats while lactate levels were increased in both groups (p<0.05). Results are expressed as mean ± SD.

Conclusion:
Worsening of stroke outcome by acute metformin treatment is associated with increased lactate accumulation in both control and diabetic rats. Increased infarct size in diabetic but not control rats may be due to greater AMPK activation in diabetes. Whether this effect is specific to metformin or general to acute glycemic control needs to be confirmed with other glucose control measures.
Abstract 2467: Factors Affecting the Discharge Disposition after Stroke
Authors: Tseng Hung-Pin , Liu Chin-Hsiung , Lin Chun-Liang , Lin Hung-Chih , Chen Pi-Tzu , Lin Feng-Jenq ,   the Taiwan Stroke Registry Investigators
Published: July 2021

Background and Purpose:
Stroke is the third leading cause of death and is the leading cause of adult disability in Taiwan. Stroke patients are frequently in need of professional care and assistance in activities of daily living. Home care may not provide adequate support for some of the disabled stroke patients. Discharge disposition after stroke is an important long-term care issue affecting the families and societies in every country, developed or developing. We have made analyses of more than 20,000 disposition arrangements 3 month after stroke in the Taiwan Stroke Registry to explore key demographic and clinical factors that may determine the disposition.

Methods:
The Taiwan Stroke Registry (TSR), sponsored by Taiwan Department of Health and engaging 39 academic and community hospitals, covers broadly the entire country with 4 steps of quality control to ensure reliability of entered data (Hsieh FI et al, Circulation, 2010). The 3 month follow-up data of 21,786 stroke admissions between 2006 and 2008 was used for analysis. Under the stratification of age and separating discharge destinations into home and nursing home, we investigated the influences of patients’ demographics, clinical characteristics, and disability levels by the Cochran-Mantel-Haenszel method. We calculated the odds ratios of factors of significant impact based on the multiple logistic regression model.

Results:
Education level, living place, main caregiver, hypertension, diabetes mellitus, heart diseases, previous stroke history, snoring, stroke types, length of stay, rehabilitation, number of complications (pneumonia, urinary tract infection, or upper gastrointestinal bleeding), and National Institute of Health Stroke Scale (NIHSS) significantly affect the discharge dispositions (p<0.05) after adjustment by age. Independent from the above variables, age carries a high impact based on yearly increase (1.02, 95% CI=1.01-1.03). Male gender (1.57, 1.35-1.82), education (0.81, 0.69-0.96), location of residence (1.70, 1.45-2.00), availability of employed caregivers (2.19, 1.82-2.63), snoring (0.84, 0.71-0.99), hemorrhagic stroke (1.46, 1.22-1.75), increase of length of stay by one day (1.01, 1.005-1.015), rehabilitation (0.78, 0.61-0.98), one complication (1.56, 1.32-1.84), and increase in NIHSS by one point (1.14, 1.13-1.15).

Conclusions:
Results showing relative weight of key determinants of patient disposition 3 months after stroke may be useful in acute care of stroke patients in facilitating disposition and in planning long-term care preparation from the perspective of individual families, institutions caring for stroke patients and the government agencies. Whether findings derived from the present study are applicable across countries remain to be determined.
Abstract 2481: Day 7 NIHSS is a Sensitive Outcome Measure for Exploratory Clinical Trials in Acute Stroke: Evidence from the Virtual International Stroke Trials Archive (VISTA)
Authors: Kerr Daniel M , Fulton Rachael L , Lees Kennedy R
Published: July 2021

Introduction:
Clinical trials in stroke typically measure outcome after 90 days. Earlier outcome assessment would reduce costs and may increase power.

Aim:
To compare the sensitivity of 4 outcome measures (mRS at 30 and 90 days, and NIHSS at 7 and 90 days, analysed as ordinal measures) to the established treatment effect of r-tPA.

Methods:
We undertook a controlled comparison of r-tPA treated patients versus untreated controls from VISTA. A multiple re-sampling approach was used. From our total sample 10,000 random samples of independent patients were drawn, each of the same size. In each sample ordinal logistic regression (adjusted for age and baseline NIHSS score) was used to test for the r-tPA treatment effect as measured by each of the 4 outcome measures. The percentage of samples yielding significant results approximates the power of each endpoint at a given sample size. This process was repeated across a range of sample sizes.

Results:
Our data included 4712 patients of whom 1934 (41%) received r-tPA. r-tPA treated patients were younger, and had more severe strokes. For our 4 outcome measures of mRS at 30 and 90 days, and NIHSS at 7 and 90 days the smallest sample sizes required to generate statistical power >80% were 620, 480, 370, and 420 respectively, making 7 day NIHSS the most sensitive endpoint. These results were supported by dichotomised analyses.

Conclusions:
7 day NIHSS score appears a sensitive endpoint that should be validated in a randomised trial dataset for use in exploratory stroke trials.
Abstract 2491: Cerebral Amyloid Angiopathy without Hemorrhagic Stroke: MRI Findings Associated with Transient Focal Symptoms
Authors: Jindal Jenelle A , Ayres Alison M , Gurol Mahmut E , Schwab Kristin , Rosand Jonathan , Viswanathan Anand , Greenberg Steven M
Published: July 2021

Background:
The clinical presentation of cerebral amyloid angiopathy (CAA) includes not only hemorrhagic stroke, but also diverse syndromes such as transient focal neurologic symptoms, progressive cognitive dysfunction, subacute confusion, and seizures. We performed a systematic analysis of the neuroimaging features of these presentations to help elucidate their underlying pathophysiologies.

Methods:
We performed a retrospective review of all patients seen at Massachusetts General Hospital from 2000-2011 with 1) diagnosis of probable/definite CAA by Boston criteria, 2) clinical presentation other than hemorrhagic stroke, and 3) available MR images (including T2*-weighted, diffusion-weighted, and FLAIR). Review of clinical data for 44 subjects meeting these criteria (performed blinded to neuroimaging) yielded 3 categories of presentation: transient focal motor, sensory, or language symptoms (n=15; mean±SD age 74.4±8.1), memory/cognitive impairment over months-years (n=15; age 71.2±10.7), and subacute headache, confusion, generalized seizure, or syncope (n=14; age 73.6±9.8). Images were analyzed without knowledge of clinical symptoms for hemorrhagic lesions, acute infarcts, and regional T2-hyperintensities.

Results:
Superficial siderosis in cortical sulci (Panel A) was present in 10 of 15 (67%) patients presenting with transient focal symptoms versus 7 of 29 (24%) in the other subgroups (p<0.01). Most locations of superficial siderosis corresponded with the localization of the patient’s transient symptoms. Conversely, a pattern of T2-hyperintensities extending to subcortical white matter and overlying cortex (Panel B) was present in 8 of 14 (57%) patients presenting with headache, confusion, or seizure/syncope versus 3 of 30 (10%) in the other subgroups (p<0.005).

Conclusions:
These results suggest that the underlying trigger for CAA-related transient focal neurologic symptoms may often be superficial siderosis. They also support an association between the alternative presentation of headache, confusion, or seizure/syncope and T2-hyperintensities suggestive of the inflammatory subtype of CAA.
Abstract 2509: Standardized Reports Are Needed To Describe Carotid Artery Stenosis
Authors: Cheng Eric , Keyhani Salomeh , Ofner Susan , Williams Linda , Bravata Dawn
Published: July 2021

Background:
Landmark clinical trials have shown that carotid procedures can greatly reduce the risk of stroke in persons with symptomatic carotid artery stenosis between 70 and 99% and can somewhat reduce the risk of stroke in persons with symptomatic carotid stenosis between 50 and 69%. Guidelines have recommended that results from carotid artery imaging tests be presented in these ranges to facilitate decision-making. We sought to determine how carotid imaging results were reported across Veterans Administration (VA) facilities.

Methods:
Carotid artery imaging results were obtained as part of a comprehensive chart review of veterans hospitalized with ischemic stroke at 127 VA hospitals in fiscal year 2007. Abstractors recorded the results of carotid ultrasound, MR angiography, CT angiography, or catheter angiography performed in the twelve months prior to admission to six months after admission. We excluded carotid artery imaging reports with results of “no stenosis”, “mild stenosis”, exact degree of stenosis <50%, or any range of stenosis <50% to focus on those reports that would likely inform decisions about carotid procedures. The unit of analysis was the carotid artery. We described how often the results were presented as an exact degree (such as 60%), as a range (such as 50 to 69%), or as a descriptive category (“moderate” or “severe” stenosis). For results described as a range, we examined how often it matched those used in landmark trials.

Results:
Of 6527 results of carotid artery imaging, there were 1315 results of greater than 50% or at least “moderate stenosis” (see
Table
). Only 234 of the reports used a range to describe the stenosis; among this set, only 55 of the reports used a 50-69% or 70-99% range to describe the stenosis.

Conclusions:
In this national healthcare system, significant carotid artery stenosis was rarely reported in a way that exactly mapped onto recommendations from landmark clinical trials and guidelines. Clinicians who order these diagnostic tests as well as clinicians who interpret these diagnostic tests should collaborate to produce standardized reports that facilitate decision-making.
Abstract 2524: Increasing the Proportion of Patients Treated with Stroke Thrombolysis: Reducing In-hospital Delays has Substantially More Impact than Extension of the Time Window
Authors: James Martin A , Monks Thomas , Stein Ken , Pitt Martin
Published: July 2021

Background
Pooled analyses show the benefit of IV alteplase for ischemic stroke up to 4·5 hours after onset, and expert guidelines have been updated to reflect this. However, the benefit from thrombolysis is critically time-dependent, and the additional benefit from extending the time window may be jeopardised by in-hospital delays.

Methods
We developed a discrete-event simulation based on prospective data from 1142 acute stroke patients arriving at our large district hospital over a two-year period to April 2011, modelling the time spent in the ED for triage and assessment, brain imaging and, if applicable, thrombolysis. Outputs from the model included arrival to treatment times (ATT), percentage of strokes thrombolysed, and the number of thrombolysed patients with a 90 day modified Rankin Scale (mRS) of 0-1. We sought to model the current stroke pathway (treatment <3 hours of onset), and compare it with developmental scenarios exploring the impact of extending treatment from 3 to 4.5 hours, of ED staff alerting the stroke service at triage, of ambulance pre-alert to the stroke service, and combinations of these measures.

Results
The model illustrates that extending the treatment window modestly increases the percentage of acute strokes thrombolysed, from 5% to 6% (95% CI 5.8-6.1%), and increases the number of thrombolysed patients with mRS 0-1 by 7 per year (95% CI 5.9-8.0). Both the triage alert and ambulance pre-alert scenarios increase thrombolysis rates to 15% (95% CI 14.9% to 15.7%); but the ambulance pre-alert reduces ATT by a mean of 27 mins (95% CI 26.3-28.4) compared to the triage alert scenario. The ambulance pre-alert scenario increases the number of thrombolysed patients with mRS 0-1 by 35/year (95% CI 32.9-37.7) compared to 22 (95% CI 20.4-23.5) in the triage alert scenario. Combining the treatment extension with either alerting measure does not increase the thrombolysis rate further (15%, 95% CI 14.7-15.1%). Sensitivity analysis illustrates that the pre-alert system is the least vulnerable to a drop in compliance rates.

Conclusions
Our simulation model shows that the greatest disability benefit accrues from measures to substantially reduce in-hospital delays to alteplase treatment - a potential three-fold increase in the proportion of patients treated. Compared to extending the time window for alteplase from 3 to 4.5 hours, eradicating in-hospital delays to treatment offers a five-fold greater disability benefit, and this should be the pre-eminent focus of service improvement for all emergency receiving hospitals.
Abstract 2542: Randomized, Placebo-Controlled Trial of Dantrolene for the Prevention and Treatment of Cerebral Vasospasm After Subarachnoid Hemorrhage - Interim Analysis
Authors: Muehlschlegel Susanne , Carandang Raphael , Hall Wiley , Ouillette Cynthia , Garland Bridget , Barton Bruce
Published: July 2021

Introduction:
Cerebral vasospasm (cVSP) after aneurysmal subarachnoid hemorrhage (aSAH) is a major cause of disability and death. Dantrolene blocks ryanodine receptor-mediated intracellular calcium release from the sarco-endoplasmic reticulum. It is neuroprotective in animal models and may attenuate cerebral vasoconstriction. Safety and feasibility of a single dose with aSAH has recently been demonstrated in humans. We present the interim safety analysis of a randomized, placebo-controlled trial using repeated doses.

Methods:
In this single-center, randomized, double-blind, placebo-controlled Phase II trial, 30 patients with aSAH are being enrolled comparing intravenous dantrolene 1.25 mg IV every 6 hours x 7 days to placebo. The primary endpoint is incidence and degree of hyponatremia (sNa ≤ 134 mEq/L) and liver toxicity (proportion of patients who develop liver function tests ALT, AST and AlkPhos >5x upper limit of normal). Secondary safety endpoints include tolerability, systemic hypotension, and intracranial hypertension. Efficacy assessments include occurrence of clinical and angiographic cVSP, and three-month clinical outcome. This pre-planned interim safety analysis was conducted after 16 patients. Statistical analysis was performed using non-parametric tests due to the small n. Longitudinal data were analyzed using Generalized Estimating Equation.

Results:
Randomization resulted in equal n=8 per group. No group imbalances were noted except that three patients in the placebo had dropped out: two due to nausea/vomiting, one due to headache. Hyponatremia occurred in n=7/8 (87.5%) in the placebo, and n=5/8 (62.5%) in the dantrolene group (χ
2
; p=0.285). Mean sNa decreased in both groups, with a maximal Δ -5±4.8 mEq/L in the placebo and -3.9±2.3 mEq/L in the dantrolene group (GEE; p=0.8333). To treat hyponatremia, 444±430 mEq of Na was used in the placebo vs. 303±380 mEq in the dantrolene group (Wilcoxon; p=0.47). No patient developed liver toxicity. Systemic hypotension occurred never in the placebo vs. once in the dantrolene group. No intracranial hypertension occurred. There were 3 adverse events reported in the placebo, vs. 9 in the dantrolene group (of which only vein irritation/infiltration were attributed to drug). There was one death in each group, both unrelated to the study.

Conclusions:
This interim analysis shows that there are no major safety concerns thus far. The DSMB has recommended the continuation of the study. Due to the small n, an efficacy analysis will be performed with the final study analysis.
Abstract 2545: Does Participation in a Stroke Registry Improve tPA Administration Rates?
Authors: Ido Moges , Clarkson Lydia , Camp Deborah , Krompf Kerrie , Frankel Michael
Published: July 2021

Background:
The purpose of the Georgia Coverdell Acute Stroke Registry (GCASR) is to improve the quality of patient care. GCASR conducts regular quality improvement activities to educate hospital staff and improve systems and processes. Administration of intravenous tissue plasminogen activator (IV tPA) is standard treatment for eligible acute ischemic stroke patients and can dramatically improve outcomes.

Purpose:
To determine whether GCASR hospitals were more likely to administer tPA to acute ischemic stroke patients than non-GCASR hospitals.

Methods:
Hospitalization data from acute care hospitals in Georgia was provided by the Georgia Hospital Association for November 2005 through December 2009. Acute ischemic stroke patients receiving tPA were identified using ICD-9 codes (433 and 434), procedure codes (9910), and healthcare common procedure system codes (J2997). A hospital was defined as a GCASR facility if it was actively participating in the registry at the time of patient hospitalization. A generalized estimating equation with robust variance estimation was applied using the SAS GLIMMIX procedure. “Hospital” was treated as a random variable. Relative risks for receiving tPA were estimated and adjusted for demographics, co-morbidities, hospital size, urbanicity, and length of stay.

Results:
A total of 55,403 patients were admitted with a principal diagnosis of acute ischemic stroke during the study period, and two percent (1,231) received tPA. Three percent of patients (871) seen at registry facilities received tPA, compared to 1.4% (360) of those seen at non-GCASR facilities. Age, gender, race, length of stay, hospital size, and participation in the registry all predicted tPA administration, either at or near significant levels (p-values from <0.0001 to 0.0646). Although IV tPA administration has increased over time in both hospital groups, patients treated at GCASR facilities were more likely to receive tPA after controlling for confounders (OR=1.64; 95% CI: 0.97-2.78), which approached significance (p=0.0646). Approximately 340 fewer people would have received tPA had all study patients been treated at non-GCASR facilities.

Conclusions:
Although all Georgia hospitals have improved their rate of tPA administration over time, GCASR hospitals maintained a higher rate than non-GCASR hospitals. This may be due in part to the quality improvement activities that registry facilities participate in and the assistance they receive. These results support the stroke registry model as a method of improving stroke patient care and outcomes.