bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TMP65: What Changes Improve Door-to-Needle Times? Results From a Single Center Door-to-Needle Improvement Initiative
Authors: Kamal Noreen , Hill Michael D , Stephenson Caroline , Demchuk Andrew M , Holodinsky Jessalyn K , Zerna Charlotte , Bugbee Erin , Vilneff Renee , Kashyap Devika , Smith Eric E
Published: July 2021

Background:
The benefit of thrombolysis is highly time dependent. Strategies and system changes to reduce door-to-needle time (DNT) have been proposed but the effectiveness of such strategies has not been fully evaluated.

Hypothesis:
Specific change strategies to the system of delivering thrombolysis significantly improve DNT. Stroke severity also affects DNT significantly.

Methods:
The Hurry Acute Stroke Treatment and Evaluation (HASTE) project was implemented in 3 phases at a single academic medical center to reduce DNT using four strategies. In HASTE-I (Jun 6 2012 - Jun 5 2013), baseline performance was analyzed with no changes made to stroke treatment. In HASTE-II (Jun 6 2013 - Jan 24 2015), three changes were implemented: 1) a STAT! stroke protocol to pre-notify the stroke team of the severity of incoming stroke patients; 2) administering tPA in the CT scanner; and 3) registering the patient as
unknown
prior to exact identification, to allow immediate order entry in our electronic health system. In HASTE-III (Jan 25 2015 - Jun 29 2015), we implemented a process to bring the patient directly to CT on the EMS stretcher. Decrease in DNT was analyzed using Wilcoxon rank sum and Kruskal Wallis tests, and multivariable linear regression. Log transformed DNT was modeled using a backward selection approach.

Results:
There were 350 patients treated with tPA during the project. The results of the univariable and multivariable analyses are shown in the table. In univariable analyses, the following strategies improved DNT: STAT! stroke, patient registered as
unknown
, and stretcher to CT. Additionally, DNT was lower if tPA was administered in the CT. The stroke severity also affected DNT. Multivariable regression showed the following factors to be significant: giving tPA in the CT, stretcher to CT, patient registered as
unknown
, and stroke severity.

Conclusions:
Stretcher to CT, patient registered as
unknown
, and administering tPA in CT were most efficacious in reducing DNT.
Abstract TMP82: Community Education-Impact of Knowing Your Sign
Authors: Peterson Kristin , Steinkoenig Victoria
Published: July 2021

Stroke remains one of the leading causes of death and disability in the United States. Even with increased community education on stroke, the most common reason for delay in seeking medical attention is lack of recognition of the signs, symptoms and time sensitivity of stroke treatment. It is compelling to see the amount of patients that do not present for emergency treatment within three hours of symptom onset. This lack of awareness and delay in arrival was found to contribute to decreased candidacy for stroke treatment and leads to increased chances of disability. The critical need for community partnerships specifically aimed at educating on recognition of stroke signs, symptoms and treatment options was identified. The goal of this project was to demonstrate the correlation between community education and decreasing symptom onset to door time.

Method:
This retrospective study performed at a Central Illinois hospital reviewed data including symptom onset to door times from January 2014 to March 2015 as one method of determining the effectiveness of community education. Intervention time frames were held between April 2014 to December 2014 with a 3 month pre and post intervention phase. Inclusion criteria: any stroke code that presented through triage or via EMS. Exclusion criteria: in house stroke codes and symptom onset that was unknown.

Results:
In the first quarter of 2014, the average time it took patients to present to the Emergency Department from symptom onset was 233 minutes. Post-implementation data revealed the average symptom onset to door time was 63 minutes which accounts for a nearly 73% decrease in arrival time.

Conclusion:
Over 20 Community Education sessions on stroke signs, symptoms and the importance of seeking prompt medical attention were held over a nine month period. This community education on stroke was effective because there was a decrease in stroke symptom onset to the Emergency Department which created more eligible patients to receive emergency stroke treatment. This study validated that by providing intense community education aimed at the recognition of stroke signs, symptoms and treatment options, more patients were eligible to receive emergent stroke treatment because the arrival time was drastically shortened.
Abstract TMP89: Prior Antithrombotic Use is Associated With Favorable Mortality and Functional Outcomes in Acute Ischemic Stroke: Evidence From Get With the Guidelines-stroke
Authors: Smith Eric E , Myint Phyo , Hellkamp Anne , Fonarow Gregg , Reeves Matthew , Schwamm Lee , Schulte Phillip , Xian Ying , Suter Robert , Bhatt Deepak , Saver Jeffrey , Peterson Eric
Published: July 2021

Introduction:
Trials have demonstrated that antithrombotic medications can prevent ischemic stroke, but it is unclear if prior therapy can also improve outcomes from those still having an acute ischemic stroke.

Hypothesis:
Antithombotics are the mainstay of treatment in primary and secondary prevention of stroke and thus their use prior to an acute event may be associated with better outcomes.

Methods:
We studied 540,993 patients with acute ischemic strokes between Oct 2011 and Mar 2014 from 1661 hospitals participating in Get With The Guidelines-Stroke. The associations between prior antithrombotic use and hospital discharge outcomes were examined, controlling for patient and hospital characteristics.

Results:
There were 250,104 (46%) stroke patients not receiving any antithrombotic prior to stroke; of whom 31.4% had a documented prior vascular indication. Patients taking antithrombotics prior to stroke were older and had more vascular risk factors. After adjustment for baseline prognostic factors, patients on chronic antithrombotics had better outcomes compared with those who did not (Table 1), regardless of whether a prior vascular indication was present or not. Similar results were observed in a subset of patients in whom NIHSS was available (n=415,034).

Conclusions:
Prior antithrombotic therapy was independently associated with improved clinical outcomes after acute ischemic stroke. Ensuring use of antithrombotics in appropriate patient populations may be associated with benefits beyond stroke prevention.

Table 1
Abstract TMP93: Elevated Oxygen Extraction Fraction Measured With Noninvasive MRI may be Discriminatory for Stroke Risk in Adults With Sickle Cell Anemia
Authors: Jordan Lori C , Gindville Melissa , Scott Allison , Strother Megan K , Kassim Adetola , Chen Sheau-Chiann , Pruthi Sumit , Shyr Yu , Donahue Manus J
Published: July 2021

Introduction:
No screening procedures exist for evaluating stroke risk in adults with sickle cell anemia (SCA). Reduced oxygen carrying capacity is present in SCA, which may initially be compensated for by an increase in cerebral blood flow (CBF) and then by increased oxygen extraction fraction (OEF).

Hypothesis:
OEF and CBF can be measured noninvasively and reproducibly with MRI using clinically-available equipment in adults with SCA; elevated OEF provides added discriminatory capacity for clinical impairment relative to vasculopathy extent and CBF alone.

Methods:
Structural, CBF-weighted, and MRA imaging, together with a noninvasive OEF-weighted T
2
-relaxation-under-spin-tagging (TRUST)-MRI method was applied in SCA adults (n=26) and race and age-matched controls (n=11). A Kruskal-Wallis test was applied to evaluate mean differences between SCA and control parameters. Linear regression assessed how elevated OEF correlated with increasing clinical impairment defined by presence of infarct, vasculopathy, or use of regular blood transfusions for SCA.

Results:
OEF had high reproducibility within the same scan session, n=37 (ICC = 0.989). Whole-brain OEF and CBF were increased in SCA adults (OEF=0.46±0.08; CBF=52.4±8.3 ml/100g/min) versus controls (OEF=0.35±0.06; CBF=43.6±5.1 ml/100g/min). Hematocrit and OEF were inversely correlated (R
2
=0.72; p<0.01). Linear regression revealed a stronger relationship of OEF than CBF with clinical impairment. In SCA adults without impairment (n=12) CBF and OEF have an inverse relationship (R
2
=0.41; p=0.01, Fig. 1A) but with clinical impairment (infarct, vasculopathy or severe pain requiring regular transfusions, n=14) CBF and OEF become uncoupled (R
2
=0.08; p=0.16; Fig. 1B) as CBF may not be able to increase further and may plateau or decline.

Conclusion:
TRUST-MRI OEF is a rapid, reproducible measure. OEF shows promise as screening tool for hemodynamic impairment and stroke risk in adults with SCA.
Abstract TMP95: Large Centralized TIA Assessment Unit Associated With Reduction of Recurrent Stroke by up to 70%
Authors: Penn Andrew M , Maclure Malcolm , Lu Linghong , Bibok Maximilian B , Morrison Jaclyn L , Votova Kristine , Penn Melanie , Balshaw Robert , Lesperance Mary L
Published: July 2021

Introduction:
Transient neurological symptoms are a common presentation in emergency departments (ED). Access to stroke specialists and advanced imaging to identify acute cerebrovascular syndrome is resource intensive. Diversion to specialized TIA units improves logistics but incurs delay. Observational studies suggest efficacy of TIA units but are limited by sample size. We hypothesized that management through a centralized TIA service reduces risk of recurrent stroke.

Methods:
Vancouver Island (VI) introduced a centralized TIA unit in 2004 to which over 15,000 referrals (ED & GP) have been made. Long-term follow-up is possible as all VI residents (∼750,000) have one electronic health record for ED visits and hospital admissions. Large referral volumes and variable unit capacity have subjected patients to a wide range of delays-to-treatment. We used variation in secondary prevention delays to examine unit efficacy. We assessed hospitalized stroke and stroke death in all ED-referred patients comparing those seen in the unit within 90 days of symptom onset with those not seen within that time.

Results:
Between 2005 and 2013 there were 11,330 referrals, of which 4,017 were from the ED and referred within 2 weeks of symptom onset. The transition times between symptom onset, referral, arrival at the unit and stroke (or censoring time) were modeled using a multi-state model (Putter et al. 2007). Age, ABCDD, gender and the unit intervention were found to be associated with transition times. The hazard of stroke for patients who attended the unit was estimated as 30% that of those who did not attend (p=0.098). Predicted stroke-free survival curves are shown for a 70 year old woman. ARR at 90-days ranged from 4.2% downto 1.4% for High to Low ABCDD respectively.

Conclusion:
This large observational study reinforces published studies suggesting TIA units reduce risk of recurrent stroke within 90 days.
Abstract TP1: Stent Retrievers in Transferred Patients: What Percentage Are Eligible for Treatment and Are They Effective?
Authors: Gao Billy , Barazangi Nobl , Chen Charlene , Wong Christine , Yee Alan , Bedenk Ann , Morrow Megan , Fernandes Julia , Kim Warren , English Joey , Tong David
Published: July 2021

Background:
New generation IA devices are highly effective; however, it is unclear if transfer patients derive similar benefit given the treatment delay intrinsic to this approach. Our aim was to determine the potential eligibility and efficacy of CT perfusion (CTP) guided IA therapy in transferred patients.

Methods:
All transferred and stent retriever treated ischemic stroke patients selected using CTP between 5/12 -1/15 were included. Baseline demographics including age, NIHSS, IV tPA use, and time points pertinent to CTP imaging and IA procedures were collected. Primary outcome was 90d mRS. Secondary endpoints included successful reperfusion and mortality. Primary safety endpoint was symptomatic ICH (sICH) rate.

Results:
Overall 401 transferred patients were potentially eligible and 22% were treated (n=90). Median age was 70 and median NIHSS 14.5 (SD 6.8). Average remote site distance was 90 (range 1- 356) miles. 73% received IV tPA. Median time of onset to reperfusion was 530 min. Median onset to CTP time was 323 min. Median CTP to groin puncture 138 min and median CTP time to reperfusion 197 min. TICI 2B or 3 reperfusion was achieved in 80%. 84 patients had 90d outcome data. Favorable outcome (mRS of 0-2) was achieved in 64%. sICH rate was 4.4%. 90d mortality was 11%.

Conclusions:
Outcomes in transferred CTP guided IA stroke therapy patients were similar to clinical trials despite onset to treatment times at least 80% longer than in recently reported studies, strongly supporting this approach. A substantial proportion of transfer patients can receive successful IA therapy using modern imaging techniques and treatments.
Abstract TP112: Role of Renexin, a Mixed Compound of Ginkgo Biloba Extract and Cilostazol, for Synaptic Plasticity in Hippocampus of Rat Model of Chronic Cerebral Hypoperfusion
Authors: Ha Yeon Soo , Cheong Jin Sung , Lee Hak-Seung , Park Hyun-Young , Cho Kwang Ho , Kim Min Sun
Published: July 2021

The impairment of cognitive function such as memory and attention has been recognized in patients with chronic mild cerebral ischemia. The hippocampal memory and long-term potentiation (LTP), a cellular correlate of learning and memory, were impaired by chronic cerebral hypoperfusion induced by permanent, bilateral occlusion of the common carotid artery (2VO).

Objectives:
The purpose of present study was to evaluate the effects of renexin on the impaired LTP and expression of mRNA genes involving neuronal plasticity in the rat 2 VO model.

Methods:
Adult male Sprague-Dawley rats were randomly divide three experimental groups into:1) Sham without 2VO, 2) 2VO+vehicle, 3) 2VO+renexin. The permanent ligation of bilateral common carotid arteries was performed to elicit chronically lower blood flow to the brain. Animals were treated with oral administration of renexin(gingko biloba 20 mg/kg/day + cilostazol 25 mg/kg/day) or vehicle every day from1 day after surgery for 3 weeks. We recorded LTP induced by brief high frequency stimulation to the Schaffer collateral-CA1 pathway of the hippocampus under anesthesia in vivo. Two hours after induction of LTP, the animal was sacrificed and the hippocampus was isolated for quantitative detection of mRNA for BDNF, Arc, Egr-1 and CREB using quantitative real-time RT-PCR technique.

Results:
Animals of 2VO+vehicle group showed a highly significant deficit in LTP induction (15 ± 3% of control fEPSP slope; n= 7; P< 0.01) 3 weeks after 2VO. On the other hand, daily oral administration of renexin showed the marked preservation of LTP induction (98 ± 17% of control fEPSP slope; n =7; P< 0.01). On the real-time RT-PCR analysis, a significant reduction of CREB, Arc and BDNF mRNA expression was observed in the hippocampus of 2VO+vehicle group compared with that of sham group (P< 0.01). In contrast, renexin treatment increased significantly the expression of these mRNAs in the hippocampus compared with that of 2VO+vehicle group (P< 0.05).

Conclusion:
These results suggest that daily oral administration of renexin can ameliorate cognitive deficit through the preservation of synaptic plasticity on the level of neural circuit in rodent model of chronic cerebral hypoperfusion.
Abstract TP117: What Have We Learned From the Pre-operative Evaluation of Patients With Moyamoya Disease?
Authors: Gandhi Shashank V , Dehdashti Amir R
Published: July 2021

Introduction & Hypothesis:
Our ability to effectively treat Moyamoya patients revolves around various preoperative imaging modalities used to assess the severity of cerebrovascular reserve compromise; however, not all are necessary for evaluation. We evaluated preoperative conventional angiography, MRI, MRA NOVA, and SPECT and their impact on management of patients with Moyamoya disease.

Methods:
A prospectively collected database of 36 Moyamoya patients was assessed to evaluate preoperative work-up. Patients were grouped based on MRI findings on presentation; ischemia, hemorrhage, and normal. Patients who did not have all of the pre-operative tests were excluded. Preoperative results were dichotomized as either normal or abnormal. Patients with bilateral disease were assessed individually for each side.

Results:
Twenty-eight patients (30 total sides) met inclusion criteria: 4 normal, 16 ischemia, and 10 hemorrhage on presentation. All patients had abnormal MR NOVA suggesting reduced CBF in the affected vascular territory. The decision on performing surgery in asymptomatic Moyamoya patients was based on abnormal finding on pre-operative MRA NOVA and/or SPECT and in symptomatic patients based on the presenting symptoms and abnormal MRA/SPECT. All patient underwent STA-MCA bypass surgery for the symptomatic or abnormal side. The two patients with bilateral disease had direct STA-MCA bypass on the symptomatic side and an indirect revascularization on the asymptomatic side. The imaging findings confirmed indication for surgery in all 28 patients.

Conclusions:
We assessed the impact of SPECT and MR NOVA on evaluation of Moyamoya patients. We confirm that all patients in this series, symptomatic or not, have abnormal CVR. Preoperative imaging can aid in establishing a baseline of CBF and CVR. However, testing did not modify the indication for treatment in Moyamoya patients, even in asymptomatic ones. We suggest to re-evaluate the need for extensive preoperative testing for symptomatic Moyamoya patients and limit the preoperative testing to diagnostic angiogram. Asymptomatic Moyamoya patients benefit from preoperative testing to clarify the need for treatment.
Abstract TP118: New Markers for Basilar Artery Atherosclerotic Plaque on Conventional T2-weighted MR Imaging
Authors: Lee Mi Ji , Cha Jihoon , Chung Jong-Won , Kim Sung Tae , Bang Oh Young , Lee Kwang Ho , Chung Chin-Sang , Kim Gyeong-Moon
Published: July 2021

Backgrounds and purpose:
In vivo visualization of intracranial atherosclerotic plaque has been studied with high-resolution wall MRI (HRMRI). However, HRMRI is not widely available in routine clinical practice. We hypothesized that increased outer wall and partial loss of flow-void of basilar artery (BA) in conventional T2 axial imaging might be suggestive of positive remodeling and atherosclerotic plaque.

Methods:
Using a consecutive stroke registry, patients with basilar artery atherosclerotic steno-occlusion were identified. Subjects with same range of age who were negative for abnormal wall thickening of the BA in HRMRI served as controls. Using conventional T2 axial images, maximal diameter and T2 plaque sign (an eccentric or complete obscuration of normal flow-related T2 signal void) within the BA were measured. We tested the diagnostic value of T2 plaque sign and maximal diameter to distinguish patients from controls.

Results:
Seventy-five patients (age range, 51-81) and 36 controls (50-81) were identified. Maximal diameter was significantly larger in patients than controls (3.87 ± 0.868 mm vs 2.68 ± 0.447 mm, p<0.001). Positivity of T2 plaque sign were 61.3% in patients with BA atherosclerosis, 71.2% in patients with >30% BA stenosis, 77.5% in >50% BA stenosis, and 96.3% in patients with >70% BA stenosis. Receiver operating characteristic curve showed high predictive power (the area under the curve 0.921, 95% CI 0.872 - 0.970, p<0.001) of maximal BA diameter to distinguish patients and controls with an optimal cutoff of 3.185 mm, (sensitivity, 78.7%; specificity, 94.4%). Sensitivity and specificity of T2 plaque sign were 61.3% and 100.0% for BA atherosclerosis of any degree. Increasing sensitivity and decreasing specificity were noted for the diagnosis of higher degree stenosis.

Conclusion:
Our data suggest that increased BA diameter and plaque sign on conventional T2 imaging are markers of basilar artery atherosclerosis. This would be helpful for earlier identification of causative stroke mechanism. Further study is needed for validation of these findings among different stroke etiologies.
Abstract TP126: Intraoperative Neurophysiological Monitoring in Carotid Endarterectomy: An Analysis of the Nationwide Inpatient Sample
Authors: Rumalla Kavelin , Singh Aditya , Mittal Manoj K
Published: July 2021

Introduction:
Carotid endarterectomy (CEA) is an effective treatment for symptomatic carotid stenosis (CS) but the ischemic complications of the procedure can be detrimental. Intraoperative neurophysiological monitoring (IONM) is used to protect neural structures during surgery. The incidence, predictors, and in-hospital outcomes associated with the use of IONM in CEA have not previously been reported.

Methods:
The Nationwide Inpatient Sample from 2007 to 2011 was queried to identify cases of CEA procedures (ICD-9-CM code 38.12) accompanied by occlusion or stenosis of the precerebral arteries (ICD-9-CM codes 433.10-1). Independent predictors of IONM utilization (ICD-9-CM code 00.94), perioperative/postoperative stroke, prolonged length of stay (LOS; defined as ≥ 75th percentile), increased hospital costs (defined as ≥ 75th percentile), and in-hospital mortality were identified using multivariable logistic regression analyses.

Results:
A total of 518,685 CEA procedures for CS were identified. The utilization of IONM (0.74%) increased from 0.06% in 2007 to 1.74% in 2011 (P<0.0001). Multivariate predictors of IONM, adjusted for demographics, hospital characteristics, comorbidities, and presentation of symptoms, included increasing comorbidity score (OR: 1.045, 95% CI: 1.01-1.08, P=0.004), African American race (OR: 1.59, 95% CI: 1.36-1.85, P<0.0001), Medicaid status (OR: 1.35, 95% CI: 1.11-1.63, P<0.0001), large hospital bed size (OR: 3.70, 95% CI: 3.03-4.51, P<0.0001), urban location (OR: 4.97, 95% CI: 3.50-4.51, P<0.0001), teaching hospital status (OR: 3.56, 95% CI: 3.24-3.91, P<0.0001) and weekend admission (OR: 1.25, 95% CI: 1.04-1.49, P=0.015). The utilization of IONM decreased the likelihood of perioperative/postoperative stroke (OR: 0.61, 95% CI: 0.38-0.97, P=0.036) and in-hospital mortality (OR: 0.37, 95% CI: 0.15-0.89, P=0.027). The use of IONM increased the likelihood of prolonged LOS (OR: 1.21, 95% CI: 1.72-2.28, P<0.0001) and total hospital costs (OR: 1.98, 95% CI: 1.72-2.28, P<0.0001).

Conclusion:
The use of IONM in CEA has increased over time. The utilization of IONM was shown to decrease perioperative/postoperative stroke and in-hospital mortality rates while increasing LOS and hospital costs.
Abstract TP127: Prevalence and Clinical Significance of Asymptomatic Extracranial Vertebral Artery Disease in Patients With Symptomatic Internal Carotid Artery Stenosis: Analysis of Stent-protected Angioplasty versus Carotid Endarterectomy (SPACE) Trial
Authors: Qureshi Adnan I , Chaudhry Saqib A , Ringleb Peter A
Published: July 2021

Background:
Extracranial vertebral artery disease is seen in patients with internal carotid artery stenosis although the clinical significance not well understood.

Methods:
We analyzed data that was collected as part of the Stent-Protected Angioplasty versus Carotid Endarterectomy (SPACE) trial which recruited patients with recently symptomatic internal carotid artery stenosis. We used Cox proportional hazards analysis to compare the relative risk of various endpoints between the three categories of extracranial vertebral artery disease (normal/hypoplastic, moderate/severe stenosis, and occlusion). The multivariate analyses were adjusted for age, gender, basic demographics and severity of carotid stenosis.

Results:
Of the 1181 subjects who had extracranial vertebral artery ultrasound evaluation, moderate to severe stenosis and occlusion of one of both extracranial vertebral arteries was diagnosed in 152(12.9%) and 57(4.8%) subjects, respectively. During the mean follow up period (±SD) of 22.1±7.1 months 102(8.6%) and 60(5.1%) experienced a stroke or died, respectively. Compared with subjects with normal or hypoplastic vertebral artery, there was a non-significant 30% higher risk of any stroke among subjects with moderate to severe vertebral artery stenosis (relative risk [RR]1.3, 95% confidence interval [CI]0.7-2.3) after adjusting for potential confounders. There was a 40% and 50% higher risk of ipsilateral stroke (RR 1.4, 95% CI0.7-2.5) and death (RR 1.5, 95% CI 0.7-3.1) among subjects with moderate to severe vertebral artery stenosis after adjusting for potential confounders. In Kaplan Meir analysis, the estimated 1 and 2 year stroke free survival for subjects with moderate to severe vertebral artery stenosis was 88% (standard error [SE]2.6%). In comparison, the estimated 1 and 2 year stroke free survival for subjects with normal or hypoplastic vertebral artery was 92.5%(SE0.8%)and 91.6%(SE0.9), respectively.

Conclusions:
There appears to be an increased risk of stroke and death in patients with symptomatic internal carotid artery stenosis with concurrent asymptomatic extracranial vertebral artery stenosis.
Abstract TP141: Navigation Services for Stroke Survivors and Caregivers Post-discharge
Authors: Richards Julia B , Larson Amy , Charbonneau Jamie
Published: July 2021

Background:
Patient navigation is a community-based intervention designed to help clients identify and overcome barriers to care. Navigation is a widely used, evidence-based model for patient-centered healthcare. It is well documented that stroke survivors and caregivers face enormous obstacles in returning to their community living situations post-stroke.

Purpose:
National Stroke Association’s Stroke Recovery Navigator Program is designed to reduce barriers to care, lower incidence of secondary stroke, eliminate re-hospitalization due to post-stroke conditions, and provide support for adjusting to community living.

Method:
National Stroke Association implemented a pilot program to determine if navigation is an effective intervention for stroke survivors and caregivers. Clients were referred to the program upon discharge from partner hospitals. Clients completed either the Reintegration to Normal Living Index (RTNLI) or the Zarit Screening Measure of Caregiver Burden (respectively) at enrollment and at graduation.

Results:
The Stroke Recovery Navigator Program received 180 referrals with 90 clients converted to active participation. Stroke survivors made up 82% of participants and caregivers 18%. RTNLI scores went up and Caregiver Burden scores went down when clients received navigation services. During the pilot phase, 12 stroke survivors were re-hospitalized, 4 for stroke-related issues; 8 for new medical issues. Post-pilot evaluations of participants showed that 95% of respondents believe the program provides a valuable service. Referral source surveys revealed that more than half of their patients received information about the program at discharge.

Conclusions:
Navigation for stroke survivors and caregivers shows increased reintegration to normal living and reduced caregiver burden scores. Clients receiving navigation were re-hospitalized below the levels documented in recent studies. Based on these findings National Stroke Association concludes that navigation post-stroke results in positive outcomes for survivors, caregivers and hospitals.
Abstract TP144: Intracortical Circuits Reveal Muscle- and Task-specific Dysfunction Contributing to Weakness Following Stroke
Authors: Little Virginia L , Walker Eric R , Patten Carolynn
Published: July 2021

Introduction:
Weakness is a prominent clinical manifestation following stroke. While central factors, including activation impairment, contribute to hemiparetic weakness, specific mechanisms remain poorly understood. Here we probed functioning of the corticospinal pathway and intracortical circuits mediating dynamic force production.

Hypothesis:
We hypothesized that impairments of intracortical inhibition and excitation contribute to deficits in plantarflexor (PF) force production capacity following stroke.

Methods:
We studied 19 chronic stroke survivors (age: 66.0±9.6 yrs; chronicity: 77.3±60.9 mo) and 7 controls (age: 61.3±9.7 yrs) and used the Short Physical Performance Battery to group stroke survivors by functional ability (i.e., HIGH, MED, LOW). We obtained peak isometric PF force during a series of maximal voluntary contractions. Single and paired pulse transcranial magnetic stimulation (TMS) was delivered over the ipsilesional hemisphere during isometric and dynamic PF contractions to assess corticomotor excitability, short intracortical inhibition (SICI), and short intracortical facilitation (SICF).

Results:
Peak isometric force (p=0.04) and cortical excitability in both medial gastrocnemius (MG) and soleus (SO) were progressively reduced across functional levels post-stroke (p’s<0.01). Controls revealed task-dependent modulation of motor evoked responses (MEPs) between isometric and dynamic contractions in MG, but not SOL while the MED and LOW groups failed to modulate MEPs. SICF revealed no differences between muscles, contraction type, or groups. In SO, controls revealed attenuation of SICI during movement. Stroke survivors revealed a progressive reduction in SICI during isometric PF across functional level while SICI increased during dynamic PF, resulting in a pattern reversal between controls and LOW (p=0.02).

Conclusion:
Deficits in dynamic PF post-stroke appear to be driven by changes in SICI rather than SICF, suggesting dysregulation of GABA-A. Impaired intracortical inhibition could reduce PF capacity by interfering with selective muscle recruitment during dynamic tasks.
Abstract TP149: Utilization of a Robotic Exoskeleton to Provide Increased Mass Practice for Gait Training and its Impact on Discharge Destination for Individuals With Acute Stroke
Authors: Russo Anthony , Perret Melissa A , Endersby Kirk , Kesten Adam G , King Marisa A , Chervin Kathleen , Nolan Karen J
Published: July 2021

Introduction:
Mass practice of task-specific activity, such as repeated stepping for gait retraining, is an integral part of acute stroke rehabilitation. New technologies including the use of a robotic exoskeleton (RE) have recently been introduced to the inpatient rehab facility (IRF). A RE can help skilled physical therapists (PT) provide repetitive stepping practice to patients who have had a stroke.

Hypothesis:
We hypothesize the use of a RE will enable PTs in an IRF to provide added stepping practice to their therapy program and influence discharge destination as compared to traditional treatment plans.

Methods:
Fifteen participants with acute stroke (<6 months post, age 58±10; height 66±5in; 176±35lbs; LOS 29±7days) were recruited for RE gait training during inpatient rehabilitation in conjunction with traditional therapy. Participants ambulated in the RE over level surfaces with the assistance of a PT (minimum of 3 sessions in the RE). Participant inclusion requirements: medical clearance, upright standing tolerance (≥15 min), intact skin, and physically fit into the device. A matched sample of participants (n=15) was selected from a hospital database (matching criteria: length of stay, admission motor FIM, age, gender and affected side). The data was analyzed using independent sample and paired sample t-tests.

Results:
Participants in the RE group walked an average distance of 212 feet in traditional PT where gait training was provided and 551 feet in RE sessions (p=.033). Discharge destination for the RE group: 10 home; 3 subacute; 2 nursing facilty and for the matched sample: 13 home; 2 subacute. Motor FIM scores significantly increased from admission to discharge: RE group (p≤.001) and matched group (p≤.001). Motor FIM gain at discharge in the RE group significantly increased compared to the matched sample, 26.4±6.4 vs. 21.6±5.9, (p=0.044).

Conclusions:
This exploratory investigation demonstrated the RE provides increased dosing of gait training. Discharge destination was not notably impacted by method of gait training. Improvement of motor FIM scores in the RE group begins to demonstrate the impact of mass practice provided by the RE. Further research is needed to objectively explore the impact of RE on functional mobility and quality of life.
Abstract TP167: Short-Term Exposures to Ambient Air Pollution and Risk of Recurrent Ischemic Stroke
Authors: Wing Jeffrey J , Adar Sara D , Sanchez Brisa N , Morgenstern Lewis B , Smith Melinda A , Lisabeth Lynda D
Published: July 2021

Background:
Recurrent strokes are associated with poor outcomes and mortality. Short-term ambient air pollution may be an important environmental risk factor for stroke recurrence. Although associations between air pollution and stroke risk have been observed, the evidence for short-term effects of air pollution on risk of stroke recurrence is in its infancy. We investigated the association between short-term changes in ambient pollution (particulate matter <2.5μm (PM
2.5
) and ozone (O
3
)) and the risk of recurrent ischemic stroke among individuals living in a bi-ethnic community.

Methods:
We identified recurrent ischemic stroke cases from the population-based Brain Attack Surveillance in Corpus Christi (BASIC) Project, an ongoing population-based stroke surveillance study in Nueces County, Texas, between 2000 and 2012. Associations between lags of 0 to 3 days PM
2.5
and O
3
levels and odds of ischemic stroke were assessed using a time-stratified case-crossover design. Conditional logistic regression models were used to calculate odds ratios (ORs) for a 10 unit change in exposure.

Results:
There were 317 recurrent ischemic strokes with mean age of 72 years (SD=12). Median levels of PM
2.5
and O
3
over the study period were 7.7μg/m
3
(IQR: 5.6-10.7μg/m
3
) and 35.2ppb (IQR: 25.0-46.1ppb), respectively. No associations were observed across the different lagged exposures (0 to 3 days) after adjusting for ambient temperature and relative humidity (Figure). Co-adjustment of both pollutants results did not change the results.

Conclusion:
No association between PM
2.5
and O
3
and risk of recurrences was observed. Research on the influence of air pollutants on risk of recurrence is still in its infancy, and more research is needed to understand the relation.
Abstract TP178: Relationship Between Deprivation and Outcome for Stroke Patients: Data From the UK National Stroke Registry
Authors: Vestesson Emma , Bray Benjamin , James Martin , Paley Lizz , Tyrrell Pippa , Cloud Geoffrey , Otago Rachel , Rudd Anthony ,   On behalf of the SSNAP Collaboration
Published: July 2021

Introduction:
Previous studies have identified that social deprivation is associated with the onset of stroke, with people from areas of higher deprivation being more likely to have a stroke at a younger age.

Methods:
Data were extracted from the national stroke register (Sentinel Stroke National Audit Programme (SSNAP)) of adults with acute ischemic stroke treated in all hospitals in England and Wales from April 2013-March 2014. The patient’s zip code of residence was used to link the data with an index of multiple deprivation, which groups zip codes into quartiles of deprivation.

Results:
Of the 66798 adults with acute stroke discharged from 266 hospitals, deprivation data was available for 63007 patients (94.3%).The median age of stroke onset for the most deprived quartile was 5 years lower than for the least deprived quartile (74, 77, 79 and 79 years respectively, Kruskal-Wallis test p<0.001). For patients in the most deprived quartiles compared to the least deprived, the rate of primary intracerebral hemorrhage was lower (9.9%, 10.5%, 10.7% and 11.7% respectively, chi2 p<0.001), the rate of diabetes was higher (22.7%, 20.6%, 17.9% and 15.8%, chi2 p<0.001), and the prevalence of congestive heart failure, hypertension and previous stroke/TIA were similar for all groups. The rate of atrial fibrillation (AF) prior to stroke was lower for more deprived patients (17.6%, 19.8%, 22.9% and 22.6%, chi2 p<0.001), but the percentage of patients on anticoagulants if in AF was similar for all groups. Mortality at 30 days was lower in the most deprived group compared to the least deprived group (12.8%, 14.6%, 15.7% and 15.4%, chi2 p<0.001).

Conclusions:
Patients living in more deprived areas have stroke at a younger age and are more likely to have a prior history of diabetes mellitus. Outcomes are similar for all groups but crude mortality at 30 days was lower for the most deprived group. This may be due to the lower median age of stroke onset, and the higher proportion of ischemic strokes. Predictive models for stroke outcome need to consider levels of deprivation and we are currently working on multivariable analysis to identify any independent effect of deprivation on mortality.
Abstract TP181: A Risk Score for All-Cause Readmissions Using Get With the Guidelines-Stroke Data Elements
Authors: Howard Kelle D , Natarajan Nagarajan , Ramakarishnan Anurekha , Ponds Kathlean , Layton Wendy , Cowperthwaite Matthew , Dhillon Inderjit
Published: July 2021

Introduction:
Readmission rates of stroke patients are commonly used as a measure of quality of care by CMS and other payers. In this study, our goal was to identify risk factors for 30, 60, and 90 day all-cause readmissions and to develop a risk score that indicates likelihood of readmission.

Methods:
We used GWTG-Stroke data elements describing 1086 stroke admissions at St. David’s Medical Center between 2013 - 2014. The principal ICD-9 diagnosis code was used to identify the reason for readmit. We used logistic regression models to predict readmission events using clinical (such as stroke type and medical history) and demographic (such as age and gender) variables. We used the models to develop a readmission risk score that is predictive of future admissions following a stroke.

Results:
Of the 1086 patients, 79 (7.3%), 116 (10.7%), and 142 (13.1%) have at least one unplanned in-hospital readmission within 30, 60, and 90 days respectively. The main readmission reasons were related to stroke, followed by syncope, fatigue/malaise symptoms, and atrial fibrillation. Our models were robust and predicted 30, 60, and 90 day readmissions (averaged over 10 random train/test splits) with 0.63, 0.64, and 0.66 accuracy, respectively (c-statistic). Significant predictors contributing to patient readmission risk include history of hypertension (OR 5.93), diagnosis of transient ischemic attack (OR 2.0), initiation of tPA (OR 2.08), discharge to rehabilitation facility (OR 3.27).

Conclusions:
The leading causes of readmission following a stroke are related to the stroke event or episodes of comorbid conditions. Our study shows promise in using GWTG data to predict readmissions, however larger cohorts of patients are needed to develop highly accurate predictive models.
Abstract TP182: Risk of Acute Ischemic Stroke Increases During Severe Flares of Inflammatory Bowel Disease
Authors: Kummer Benjamin R , Merkler Alexander E , Gialdini Gino , Kamel Hooman
Published: July 2021

Introduction:
Flares of inflammatory bowel disease (IBD) have been associated with venous thromboembolism, and recent studies suggest an association between IBD and myocardial infarction. The association between IBD flares and cerebral thrombotic disease is less clear. We therefore sought to evaluate the risk of cerebral venous and arterial stroke during IBD flares.

Hypothesis:
IBD flares are associated with an increased risk of a cerebral thrombotic event.

Methods:
We used data on all admissions at nonfederal acute care hospitals in California, Florida, and New York to identify patients with a primary ICD-9-CM diagnosis code for ulcerative colitis or Crohn’s disease between 2005 and 2012. Patients with a documented abdominal surgery during the index hospitalization were excluded. An IBD flare was defined as a period of 120 days from the start of the index IBD-related hospitalization. Our outcomes were ischemic stroke and cerebral venous sinus thrombosis. We used a self-controlled case series design in which we compared the risk of a thrombotic event in the 120 days after hospitalization versus the risk during the 120 days prior to hospitalization.

Results:
We identified 31,993 patients with IBD, of whom 98 (0.31%) developed ischemic stroke. As compared with the control period preceding the index hospitalization, the risk of stroke was significantly elevated during the 120 days after IBD-related hospitalization (incidence rate ratio [IRR] 2.0; 95% confidence interval [CI] 1.3-3.0). In subgroup analyses, this elevated risk was apparent only in the 16,280 patients older than the median age of 44 years (IRR 1.9; 95% CI, 1.27-2.95), and not in the 15,713 patients younger than 44 years of age, among whom we identified only one stroke. We found only one patient with a documented venous sinus thrombosis and thus could not estimate the risk associated with an IBD flare.

Conclusion:
We found an association between IBD-related hospitalization and the risk of ischemic stroke in older patients. These results build on recent studies suggesting an association between IBD and the risk of arterial thrombotic events. Further research is needed to better define the association between IBD and cerebrovascular events, especially rare events such as cerebral sinus thrombosis.
Abstract TP190: Bone Mineral Density is Inversely Related to Cerebral Pulsatility Index in Patients With Acute Ischemic Stroke
Authors: Han Sang Won , Park Joong Hyun , Lee Jong Yun , Ahn Seong Hwan , Lee Kyung-Yul
Published: July 2021

Introduction:
Atherosclerosis and osteoporosis are two major public health problems. These are both multifactorial and degenerative diseases that accompany aging. Co-morbidities are common, with a high prevalence of cardiovascular risk factors including hypertension, smoking, and sedentary lifestyle. Several studies have suggested a relationship between atherosclerosis and osteoporosis, with a significant correlation between coronary artery calcium and bone mineral density (BMD). The pulsatility index (PI) is designed to measure vascular resistance and characterizes the shape of the spectral waveform. The PI was increasing with age but alterations in PI are the reflection of multifactorial, pleiotropic events occurring in the cardio and cerebral vascular system. Atherosclerosis of the large proximal arteries and the intracranial vessels are important factors for increased PI.

Hypothesis:
We hypothesized that the transcranial Doppler (TCD) PI would reflect the atherosclerotic component of intracranial vessels which in turn is related to systemic atherosclerosis. In this context, we investigated the relationship between TCD PI and BMD in acute ischemic stroke patients.

Methods:
Patients having their first ischemic stroke within 7 days were screened for the study. Doppler signals from the main stem of the middle cerebral artery (MCA) were obtained transtemporally with a traditional 2-MHz transducer at depths of 56, 58, and 60 mm. BMD was measured at total hip and lumbar spine in the anterior-posterior projection, using dual-energy x-ray absorptiometry.

Results:
A total of 146 patients were enrolled in the study and the mean age was 68.3±10.34 years. Multiple linear regression analysis reveals that age (p<0.001) and BMD T-score (p=0.028) were significantly associated with increased TCD PI. Old age and decreased T-score were significantly related to increased TCD PI. Age adjusted scatterplots showed that BMD T-score was inversely related to TCD PI in acute ischemic stroke patients (r=-0.202, p=0.028).

Conclusions:
Our findings indicate that decreased BMD may be associated with atherosclerosis in the cerebral circulation.
Abstract TP198: Impacts of Periodontitis on Nonfatal Ischemic Stroke: Comparison With Hypertension and Diabetes Mellitus
Authors: Kim Hyun-Duck , Shin Myung-Seop , Ahn Yoo-Been
Published: July 2021

Background and objectives:
Hypertension and diabetes mellitus (DM) have been two major causes of stroke, while the impact of periodontitis on nonfatal ischemic strokes (NFIS) is still underestimated. Hence, we aimed to evaluate the association of periodontitis with NFIS and to compare its impacts with those of hypertension and DM.

Methods:
A case-control study was performed with 143 hospitalized NFIS cases and 214 population controls. Medical specialists diagnosed NFIS using brain imaging with CT and MRI. A dentist assessed periodontitis using the clinical attachment level with a UNC-15 manual probe. Potential confounders were interviewed using systematic questionnaires. Multivariable logistic regression analyses including subgroup analyses were applied.

Results:
After controlling for potential confounders, periodontitis was strongly associated with NFIS. The adjusted odds ratio (AOR) was 6.4 for periodontitis. Periodontitis has the same association as hypertension. AOR of periodontitis was 2.5 times higher than that of DM. In 40-59 years old adults and smokers, periodontitis showed higher association than hypertension and DM. In females and non-smokers, periodontitis had lower association than hypertension, but higher than DM. Hypertension and diabetes were synergistic to periodontitis.

Conclusions:
Overall, periodontitis had the almost same strength of the association with NFIS as hypertension, but higher than DM.
Abstract TP201: Diabetes and the Risk of Death and Stroke Recurrence Following Ischemic Stroke
Authors: MacDougal Erin L , Wing Jeffrey J , Herman William H , Morgenstern Lewis B , Lisabeth Lynda D
Published: July 2021

Background and Purpose:
Diabetes mellitus (DM) is a well-established risk factor for ischemic stroke (IS), but the literature is inconsistent on the effect of DM on outcomes after IS. We sought to determine if DM increases the risk of mortality and recurrence after IS, and if these associations are greater in Mexican Americans (MA) than non-Hispanic whites (NHW).

Methods:
IS cases, all-cause mortality, and recurrent strokes were identified from the Brain Attack Surveillance in Corpus Christi (BASIC) project (2006-2012). Sociodemographics and clinical data were obtained from medical records and interviews. Cumulative mortality and stroke recurrence risk were estimated at 30 days and 1 year using Kaplan-Meier analysis and Cox proportional hazards models. Effect modification by ethnicity was examined.

Results:
There were 1,301 IS cases, 46% with a history of DM, median age 70 (IQR: 58-81), and 61% MA. Patients with DM were younger and more likely to be MA compared to patients without DM. Risk of 30-day and 1-year mortality was 8.4% and 20.5% for those with DM and 9.5% and 20.8% for those without DM, respectively. Risk of 30-day and 1-year stroke recurrence was 1.2% and 7.5% for those with DM and 1.5% and 5.8% for those without DM, respectively. Unadjusted, DM was not a significant predictor of mortality or recurrence (see table). After adjustment, DM predicted mortality (30-day HR=1.58, 95% CI: 0.98-2.53; 1-year HR=1.48, 95% CI: 1.10-2.00) but not stroke recurrence (1-year HR=1.28, 95% CI: 0.78-2.08). Effect modification by ethnicity was not significant (p>0.2 for all models).

Conclusions:
Given that patients with DM were significantly younger than patients without DM, the crude association between DM and mortality revealed no difference. However, after accounting for age and other factors, patients with DM were 50% more likely to die at 1 year after IS compared to patients without DM.