bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract W P155: Racial Differences in Ischemic Stroke Subtypes: The Greater Cincinnati/Northern Kentucky Stroke Study (GCNKSS)
Authors: Kissela Brett , Khoury Jane , Alwell Kathleen , Moomaw Charles J , Woo Daniel , Flaherty Matthew L , Adeoye Opeolu , Ferioli Simona , Martini Sharyl , de los Rios Felipe , Mackey Jason , Kleindorfer Dawn
Published: July 2021

Background:
It is well known that blacks have higher stroke incidence rates than whites. It is commonly believed that whites have more cardioembolic (CE) and large vessel (LV) ischemic strokes (IS). However, using data from 1993-94, we showed that blacks have higher rates of every IS subtype. We sought to see if this pattern persisted in 2010 within a large, biracial population of 1.3 million representative of the US.

Methods:
The GCNKSS is a population-based stroke epidemiology study from five counties in the Greater Cincinnati region. During 2010, we captured all hospitalized strokes by screening ICD-9 codes 430-436. We also captured out-of-hospital strokes by sampling primary care offices and nursing homes. Study nurses abstracted all potential cases. Physicians adjudicated each possible event and then further subtyped IS based on available test results using established methods. Incidence rates per 100,000 and associated 95% confidence intervals (CI) were estimated for each subtype using first-ever IS, with weighting of out-of-hospital event sampling, then age- and sex- adjusted to the 2000 US population. Black/white risk ratios (RR) and 95% CI were also calculated.

Results:
In 2010 there were 2219 IS in 2116 patients, and 1693 first-ever IS. Of the 1693 incident IS, 944 (57%) were female, 346 (21%) black, with mean age 69 years. There were 285 (18%) small vessel, 465 (27%) CE, 218 (12%) LV, 107 (6%) other identified cause, and 617 (37%) undetermined. The table shows incident IS rates by subtype and the associated RR. For each subtype of IS, blacks had a higher point estimate than whites in 2010. In 2010, the RR CI’s cross 1.0 for CE and LV, thus the RR is not statistically significant.

Conclusion:
It is not clear if these data represent significant differences for CE and LV subtypes in 2010 or statistical variation between periods. Regardless, stroke prevention efforts for blacks should include strategies relevant to all IS subtypes, and not just those for small vessel disease.
Abstract W P161: Incidence and Characteristics of Post-Stroke Seizures: A Population-Based Study
Authors: Bryndziar Tomas , Sedova Petra , Kramer Neha M , Mandrekar Jay , Brown Robert D , Klaas James P
Published: July 2021

Background & Purpose:
Seizures are a recognized complication of stroke. However, available data are conflicting in terms of incidence, risk factors for occurrence, and impact on functional outcome and mortality. The aim of this study was to assess the incidence and characteristics of seizures following ischemic stroke in a well-defined population, and their effect on long-term patient outcome.

Methodology:
Utilizing the Rochester Epidemiology Project medical record linkage system, we identified all incident cases of ischemic stroke (IS) that occurred between January 1, 1990, and December 31, 1994. We identified all patients who developed seizures following first IS. Detailed data regarding stroke (including TOAST subtype, anatomic location, functional outcome), seizures (date, type, functional outcome, recurrence, presence of status epilepticus, complications, treatment, EEG findings), and patient status at the last follow-up were recorded and analyzed.

Results:
We identified 490 patients with first IS. Mean follow-up was 6.5 years (range 0.0 - 23.8). Of these, 35 (7.1%) developed seizures. Early seizures (occurring within 14 days of stroke) were present in 13 (37.1%), of which 9 (69.2%) had their seizure within the first 24 hours. Partial seizures were the most common type (23 patients, 65.7%). Status epilepticus occurred in two cases (5.7%). Tongue biting was the most common complication of poststroke seizures (4 patients, 11.4%). Treatment with antiepileptic drugs (AEDs) was initiated in 32 cases (91.4%). Only one drug was necessary for seizure control in all treated patients. The mean modified Rankin Scale score was 2.9 (SD 1.48) after the first IS, and worsened to 3.3 (SD 1.43) after the first seizure. Mortality at the last follow-up was higher in the seizure group compared to the non-seizure group, even after adjusting for TOAST subtype (HR 1.52; 95% CI 1.07 - 2.16; P = 0.02).

Conclusion:
Seizures are mostly a late complication of IS. They do not bear a high risk of life-threatening complications and are readily controllable by a single AED. However, patients who developed poststroke seizures tended to have a worse functional outcome and an increased mortality.
Abstract W P163: Ischemic and Hemorrhagic Cerebrovascular Events after Left Ventricular Assist Devices
Authors: Tahsili-Fahadan Pouya , Curfman David R , Davis Albert A , Yahyavi-Firouz-Abadi Noushin , Nassif Michael E , LaRue Shane J , Ewald Gregory A , Zazulia Allyson R
Published: July 2021

Introduction:
Left ventricular assist devices (LVADs) are increasingly implanted for advanced heart failure either as a bridge to transplantation (BTT) or destination therapy (DT). The reported incidence of cerebrovascular events (CVE) following LVAD is 8-25%. The effects of medical comorbidities and perioperative events on the development of CVE are unclear.

Methods:
CVEs were retrospectively identified from the Barnes-Jewish Hospital LVAD database consisting of 373 patients with mean LVAD support of 13.5 months (range 0 days-8.2 years); Heartmate II 87%, Heartware 13%. Demographic, clinical, and outcome data were collected and analyzed in patients with and without CVE using standard statistical methods.

Results:
CVE occurred in 71 patients (19%) at a rate of 0.17 per patient-year 24.5±30.7 months after implantation. Coronary artery disease (P=0.007), diabetes mellitus (P=0.02) and LVAD indication of DT (P=0.04) were more common in patients with CVEs. Duration of cardiopulmonary bypass, hospital length of stay and incidence of bacteremia were not different between those with early CVE (within 30 days of implantation, 35%) and without CVE. CVEs were ischemic (ICVE) in 35 (49%), hemorrhagic (HCVE, including intracerebral, subarachnoid, and subdural) in 26 (37%), and both in 10 (14%). Patients with ICVE and HCVE did not differ in demographic variables, pre-LVAD co-morbidities, post-LVAD complications, NIH Stroke Scale at time of event, or anti-thrombotic regimen (ATR), except that events in those on no ATR were only ischemic. Patients with HCVEs were more likely to be discharged with no ATR (P=0.015). Mortality was significantly higher in patients with CVE (59.1% vs. 29.2% in those without CVE) but did not differ by CVE type. In patients with CVE, 57.1% of deaths were secondary to the CVE (ICVE 25%, HCVE 93.7%, P<0.001). Among BTT patients, only 14.6% with CVE underwent transplantation vs. 39.8% without CVE (P =0.002).

Conclusions:
CVE remains a serious complication of LVAD support for advanced heart failure and is associated with increased mortality and lower rates of heart transplantation. Further investigations to identify risk factors for CVEs in LVAD patients and potential preventive measures including optimal ATRs are warranted.
Abstract W P176: Self-reported Pre-Stroke Physical Activity Levels Influence Functional Ability Following Incident Stroke
Authors: McDonnell Michelle N , Hillier Susan L , Roth David L , Judd Suzanne E , Haley William E , Esterman Adrian J , Wadley Virginia G , Howard Virginia J
Published: July 2021

Background and Purpose:
Emerging evidence suggests that stroke recovery is influenced by pre-stroke physical activity (PA). The purpose of this study was to examine whether prospectively collected pre-stroke PA levels were associated with functioning one year post-stroke in survivors of a first stroke.

Methods:
PA was assessed during baseline interviews of participants in the REasons for Geographic and Racial Differences in Stroke (REGARDS) observational study. Participants who experienced a first-ever stroke event during follow up were enrolled in an ancillary study. Approximately 12 months following stroke incidence, survivors and their informants were interviewed by telephone, and an in-home assessment of functional ability was conducted (n = 203). The association between pre-stroke PA and post-stroke function was assessed.

Results:
Participants reported baseline PA as either no vigorous PA (n = 65), or PA once or more per week (n = 138). Individuals who exercised at least once per week had significantly greater function at one year following stroke as assessed with the NIHSS, the Barthel Index and the Stroke Impact Scale physical domain score. In the multivariate model, race, education, sex, age, length of hospital stay and discharge destination were associated with functioning and attenuated this relationship. However, the significant association between pre-stroke PA and the NIHSS remained (p = 0.003).

Conclusions:
Self-reported PA prior to stroke was associated with significantly lower NIHSS scores one year after stroke. Other physical function measures were attenuated by factors such as female sex and African American race which were strongly related to poorer function.
Abstract W P200: Wake-up Stroke Is Associated With Greater Diastolic Blood Pressure Variability
Authors: Lundholm Michelle D , Rooney Melissa , Corado Carlos E , Ruff Ilana M , Curran Yvonne , Bernstein Richard A , Attarian Hrayr , Prabhakaran Shyam
Published: July 2021

Background:
Wake-up strokes (WUS) account for approximately 20-30% of strokes. Prior studies have failed to consistently identify specific factors associated with WUS. Some authors have suggested a link to obstructive sleep apnea (OSA) though the pathophysiology of this association remains unknown. We hypothesized that blood pressure variability (BPV), a common finding in OSA, is greater in WUS versus non-WUS patients.

Methods:
From a single-center prospective cohort study of ischemic stroke patients admitted between August 2012 and July 2013, we identified WUS vs. non-WUS patients. WUS was defined as stroke symptoms noted first on awakening compared to those that occurred at any other time. BPV was calculated as standard deviation of the mean during the first 24 hours after hospital arrival. We assessed 24-hour BPV, as a continuous measure and in quartiles, in WUS vs. non-WUS patients using univariable and multivariable statistics. A p-value <0.05 was considered significant.

Results:
Among 344 patients (65.0+/-16.0 years; 50.9% male; 63.7% white; median NIHSS score 3), 72 were WUS (20.9%). On univariable analyses, demographic, medical history, body mass index, and clinical characteristics were not different between WUS and non-WUS strokes, with the exceptions that WUS patients were older (68.7 vs. 64.0 years; p=0.025), more frequently had prior ischemic stroke (30.6% vs. 16.9%, p=0.010), and no WUS patient received intravenous thrombolysis (p<0.001). Initial systolic (p=0.779) and diastolic BP (p=0.647) were similar between groups. Greater diastolic BPV (10.7 vs. 9.5, p=0.025), however, occurred in WUS patients. In multivariable analysis, prior ischemic stroke (OR 2.03, 95% 1.10-3.73) and highest quartile (>=11.5 mmHg) of diastolic BPV (OR 2.19, 95% CI 1.24-3.85) were independently associated with WUS.

Conclusions:
In this prospective study, we observed that diastolic BPV during the first 24 hours is more common in WUS versus non-WUS patients. While the implication of this finding is uncertain, we speculate that increased BPV might trigger WUS. Further research is required.
Abstract W P211: Clinical Characteristics of Pseudo Negative Cases in Prehospital Triage for Stroke
Authors: Tonomura Shuichi
Published: July 2021

Objective:
The accuracy of prehospital diagnosis for stroke by emergency medical services (EMS) is improved using instruments for symptom recognition. On the other hand, prehospital misdiagnosis for stroke and subsequent delay in presentation to a hospital with stroke expertise play a critical role in the exclusion of potential therapeutic candidates. Our study aims to investigate the clinical characteristics of pseudo-negative cases in prehospital triage for stroke/TIA by EMS.

Methods:
From April 2013 to April 2014, consecutive 644 acute stroke patients were transferred by EMS to our hospital. We investigated prehospital diagnosis, Cincinnati prehospital stroke scale (CPSS) by EMS, neurological symptoms and complaints of patients themselves at stroke onset. We also examined activity of daily life (ADL) and cognitive impairments before stroke onset, and stroke subtypes in final diagnoses.

Results:
Among 644 acute stroke patients, 36 patients (22 men, mean 72.5±4.4 years old) were pseudo-negative cases in prehospital triage for stroke and had no abnormalities in CPSS by EMS. When EMS arrived at emergency site, 12 patients (33%) had loss of consciousness. Before stroke onset, 6 patients (17%) had impaired ADL (modified Rankin Scale >2), and 5 (14%) cognitive impairment. Among the stroke subtypes, the proportion of small vessel occlusion (22.4%, p=0.0025) and transient ischemic attack (TIA) (25%, p=0.0021) was significant higher in pseudo negative cases in prehospital triage; on the other hand, intracranial hemorrage (11%, p=0.0028) was lower. In complaint of patients themselves at stroke onset, weakness in one or two extremities was reported in 20 patients (56%), abnormal speech/language in 13 (36%), however all of them were not clarified by EMS.

Conclusion:
This study showed that small vessel occlusion and TIA tend to be misdiagnosed in a prehospital triage by EMS. The complaint of patients themselves at stroke onset is important to prehospital diagnoses by EMS.
Abstract W P235: The Nuclear Receptors FXR and Nur77 Exhibit Neuroprotective Effects in the Ischemic Mouse Brain
Authors: Strecker Jan-Kolja , Hucke Stephanie , Diederich Kai , Schmidt Antje , Klotz Luisa , Minnerup Jens
Published: July 2021

Introduction:
FXR and Nur77, members of the nuclear hormone superfamily, have been shown to modulate pro- and anti-inflammatory responses by immune cells, such as macrophages or T cells. As ischemic stroke induces an inflammatory response accompanied by activation and recruitment of immune cells, the aim of this study was to investigate the influence of nuclear receptors Nur77, FXR as well as FXR activation by the agonist GW4064 in cerebral ischemia-reperfusion (I/R) injury.

Methods:
Transient middle cerebral ischemia (MCAO) was induced in adult mice assigned to 4 groups: placebo, Nur77-deficient, FXR-deficient and FXR-ligand GW4064-treated (each n=7-8). A priori survival-time was set to 72 hours. Mice underwent functional tests and histological studies were performed for evaluation of infarct volume, immune cell activation/immigration and neuronal apoptosis.

Results:
MCAO led to delayed (24-48h after I/R) but severely worsened functional outcome in Nur77 and FXR-ko mice compared to wildtype animals (p<0.001, ANOVA+Bonferroni post-hoc). FXR- and Nur77-ko mice developed increased infarct volumes (Nur77, p<0.05) and had elevated TUNEL+-cell counts within the ischemic lesion (FXR, p<0.05). In contrast, treatment with FXR-agonist GW4064 resulted in improved functional outcome compared to placebo-treated mice. Evaluation of microglia and monocytes/macrophages showed an increased F4/80+-cell count 72h following MCAO in GW4064-treated mice.

Conclusion:
Deficiency of nuclear receptors Nur77 and FXR significantly worsened functional outcome, increased infarct size and cell apoptosis, whereas treatment with nuclear receptor agonist GW4064 led to improved rotarod performance and altered F4/80+-immune cell response. These results suggest a crucial involvement of the nuclear receptors Nur77 and FXR in pathways relating to post-stroke inflammation and tissue damage development.
Abstract W P238: Selective Deletion of Pi3-kinase Gamma in the Brain Inhibits Tissue Plasminogen Activator-induced Brain Hemorrhage
Authors: Jin Rong , Zhu Xiaolei , Wang Cuiping , Nanda Anil , Granger D Neil , Li Guohong
Published: July 2021

Background:
PI3-kinase gamma (PI3Kγ), a key modulator in inflammation, is involved in many inflammatory diseases. We recently reported that PI3Kγ deficiency protects the brain from ischemic injury in PI3Kγ-/- mice by reducing blood-brain barrier damage and tissue infarction through inhibition of NF-kB-dependent inflammation, mainly involved in reduced MMP-9 activity in ischemic brain endothelium, microglia activation, and neutrophil infiltration into the ischemic brain. Meanwhile, we reported that ischemic brain endothelium, activated microglia, and infiltrating neutrophils represent the major cellular sources of PI3Kγ expressed in the brain within 24 h after cerebral ischemia. Brain hemorrhage is a serious complication of recombinant tissue plasminogen activator (tPA) therapy for ischemic stroke. In this study, we further investigated potential involvement of PI3Kγ, in particular the expression of PI3Kγ in the brain, in tPA-induced brain hemorrhage after ischemic stroke.

Methods and Results:
Focal ischemic stroke was induced by transient middle cerebral artery occlusion and reperfusion. PI3Kγ deficiency in PI3Kγ-/- mice not only reduced tissue infarction but also almost completely blocked brain hemorrhage induced by delayed tPA treatment at 6 hours after stroke. Bone marrow chimeras reveal that chimeric mice lacking PI3Kγ in the brain (WT
BM
→KO) blocked the delayed tPA-induced brain hemorrhage effectively as found in PI3Kγ-/- mice while chimeric mice lacking PI3Kγ expressed in leukocytes (KO
BM
→WT) had minimal effect on the tPA-induced brain hemorrhage. These effects could be attributed to a profound inhibition of MMP-9 activity in ischemic brain endothelium found in both PI3Kγ-/- mice and (WT
BM
→KO) chimeric mice but not in (KO
BM
→WT) chimeric mice, as determined by double IHC staining of MMP-9 in brain endothelial cells and by zymographic analysis of MMP-9 activity using microvessels isolated from the brain.

Conclusion:
Our findings suggest that PI3Kγ in the brain may play a predominant role in delayed tPA-induced brain hemorrhage after ischemic stroke. Our future study will define the role of PI3Kγ derived from brain endothelial cells versus microglia by generation of tissue/cell-specific knockout mice using the Cre-loxP system.
Abstract W P251: Novel Platelet-Activating Factor Receptor Antagonists Attenuate Brain Injury after Experimental Stroke
Authors: Bazan Nicolas G , Khoutorova Larissa , Alvarez-Builla Julio , Belayev Ludmila
Published: July 2021

INTRODUCTION:
Platelet-activating factor (PAF) is a bioactive phospholipid that regulates synaptic activity and when overproduced is a potent mediator of leukocyte functions, including platelet aggregation and inflammation. PAF concentration increases during ischemia-reperfusion and is a mediator of neurotoxicity. The inhibition of this process plays a critical role in neuronal survival. We synthesized various analogues and identified them as PAF receptor antagonists, which were then selected for
in vivo
experiments to evaluate anti-ischemic activity.

METHODS:
Physiologically controlled Sprague-Dawley rats received 2 h MCAo by poly-L-lysine-coated intraluminal suture. LAU compounds (LAU-0901, LAU-09015, LAU-09018, LAU-09019, LAU-09020 or LAU-09023; 30 mg/kg) or vehicle (45% cyclodextran) was administered IP at 2 h from onset of MCAo. Neurological status was evaluated during occlusion (at 60 min) and on day 1, 2, 3 and 7. Histopathology was carried out on day 7.

RESULTS:
Physiological variables were stable and showed no significant differences between groups. All LAU compounds significantly reduced the neurobehavioral deficit compared to the vehicle group, beginning from day 1 and persisting through the 7 day survival period. Histologically, the vehicle group showed large hemispheric infarcts with pan-necrosis. By contrast, LAU-treated rats showed preserved hemispheric structure and small subcortical infarcts. Treatment with LAU (LAU-0901, LAU-09015, LAU-09018, LAU-09019, or LAU-09023) significantly reduced total infarct volume compared to the vehicle group by 68%, 52%, 40%, 51% and 54%, respectively.

CONCLUSION:
Our results clearly indicate that novel LAU PAF receptor antagonists are highly neuroprotective on behavior and reduction of brain infarction in experimental stroke. These compounds may provide the basis for future therapeutics in patients suffering ischemic stroke.
Abstract W P253: Repeated Remote Ischemic Conditioning (RIC) after Intracerebral Hemorrhage Regulates Macrophage Polarization and CD36 Expression to Promote Hematoma Resolution
Authors: Vaibhav Kumar , Khan Mohammad B , Baban Babak , Ahmed Heba , Wang Philip , Chaudhary Aizaz , Fagan Susan C , Hess David C , Hoda Md Nasrul , Dhandapani Krishnan M
Published: July 2021

Background:
RIC-therapy during sub-arachnoid hemorrhage in humans was found well tolerated. We tested the hypothesis that repeated daily RIC-therapy would improve post-ICH outcomes in mice.

Methods:
ICH was induced by collagenase injection into the brain of CD1 male mice (4-mo old). Mice were randomized for either once daily RIC-therapy or related sham-procedure starting 2-hours post-ICH until sacrifice. RIC-therapy post-ICH was also tested in mice pre-treated with clodronate-liposome consequently deficient in macrophage population. Laser speckle imager (LSCI) was used to detect changes in peripheral ischemia resulting from space occupying hematoma. SWI/ FLASH (T2*W) MRI was used to estimate hematoma size. Behavioral outcomes were assessed by focal deficit score and beam walk challenge. Hemoglobin content in the brain tissue by spectrophotometry, macrophage polarization with CD36 expression in peripheral blood by flowcytometry, and histopathological analyses in the brain, were also performed. Statistical significance was determined at p<0.05.

Results:
Even after 5-days post-ICH, peripheral cerebral ischemia was evident, which was significantly attenuated by RIC-therapy due to reduced hematoma size. Effect of RIC-therapy on hematoma resolution was abolished in the clodronate-liposome treated mice. Higher focal deficit score and impaired fine motor coordination were significantly evident in ICH mice, which was attenuated by RIC-therapy. Post-ICH increased hemoglobin content at day 5 was significantly reduced by RIC-therapy. Interestingly, repeated RIC-therapy promoted macrophage polarization towards M2 (anti-inflammatory) phenotype with increased CD36 expression. At 2-weeks post ICH, cresyl violet and Luxol-Fast blue staining showed significantly increased cell death and white matter degeneration (WMD), respectively, in the ICH mice. RIC-therapy after ICH significantly reduced the cell death and WMD in a 2-weeks follow up.

Conclusion:
Human subjects deficient in CD36 have impaired capability of hematoma resolution. Long-term RIC-therapy might be helpful in spontaneous hematoma resolution via increased M2-type macrophage and CD36 expression.
Abstract W P272: Healthcare Resource Availability, Acute Ischemic Stroke Outcomes and Quality of Care
Authors: O'Brien Emily C , Wu Jingjing , Schulte Phillip J , Fonarow Gregg C , Hernandez Adrian F , Schwamm Lee H , Peterson Eric D , Bhatt Deepak L , Smith Eric E
Published: July 2021

Background:
Healthcare resources vary by geographic region, but the association between hospital-based resources and acute stroke outcomes has not been well-characterized.

Methods:
We used data from Get With The Guidelines-Stroke (GWTG-Stroke), a national, inpatient quality improvement initiative, and the Dartmouth Atlas of Healthcare (DAH) to examine the association between regional healthcare resource availability, stroke care, and outcomes. We categorized each hospital resource region (HRR) according to whether it was above or below the 2006 national median in availability of six resources: neurologists, radiologists, ER physicians, rehabilitation specialists, hospital-based RNs, and inpatient beds. Each HRR was then classified as High (>50th percentile in at least 5 resource categories), Medium (>50th percentile in 3 or 4 categories), or Low resource (>50th percentile in fewer than 3 categories). We used multivariable logistic regression to examine healthcare resource level and in-hospital outcomes.

Results:
Of 1,480,308 ischemic stroke patients admitted from 2006-2013, 28.8% were hospitalized in low resource HRRs, 44.4% in medium resource HRRs, and 26.9% in high resource HRRs. Demographic distributions were similar across resource levels. In unadjusted models, global p-values were non-significant and all standardized differences between resource levels were <10% for the defect free care composite measure and all but one individual quality measure (discharge statin therapy). Adjusted length of stay and in-hospital mortality were similar across all resource levels, including in a sensitivity analysis adjusting for NIHSS (recorded in 60.7%; data not shown).

Conclusions:
Among hospitals participating in GWTG-Stroke, differences in regional resource availability did not influence acute ischemic stroke quality of care or in-hospital outcomes.
Abstract W P298: Simulation Based Acute Stroke Training for Neurology Residents
Authors: Khanal Deependra , Hocker Sara
Published: July 2021

Background:
The majority of patients presenting with acute stroke in teaching hospitals are assessed by neurology residents. Simulation based training has been shown to be an effective teaching tool in medical education. We sought to determine whether simulation based training improves learner confidence in the evaluation and management of acute ischemic stroke.

Methods:
We devised a simulated acute stroke scenario utilizing a standardized patient instructed to act out a right hemispheric syndrome and an emergency department nurse. Scenarios were performed in May/June of 2013 and April/May of 2014. Laboratory values, vitals, electrocardiogram and a normal head computerized tomography scan were shown to the residents. Residents were expected to efficiently take a focused history, perform an NIHSS exam, evaluate exclusion and inclusion criteria, obtain informed consent for thrombolysis administration and give the correct dose of t-PA. Following t-PA administration, the patient develops an acute severe headache and the learner is evaluated on whether they immediately discontinue the infusion and initiate appropriate management steps for t-PA associated hemorrhage. Following the scenario the learner met one on one with staff for a debriefing session. Learner confidence in the management of acute stroke was assessed before and after the simulation experience using a 5 point Likert scale with 1=novice, 3=competent and 5=expert. Following the simulation, learners were asked to evaluate the experience (poor, needs improvement, good or outstanding).

Results:
21 Neurology residents completed the scenario (11 in 2013 and 10 in 2014). Learner confidence improved from mean 2.81(SD-0.88) to 3.36(SD-0.73), p=0.03. Evaluations were favorable with all residents reporting a ‘good’ or ‘outstanding’ experience.

Conclusion:
We have demonstrated that simulation training in the evaluation of acute ischemic stroke among neurology residents is feasible and improves learner self-confidence.
Abstract W P339: Time Is Brain: A Tale of Unintended Consequences
Authors: Santora Carolyn , Cammarata Dan , Conlon Eileen , Dowdy Eileen , Ferrara Kathleen , Guido Michael , Kabacinski Andrea , Mount Julie , Rowe Alison
Published: July 2021

Background:
There is a narrow therapeutic range for thrombolysis in stroke. “Time is Brain” emphasizes the concept that nervous tissue is rapidly lost as stroke progresses. Research suggests 1.9 million neurons are lost each minute of untreated stroke. Urgency to treat led to the practice of estimating weight on arrival. Unfortunately, expediency of weight estimation can result in over or under dosing. After a devastating adverse outcome related to misdose of tPA based on estimated weight, SBUH implemented a protocol that ensures actual weight measurement before administration of thrombolytics without delaying time to treatment.

Process:
Our state accredited stroke program is recognized with the AHA Gold Plus Award. Door to needle time for tPA was below 60 minutes. Estimated weight dosing was standard as supported in the NINDS t-PA stroke study as not having negative impact on outcome. At SBUH in 2013 a patient had estimated weight entered of 90 kg. A CT Scan was performed within 9 minutes and tPA dose of 81 mg given within 57 minutes. Stroke symptoms resolved. This was an apparent successful implementation of protocol. Five hours later patient had mental status changes and emergent CT Scan revealed catastrophic intracranial hemorrhage. The patient died 13 hours later. It was believed that this patient was among the 6.9% that experience this known complication of tPA. A review of the chart revealed that the measured weight entered on the stroke unit did not match the estimated weight; the calculated dose was 40% more than should have been. The error was disclosed to the family and a deep dive and RCAs were completed. The error was reported to TJC and the state DOH.

Outcomes:
EPR changes including soft stops, changes in the weight fields, and process changes including a tPA time out and equipment use to ensure measured weights were implemented. The new processes did not compromise door to needle time. Average Door to needle time pre implementation was 66.88 minutes. Post implementation time is 63.1.

Conclusions:
The expediency of weight estimation can result in over or under dosing of tPA. At SBUH, we implemented a process that ensures actual weights before administration of thrombolytics but does not delay time to treatment. This is a safer and more effective process for stroke care.
Abstract W P340: Emergency Department Nurses Collaborate With Long Term Care Facilities for Stroke Patients
Authors: Strom Jamie L
Published: July 2021

Background and Purpose:
Stroke treatment is often delayed before patients reach the emergency department (ED). Some patients arrive in time to receive medication that can reverse new stroke symptoms. Some are not as fortunate. They are either admitted to the palliative unit, or discharged only to live with their new disabilities possibly for the rest of their lives.

In 2013, nurses observed many long term care (LTC) patients were not getting to the ED in time to receive tPA (tissue plasminogen activator), a medication used to reverse stroke symptoms. The purpose of this process improvement was to increase the number of LTC patients with stroke symptoms arriving in the ED within the tPA window.

Methods:
To determine how many patients from nursing homes were missing the tPA window, data from the ED’s records was abstracted from the month of June 2013. The sample size was all patients who presented with possible stroke symptoms, and who were also from LTC facilities. Surprisingly, 100% of LTC patients presenting with stroke symptoms missed the tPA window. With the support of ED leadership, we decided to raise awareness about the tPA window in the LTC facilities. No evidence existed from ED’s related to LTC patients and the tPA window. Approximately 1,000 unused stroke pamphlets were collected. A PowerPoint presentation based on AHA guidelines was used. A lecture occurred at the community’s senior services meeting, and many LTC administrators were willing to adopt this education initiative at their facilities. ED staff became involved and helped conduct the in-services. In exchange for their volunteering, they received credit to help with career ladders at their hospital.

Results:
The number of possible stroke patients from LTC facilities getting to the ED within eight hours of the last time seen normal (LTSN) has increased from 0% in June 2013, to 25% in March 2014.

Conclusions:
Stroke education teams of ED nurses showed improvement in LTC patients arriving in the ED within the tPA window. In conclusion, it is encouraged that other ED staff volunteer to teach in LTC facilities in their own communities, in assisting their stroke patients as well.
Abstract W P36: Timing Of Collateral Circulation In Acute Stroke And Its Effect On Predicting Outcomes
Authors: Yeo Leonard , Paliwal Prakash , Teoh Hockluen , Chan Bernard , Seet Raymond , Sharma Vijay
Published: July 2021

Background:
We previously reported that Miteff scoring system on pre-tPA CTA was able to predict good functional outcomes in AIS, conversely substantial collateral recruitment on the 24hr CTA led to worse outcomes. We now aimed to determine if the degree of collateral circulation at a specific timing affects its ability to prognosticate outcomes.

Methods:
Patients treated with IV-tPA during 2018-2012 were included. Patients were stratified by onset-to-CTA timing from 0-60, 61-120, 121-180 and >180 minutes. Two independent neuroradiologists evaluated intracranial collaterals using the Miteff’s system, Maas system, and Alberta Stroke Program Early CT score (ASPECTS) 20-point methodology. Good and severely poor outcomes at 3-months were defined by modified Rankin Scale (mRS) score of 0-1 points and 5-6 points, respectively. SICH was intracranial bleed with NIHSS increase of ≥4 points.

Results:
250 Consecutive AAIS patients were included. 52 patients in the 0-60 group, 89 in the 61-120 group, 59 in the 121-180 group and 40 patients in the >180 group. On multivariate analysis from 0-120 minutes, good collaterals by Miteff classification showed a trend to good outcomes (OR 2.460 95%CI 0.985- 9.770, p =0.06) and significantly prevented severely poor outcomes (OR 0.199 95% CI 0.053-0.743, p=0.016) and SICH (OR 0.196 95%CI 0.045-0.862, p=0.03). However the association with prevention of unfavourable outcomes was no longer present in the 121 -180 and > 180 minutes groups.

Conclusions:
Good collaterals are associated with better functional outcomes however this benefit may be time dependent.
Abstract W P395: Aging Alters Vascular Stiffness in the Posterior Cerebral Artery in C57bl/6 Mice
Authors: Diaz-Otero Janice M , Jackson William F , Dorrance Anne M
Published: July 2021

Aging is a major risk factor for cardiovascular disease in part as a result of dysfunctional arteries. Arterial stiffening with age is considered to be an independent predictor of cardiovascular disease. Age-related artery remodeling in large conduit arteries increases the risk of stroke and dementia. Atherosclerotic elderly mice exhibit aorta outward remodeling compared to young mice. Also, peripheral resistance arteries remodel with age. Less is known on how aging alters the morphology of cerebral arteries. Historically young mice have been used in many stroke studies, however the STAIR criteria for preclinical testing clearly states that potential neuroprotective drugs need to be tested in aged mice. It is therefore important to understand how aging affects cerebral artery structure. The effects of aging have not been investigated in the posterior cerebral artery (PCA). The PCAs provide blood flow support when the middle cerebral artery is occluded or when blood flow to the brain is decreased by carotid artery stenosis. We hypothesized that aging would increase the PCA lumen diameter and wall thickness in C57BL/6 mice. PCAs were collected from 5 month (n=7) and 24 month (n=7) old mice for assessment of vessel structure by pressure myography. All results are presented as mean ± SEM, young vs old. The old mice weighed significantly more than the young mice (28.85±0.36 vs 33.27±1.04 grams p<0.05). Surprisingly, aging caused limited changes to the structure of the PCA. Statistically significant changes in the outer diameter (126.9± 2.5 vs 141.6 ± 3.3μm, ANOVA p <0.05) and lumen diameter (100.9± 2.4 vs 115.8± 3.2μm ANOVA p <0.05) where only observed at an intralumenal pressure of 20mmHg. Changes observed at such a low intralumenal pressure are unlikely to be physiologically relevant. Aging had no effect on the wall-to-lumen ratio, wall thickness, or distensibility. Aging did increase artery stiffness assessed by calculating the slope of the individual stress strain curves (beta coefficient: 5.13± 0.42 vs 6.71± 0.42, t-test p <0.05). Increased artery stiffness is associated with an increased risk of cardiovascular disease. In the absence of a change in the wall thickness this increased stiffness is likely to be due to changes in extracellular matrix deposition.
Abstract W P397: Severity of White Matter Hyperintensities Is Associated With Impaired Cerebral Autoregulation During Cardiac Surgery
Authors: Faigle Roland , Gottesman Rebecca , Hori Daijiro , Kraut Michael , Hogue Charles
Published: July 2021

Introduction:
Impaired autoregulation during cardiac surgery with cardiopulmonary bypass (CPB) is associated with perioperative mortality and morbidity. Identifying risk factors for impaired autoregulation during CPB surgery may facilitate risk stratification, and guide intra- and postoperative monitoring of high-risk patients.

Hypothesis:
We hypothesized that severity of white matter hyperintensities (WMHs) detected with MRI is associated with impaired cerebral autoregulation during CPB surgery.

Methods:
From a prospective cohort of 280 patients whom underwent cerebral autoregulation monitoring during CPB, 97 patients had research brain MRIs within 5-7 days of surgery. Intraoperative autoregulation monitoring was performed by generating a continuous moving Pearson’s correlation coefficient between mean arterial pressure (MAP) and cerebral blood flow velocity of the middle cerebral arteries measured with transcranial Doppler to generate the mean velocity index (Mx). Impaired autoregulation was defined as an Mx ≥ 0.4 at all MAPs. WMHs were assessed by blinded review of FLAIR images of all patients. WMHs were graded on a 0 to 9 scale. Logistic regression was used to explore associations between the degree of WMHs and impaired autoregulation as the primary outcome.

Results:
Twenty-two (22.7%) of 97 patients had impaired autoregulation. Age, sex, race, and other medical comorbidities did not significantly differ between patients with intact and impaired autoregulation. In univariate analysis, each 1-point increase in white matter (WM) score was associated with 1.64-fold increased odds (95% confidence interval [CI] 1.18-2.27, p=0.003) of impaired autoregulation. WM score remained an independent predictor of impaired autoregulation after adjusting for age, sex, race, hypertension, and prior stroke (OR 1.79, 95% CI 1.21-2.63, p=0.003). In adjusted models, severe white matter disease (WM score ≥3) was associated with nearly 5-times higher odds of impaired autoregulation compared to a WM score <3 (OR 4.75, 95% CI 1.58-14.27, p=0.005).

Conclusions:
WMHs are independently associated with impaired cerebral autoregulation during cardiac surgery and may increase the risk for perioperative morbidity and mortality.
Abstract W P425: Sepsis in Intracranial Hemorrhage: Does Stroke-Induced Systemic Immunosuppression Play a Role?
Authors: Rajagopalan Swarna , Ronca Richard , Azizi Ausim
Published: July 2021

INTRODUCTION:
Infection is a significant cause of mortality in patients with both ischemic and hemorrhagic stroke. This is thought to occur as a result of stroke-induced systemic immunosuppression (SIIS). The role of cerebral damage pre-disposing to sepsis has only been addressed in a few studies for ischemic stroke, and literature is sparse in Spontaneous Intracerebral Hemorrhage (SICH) patients who have higher mortality, greater disability and require more intensive medical care. We sought to determine identify predictors of SIIS and sepsis, so we may be able to recognize and intervene early.

METHODOLOGY:
We retrospectively analyzed 40 patients with SICH admitted to the NICU between January 2012 and January 30, 2014. We included patients with SICH. We excluded patients with multi-compartmental hemorrhage and patients lacking outcome data. Patient demographics including age, gender, location, volume of SICH, GCS, and total lymphocyte counts from days one to five of hospitalization was recorded. Data was divided into a non-infection group, where patients lacked any clinical or laboratory evidence of infections, and an infection group. Statistical analysis was performed to compare lymphocyte depletion over time between patients that developed an infection and those that did not.

RESULTS:
From the cohort of 40 patients with SICH, 20 developed an infection during their hospital course. Total lymphocyte counts were lower on all five days in the infection group compared to the non-infection group and became significant on day four of hospitalization (1 in the infection group vs. 2.1 in the non-infection group, p<0.01. Lymphopenia preceded clinical signs and symptoms of infection, which occurred in average on day 5.8 of hospitalization. Patients in the infection group had greater hemorrhage volume (32.5 ml vs. 15.5 ml) and poorer GCS scores on admission (12.7 vs. 11.8) although these differences did not reach statistical significance.

CONCLUSION:
The incidence of sepsis is high in SICH patients, and these patients have worse prognostic parameters. Our data suggests identification of lymphopenia may be a significant predictor of development of clinical infection in these patients. Future studies with larger sample sizes are warranted.
Abstract W P45: High Resolution Images of Perforating Arteries With 7T MRA in Acute Subcortical Infarction
Authors: Ohba Hideki , Harada Taisuke , Sasaki Makoto , Ohura Kazumasa , Natori Tatsunori , Narumi Shinsuke , Ohura Mao , Kato Tadayoshi , Terayama Yasuo
Published: July 2021

Introduction:
Patients with acute subcortical infarction show various clinical courses according to the pathology of perforating artery so that the noninvasive and precise neuroradiological evaluation of these arteries is very important for prevention of progression and recurrence of the disease. 7 Tesla (7T) - MRI (Magnetic Resonance Imaging) makes it possible to visualize perforating arteries in a way that would not otherwise be possible using conventional MRI. We attempted to assess perforating arteries and infarct lesions in the lenticulostriate artery (LSA) area using 7T- High resolution MRA (Magnetic Resonance Angiography), and to evaluate the association between image findings and clinical courses of treatment.

Method:
We included 13 patients (M:F = 7:6, mean age: 65 years old) with acute noncardioembolic stroke in LSA area detected by 1.5-T MRI. 7T MRI was acquired among these patients within 2 weeks after onset to visualize responsible LSA and to measure the volume of infarction by 7T-MRI- 3D-TOF MRA, 3D-FLAIR. We also evaluated the association between these results and the severity of stroke by National Institute of Health Stroke Scale (NIHSS).

Results:
Perforating arteries in the basal ganglia area were clearly visualized in all patients using 7T MRA. According to the location of occlusion and ischemic lesion, patients were categorized into 3 groups (A, B, and C): Group A - patients with proximal branch occlusion of LSA (2 cases), Group B - patients with occlusion of LSA adjacent to the ischemic lesion (7 cases), Group C - no occlusions (4 cases) in LSA associated with infarction.

Significant association between overall infarct volume and NIHSS(r=0.636, p=0.020)was observed, whereas infarct volume of each group was not associated with NIHSS. Clinical outcome were not associated with volume of infarction in all cases(p=0.12). However, there were no patients whose symptoms progressed in Group C.

Conclusion:
7 T-MRA can provide a clear visualization of perforating arteries and occluded lesions. It can be a useful and noninvasive diagnostic tool to study clinical prognosis after treatment in acute subcortical infarction.
Abstract W P47: Developing an Acute Lesion Atlas from Patients with Middle Cerebral Artery Stroke
Authors: Annasamudram Abhijith , Esterquest David , Marin Bianca Maria , McSweeney Melissa , Brandstatt Kelly , Voss Joel , Prabhakaran Shyam
Published: July 2021

Background and purpose:
Chronic lesion locations are associated with neurologic outcomes. However, voxel-based acute infarct maps have not been used to predict long-term deficits and outcomes. The combination of ischemic lesion volume and location may aid in acute outcome prediction models. We evaluated the feasibility of voxel-based lesion mapping in acute ischemic stroke patients.

Methods:
In a retrospective study of patients with suspected middle cerebral artery (MCA) territory strokes, we identified acute infarcts on the diffusion-weight imaging (DWI; b=1000) sequences and confirmed them on the apparent diffusion coefficient (ADC) sequences using a semi-qualitative approach. Only patients with all three sequences available were included in the study. We then manually created a lesion map for each patient. Lesions were overlaid on T1-weighted images and transformed to standardized stereotactic space. We overlaid the volumetric lesion masks from all patients to create a composite acute lesion atlas.

Results:
Among 164 patients, 5 (3.1%) patients had no clear acute lesion and 9 (5.5%) had technical problems with normalization or overlaying, leaving 150 (91.5%) patients for analysis (mean age 66.1 years; 52.0% male; 66.7% white; median NIHSS scale 4). A composite acute lesion atlas was developed (Figure) with regions of high overlap easily visible, suggesting high statistical power for acute lesion-outcome prediction modeling.

Conclusion:
Acute ischemic lesions can be reliably mapped and used to create aggregated infarct atlases. The considerable overlapping regions in stroke patients might provide sufficient power to detect highly correlated lesion-outcome relationships. The proposed technique may provide a time-sensitive method for identifying acute infarct location, predicting the course of recovery, and selecting patients for early interventions.
Abstract W P55: Practice Diversity Among US Neurologists with Respect to the 3 to 4.5-Hour Window for Acute Stroke Thrombolysis
Authors: Mutgi Sunil , Lafountain Nicholas , Grose Noah , Torbey Michel T , Behrouz Reza
Published: July 2021

BACKGROUND:
In 2009, the AHA/ASA endorsed extending the Acute Stroke IV tPA treatment window to 4.5 hours. Four additional exclusionary criteria were advised for treating patients in this extended window. It is unknown how the practice of stroke care has evolved since then. We developed an online survey aimed to evaluate the current practice patterns of neurologists when treating patients in the 3 to 4.5 hour therapeutic window.

METHODS:
We developed a survey utilizing SurveyMonkey.com. The survey included 6 questions, 1. Subspecialty, 2. Frequency of informed consent when giving IV tPA in the 3 to 4.5 hour window, 3-6. Frequency excluding patient's from treatment in the 3 to 4.5 hour window for any of the additional exclusionary criteria. Answer options for questions 2-6 included: always, often (>50% of the time), seldom(<50% of the time), and never. The publicly available AHA/ASA online member directory was utilized to identify physicians meeting criteria: Council: Stroke, Specialty: Neuro/Stroke, Country: USA. The electronic survey was sent by email to 1000 identified physicians.

RESULTS:
260 physicians responded, 230 completed the survey in its entirety and were included in our results. Subspecialties were: 83% vascular neurology, 13% general neurology, and 3% other neurology. Informed consent was always obtained by 33%, often by 22%, seldom by 16%, and never by 28%. Responses for specific exclusion criteria for the 3 to 4.5-hour window were as follows: 1) 34% always excluded patients age >80, 23% often, 29% seldom, and 13% never; 2) 31% always excluded patients with concomitant history of diabetes mellitus and stroke, 21% often, 27% seldom, and 22% never; 3) 28% always excluded patients on warfarin with normal INR, 12% often, 15% seldom, and 46% never; 4) 36% always excluded patients with NIHSS >25, 24% often, 28% seldom, and 12% never.

CONCLUSION:
Among US neurologists who care for stroke patients, there is notable diversity in practice with respect to IV thrombolysis within the 3 to 4.5-hour window. This may depict disparities in individual interpretation and acknowledgement of the scientific data pertaining to the extended window. There is a tendency towards obtaining informed consent and adherence to all four exclusion criteria, but not universally.