bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 2544: CT Brain Alert Specific for Stroke Significantly Improves Door to CT Brain Time in a Rural Hospital Setting
Authors: Rankin Pauline M , Jones Laura , McLaughlin James
Published: March 2022

P> National Studies from the American Heart Association/American Stroke Association's Get with the Guidelines quality improvement initiatives show that brain imaging in acute stroke care is not performed within the recommended 25 minutes in the majority of cases and quality improvement initiatives need to focus on reducing door to imaging times. UPMC Northwest, a 126 bed rural hospital serving Northwest Pennsylvania, began a quality assurance initiative for monitoring CT brain times in 2003 to evaluate guideline compliance and identify areas of change to improve door to CT brain start times in acute stroke patients. Based on the data collected on door to CT start times from STAR radiology information system and GWTG-Stroke data base, the stroke team committee convened to identify barriers, discuss process change and to ensure the implementation of change within the institution. A potential barrier identified was that all CT brain studies were ordered STAT in the Emergency Service setting and CT staff could not identify stroke verses non-stroke patients quickly. The stroke Team Committee assessed the hypothesis that development of an alert system enabling CT staff to quickly identify acute stroke patients would improve door to CT start times. An acute stroke alert protocol was added to the CT brain scan order to include “acute stroke” in the order set. The stroke alert enabled CT staff to quickly identify an order for the acute stroke patient and prepare the CT scanner. The acute stroke protocol was activated in 2004 and data collected on 1481 patients from October 2004 to December 2010 showed improvement of door to CT start times from 38 minutes in 2004 to 9.5 minutes in 2010, an improvement of 28.5 minutes. Other initiatives instituted to reduce acquisition time of critical CT brain scan information included a contracted tele-radiology group for round the clock radiologist coverage, phone calls from Emergency Service to CT staff to alert of an acute stroke patient prior to arrival and education for all hospital staff on acute stroke treatment guidelines. In conclusion, implementation of an acute stroke alert for CT brain has significantly decreased the time from door to CT brain scan for acute stroke patients entering UPMC Northwest, facilitating brain saving treatment and promoting awareness for ongoing stroke care quality improvement.
Abstract 2585: Disparities in Evaluation by Certified Primary Stroke Centers within the REGARDS cohort
Authors: Mullen Michael T , Kasner Scott E , Howard Virginia J , Judd Suzanne , Branas Charles C , Albright Karen C , Rhodes J. D , Kleindorfer Dawn , Carr Brendan G
Published: March 2022

Background:
There are known disparities in stroke incidence and mortality on the basis of race, income, region, and population density. Disparate access to specialized stroke care may contribute to these disparities. We sought to evaluate access to Joint Commission certified primary stroke centers (PSC) by race, education, income, population density, and region within the REGARDS cohort.

Methods:
The REasons for Geographic and Racial Differences in Stroke (REGARDS) study is a prospective population-based cohort of adults 45 years or older. 30,239 participants were recruited between 1 2003 and October 2007. Participants are contacted at 6 month intervals to ascertain suspected stroke events. The analysis was limited to the first suspected stroke event for each subject between 12/9/2005 and 1/6/2011. Medical records were retrieved and we determined if the evaluating hospital was a certified PSC at the time of the event. Region was dichotomized to stroke-belt or non-belt. Population density was dichotomized to urban or non-urban. Subjects evaluated at a PSC were compared to those evaluated at a non-PSC. Multivariable regression was used to determine independent predictors of PSC evaluation.

Results:
There were 1000 suspected stroke events during the study interval, of which 204 were evaluated at a certified PSC. Women were less likely to be evaluated at a PSC than men, 17.8% vs 23.0% (p=0.04). Subjects with a history of stroke were less likely to be evaluated at a PSC than those without a history of stroke, 15.1% vs 21.6% (p=0.04). Subjects who reside in non-urban locations were less likely to be evaluated at a PSC than those in urban areas, 9.1% vs 23.9% (p<0.001). Subjects residing within the stroke belt were less likely to be evaluated at a PSC than those living in other regions, 14.7% vs 27.3% (p<0.001). In the univariate analyses, no disparities were found on the basis of race, education, or income. In the multivariable analysis, living in non-urban areas (OR 2.6, 95% CI 1.5-4.5), living within the stroke belt (OR 1.9, 95% CI: 1.3-2.7), and having a prior history of stroke (OR 2.2, 95% CI 1.3-3.7) predicted evaluation at non-certified hospitals.

Conclusion:
Disparities in evaluation by certified PSC’s are related to geographic factors, region and population density, but not to most individual characteristics including race, education, or income. Despite an increased burden of cerebrovascular disease in the stroke belt and in rural areas, subjects in these areas were less likely to be treated at certified hospitals. This may be attributable to a reduced number of stroke centers in these locations. Public policy and systems planning should ensure specialized stroke care is rapidly accessible in areas with the greatest need.
Abstract 2636: Magnetic Resonance Oxygen Metabolic Index Distinguishes infarct from peri-infarct tissue better than ADC and PWI In hyperacute ischemic Stroke Patients
Authors: An Hongyu , Ford Andria L , Eldeniz Cihat , Chen Yasheng , Vo Katie D , Derdeyn Colin P , Powers William J , Lee Jin-Moo , Lin Weili
Published: March 2022

Background:
Diffusion (DWI) and perfusion weighted imaging (PWI) have been extensively studied to delineate irreversibly-injured tissue (that will progress to infarct) from reversibly-injured tissue (that will remain viable). An MR-based method, oxygen metabolism index (MROMI), may provide relevant metabolic information critical for determining tissue viability. We compared the ability of hyperacute MROMI, mean transit time (MTT), and apparent diffusion coefficient (ADC) to distinguish brain tissue that infarcted one month later from an initially hypoperfused region that survived, and contralateral mirror brain regions.

Methods:
Ischemic stroke patients were imaged at <4.5hr and at 1 month after stroke onset. Dynamic susceptibility contrast method measured cerebral blood flow (CBF) and MTT. An asymmetric spin echo sequence measured oxygen extraction fraction (OEF). MROMI=CBF x OEF. Co-registration and segmentation aligned images and separated gray from white matter, respectively. Hypoperfusion was defined as tissue with MTT > 4sec + the contralateral median MTT. Three ROIs were defined: (1) ROI
Infarct
(final infarct as manually outlined on the 1month FLAIR); (2) ROI
Peri
(acutely hypoperfused, but not included in the final infarct); and (3) ROI
Mirror
(the contralateral mirror region of the ROI
Infarct
. Each patient’s ROIs were normalized (n) to the contralateral hemisphere as follows: nMTT= MTT-contralateral median MTT, nADC= ADC/contralateral median ADC, and nMROMI=MROMI/contralateral median MROMI. nMROMI was calculated in gray and white matter separately. The 3 ROI’s were compared for nMROMI, nMTT and nADC using the Kruskal-Wallis test with Dunn’s post-tests.

Results:
25 patients were imaged at 2.9 ± 0.7 hrs and 1 month after stroke onset. Mean values for nMTT, nADC, and nMR-OMI were obtained for the 3 ROI’s (ROI
Infarct
ROI
Peri
and ROI
Mirror
) for each patient. Significant differences were found between ROI
Infarct
and ROI
Mirror
(P<0.001) for all three parameters (nMTT, nADC and nMROMI). However, only nMROMI demonstrated a significant difference between ROI
Infarct
and ROI
Mirror
(P<0.05) (
Figure
). Both nMTT and nADC values in ROI
Infarct
varied greatly across patients and no significant differences between ROI
Infarct
and ROI
Peri
were found.

Conclusions:
Identifying tissue that would die from hypoperfused but survived tissue is challenging during acute ischemia. Our results have demonstrated that hyperacute MROMI show significant differences between these two regions, while MTT and ADC did not, likely due to high inter-individual variability using the latter parameters.
Abstract 2654: Central Nervous System Infections And Risk of Stroke - A Population-Based Analysis
Authors: Chi Nai-Fang , Hu Chaur-Jong , Chien Li-Nien , Chiou Hung-Yi
Published: March 2022

Introduction:
Central nervous system (CNS) infections include meningitis, encephalitis, and myelitis caused by various pathogens. Although CNS infections are treatable, its inflammatory process causes irreversible brain damage and neurological sequeale such as seizures, cognitive dysfunction, and focal neurological deficits in nearly 20% of the patients. Cerebrovascular complication is believed to be a common mechanism of neurological sequelae in CNS infections, but the risk has rarely been reported. Earlier researches have shown an acute respiratory or urinary tract infection episode transiently increases vascular events including stroke and acute myocardial infarction (AMI). Current studies were usually with inadequate sample sizes to find the risk of vascular complications relevant to CNS infections. Consequently, the association between CNS infections and stroke, as well as AMI, is still unclear.

Hypotheses:
Central nervous system (CNS) infections may increase the risk of vascular diseases including stroke and acute myocardial infarction (AMI).

Methods:
To investigate the risks, we conducted a retrospective cohort study by the Taiwan National Health Insurance Research Database. The study cohort comprised all adult patients with diagnoses of CNS infections during 2000 to 2005 (n=440). The comparison group comprised randomly selected patients (5 for one subject of CNS infections, n=2,200) matched with the study group by their age and sex. Patients were tracked from their index visits for at least 1 year and mean of follow-up periods among patients with and without CNS infections were 3.8 years and 4.1 years. The Kaplan-Meier survival estimations were used to compare the differences in stroke and AMI-free survival rate of patients with and without CNS infections after adjusting censoring cases. Parametric survival models were used to examine the hazard risks of stroke and AMI of CNS infections cases and their comparison controls.

Results:
After adjusting the patients demographic characteristics and comorbidities, the risk of patients with CNS infections developing stroke were 5.6 times greater than their comparison group (the incidence rate of stroke for patients with and without CNS infections were 16.84 and 3.03 per 1000 person-year). More than 70% of the stroke events were occurring within one year after CNS infections. The risk of AMI was not found as we compared patients with and without CNS infections.

Conclusions:
The population-based cohort study suggested that adult patients with CNS infections have higher risk to develop stroke but not AMI, and the risk is marked within a year after infections.
Abstract 2684: Clopidogrel Load For Emboli Reduction In Patients With Symptomatic Carotid Artery Stenosis Undergoing Urgent Carotid Endarterectomy (CEA): A Multicenter Pilot Feasibility Study
Authors: Tsivgoulis Georgios , Kerasnoudis Antonios , Krogias Christos , Vadikolias Konstantinos , Barlinn Kristian , Meves Saskia , Athanasiadis Dimitrios , Heliopoulos Ioannis , Alexandrov Andrei V
Published: March 2022

Background&Purpose:
Microembolic signals (MES) on transcranial Doppler (TCD) are an independent risk factor for recurrent stroke and neurological deterioration in patients with extracranial symptomatic and asymptomatic carotid artery disease (CARAD). Clopidogrel load (300mg) combined with dual antiplatelet therapy has been shown to reduce asymptomatic embolization in patients with symptomatic CARAD. We sought to determine feasibility of clopidogrel load in decreasing asymptomatic embolization in patients with symptomatic CARAD undergoing urgent CEA within the first 8 days from the index event.

Subjects&Methods:
Consecutive patients with symptomatic CARAD (70%-99% stenosis) and presence of MES on 1-hour baseline (<24 hours from the index event) TCD-monitoring of ipsilateral middle cerebral artery (MCA) were treated with clopidogrel load followed by clopidogrel 75mg±aspirin 100mg during the elapsed time period between hospital admission and urgent CEA at three tertiary care stroke centers. Repeat 1-hour TCD monitoring was performed the day before surgery. Bleeding complications during surgery and recurrent strokes/TIAs during the first month following the index event were prospectively documented. Functional independence at three months was evaluated using the modified Rankin Scale (mRS) Score.

Results:
A total of 9 symptomatic CARAD patients (mean age 66±6years, 89% men, 56% ischemic strokes, median NIHSS 4 points, interquartile range 0-8, 44% TIAs) were treated with clopidogrel load followed by dual (66%) or single (33%) antiplatelet therapy. MES count was significantly reduced between baseline (<24 hours from index event, median count 8 MES/hr, interquartile range 6-17) and repeat (4-7 days from index event, median count 0 MES/hr, interquartile range 0-4; p=0.008 by Wilcoxon Signed Ranks Test) TCD-monitoring. The mean MES frequency reduction (compared to baseline) was 89% (95%CI:77%-100%). No bleeding complications (0%) or recurrent strokes (0%) were documented. All patients were functionally independent (mRS-scores of 0-1) at three months.

Conclusions:
Our pilot study shows feasibility of administering clopidogrel load followed by dual or single antiplatelet therapy to reduce asymptomatic embolization in patients with symptomatic CARAD who are scheduled to undergo urgent CEA. The present findings are subject of a larger ongoing multi-center study.
Abstract 2686: Plasma HMGB1 Concentration Correlates With The Inflammatory Response Following Stroke
Authors: Schulze Juliane , Zierath Dannielle , Tanzi Patricia , Shibata Dean , Dressel Alexander , Cain Kevin , Becker Kyra
Published: March 2022

Background:
There is an inflammatory response following ischemic stroke that appears to contribute to brain injury and worsen outcome. High-mobility group box 1 (HMBG1) is a nuclear protein that is released from necrotic cells and serves as a “danger signal” which can initiate an inflammatory response in a non-infectious environment. We assessed whether early systemic HMGB1 could serve as a marker for infarct size and predict outcome and whether plasma HMGB1 would correlate with systemic markers of inflammation.

Methods:
Plasma HMGB1 concentrations were analyzed in 114 patients with ischemic stroke at 1 (N=38), 3 (N=98), 7 (N=95), 30 (N=89), 90 (N=71), 180 (N=70) and 365 (N=24) days (blood samples were not available for all patients at all time points). A group of 40 “healthy” volunteers served as controls. Infarct volume was determined on diffusion weighted MRI and stroke severity by NIHSS score. The association between plasma HMGB1 and laboratory markers of inflammation was analyzed at each time point. Significance was set at
P
<0.05.

Results:
There was only a modest correlation between the NIHSS score, infarct volume and early plasma HMGB1 (highest value by day 3) after stroke (r=0.248,
P
=0.009 and r=0.217,
P
=0.024, respectively). In comparison to controls, plasma HMGB1 was elevated to 30 days after stroke; patients with more severe strokes had higher plasma HMGB1 than patients with less severe stroke (
Figure
). There was a robust correlation between plasma HMGB1 and white blood cell (WBC) counts that was independent of stroke severity at 1 day after stroke (r=0.449,
P
=0.005). This relationship between plasma HMGB1 and WBC count persisted to 1 year after stroke (r=0.551,
P
=0.008) and was driven by polymorphonuclear cells (PMNs). Initial plasma HMGB1 was not predictive of long term outcome.

Conclusions:
Plasma HMGB1 is elevated following ischemic stroke, and is higher in patients with more severe strokes. The robust and independent association of HMGB1 with WBC counts following stroke suggests that these cells may be the primary source of plasma HMGB1 following stroke.
Abstract 2691: Multicenter, International Study of Stroke in the Young (MISSY): Initial Results on Racial Disparities in Early Outcomes
Authors: Tsivgoulis Georgios , Sharma Vijay K , Balucani Clotilde , Martin-Schild Sheryl , Bathala Lokesh , Palazzo Paola , Barlinn Kristian , Athanasiadis Dimitrios , Katsibari Chaido , Chaudhary Asad , Bogiatzi Chrysi , Patousi Athanasia , Flamouridou Maria , Tsakaldimi Soultana , Alexandridou Martha , Vadikolias Konstantinos , Heliopoulos Ioannis , Stamboulis Elefterios , Piperidou Charitomeni , Alexandrov Andrei V
Published: March 2022

Background&Purpose:
Strokes in young adults differ from cerebrovascular events in the general population due to a wider variety of etiopathogenic mechanisms as well as by incidence and outcomes. Limited data exist regarding racial disparities in stroke outcomes in this specific age subgroup. We sought to prospectively evaluate potential racial disparities in early outcomes of young individuals with stroke in a multicenter, international study.

Subjects&Methods:
We prospectively evaluated consecutive first-ever stroke patients aged 18-45 years old who were admitted in 7 tertiary care stroke centers in North America (n=2), Europe (n=3) and Asia (n=2) over a four-year period (2008-2011). Demographics, vascular risk factors, etiopathogenic mechanism of stroke and stroke severity at hospital admission (assessed using the NIHSS-score) were documented. Early functional outcome at 1 month following stroke onset was evaluated using modified Rankin Scale (mRS) score.

Results:
A total of 826 young adults (mean age 37±7years; 60% men; 49% Caucasians, 19% African-Americans and 32% Asians; median baseline NIHSS-score 6 points, interquartile range 3-14) have been evaluated during the study period with first-ever ischemic (84%) or hemorrhagic (16%) stroke. Baseline stroke severity differed between Caucasians (median NIHSS-score 4 points, interquartile range 2-10), African-Americans (median NIHSS-score 7 points, interquartile range 3-15) and Asians (median NIHSS-score 9 points, interquartile range 5-14; p<0.0001 by Kruskal-Wallis test). Early favorable functional outcome (defined as a 30-day mRS-score of 0-1) was different among racial subgroups (59% in Caucasians, 38% in African-Americans and 36% in Asians; p<0.0001). Race was independently (p=0.017) associated with functional outcome in multivariate logistic regression models adjusting for age, gender, vascular risk factors, baseline stroke severity and stroke subtype. Asian young adults with stroke were less likely to achieve an early favorable outcome (OR: 0.42, 95%CI: 0.22-0.79; p=0.008) compared to Caucasians. The former association was not significant for African-Americans (OR: 0.93, 95%CI: 0.55-1.55; p=0.767) compared to Caucasians.

Conclusions:
Racial disparities in early functional outcome following first-ever stroke in young individuals appear to be independent of other known outcome predictor variables. Asian young adults with stroke tend to have a lower likelihood to achieve functional independence at 30 days following stroke onset. The underlying mechanisms of the former association deserve further investigation.
Abstract 2698: Immediate Cerebrovascular and Brain Metabolic Effects of Remote Ischemic Preconditioning
Authors: Dusick Joshua R , Hamilton Robert , Bilgin-Freiert Arzu , Vespa Paul , Hu Xiao , Asgari Shadnaz , Gonzalez Nestor
Published: March 2022

Objective:
Remote ischemic preconditioning (RIPC) is a phenomenon by which brief periods of sublethal ischemia in one tissue confers immediate and delayed protection from ischemic injury to distant tissues. A better understanding of the effect of RIPC in the target organs in humans is necessary before this technique can be successfully translated into clinical practice. We investigated the immediate cerebral hemodynamic and metabolic effects induced by RIPC in the setting of subarachnoid hemorrhage (SAH).

Methods:
Patients with SAH aged 18-80 received 3 or 4 sessions of RIPC on non-consecutive days, 4-12 days after SAH. Each session consisted of four 5-minute rounds of lower limb ischemia, each followed by 5 minutes of reperfusion. During RIPC sessions, continuous ICP and transcranial Doppler (TCD) were recorded. A morphological clustering and analysis algorithm (MOCAIP) of ICP and TCD curves was used to evaluate the vascular changes. Microdialysis was used for brain metabolic assessment. Positive and negative controls for vasoreactivity and non-RIPC SAH microdialysis controls were used for comparison.

Results:
Seven RIPC sessions were performed in 4 patients (50% male, mean age 52, Fisher 4, H&H 2-4). During RIPC, there were no systemic changes in BP, HR or CVP. ICP increased in all but one session with a mean change of 8 to 15mmHg (p<0.001), not associated with pain or vital changes. TCD showed a tendency for ICA velocity increase (34.5 to 37cm/sec, p=0.61) and a significant MCA velocity decrease (111 to 87cm/sec, p=0.04). The MCA effect was not sustained beyond the RIPC period. ICP and TCD MOCAIP showed 20 and 3 metrics with directional variance consistent with positive controls for vasodilation. Vasodilation did not persist after the RIPC session. Microdialysis showed no significant variation in glucose, lactate or pyruvate. There were significant reductions in L/P ratio (31 to 28, p=0.002) and in glycerol (126 to 113μ g/L, p=0.009) despite TCD and angiographic evidence of vasospasm in 2 patients.

Conclusions:
In the setting of SAH, RIPC produces immediate, temporary hemodynamic changes characterized by vasodilation of the cerebral circulation. RIPC also reduced brain glycerol levels detected by microdialysis, indicating preservation of the integrity of cellular membranes and potentially reduction of oxidative stress.
Abstract 2743: Effectiveness of Early Dual Antiplatelets in Patients with TIA and Minor Stroke: Post-hoc Analysis of CLAIR Study
Authors: Lau Alexander Y , Zhao Yudong , Chen Christopher , Leung Thomas W , Fu Jianhui , Huang Yining , Wong Ka Sing Lawrence , Markus Hugh S ,   for CLAIR study investigators
Published: March 2022

Background
Patients with symptomatic intracranial atherosclerosis are at high risk of early recurrent stroke. Dual antiplatelet therapy appears promising for early secondary prevention of stroke or TIA, yet the ideal patients to benefit from this regime have not been identified.

Methods
We investigated the efficacy and safety of early dual antiplatelets use in TIA and minor stroke patients (NIHSS 0-3) by performing a post-hoc analysis of CLAIR (Clopidogrel plus aspirin versus aspirin alone for reducing embolisation in patients with acute symptomatic cerebral or carotid artery stenosis) study - a randomized, open-label, blinded-endpoint study in patients who had symptomatic large artery atherosclerosis, in whom micro-embolic signals (MES) were present on transcranial doppler monitoring. MES was used as surrogate marker for recurrent stroke risk. Analysis was by modified intention to treat.

Results
Sixty-five of 100 patients recruited had TIA or minor stroke (NIHSS 0-3); 30 received dual therapy (aspirin 75-60mg daily and clopidogrel 300mg day 1 then 75mg daily) and 35 received aspirin alone (75-160mg daily) for 7 days. 93% patients had intracranial stenosis. Mean onset-to-randomization was 2.3 days in dual therapy group and 3.2 days in monotherapy group (p=0.03). At day 7, 9 of 29 patients in dual therapy group and 18 of 34 patients in monotherapy group for whom data were available had ≥ 1 MES (relative risk reduction 41.4%, 95% CI 29.8-51.1, p<0.001). The median number of MES on day 7 was 0 in dual therapy group and 1.0 in monotherapy group (p=0.02). Two patients in monotherapy group had recurrent stroke. No patients had intracranial or severe systemic hemorrhage, except two patients in dual therapy group had minor bleeding.

Conclusion
Early dual therapy with clopidogrel and aspirin reduces MES at day 7 among patients with predominant intracranial atherosclerosis who had minor ischemic stroke or TIA, without causing significant bleeding complications.
Abstract 2795: Early Impairment of Collateral flow from Posterior circulation is a Determinant of Stroke recurrence in Adult Moyamoya disease
Authors: Noh Hyunjin , Kim Gyeong-Moon , Kim Suk Jae , Bang Oh Young , Chung Chin-Sang , Lee Kwang Ho
Published: March 2022

Early impairment of collateral flow from posterior circulation is a determinant of stroke recurrence in adult moyamoya disease

Hyun Jin Noh,MD
1
, Suk Jae Kim,MD
1
, Jong Soo Kim
2
, Seung-Chyul Hong
2
, Keon Ha Kim
3
, Pyeong Jun
3
, Oh Young Bang
1
, Chin-Sang Chung
1
, Kwang Ho Lee
1
, Gyeong-Moon Kim, MD
11
Department of Neurology,
2
Neurosurgery, and
3
Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea

BACKGROUND:
Adult moyamoya disease (MMD) is a progressive arteriopathy with high recurrence rate of ischemic stroke. But factors associated with the symptom recurrence in adult MMD have not been evaluated. The purpose of present study is to evaluate determinants of recurrent ischemic stroke in symptomatic adult MMD.

METHODS:
In this retrospective cohort, symptomatic adult MMD patients who were not surgically treated at Samsung medical center were enrolled between 1998.03 - 2010.03. All patients underwent conventional angiography, brain MRI, and MR angiography. Clinical and neuroimaging variables were analyzed to identify risk factors associated with recurrent ischemic stroke.

RESULTS:
Among 38 patients enrolled, 15 patients (9 female, mean age 45.4±3.6 yrs) were identified as recurrent ischemic stroke and 23 patients (14 female, mean age 41.3±7.0 yrs) without. Mean follow-up duration was 56.3±6.2 months. Multivariable regression analysis revealed group with recurrent ischemic stroke had a more chance to have significant stenosis in posterior cerebral arteries (PCA) than those without recurrent ischemic stroke (OR 6.48, 95% Confidence Interval 1.48 -28.33, P=0.015). The sensitivity of PCA stenosis was 60 %, the specificity 78.2 %, the positive predict value 64.2 %, and the negative predict value 75 %. However, there was no difference between groups in terms of the angiographic grading score, vascular risk factors, laboratory findings and medications.

CONCLUSION:
Our findings suggest that early impairment of collateral flow from posterior circulation may contribute to the recurrent ischemic stroke in adult MMD.
Abstract 2833: Transfers to Tertiary Care Hospitals Improve Outcome in Patients with Subarachnoid Hemorrhage but not Intracerebral Hemorrhage
Authors: Grigoryan Mikayel , Chaudhry Saqib A , Rodriguez Gustavo J , Suri M. Fareed K , Qureshi Adnan I
Published: March 2022

Background:
Patients with ischemic stroke are being increasingly transferred after initial evaluation at an outside hospital under the drip-and ship paradigm. However, the value of such practices for hemorrhagic strokes cannot be assessed due to limited data on proportion and outcomes of patients who are transferred from an outside hospital to a tertiary care center.

Objective:
We sought to determine the proportion and outcomes of patients with subarachnoid hemorrhage (SAH) and intracerebral hemorrhage (ICH) who are transferred from outside hospital to a tertiary care center in United States

Methods:
We analyzed patient data from the Nationwide Inpatient Sample, the largest all-payer inpatient care database in the United States, for the 2005-2008 years. All patients with primary diagnoses of SAH or ICH were identified using ICD-9 CM codes. For each diagnosis, baseline characteristics, hospital complications, and outcomes were compared between the patients admitted locally and patients transferred to tertiary hospitals using univariate and multivariate logistic regression.

Results:
The absolute numbers and proportions of patients transferred to tertiary hospitals were 11806 (25.7%) and 14282 (10.5%) for SAH and ICH, respectively. In univariate analysis, transferred SAH patients were significantly more likely to be discharged home compared to those who were admitted locally (p<0.001) and had significantly lower in-hospital mortality rates (p<0.001); whereas in transferred ICH patients these outcomes did not differ significantly (p=0.05 and p=0.68, respectively). When adjusted for baseline differences, transfer between hospitals was associated with lower rates of in-hospital death among patients with SAH (OR=0.71 [95%CI =0.61-0.82], p<0.001), but did not effect in-hospital mortality among patients with ICH (OR=0.93 [95%CI =0.84-1.04], p=0.22). There was a non-significant trend in transfer between hospitals to be associated with higher rates of home discharges among patients with SAH (OR=1.11 [95%CI =0.97-1.28], p=0.07), while transfer between hospitals resulted in significantly lower rate of patients with ICH to be discharged home (OR=0.87 [95%CI =0.78-0.97], p=0.01)

Conclusion:
Transfers to tertiary hospitals appears to be associated with better clinical outcomes in patients with SAH but not with ICH. Our results warrant a critical evaluation of transfer between hospitals in patients with ICH.
Abstract 2835: Hyperdense MCA as a Predictor of Stroke Severity: Does Size Matter?
Authors: Mittal Manoj , Seet Raymond , Yi Zhang , Rabinstein Alejandro
Published: March 2022

Background and Objective
Hyperdense MCA (HDMCA) sign is an early sign seen on CT head after acute ischemic stroke indicating acute arterial thrombosis. It has been reported as a predictor of stroke morbidity and mortality. The relationship of
size
of hyperdense middle cerebral artery (MCA) sign with stroke volume and functional outcome has not been sufficiently studied.

Methods
We did a retrospective analysis of prospectively collected data from 206 cases of acute ischemic stroke eligible for IV rt-PA by time criteria, admitted to Mayo Clinic from March, 2002 through June, 2011. Admission CT Head was studied to identify HDMCA sign which was further subcategorized according to size. CT head at 24 hours after intravenous tissue plasminogen activator was used to calculate Alberta Stroke Program Early CT Score (ASPECTS) to measure ischemic damage area. Functional outcome was assessed using the modified Rankin score at 3 months and dichotomized into less than equal to 2 (good outcome) and more than 2 (bad outcome). Univariate analysis including t-test, Chi-square, and Fisher Exact test was used when appropriate.

Results
Mean admission NIHSS score was 11±7. HDMCA sign was seen in 99 (48%) patients: 100% MCA occlusion (7) 76-100% M1 (17), 50-75% M1 (17), less than 50% M1 (6), MCA dot sign (23), sylvian dot sign (21) and sylvian MCA sign, defined as any sylvian MCA occlusion bigger than a dot (8). Univariate analysis showed statistically significant associations between our HDMCA classification and ASPECTS at 24 hours (p<0.001) and modified Rankin score at 3 months (p<0.001). Smaller infarctions (ASPECTS >8) were observed more often with lower MCA clot burden; MCA dot (48%), less than 50% MCA (80%), sylvian dot (57%) and sylvian MCA (38%), 50-75% M1 (6%), 75-100% M1 (0%) and 100% MCA (0%). Good outcome (mRS≤2 at 3 months) was seen more often with lower MCA clot burden; MCA dot (52%), less than 50% MCA (67%), sylvian dot (67%) and sylvian MCA (63%). Conversely, larger HDMCA size was associated with poor outcome (mRS>2); 50-75% M1 (100%), 75-100% (88%) and 100% MCA (100%).

Conclusion
The size of the HDMCA sign size is an important predictor of ischemic stroke mortality and morbidity. HDMCA should be measured upon admission as it may help refine prognostication and identify patients who could benefit from endovascular rescue therapy after intravenous thrombolysis.
Abstract 2850: Natural History of first ever symptomatic Internal Carotid Artery Occlusion (ICAO)
Authors: Nanduri Sunanda , Yenugadhati Vamsi , Ku Andrew , Jovin Tudor
Published: March 2022

INTRODUCTION:
Because the natural history of stroke due to ipsilateral ICAO is poorly established, we sought to assess it in a cohort of patients presenting with first ever acute stroke or TIA ipsilateral to an occluded extracranial ICA at a centre where emergent revascularization of ICAO’s (operative or endovascular) is not routinely contemplated.

METHODS:
Retrospective medical records review of patients admitted to a large academic tertiary care center between January 2006 and April 2011. Inclusion criteria were: 1. First time presentation. 2. Hemispheric ischemic symptoms ipsilateral to an extra-cranial ICAO diagnosed by CT angiography, MR angiography or conventional angiography. 3. Available clinical outcomes 3 months to 1 year. Favorable outcomes were expressed as mRS 0 - 2. All patients were treated with state of the art medical management in compliance with AHA guidelines for treatment of patients with acute ischemic stroke. Delayed revascularization occurred only when partial recanalization on medical therapy was observed.

RESULTS:
Out of 106 patients identified, 97 had available clinical outcomes. For a detailed description of the cohort see
Table-1
. Overall good outcomes were achieved in 26% of patients with an in-hospital mortality of 9.2% and a 3-month to 1-year mortality of 24%. Patients with Tandem Occlusion (TO) had significantly higher NIHSS at presentation and significantly worse outcomes compared to those without TO (mean NIHSS 17 vs. 7, p<0.0001 and mRS<2 in 9% vs. 31%, p=0.042).

CONCLUSION:
The natural history of first ever stroke due to extracranial ICA occlusion is poor and is comparable to that of stroke due to large vessel intracranial occlusion. Patients with tandem occlusions have significantly worse outcomes than patients with non-tandem occlusions. Our results may provide useful information for planning of future randomized trials comparing revascularization with standard medical therapy in patients with symptomatic ICAO.
Abstract 2900: Fasting Glucose On 14 Day After Onset predicts One-year poor Outcome In Aneurysmal Subarachnoid Hemorrhage
Authors: Bian Liheng , Liu Liping , Liu Gaifen , Wang Yilong , Wang Chunxue , Wang Anxin , Zhao Xingquan
Published: March 2022

Background and purpose:
Admission hyperglycemia is associated with 3-month and/or 6-month poor outcomes after aneurysmal subarachnoid hemorrhage, but the effect of prolonged hyperglycemia on long-term outcomes is not very clear. We studied the relationship between 14
th
day fasting glucose and 1-year outcome after aneurysmal subarachnoid hemorrhage.

Methods:
A prospective study of aneurysmal subarachnoid hemorrhage from August 2007 to August 2010 was used to analyze the effect of fasting glucose on admission and 14
th
day respectively on 1-year outcome assessed with the modified Rankin scale. Onset to admission longer than 14 days were excluded from analysis, as well as patients died within the first 14 days post-onset. A total of 322 patients (female 54.7%, average age: 53.9±11.6 yr, 310 patients admitted within 7 days) were used to assess the relationship between poor outcomes and fasting glucose, and medical history, Fisher scale, Hunt and Hess grade, Glasgow Coma Scores. Poor outcome (death and dependency) was defined as modified Rankin scale 3-6 at 1 year. Multivariate Cox regression analysis was performed to assess risk factors for 1-year outcome.

Results:
The mean fasting glucose on 14
th
day of poor outcome patients was higher than that of good outcome patients [(7.11±3.35) vs. (5.43±1.55) mmol/L,
p
<0.001]. Fasting glucose at admission in poor outcome patients was also higher than that of good outcome ones[(6.90±2.61) vs. (5.92±1.74) mmol/L,
p
=0.005]. After adjusting for Hunt and Hess grade, history of hypertension and Fisher scale, fasting glucose on 14
th
day was an independent predictor of poor outcome (odds ratio, 1.278; 95% CI, 1.098 to 1.487;
P
=0.0016). Meanwhile, glucose level on 14
th
day was found to be associated with 1-year death (adjusted HR, 1.183; 95%CI, 1.087 to 1.288) after adjusting for Fisher scale, Glasgow Coma Scale and treatment methods. However, fasting glucose at admission wasn’t independent predictor of 1-year death and dependency in Logistic regression and death in Cox regression.

Conclusions:
After aneurysmal subarachnoid hemorrhage, the fasting glucose levels on 14
th
day are associated with an increased risk of 1-year death and dependency. Further studies are needed to confirm these results.
Abstract 2905: Changes Of Systemic Thrombolysis Rates In A Large Hospital-based Stroke Registry
Authors: Singer Oliver C , Hamann Gerhard F , Misselwitz Bjoern , Steinmetz Helmuth , Foerch Christian ,   Arbeitsgruppe Schlaganfall Hessen (ASH)
Published: March 2022

Objectives:
This analysis determines changes in systemic thrombolysis rates in a large state-wide stroke data set covering an observation period of 7 years following the approval of rtPA therapy in Germany.

Methods:
A prospective hospital-based stroke registry covering the entire Federal State of Hesse, Germany was analyzed. All patients admitted between 2003 and 2009 with a final diagnosis of ischemic stroke (ICD-10: I63) were selected. The relationship between thrombolysis rates, onset-to-admission time, patient age, and initial stroke severity (assessed by the Modified Rankin Scale (MRS)) was analyzed. One-way ANOVA was performed to test for significant changes during the observation period.

Results:
We identified 88.340 patients with ischemic stroke. Thrombolysis rates increased continuously from 2.5% in 2003 to 8.4% in 2009. In patients admitted within 3h after symptom onset, thrombolysis rate was 2.5 fold higher in 2009 (25.4%) as compared to 2003 (10.5%). Mean age (+/-SD) of thrombolyzed patients increased from 68.7 (+/-11.5) years in 2003 to 70.7 (+/-13.4) years in 2009 (p=0.014 for trend), but remained stable in the entire cohort. In contrast, stroke severity decreased both in rtPA treated patients (initial mean MRS score 3.9 in 2003 and 3.5 in 2009 (p<0.001 for trend)), and in the entire cohort (3.1 (2003); 2.9 (2009), p<0.001 for trend).

Conclusions:
Thrombolytic therapy is increasingly used in acute ischemic stroke, particularly in patients admitted within the 3h time window. Several factors as improved clinical pathways, increasing personal experience and financial incentives may contribute to this development. In addition, our data suggest that higher treatment rates are at least partially explained by spreading rtPA application towards older and less severely affected patients.
Abstract 2912: Quantitative T2'-Imaging detects Increased Oxygen Extraction in High-Grade Internal Carotid and Middle Cerebral Artery Stenosis
Authors: Seiler Alexander , Wagner Marlies , Hattingen Elke , Magerkurth Joerg , Jurcoane Alina , Deichmann Ralf , Neumann-Haefelin Tobias , Singer Oliver C
Published: March 2022

Background and Purpose:
Quantitative T2'-imaging (qT2') detects regional changes in the relation of oxygenated and deoxygenated hemoglobine (Hb) using their different signal characteristics in gradient echo imaging. In contrast to classical T2* imaging, T2’-imaging is corrected for spin-spin effects. Regional differences in Hb oxygenation might reflect areas with increased oxygen extraction for compensation of reduced perfusion pressure. The aim of the study was to investigate qT2’-imaging in perfusion-restricted areas in patients with high-grade stenoses of brain-supplying arteries. We hypothesized that T2’-values are lower in perfusion-restricted areas as compared to normal perfused tissue.

Methods:
18 patients (15 men, 3 women; mean age 54 years, SD±12.8) with sonographic unilateral symptomatic or asymtpomatic high-grade extracranial ICA stenosis/occlusion (>70%, NASCET criteria), or MR-angiographic proven unilateral high-grade (>50%) intracranial ICA or proximal MCA stenosis/occlusion were included. Patients with significant bilateral stenoses were excluded. MRI comprised perfusion-weighted imaging and quantitative, motion corrected T2’-imaging. Time-to-peak (TTP)- and mean-transit-time (MTT)-maps were thresholded for different degrees of perfusion delays (e.g. >0 sec, >2 sec) in relation to the contralateral, healthy hemisphere. Mean T2’-values in perfusion-restricted areas were compared to T2'-values in corresponding contralateral or ipsilateral, normoperfused areas. Data are given as mean (+−SD).

Results:
Mean size of perfusion-restricted areas in TTP-maps (TTP-delay >0 sec) was 10.8 ml (+−6.3) and 11.5 ml (+−6.2) in MTT-maps (MTT-delay >0 sec) decreasing to 4.5 ml (+−4.7) in areas with a TTP-delay >4 sec and 6.9 ml (+−5.5) in areas with a MTT-delay >4 sec, respectively. T2'-values were significantly (p<0.01) lower in all perfusion-restricted compared to corresponding contralateral brain areas: For TTP-delay >0 sec, T2’-values were (ipsilateral) 115.2 ms (+−9) vs. (contralateral) 125.4 ms (+− 11.5). For MTT-delay >0 sec T2’-values were (ipsilateral) 114.5 ms (+−9.1) vs. (contralateral) 127.7 ms (+− 9.5). Differences in T2’-values increased with the severity of the hypoperfusion. Ipsilateral T2’-values outside the perfusion-disturbed areas did not differ from contralateral T2’-values.

Conclusions:
Motion-corrected T2'-imaging detects areas with increased oxygen extraction within perfusion-restricted tissue in patients with high-grade occlusive vessel disease. T2’-imaging may add important information on the severity of the perfusion-disturbance with respect to its metabolic consequences. Its general suitability and its value for clinical decision making needs further evaluation as well as a thorough comparison with the current gold standard for the assessment of cerebral oxygen consumption, PET.
Abstract 2968: Outcomes Of Young Acute Ischemic Stroke Over The Last Decade: Insights From Nationwide Inpatient Sample
Authors: Kansara Amit , Chaturvedi Seemant , Bhattacharya Pratik
Published: March 2022

Background:
The burden of young ischemic stroke has increased over the years. However, outcomes of young patients with acute ischemic stroke (AIS) remain unknown. Over the last decade, with increasing utilization rate of iv tpa, our objective was to evaluate trends in survival and discharge outcomes of young AIS patients in the United States.

Methods:
Data from the Nationwide Inpatient Sample for the years 2001 through 2009 were reviewed. Hospitalizations with a discharge diagnosis of an acute ischemic stroke (ICD-9 codes: 433.01, 433.11, 433.21, 433.31, 433.81, 433.91, 424.01, 434.11, 434.91 and 436) were included. Nationwide estimates of deaths and discharge destination were calculated for each year within the young AIS subset. The Cochrane Armitage test was used to assess trend across the years

Results:
From 2001 through 2009, there were an estimated 4,917,217 admissions for acute ischemic stroke. Out of that, 204,703 (4.16%) were young patients with AIS. Thrombolysis in young ischemic stroke increased from 354 (1.84% of young AIS) in 2001 to 1237 (4.97%) in 2009 (p<0.0001). There was a progressive decrease in mortality in young AIS patients, from 6.81% in 2001 to 5.43% in 2009 (trend p= 0.027). Discharge to home or home with home health did not show any significant change (trend p= 0.52). Discharge to rehabilitation facilities showed significant increase over the years, 3.42% in 2002 to 12.7% in 2009 (trend p <0.0001). Discharge to other facilities other than rehabilitation showed significant decrease over the years, 29.1% in 2001 to 17.8% in 2009 (trend p<0.0001). Rate of intracranial hemorrhage, 2.70% in 2001 to 2.69% in 2009, did not show any significant change despite increasing use of iv tpa (trend p=0.39).

Conclusion:
Over the last decade, deaths from AIS among young patients have decreased. The increase in rehabilitation placement and decrease in nursing home discharges suggest improving neurologic outcomes. Modern treatments such as stroke units, thrombolysis, and mechanical thrombectomy may be responsible for the reductions in mortality and morbidity.
Abstract 2974: Sex Differences in Correlation of Cerebral Infarction Volume with Functional Outcome
Authors: Morton Johanna L , Wisco Dolora , Tateishi Yohei , Aoki Junya , George Pravin , Gabor Toth , Hussain Muhammad S , Uchino Ken , Katzan Irene , Gebel James
Published: March 2022

Background:
Studies have suggested worse functional outcomes in women after acute ischemic stroke. Following intravenous thrombolysis, they have higher recanalization rates; however, sex-based differential outcomes are poorly studied in large vessel occlusion +− intra-arterial therapy. We sought to ascertain the correlation between infarcted brain tissue volume and functional outcome in women as compared to men who were potential neurointerventional therapy candidates.

Methods:
We retrospectively queried our prospectively maintained acute potential neurointerventional candidate and neuroimaging patient database (n=283) and correlated final DWI cerebral infarction volume with functional outcomes as measured by the modified Rankin Scale [MRS] at hospital discharge and 30 days.

Results:
Median age was 69 [56,79] and 185 patients received intra-arterial therapy including 103 women (55.7%). There were no differences in age or admission NIHSS score, initial or final DWI infarction volumes, premorbid MRS, site of large vessel occlusion, pre-intervention collateral grade, TIMI or TICI grade, or recanalization rate between the sexes. Spearman correlation coefficients (r
2
) between final DWI infarction volume and functional outcomes for neurointerventionally treated men as compared to women were 0.45 [men, p=.0009] versus (vs) 0.12 [women, p=.41] for discharge MRS; 0.78 [men, p<.0001] vs -0.27 [women, p=.17] for 30 day MRS, and 0.78 [men, p<.001] vs -0.26 (women, p=.26]. For all women vs men irrespective of treatment, the r
2
values were 0.53 [men, p<.0001] vs 0.35 [women, p=.009] for discharge MRS; 0.60 [men, p<.0001] vs 0.05 [women, p=.73] for 30 day MRS; and 0.68 [men, p<.001] vs -0.078 [women, p=.66]. These differences were confirmed by an ordinal logistic regression analysis.

Conclusions:
Despite comparable baseline functional status, treatment rate, occlusion site, initial and final infarction volumes, and recanalization rates, final infarction volume correlates strongly with functional outcome in men but not in women. This data suggests fundamental differences in neurophysiological or social factors between men and women in response to acute large vessel stroke, the nature of which deserves to be more fully investigated.