bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WMP92: Location of Hemorrhage Predicts Hematoma Expansion and Poor Clinical Outcome
Authors: Yogendrakumar Vignan , Demchuk Andrew M , Aviv Richard I , Rodriguez-Luna David , Molina Carlos A , Blas Yolanda Silva , Dzialowski Imanuel , Czlonkowska Anna , Boulanger Jean-Martin , Lum Cheemun , Gubitz Gord , Padma Vasantha , Roy Jayanta , Kase Carlos S , Bhatia Rohit , Hill Michael D , Dowlatshahi Dar ,   PREDICT/Sunnybrook ICH CTA Study Group
Published: July 2021

Background:
Baseline volume, spot sign, and coagulation status all predict early hematoma expansion (HE) in intracerebral hemorrhage (ICH). However, the role of ICH location on HE remains unclear. We hypothesized that lobar-located ICH would facilitate HE as it provides a larger potential volume for expansion as compared to deep locations. However, due to the close proximity of critical structures and increased risk of ventricular rupture, we also hypothesized that deep ICH would have a paradoxically increased risk of mortality and morbidity. Our objective was to assess the effect of lobar vs. non-lobar hemorrhage on HE and clinical outcome.

Methods:
We analyzed data from the prospective multicentre PREDICT study where patients with ICH presenting to hospital under 6 hours of symptom onset received a baseline CT, CTA, 24 hour follow-up CT, and 90-d mRS. ICH location was categorized as lobar vs deep, and primary outcomes were significant HE (>6mL) and poor clinical outcome (mRS >3). Multivariable regression with stepwise selection was used to adjust for relevant covariates. Sensitivity analysis was conducted by expanding the inclusion criteria to include patients who died or were treated with Factor VIIa and/or surgery prior to follow-up CT.

Results:
Among 302 patients meeting the inclusion criteria, lobar hemorrhage was associated with increased hematoma expansion >6mL (p=0.003), poor clinical outcome (p=0.011) and mortality (p=0.017). When adjusted for covariates, lobar hemorrhage independently predicted significant hematoma expansion (aOR 2.3 [95% CI: 1.2-4.4], p=0.02). Sensitivity analysis included a total of 353 patients and lobar location was no longer significantly associated with poor outcome (p=0.198). This appeared to be related to a higher proportion of IVH in the excluded population (33% Primary vs. 65% Excluded, p<0.001).

Conclusion:
Lobar hemorrhage led to expansion and poor clinical outcome in the primary analysis population. Sensitivity analysis of the excluded population revealed that deep bleeds are associated with a higher degree of mortality and morbidity, likely due to a higher frequency of IVH. Our findings suggest that baseline ICH location should be considered for risk stratification algorithms.
Abstract WP11: Comparative Safety and Efficacy of the Trevo, Penumbra and Solitaire Devices in Treatment of Acute Ischemic Stroke
Authors: Brinjikji Waleed , Cloft Harry J , Murad Mohammad H , Kallmes David F
Published: July 2021

Background and Purpose:
We performed a systematic review and meta-analysis comparing rates of recanalization, good neurological outcome, and mortality between patients treated with three modern devices used for endovascular treatment of acute ischemic stroke.

Materials and Methods:
We performed a comprehensive literature search on studies reporting outcomes of endovascular treatment of acute ischemic stroke. We selected studies including≥30 patients treated with either the Trevo stent-retriever, Penumbra aspiration system or the Solitaire stent-retriever. Outcomes studied included mrs≤2, 90-day mortality, symptomatic and intracranial hemorrhage (sICH), recanalization. Outcomes were pooled across studies using a random-effects meta-analysis.

Results:
27 articles with 2666 patients were included (1514 Solitaire, 260 Trevo and 892 Penumbra). Rates of good neurological outcome (mRS≤2) were higher in the Solitaire group (54.0%, 95%CI=49.0-58.0%) than the Penumbra group (39.0%, 95%CI=31.0%-47.0%) (P<0.01). There was a trend towards higher rates of good neurological outcome in the Solitaire compared to the Trevo group (P=0.08). Rates of 90-day mortality were significantly lower in the Solitaire group (16.0%, 95%CI=11.0%-22.0%) than in the Penumbra group (27.0%, 95%CI=24.0%-30.0%) (P<0.01) and the Trevo group (23.0%, 95%CI=13.0-33.0)(P=0.01). Recanalization rates were similar between groups at 80.0% (95%CI=75.0%-84.0% for the Solitaire group, 82.0% (95%CI=75.0%-88.0%) for the Penumbra group (P=0.54) and 76.0% (95%CI=68.0-83.0) for the Trevo group (P=0.13 vs Penumbra and P=0.27 vs. Solitaire).

Conclusions:
Meta-analysis of incidence rates in noncomparative series reporting on over 2500 patients suggests that the Solitaire device maybe associated with superior neurological outcomes and lower rates of 90-day mortality. Comparative studies are needed to confirm these observations.
Abstract WP149: Greater Recovery of Upper Limb Function in Moderate/Severely Impaired Chronic Stroke in Response to Customized Whole Limb vs Prescribed Focused Training
Authors: Daly Janis , McCabe Jessica P , Monquiewicz Michelle , Holcomb John , Pundik Svetlana
Published: July 2021

Introduction:
The purpose of this study was to compare the following three treatments of upper limb motor impairment in chronic moderate/severely impaired stroke survivors: 1) Customized whole limb motor learning (Whole ML), including shoulder/elbow robotics (ROB) and functional electrical stimulation (FES); 2) prescribed shoulder/elbow ROB + motor learning (S/E ROB ML); and 3) prescribed wrist/hand FES + ML (W/H FES ML).

Methods:
Subjects with chronic stroke were stratified according to relative level of impairment (Fugl-Meyer coordination Test) in wrist/hand versus shoulder/elbow. Their stratification category dictated the treatment group to which they were allocated, as follows: 1) WHOLE ML (n=18), equal distal and proximal impairment; 2) S/E ROB ML (n=10 ), greater shoulder/elbow impairment; and 3) FES ML (n=8), greater wrist/hand impairment. Treatment was 5 days/wk, 5 hrs/day, 60 sessions. Primary measure was the Arm Motor Assessment Tool, 13 complex tasks, Functional Scale (AMAT-F), acquired at baseline and at follow-up, 3 months after last treatment. Secondary measures were subscales, AMAT-F Shoulder/Elbow (AMAT-F S/E) and AMAT Wrist/Hand (AMAT-F W/H). Statistical analyses were Kruskal Wallace model to account for group size differences; group comparisons and within-group pre-/follow-up comparisons were analyzed (and multiple comparisons corrections).

Results:
All three groups had significant within-group gain for AMAT-F (p=.0007; p=.039; p=.047, respectively; similar results were shown for AMAT S/E subscale. Only the Whole ML group had significant gain in AMAT W/H (p=.007). Gain for all three groups exceeded the threshold for clinically significant gain in AMAT-F (.21 points), as follows: Whole ML (.66 points, 3 x’s the threshold); S/E ROB ML (.53 points, 2.5 x’s); W/H FES ML (.46 points, 2 x’s).

Conclusion:
For the customized whole limb motor learning group there was greater improvement in upper limb function versus the two groups that received prescribed, focused training for either shoulder/elbow or wrist/hand, according to the AMAT-F clinically significant threshold and according to the AMAT-F W/H subscale.
Abstract WP15: Rates of Successful First-pass Recanalization During Thrombectomy for Acute Ischemic Stroke are Higher in the Absence of a Hyper-dense Vessel Sign
Authors: Kenmuir Cynthia L , Al-Bayati Alhamza R , Shoirah Hazem , Aghaebrahim Amin , Ducruet Andrew F , Jankowitz Brian T , Jovin Tudor G , Jadhav Ashutosh P
Published: July 2021

Background and Purpose:
Rates of high quality recanalization after endovascular thrombectomy in acute ischemic stroke are excellent, but not all vessels are easily or quickly recanalized. Physical characteristics of the occlusion may affect recanalization. The hyper-dense vessel sign (HDVS) is an easily obtained marker of clot density and was hypothesized to predict success of recanalization.

Methods:
A prospectively maintained database of patients undergoing mechanical thrombectomy was retrospectively analyzed. The final quality of recanalization was scored by the treating interventionalist. The presence or absence of HDVS was scored blinded. HDVS was defined as an absolute HU >43 and ratio versus contralateral vessel of >1.2 on non-contrast head CT.

Results:
408 patients were treated with endovascular thrombectomy between August 2012 to July 2015. Mean age was 67.7. 53% were men. Mean NIHSS was 17. 88% were MCA occlusions and 11% were basilar occlusions. Mean ASPECT was 8.6 for MCA occlusions. 90.6% of patients were successfully revascularized with TICI2b/3. HDVS was identified in 43.3% of patients. 40.5% of patients had TICI2b/3 reperfusion after the first pass of attempted thrombectomy. Manual aspiration thrombectomy was the first technique in 45.6% and stentreiver mediated manual aspiration thrombectomy was used first in 54.4% of cases. Of 357 attempted MCA thrombectomies, 43.3% had a HDVS. Of 44 attempted basilar thrombectomies, 56.7% had a HDVS. TICI 2b/3 reperfusion on first-pass was associated with absence of HDVS (p=0.001). Time from puncture to reperfusion was significantly increased with HDVS (p=0.003).

Conclusion:
Patients with a hyper-dense vessel sign have less successful first-pass revascularization with increased times to reperfusion versus patients without a hyper-dense vessel sign. The presence of HDVS may be indicative of more refractory occlusions and may warrant novel and multimodal methods of revascularization.
Abstract WP152: Characteristics of Stroke Survivors Treated in an Interdisciplinary Outpatient Rehabilitation Program Who Return to Work
Authors: Breen Joan , Andrusin Jeanne , Ferlito Tom
Published: July 2021

Background:
Return to Employment and driving are goals for many stroke survivors. Little is known about the frequency and characteristics of patients returning to work.

Methods:
Prospective observational study of stroke patients treated between 12/2011-1/2015 in an interdisciplinary outpatient rehabilitation program that addresses physical, psychosocial, cognitive, communicative, risk factors, driving, and vocational issues.

Results:
Of 96 consecutive patients, 48% were working prior to their stroke. 44% (70% men, 30% women) of those working prior to their stroke returned to work upon program completion. On admit, these returning workers had an average age of 56 years, average NIHSS score of 3.4(range 0-9), 40% were aphasic, 65% needed assistance with ADL's(55% with {mRS} of 3 and 10% with {mRS} of 4). 15 of these suffered ischemic strokes( 4 Left, 4 Right, 3 Bi-lateral hemisphere, 4 posterior circulation), and 5 had hemorrhages. All patients working prior to their stroke were also driving, and 15% of these were driving on admit. 90% of those who returned to work also returned to driving. In those returning to work, Stroke Impact Scale(SIS) scores improved an average of: mood 12%, ADL’s 15%, participation 24%, and stroke recovery domain 16%. These patients received an average of 21 physical therapy visits, with 6 minute walk and Berg Balance scores improving an average of 112% and 11% respectively. Multiple other demographic, risk factor, and outcome measures are collected. An additional 9% of patients were work capable on discharge. In comparison, 19 of those not returning to work had ischemic strokes, 7 had hemorrhages. This group had average age 57, average NIHSS score 6.8(range2-16), 42% aphasic, 89% needed assistance with ADL’s (58% with {mRS} of 3 and 31% with {mRS} of 4), and 28% returned to driving. Average length of stay was 4 (range 0.25-12) and 6 months(range 2-12) in those returning and not returning to work respectively.

Conclusions:
These findings demonstrate that outpatient rehab programs can promote stroke recovery, return to work and driving. Further collection of characteristics and rehabilitation outcomes of patients returning to work can help direct rehabilitation efforts for patients with return to work goals.
Abstract WP155: Increased Physician and Physical Therapist Communication is Associated With Earlier Mobility and Decreased Length of Stay in the Cerebrovascular and Trauma Neuroscience Population
Authors: Burch Danielle , Bernert Silke , Fraser Justin F
Published: July 2021

Background and Purpose:
There is growing interest in methods for early rehabilitation in patients with acute neurologic conditions. The purpose of this study was to identify whether increased coordination between the physical therapist and an attending cerebrovascular neurosurgeon through daily multidisciplinary rounds would correlate with positive changes in overall care.

Hypothesis:
We evaluated the hypothesis that a physical therapist participating in cerebrovascular neuroscience rounds would decrease the time to initial physical therapy (PT) consult, decrease hospital length of stay (LOS), decrease Intensive Care Unit (ICU) LOS, and decrease ventilator days.

Methods:
A retrospective review was performed of 235 patients who were admitted to the neuroscience service under a single cerebrovascular neurosurgeon over a 16-month period (April 2014 through July 2015) in a level-I trauma hospital. The study consisted of an eight-month pre-intervention period (n=117) where the physical therapist did not attend physician rounds and an eight-month post-intervention period (n=118).

Results:
In the post-intervention group the PT assessment occurred on average 1.57 days sooner than before the physical therapist participated in neuroscience physician rounds (p<0.001). Hospital LOS decreased by an average of 3.46 days (p=0.04) and ICU LOS decreased on average by 1.83 days (p=0.05) in the post-intervention group. Ventilator days decreased on average by 0.55 days, which was not statistically significant (p=0.26).

Conclusions:
In conclusion, daily coordination with multidisciplinary rounds between the physician and the physical therapist was associated with decreased time to initial PT assessment, decreased hospital LOS, and decreased ICU LOS in the neuroscience population.
Abstract WP158: Case Fatality and Risk Factor Trend Contributions to Stroke Mortality in Non-Hispanic Blacks and Non-Hispanic Whites, 1999-2012
Authors: Penko Joanne , Moran Andrew E , Mason Antoinette , Coxson Pamela G , Pletcher Mark J , Guzman David , Sidney Stephen , Kim Anthony S , Goldman Lee , Bibbins-Domingo Kirsten
Published: July 2021

Introduction:
Stroke death rates have declined nationally, but less in men and non-Hispanic Blacks. We quantified case-fatality and risk factor trend contributions to non-Hispanic Black and non-Hispanic White 1999-2012 stroke mortality trends.

Methods:
The CVD Policy Model is a computer simulation of heart disease and stroke incidence, prevalence, and mortality in US adults ≥ 35 years old. We modeled mean systolic blood pressure (SBP), low-density lipoprotein (LDL), and body mass index (BMI), prevalence of diabetes and smoking, and case fatality for 1999-2002, 2003-06, and 2007-12 by sex and race (NHANES; NHDS) to predict stroke mortality trends and these predictions were compared with observed data (CDC Wonder; ICD-10 I60-69). We then simulated the effects of isolated risk factors on stroke mortality in younger (age 35-64 years) and older (age 65-84 years) men and women.

Results:
Model predictions mirrored observed trends for stroke mortality in Whites (men: predicted -27.0% v. observed -29.2%; women: -34.8% v. -33.3%) and Blacks (men: -23.8% v. -22.2%; women: -31.0% v. -30.0%). Case fatality was the main contributor to the observed decrease in stroke mortality (approximately -25%) but did not explain differences between race groups. Combined risk factor trends contributed to decreased mortality in women (-12.8% in Whites; -8.7% in Blacks), but not men. Decreased mean SBP contributed in all women (-10.7% to -12.6%, depending on age/race) and older men (-4.0%), but not young men. Increased diabetes prevalence offset improvements in stroke mortality in older White men (+2.5%), younger Blacks (men: +4.0, women: +1.5%) and, to a larger degree, older Blacks (men: +9.9%, women: +5.6% ).

Conclusions:
Reduced case fatality was the strongest driver of decreased stroke mortality from 1999-2012 overall, while risk factor trends explained gender and race differences. Targeting high blood pressure in young adult men and preventing diabetes at all ages could further decrease stroke mortality and reduce racial differences. Blacks would benefit most from more aggressive stroke risk factor control.
Abstract WP184: Allopurinol Use and Risk of Atrial Fibrillation
Authors: Boyle Shona , MacIsaac Rachael L , Padmanabhan Sandosh , Walters Matthew , Touyz Rhian , Dominiczak Anna , Dawson Jesse
Published: July 2021

Introduction:
Recent data suggest Allopurinol use is associated with a decreased risk of stroke but the mechanism is unclear. Atrial fibrillation (AF) is a known risk factor for stroke and Allopurinol has numerous cardiac effects including left ventricular hypertrophy regression and improved myocardial energetics. We hypothesized that Allopurinol use is associated with a reduced risk of AF and tested this using data from the UK Clinical Practice Research Datalink (UKCPRD).

Methods:
The UKCPRD contains verified prescription data. We included older adults (>65 years) with hypertension to miminise income-based confounding (free prescriptions in UK), ensure adequate follow up (subject to primary care surveillance in UK) and because these are risk factors for AF. Multivariable Cox proportional hazards models, assessing the effect of Allopurinol exposure over a 10-year period were used to estimate hazard ratios for AF. Allopurinol exposure was a time-dependent variable. A propensity-matched design was also used to reduce potential for confounding along with independent analyses for high (≥300mg) and low (<300mg) dose Allopurinol.

Results:
A total of 2368 Allopurinol exposed and 41663 unexposed patients were included in our UKCPRD extract. After propensity matching (n=2074 per group) there was no relationship between Allopurinol exposure and risk of AF (HR=0.881, 95% CI (0.730, 1.062). The same was seen with high dose Allopurinol (n=1081 per group) (HR=0.881, 95% CI (0.699, 1.125). Low dose Allopurinol (n=993 per group) was associated with reduced risk of AF (HR=0.731, 95% CI (0.555, 0.961). This association persists when comparing low vs. high dose Allopurinol (n=1789) (HR=0.698, 95% CI (0.534, 0.912).

Conclusions:
Use of low dose Allopurinol was associated with a decreased risk of AF in a large cohort of hypertensive patients. However, this was not evident in the high dose Allopurinol patients. Reasons for this warrant further examination.
Abstract WP196: Chronic Kidney Disease and the Burden of Microvascular Brain Damage
Authors: Zurru Maria C , Alonzo Claudia , Brescacín Laura , Colla Machado Pedro E , Linares Geraldina , Camera Luis , Cristiano Edgardo , Waisman Gabriel
Published: July 2021

Introduction:
chronic kidney disease (CKD) coexists with microvascular brain damage. This cerebrorenal connection is considered to involve small vessel disease in both the kidney and brain, based on their hemodynamic similarities.

Hypothesis:
to evaluate the relationship between microvascular brain damage (white matter hyperintensities -WMH-, microbleeds -MB- and silent brain infarcts -SBI-), and glomerular filtration rate (GFR) in a cohort of ischemic stroke patients.

Methods:
patients were prospectively included in a multidisciplinary secondary stroke prevention program. Pre-stroke vascular risk factor profile and control were obtained from electronic medical records and the burden of microvascular brain damage was evaluated on admission MRI. For the purpose of the analysis three groups were defined according to GFR estimated by Cockroft-Gault formula: >60, 30-60 and <30 ml/min/1.73 m2. Periventricular and deep WMH were classified according to Fazekas scale as low grade (0-1) and high grade (2-3); MB and SBI (lacunar and non-lacunar) were analyzed as dichotomous variables. Exclusion criteria: TIA and patients without MRI.

Results:
808 patients (mean age 77±11 years, 59% females) were included. GRF was inversely related to age (70±11, 83±6, 85±8 years; p 0.0001), female sex (48%, 69%, 66%; p 0.001), hypertension (76%, 89%, 91%; p 0.0001) and AF (16%, 21%, 34%; p 0.08) prevalence. Chronic microvascular brain damage burden was inversely related to e-GFR (table).

Conclusion:
decreased GFR indicates small vessel disease not only in the kidney but also in the brain. As small vessel disease is a systemic disorder, information about disease in one organ may suggest damage in the other.
Abstract WP21: Primary Thrombectomy Within 3 Hours of Onset in Acute Ischemic Stroke From Large Artery Occlusion (PAST3-LAO)- A Pilot Study
Authors: Lodi Yahia M , Reddy Varun , Petro George , Hourani Anas , Chou Chun-An
Published: July 2021

Background:
Based on recent trials, AIS due to large artery occlusion (LAO) is resistant to IV thrombolysis and adjunctive stent retriever thrombectomy (SRT) is associated with better recanalization rates and outcomes.Despite the benefit with endovascular therapy 39% to 68% of patients were either disabled or dead.Thrombectomy in AIS with LAO within 3 hours (IV t-PA window) is performed as secondary therapy after IV thrombolysis, which may be associated with delay in enrollment and recanalization.

Objective:
Primary objective is to evaluate the safety, feasibility and recanalization rate of primary SRT (without IV tPA) within 3 hours in AIS with NIHSS >10 from LAO.Secondary objective is to determine the functional outcome in 30-days and 90-days.

Methods:
Based on institutionally approved protocol patients with LAO with LCB within 3 hours were offered primary SRT alone as an alternative to IV rtPA, after informed consent.Consecutive patients who underwent primary SRT for LAO within 3 hours from 2012 to 2014 were enrolled.Outcomes were measured using modified Rankin Scale.

Results:
18 patients with LAO; mean age 62.8±15.3 years and mean NIHSS 16±5; chose primary SRT after informed consent.Thrombectomy was performed using new generation stent-retriever device in addition to small intra-arterial rtPA (2-10 mg).Number of passes was 1.6±0.9.Near complete (TICI2b in 1) and complete (TICI3 in 17) recanalization was observed in all (100%) patients.Mean time to recanalization from symptoms onset was 188.5±82.7 and from groin puncture was 64.61±40.14 minutes.Immediate post-thrombectomy, 24 hour and 30 day NIHSS score was 4.4±3.7, 1.9±3.2 and 0.3±0.9 respectively.There was no procedure related complication.Asymptomatic perfusion related hemorrhage developed in 6 patients (33%).30 days good outcome was observed in all cases (mRS0= 38.9%, mRS1=44.4%, mRS2=16.7%). 90 days good outcome was observed as follows (mRS0= 50.0%, mRS1=44.4%, mRS2=5.6%).

Conclusion:
Our pilot study demonstrates that primary SRT in AIS due LAO occlusion with LCB is not only safe and feasible, but associated with complete recanalization and good functional outcome.Larger randomized controlled studies are needed.
Abstract WP227: Noninvasive Blood Flow Measures in Atherosclerosis of the Posterior Circulation: Quantitative MRA Bests TOF Signal Intensity Ratio in VERiTAS
Authors: Liebeskind David S , Prabhakaran Shyam , Feldmann Edward , Du Xinjian , Rose-Finnell Linda , Woolf Graham W , Pandey Dilip K , Richardson DeJuran , Thulborn Keith R , Elkind Mitchell S , Zipfel Gregory J , Silver Frank L , Kasner Scott E , Aletich Victor A , Caplan Louis R , Derdeyn Colin P , Gorelick Philip B , Charbel Fady T , Amin-Hanjani Sepideh ,   for the VERiTAS Investigators
Published: July 2021

Background:
Fractional flow across an atherosclerotic lesion measured with TOF-MRA signal intensity ratio (SIR) may be used to gauge hemodynamic severity and to predict subsequent stroke. The degree of flow impairment may also be ascertained by quantitative MRA (QMRA). We analyzed performance of these noninvasive imaging parameters to estimate risk of subsequent posterior circulation events in VERiTAS.

Methods:
TOF-MRA data and QMRA were simultaneously acquired in VERiTAS. SIR were derived from TOF source images and normalized for analysis with volume flow ratios (VFR) on QMRA at standard anatomical landmarks and across the maximal stenosis. Statistics analyzed the correlation between SIR and VFR, and the ability of each to predict clinical events.

Results:
72 subjects (mean age 65.6±10.3 years, 32 (44%) women) with posterior circulation atherosclerosis were enrolled in VERiTAS. Posterior communicating artery (PCOMM) flow to the posterior circulation was detected in 85% on the right, in 86% on the left, with bilateral PCOMM flow in 78%. Fractional flow measures or SIR across the maximal stenotic lesion evident on TOF MRA was reduced in 43%, increased in 16%, with no change in 40%. SIR from the proximal to distal basilar artery segments increased in 62%, was unchanged in 33% and decreased in 4% of cases. SI and VFR exhibited limited correlation at corresponding arterial segments. QMRA VFR indicative of low distal flow status predicted subsequent clinical events, unlike SIR.

Conclusions:
Evaluation of hemodynamics in posterior circulation atherosclerosis reveals superiority of QMRA to SIR in prospectively predicting recurrent ischemia. Collateral circulation, tandem disease and unique aspects of vertebrobasilar atherosclerosis likely influence the utility of SIR on TOF MRA.
Abstract WP230: No Difference of Cerebral Perfusion Between Transient Global Amnesia With and Without Acute Focal Lesion in Hippocampus
Authors: Ahn Seong Hwan , Chung Ji Yeon , Choo In Sung , Lee Kyung Yul , Kang Hyun Goo , Han Sang Won
Published: July 2021

Introduction:
In transient global amnesia (TGA), the etiology or pathogenesis is still in debate. It has been commonly suggested that TGA might be related to an ischemic event, migraine, or epileptic seizures. With the characteristic findings of diffusion-weighted images (DWI), cerebrovascular disease can be regarded as a cause of TGA.

Hypothesis:
Transient global amnesia may be associated with regional cerebral perfusion, especially in patients with DWI lesions. The aim of the present study is to reveal the clinical or radiological difference between TGA patients with and without acute lesions.

Methods:
We identified retrospectively TGA patients who fulfilled the standard criteria from January 2010 through March 2015. Within 72 hours from symptom onset, all patients were evaluated with brain MR images and an electroencephalography. According to the presence of acute lesion in the hippocampus, clinical features, vascular risk factors, and regional perfusion status with SPECT images were compared.

Results:
Of 61 TGA patients (mean age 60.6, female 18 patients), 20 patients had acute focal lesions in the hippocampus (size: 3.36 ± 0.64mm, 7 in the right, 9 in the left, and 2 in bilateral lesions). All lesions were located in the lateral border (CA1 region) of the hippocampus. In the comparison of clinical features, the duration of amnestic symptom was shorter in the lesion negative group than in the lesion positive group (5 hours, IQR 2.5-8.8 vs. 8 hours, IQR 5-13.5, p=0.07). However, there was no difference between TGA patients with and without DWI lesions in cerebrovascular risk factors or laboratory results. Of 23 patients underwent a cerebral SPECT, 6 patients who had DWI lesions had no abnormal findings. Of 17 patients without lesions, only 3 patients exhibited mild focal perfusion defect in both medial temporal, left frontal, and left fronto-temporal region, respectively.

Conclusions:
Except amnestic symptom duration, we failed to reveal any clinical difference including perfusion defect between TGA patients with and without DWI lesion. It might suggest the low probability of hypoperfusion in the hippocampus regardless of the presence of brain DWI lesions.
Abstract WP244: How Many Potential Mechanical Thrombectomy Patients Are Missed Because of Emergency Medical Systems Transport Windows of 4.5 Hours or Less Since Last Known Normal in the Field?
Authors: Allen Evan , Banerjee Paul , Richards Donald , Sombutmai Chut , Thomas Abraham P , Walley Megan , Basignani Cherlynn
Published: July 2021

Intro:
Many EMS transport protocols exclude patients last known normal (LKN) >4.5 or >6 hours from transport to Comprehensive Stroke Center (CSC) as acute stroke codes. Because recent Mechanical Thrombectomy (MET) studies enrolled few patients last known normal (LKN)
>
6 hours prior to imaging, the incidence of CTP or ASPECTS suggesting possible benefit from MET in this time window for Large Vessel Occlusion (LVO) ischemic stroke is unclear.

Method:
Through retrospective review of a prospective database, the percentage of LVO patients with ASPECTS or CTP suggesting possible benefit from MET, defined as ASPECTS score >5 or salvageable penumbra and <70ml ischemic core on CTP, was compared between a group of 42 patients imaged
>
6 hours since LKN and 106 patients imaged <6 hours since LKN.

Results:
33% (14 of 42) of LVO patients LKN
>
6 hours at time of CTP imaging (median 8 hours, range 6-20 hrs) received MET based on favorable CTP imaging and disabling clinical deficits. This was not statistically significantly different than the 40.5% (43 of 106) of LVO patients LKN < 6 hours at time of CTP imaging (median 128 min) that received MET based on same criteria (OR 95% CI, 0.73 0.34 – 1.55; P=0.42). The LKN
>
6 hour MET patients (median NIHSS 18) had a trend towards less frequent favorable home or rehab discharge destination than the LKN < 6 hour MET patients (median NIHSS 16) (29% vs 57%, OR 0.3040, 95 % CI: 0.08 to 1.12, P = 0.07). There were no significant differences between the
>
6 hour and <6 hour groups in factors associated with poor outcome after intervention or poor collateral circulation: median ASPECTS score (9 for both), percentage of ASPECTS scores >5 (80% vs 90%, p=0.31) median age (74 for both), ED glucose >150 mg/dl (16.6% vs 23.5%, p= 0.51), Atrial fibrillation (38% vs 37%). With a 30 minute door-to-CTP time, a
<
4.5 hour LKN EMS transport policy would have excluded 24.5% of patients who received MET at our CSC. 6, 8, 10 and 13 hour LKN EMS transport windows would have excluded 11%, 9%, 2% and 0% MET intervention patients respectively.

Conclusion:
<
4.5 hour LKN EMS transport protocols may exclude a significant number of LVO patients with CTP and ASPECTS results possibly suitable for MET. These data need to be confirmed with a prospective multicenter study.
Abstract WP247: Paramedic Perspectives on Prehospital Stroke Care: A Qualitative Analysis
Authors: Oostema J A , Tecos Maria , Sleight Deborah , Mavis Brian
Published: July 2021

Introduction:
Ischemic stroke patients who arrive by emergency medical service (EMS) receive faster emergency department evaluations and improved rates of thrombolytic treatment. However, EMS stroke recognition and compliance with prehospital stroke quality measures are inconsistent. We hypothesized that EMS stroke care is influenced by a complex interaction of knowledge, beliefs, and system-level variables that influence behavior.

Methods:
Focus groups of paramedics from a single urban/suburban county were assembled to discuss their experiences identifying and transporting stroke patients. Focus groups were conducted using a semi-structured interview format and audio recorded. Transcripts of focus groups were qualitatively analyzed to identify themes, subthemes, and patterns of paramedic responses. The Clinical Practice Guidelines Framework provided the initial coding scheme, which was modified during the coding process by three coders using grounded theory methods, who came to consensus on which codes to apply.

Results:
Three focus groups (n=13) were conducted to reach theme saturation. Overall, paramedics reported high confidence in clinical gestalt for assessing stroke patients and a strong desire to “do the right thing,” but were unfamiliar with published guidelines. Paramedics identified variability in the clinical presentations of stroke, inadequate or inconsistent hospital guidance, and lack of feedback regarding care as principle barriers to ideal prehospital stroke care. Participants reported conflicting hospital guidance regarding the appropriate time frame for a high priority transport and hospital prenotification. Feedback regarding final diagnosis was viewed as critical for developing improved clinical acumen. Direct to CT protocols were cited as an effective way to integrate EMS into hospital stroke response.

Conclusion:
In this qualitative analysis, paramedics expressed a desire for clear, hospital-directed guidance and consistent feedback regarding outcomes for suspected stroke patients.
Abstract WP252: EMS Use After Acute Ischemic Stroke in Korean Population: Familyism may not Help
Authors: An Kyungeh , Shin Cha-Nam , Sim Jeongha
Published: July 2021

Introduction:
Acute ischemic stroke (AIS) is a leading cause of mortality and disability, and many die before reaching to a hospital or in an emergency department in Korea. Emergency medical services (EMS) play a pivotal role in optimizing survival rate by providing onsite treatment and speedy transportation of patients. Yet, many fail to use EMS, and subsequently, fail to receive a reperfusion therapy within the time window. This study aimed to identify factors associated with the EMS use.

Hypothesis:
We hypothesize that among AIS patients, (1) EMS use will shorten the pre-hospital delay time; (2) patients’ living condition (living alone, living in rural area) and presence of noticeable symptoms will be associated with EMS use; (3) familyism will influence the decision on health and EMS use among AIS patients.

Methods:
160 consecutive patients participated to a structured interview. Decision time, transportation time and the overall pre-hospital delay time were compared between EMS- and other transportation-users. Patients’ living condition, history of stroke, symptom experience, first contacted person for a decision making were examined for the association with EMS use.

Results:
Only 30.9% used an EMS. Both decision time (median 120 vs. 480 min.,
p=
0.002) and the overall pre-hospital delay time (median 140 vs. 625 min.,
p=
0.004) were significantly shorter in EMS users than other transportation users. EMS use was associated with the presence of hemiparesis (
p=0.003
), first contacted person at the presence of symptoms (
p=0.032
), and was inversely associated with failure to recognize the urgency of symptoms (
p
=0.006). A logistic regression revealed that presence of hemiparesis (
p=0.014
), recognizing the symptom’s urgency predicted the use of EMS (
p
=0.033).

Conclusion:
While EMS was underutilized by stroke patients, neither living with family nor living in urban area played a positive role in EMS use. Familyism-based cultural norm of contacting adult children in a crisis did not favorably contribute to the EMS use nor to early arrival at the hospital. Failure to recognize urgency was a prominent barrier to EMS use, and that warrants more targeted education for people at risk of a new or a recurrent stroke to improve EMS use and better outcomes.
Abstract WP271: Stroke Extensively Alters the Cerebral Expression of Transcribed Ultraconserved Regions of the Genome
Authors: Mehta Suresh L , Dharap Ashutosh , Vemuganti Raghu
Published: July 2021

The mammalian genome harbors 481 DNA elements (200-779 bp) that show 100% homology between humans, rats and mice despite millions of years of phylogenetic separation. These elements are actively transcribed into noncoding RNAs called transcribed ultraconserved regions (T-UCRs). Physiological function of T-UCRs is not yet evaluated in detail. Their role in various brain pathologies is also not known. Using microarray analysis, we currently evaluated the expression profiles of T-UCRs at 3h, 6h and 12h of reperfusion following transient middle cerebral artery occlusion (MCAO) in adult rats. Under normal physiological conditions, 61 intragenic and 46 intergenic T-UCRs were expressed in rat cerebral cortex. Surprisingly, 54 of the 61 intragenic T-UCRs displayed a negative correlation with their host gene expression. Following transient MCAO, expression of 67 T-UCRs (20 up- and 47 down-regulated) were altered at one or the other reperfusion time points. Of those altered, 39 are intragenic and 28 are intergenic. Temporally, 55 (11 up and 44 down) were altered at 3h, 53 (15 up and 38 down) at 6h and 62 (16 up and 46 down) at 12h of reperfusion. Interestingly, 36 T-UCRs were altered at all-time points of reperfusion and 4 of those were altered by >5 fold (uc.34 and uc.226 were up-regulated, and uc.286 and uc.417 were down-regulated). In addition, we observed a congenic expression of some T-UCRs (uc.208/uc.209, uc.460/uc.462/uc.465). Functional significance of T-UCRs altered after stroke was predicted by clustering multiple bioinformatics analysis tools (GeneMANIA, PANTHER, and WebGestalt) using the host genes and the nearest upstream and downstream genes as anchors. The products of T-UCR associated genes are involved in the regulation of diverse biological functions including metabolism, development and cellular process. This first time observation suggests that T-UCRs altered after ischemic stroke could have functional significance in post-stroke brain damage and plasticity.
Abstract WP276: Drag Reducing Polymers Based Resuscitation Fluid Improves Cerebral Microcirculation After Mild Traumatic Brain Injury and Hemorrhagic Shock
Authors: Lara Devon , Statom Gloria , Bragina Olga A , Kameneva Marina V , Nemoto Edwin M , Bragin Denis E
Published: July 2021

Introduction:
Hemorrhagic shock (HS), causing arterial hypotension, often occurs after traumatic brain injury (TBI). Current resuscitation fluids do not ameliorate the impaired cerebral microvascular perfusion leading to hypoxia, neuronal death, increased mortality and poor neurological outcome. Nanomolar concentrations of intravascular blood soluble drag reducing polymers (DRP) were shown to increase tissue perfusion and oxygenation and decrease peripheral vascular resistance by rheological modulation of hemodynamics. We hypothesized that the resuscitation fluid with DRP would improve cerebral microcirculation, oxygenation and neuronal recovery after TBI combined with HS (TBI+HS).

Methods:
Mild TBI was induced in rats by fluid percussion pulse (1.5 ATA, 50 ms duration) followed by induced by phlebotomy arterial hypotension (40 mmHg). Resuscitation fluid (lactated Ringers, LR) with DRP (DRP/LR) or without (LR) was infused to restore mean arterial pressure (MAP) to 60 mmHg for one hour (pre-hospital care), followed by re-infusion of blood to a MAP of 100 mmHg (hospital care). Using
in vivo
2-photon laser scanning microscopy over the parietal cortex we monitored changes in microvascular blood flow, tissue oxygenation (NADH) and neuronal necrosis (i.v. propidium Iodide) for 5 hr after TBI+HS. Doppler cortical flow, rectal and cranial temperatures, arterial pressure, blood gases and electrolytes were monitored.

Results:
TBI+HS compromised brain microvascular flow leading to tissue hypoxia followed by neuronal necrosis. Resuscitation with DRP/LR compared to LR better improved cerebral microvascular perfusion (82 ± 9.7% vs. 62 ± 9.7%, respectively from pre-TBI baseline, p<0.05, n=7), attenuated capillary microtrombi formation and re-recruited collapsed during HS capillaries. Improved microvascular perfusion increased cortical oxygenation reducing hypoxia (77 ± 8.2% vs. 60 ± 10.5%, by DRP-LR vs. LR, respectively from baseline, p<0.05) and decreased neuronal necrosis (21 ± 7.2% vs. 36 ± 7.3%, respectively as a percentage of total neurons, p<0.05).

Conclusions:
DRP/LR resuscitation fluid is superior in the restoration of the cerebral microcirculation and neuroprotection following TBI + HS compared to volume expansion with LR.
Abstract WP280: Caveolin-1, Ring Finger Protein 213, and Endothelial Function in Moyamoya Disease
Authors: Chung Jong-Won , Kim Suk Jae , Hwang Jaechun , Lee Mi Ji , Choe Hanna , Oh Mi Jeong , Kim Soo Yoon , Cho Yeon Hee , Moon Gyeong Joon , Cha Jihoon , Kim Keon Ha , Jeon Pyeong , Yeon Je Young , Yeon Je Young , Kim Jong-Soo , Hong Seung Chyul , Ki Chang-Seok , Kim Gyeong-Moon , Chung Chin-Sang , Lee Kwang Ho , Bang Oh Young
Published: July 2021

Background:
Moyamoya disease (MMD) is a unique cerebrovascular occlusive disease of unknown etiology. Ring finger protein 213 (RNF213) was identified as a susceptibility gene for MMD in East Asian. However, the pathogenesis of MMD is still unclear.

Methods:
We prospectively analyzed clinical data for 139 patients with MMD (108 definite MMD, 31 probable MMD) and 61 patients with intracranial atherosclerotic stroke (ICAS), and 68 healthy subjects. We compared the genetic (RNF213 variant) and protein biomarkers for caveolae (caveolin-1), angiogenesis (vascular endothelial growth factor [VEGF] and receptor [VEGFR2], and antagonizing cytokine [endostatin]) and endothelial dysfunction (asymmetric dimethylarginine [ADMA], nitric oxide and its metabolites [nitrite and nitrate]), between patients with MMD and ICAS. We then performed the path analysis to evaluate whether a certain protein biomarker mediates the association the genetic and MMD.

Results:
Caveolin-1 level was decreased in patients with MMD and this level was markedly decreased in RNF213 variant carriers. Circulating factor such as VEGF and receptor were not different among the groups. Markers for endothelial dysfunction were significantly higher in patients with ICAS, but normal in MMD. The path analysis showed that the presence of the RNF213 variant was associated with caveolin-1 level that led to MMD. The level of combined marker of MMD (caveolin-1) and ICAS (ADMA, marker for endothelial dysfunction) predicted MMD with a good sensitivity and specificity.

Conclusions:
Our results indicate that MMD is primarily caveolae disorder, dysregulation of endothelial vesicular trafficking and signal transduction, but not related to endothelial dysfunction or dysregulation of circulating cytokines.
Abstract WP333: Clinical Research Coordinators' Barriers and Best Practices to Minority Recruitment in Stroke Clinical Trials
Authors: Rivera Jazmin , Southwick Lauren , Parikh Nina S , Haley Sean , Boden-Albala Bernadette
Published: July 2021

Background:
Poor recruitment and retention of clinical trial participants continues to be a major contributor to the early termination of many clinical trials.

Specifically, low racial-ethnic minority and female participation rates can limit scientific, economic, and ethical value of a clinical trial. Previous literature has explored patient-centered enrollment barriers, while research has yet to investigate recruitment challenges facing clinical research coordinators (CRCs).

Aim:
To gain insight of the barriers facings CRCs with particular attention to minority and female recruitment efforts.

Methods:
Two semi-structured focus groups were conducted with a purposive sample of stroke CRCs in 2013 (N=17) and 2014 (N=23). Discussion topics included: 1) integrating NIH Inclusion Policy into trial design and recruitment strategies; 2) experiences recruiting minorities and women in stroke/neurological trials; and 3) strategies to enhance minority and female involvement. Two reviewers independently developed an initial set of base codes (n=6). Reviewers met and reconciled their independent coding using the 2013 transcript before applying the same process to the 2014 transcript. Codes and sub-codes were used to identify thematic areas.

Results:
Both focus groups included majority female participants with nearly half holding nursing degree. Codes informed three thematic areas: administration, enrollment and “other.” Administrative findings highlight organizational barriers. Enrollment findings identified challenges related to the severity of condition and time limitations. The “other” theme cut across administration and enrollment, often informed by coordinators’ personal experiences. Personal barriers include biases and uncertainty approaching patients from diverse backgrounds. Participants identified coordinator conferences, trainings, Internet resources, direct support from PIs and team building between hospital and research staff as key strategies.

Conclusion:
Our findings identified multi-dimensional organizational, administrative and resource barriers and the need for more focused CRC support to enhance participant recruitment efforts in stroke clinical research.
Abstract WP349: Feeding Status After Stroke and Effect of Glyceryl Trinitrate: Data From the Efficacy of Nitric Oxide in Stroke (ENOS) Trial
Authors: Woodhouse Lisa , Hamdy Shaheen , Smithard David , Cohen David , Sprigg Nikola , Bath Philip M
Published: July 2021

Background:
Post-stroke dysphagia is common, associated with poor outcome, and patients often require non-oral feeding/fluids. The relationship of feeding status on outcome, and treatment with transdermal glyceryl trinitrate (GTN) was studied in the ENOS trial.

Methods:
ENOS assessed GTN (5 mg vs none for 7 days) in 4,011 patients with acute stroke and high blood pressure. Feeding status (oral = normal diet, soft diet; non-oral = nasogastric tube, percutaneous endoscopic gastrostomy tube, parenteral fluids, none) was assessed at baseline and day 7. The primary outcome was the modified Rankin Scale (mRS) measured at day 90. Analyses of outcomes were adjusted for baseline covariates. †2p<0.001.

Results:
In comparison with oral feeding, non-oral patients (N=1331, 33.2%) were older (73.9 vs 68.5 years†), more likely to be female (47.3 v 40.4%†) and had more severe stroke (Scandinavian Stroke Scale 24.6 v 38.3†). By day 7, 56.8% patients had improved from non-oral to oral feeding, and 4.4% had deteriorated. Non-oral feeding at baseline was associated with more impairment at day 7 (SSS 29.0 v 43.7†), and higher mRS 4.0 (1.7) v 2.7 (1.6)†) and death (23.6% v 6.8%†) at day 90. Although GTN did not modify feeding status overall, randomisation to GTN <6 hours of stroke was associated with a significant shift to improved feeding status at day 7 (OR=0.61, 95% CI 0.38-0.98).

Conclusions:
Non-oral feeding status is common in acute stroke and associated with more impairment, dependency and death. Very early administration of GTN improved feeding status, a finding that requires further testing.
Abstract WP356: Eligibility Criteria in Clinical Trials on Intracerebral Hemorrhage Applied to an Unselected Cohort: The Lund Stroke Register
Authors: Hansen Björn M , Ullman Natalie , Norrving Bo , Hanley Daniel F , Lindgren Arne
Published: July 2021

Introduction:
Strict patient selection in medical or surgical trials on intracerebral hemorrhage (ICH) is needed to optimize therapeutic benefit but limits trial enrolment as well as overall applicability of results. We studied the applicability of previous, current, and planned large interventional ICH trials by applying each trial’s defined inclusion criteria to an unselected cohort of ICH patients.

Methods:
Large interventional ICH trials were identified via trial registration databases. To estimate eligibility rates, each trial’s inclusion criteria were applied on an unselected consecutive group of first-ever ICH patients from the prospective hospital-based Lund Stroke Register. Subsequently, 30 day survival status was obtained from the National Census Office and 90 day poor functional outcome (modified Rankin Scale ≥4 or death) from the Swedish Stroke Register or medical files.

Results:
Among 253 included ICH patients, estimated eligibility rates ranged from 2-38% for the identified 11 large interventional ICH trials (Figure 1). Patients not eligible for any of the trials (N=91, 36%) had: more extensive intraventricular hemorrhage (p<0.001); lower baseline level of consciousness (p<0.001); higher rate of cerebellar ICH and lower rates of lobar ICH (p<0.001). No significant age, sex, or ICH volume differences were observed. The 30 day mortality rates among eligible patients were 0-33% depending on selected trial. The mortality rate for patients not eligible for any trial was 55% vs 19% for patients eligible in ≥1 trial (95% CI: 45-65% vs 13-25%; p<0.001). Non-eligible ICH patients more frequently had poor functional outcome (75% vs 49%; 95% CI: 65-85% vs 41-57%; p<0.001).

Conclusions:
There is great variation in proportions of unselected ICH patients eligible for inclusion in treatment trials. Even in trials with broad entry criteria only a minority is eligible, which need to be considered when translating ICH-trial results into clinical practice.