bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract 3626: Cranio Cervical Arterial Dissection; Radiologic Variants And The Natural History, Treatment, And Prognosis
Authors: Al-Mufti Fawaz , Lee Seon Kyu , Kim Benny , Medin Karen , Gerber Oded , Roque Clemente
Published: July 2021

Background and Objective:
Craniocervical arterial dissection (CCAD) is believed to have a relatively benign natural history & generally is managed with anticoagulation or antiplatelet therapy.The purpose of this study is to identify whether clinicoradiological parameters affect prognosis of CCAD.

Methods: 26
patients(M: F=12:14, mean age=41.57) with clinical evidence of CCAD and at least one of the following suggestive imaging findings on either CT Angiography or MR angiography were included. Suggestive imaging findings include:1) arterial stenosis,2) arterial occlusion, 3) ectatic change of lumen,4) pseudoaneurysm,and 5) dissection flap. The temporal clinical and radiological evolution of CCAD findings were analyzed by a stroke neurologist and neuroradiologist respectively.

Results:
69.2% had spontaneous dissections (n=18/26), and 30.7%had a history of trauma (n=8/26). 15 patients presented with strokes(15/26, 57.6%), three patients had TIA(11.5%), 13 patients had neck pain (50%), and 6 patients presented with Horner’s syndrome (21%). Anterior circulation dissection contributed 23%(6/26) of all dissections and posterior circulation dissections were 76.9%(20/26), while the vast majority of cases were unilateral,3.8% of cases were bilateral(1/26). Although 38.4% (n=10/26) were lost to follow up, 61%(n=16/26) had at least one follow up vascular imaging study. Neuroradiologic evaluation of these patients revealed arterial stenoses, arterial occlusions, ectatic changes of the lumen, pseudoaneurysms, and dissection flaps. Pseudo aneurysms were present in 15.4%(n:4/26) of cases.Recanalization had occurred in 75% (12/16), while 25 % did not recanalize within 2-5 months with a mean duration of 71 days.All patients were managed with anticoagulation or antiplatelet therapy. During the follow up period, all patients were stable, without any additional neurologic sequelae.50%(n=4/8) of the traumatic cases were associated with stroke while spontaneous dissections were associated with strokes in approximately 61%(n=11/18).With regards to age we found that 70% of patients between the ages of 38 - 65 years of age had developed strokes while only 30% of those aged 21 - 35 years old had developed strokes.

Conclusion:
The results revealed a distinction in the prognosis based upon age and the CCAD subtypes. Younger patients were less likely to present with a stroke than their older counterparts.Radiologic subtypes of CCAD as previously demonstrated in our previous study(Lee et al) supported our data which revealed that patients with pseudoaneurysm and intimal flap do not change over time despite treatment.With medical management, more than half of the arterial stenoses after craniocervical dissection improved within a relatively short period of time and no further neurologic sequelae were observed.
Abstract 3666: Common Polymorphisms in Familial Vascular Malformation Genes do not Show Association with Sporadic Brain Arteriovenous Malformation
Authors: Weinsheimer Shantel , Bendjilali Nasrine , Pawlikowska Ludmila , Kwok Pui-Yan , Lawton Michael T , Zaroff Jonathan G , Sidney Stephen , McCulloch Charles E , Kim Helen , Young William L
Published: July 2021

Background:
The genetic basis of brain arteriovenous malformation (BAVM), a tangle of abnormal vessels directly shunting blood from the arterial to venous circulation, is unknown. However, there are two rare vascular disorders with known familial mutations in which a subset of patients display a BAVM phenotype: hereditary hemorrhagic telangiectasia (
ACVRL1
,
ENG
, and
SMAD4
mutations) and capillary malformation-arteriovenous malformation (
RASA1
mutations). To investigate whether variants in these four vascular malformation genes are associated with sporadic BAVM, we performed a case-control study, evaluating both single nucleotide polymorphisms (SNPs) and copy number variation (CNV).

Methods:
We used genome-wide data (Affymetrix SNP 6.0) from 319 cases and 496 healthy controls. There were 27 unlinked SNPs (r
2
<0.8) on the array with minor allele frequency >1% and in Hardy-Weinberg equilibrium (p>0.01) mapping within 20kb of the four genes:
ACVRL1
(n=16),
ENG
(n=6),
SMAD4
(n=2), and
RASA1
(n=3). Single SNP association was tested using multivariate logistic regression in PLINK, adjusting for age, gender, and top 3 principal components of ancestry (to control for population stratification). The Bonferroni method (p<0.0019) was used to correct for multiple comparisons. CNVs in these genes were called using the PennCNV algorithm.

Results:
Two SNPs located upstream and downstream of
ACVRL1
were associated with BAVM at nominal p<0.05: rs10783480 (OR=0.69, 95% CI=0.50 - 0.96, p=0.029,) and rs11169956 (OR=0.69, 95% CI=0.48 - 0.99, p=0.046). However, these SNPs were not associated with BAVM after correction for multiple testing of all SNPs. Polymorphisms in the
RASA1
,
ENG
, and
SMAD4
genes were not significantly associated with BAVM (p>0.05). We observed one CNV, a duplication that mapped to the
ACVRL1
gene, in one control. We did not observe any CNVs mapping to
RASA1
,
ENG
, or
SMAD4
.

Conclusions:
Common SNPs and CNVs in four vascular malformation genes associated with inherited disorders displaying BAVM were not significantly associated with sporadic BAVM. A previously reported
ACVRL1
intronic SNP (rs2071219) was not on the Affymetrix array and none of the existing
ACVRL1
SNPs tagged this SNP. Further, rare polymorphisms in these genes were not genotyped and may contribute to BAVM risk.
Abstract 3701: A Novel Web based modified Rankin Scale program for certification and patient self assessment scoring in the Antihypertensive Treatment in Acute Cerebral Hemorrhage (ATACH II) Trial
Authors: Khatri Rakesh , Connelly Bo , Chaudhry Saqib , Maland Erik , Abbott Emily , Qureshi Adnan , Tekle Wodowossen G , Khan Amir , Hassan Ameer E , Algiers Lawrence
Published: July 2021

Background:
The modified Rankin Scale (mRS) is a commonly used disability scale in clinical trials pertaining to acute stroke. Previous studies suggest that requiring the use of certification programs can improve the accuracy of mRS grading. We developed two mRS video tools for use in the multinational ATACH II trial. These tools train medical professionals on assessing mRS and enable patients, or their caregivers, to ascertain their own mRS score.

Methods:
After conducting a thorough literature review and interviewing numerous accomplished neurologists, we focused the development of our mRS resources around two concepts: key differentiating points and standard interview questions. The certification program consists of two elements: an educational video and an assessment. The educational video describes the mRS scale in four formats: Power Point slides with narrator explanation, simulated clinical interviews, videos of patients outside of the clinical setting, and narrator overview of specific levels. After watching this video, users proceed to the assessment where they are asked to assess the mRS score of six patients based on visual assessment and specific answers to the six foundation interview questions. Users are required to assess all six scenarios correctly in order to pass.

Results:
To date 61 individuals have taken the certification course and test. 54 passed (88.5%) and 7 failed (11.4%) the test. The pass rate was very high in physicians and study coordinators (95.7% and 80.6%).

Conclusion:
A novel web based tool for mRS certification is described. We are currently designing validation studies for each of these tools. Pilot study is undergoing to validate the patient self assessment grading.
Abstract 3720: Antiplatelet Medication and Bleeding Complications with External Ventricular Drains
Authors: Weinreb Jeffrey , McLaughlin Tara , Yosufzai Mohammed , Sansing Lauren H , KURESHI INAM U
Published: July 2021

Introduction:
External ventricular drains (EVD) are routinely used in the neurosurgical operating room and the neurointensive care unit to treat patients with severe traumatic brain injury and intracranial hemorrhages. EVD insertion has been associated with hemorrhagic complications in patients taking anticoagulants and standard of care dictates reversal of anticoagulation prior to EVD insertion. However, the risk of bleeding from EVD insertion in patients on antiplatelet medications is unknown. In this retrospective study, we determined the bleeding complication rates in patients on and off antiplatelet therapy.

Methods and Materials:
Hospital procedure codes were searched to identify all patients who received an EVD from August 2008 and June 2011, regardless of indication. Computerized medical records, neuroimaging, and the Hartford Hospital Stroke Center Database were utilized to record medication use and bleeding complications. Patients who received anticoagulant therapy such as warfarin were excluded. A bleeding complication was defined as visible hemorrhage on a CT or MRI scan after EVD placement at any point along the EVD tract on any scan after placement. Review of neuroimaging was performed blinded to medication use. Analyses were performed to ascertain the correlation between antiplatelet therapy and bleeding complications following EVD placement.

Results:
163 patients met the inclusion criteria and 19 patients were taking an antiplatelet medication. The overall occurrence of bleeding complications after an EVD was 14 out of 163 (8.6%). The data suggest an association between antiplatelet medication use and EVD bleeding complications (6.9% in patients not on an antiplatelet medication vs 21.1% in patients taking an antiplatelet medication, p=0.062).

Conclusion:
Although not statistically significant, this exploratory study identified a trend towards higher bleeding complications from EVD placement in patients on antiplatelet therapy. This is an important observation in reevaluating EVD insertion protocols. A larger study will likely establish statistical significance and can determine whether clinical outcomes were affected by bleeding complications. Future studies may then evaluate interventions to reduce bleeding (e.g. platelet transfusions for patients on antiplatelet therapy).
Abstract 3726: Rate of Inappropriate Statin Use after Intracerebral Hemorrhage
Authors: Woo Daniel , Comeau Mary , Flaherty Matthew L , Brown Mark , Haverbusch Mary , Moomaw Charles , Martini Sharyl , Adeoye Opeolu , Kleindorfer Dawn , Kissela Brett , Broderick Joseph P , Langefeld Carl
Published: July 2021

Background:
Statin use has been associated with an increased risk of intracerebral hemorrhage (ICH) and an increased risk of recurrent ICH. Statin use after ICH would be justified for indications where the benefits outweigh the risks of complications per randomized trial evidence. We evaluated the use of statins after ICH in both academic and community hospitals in a population-based study.

Methods:
The Genetic and Environmental Risk Factors for Hemorrhagic Stroke Study (NS36695) prospectively identifies hemorrhagic strokes in the Greater Cincinnati/Northern Kentucky region. Chart abstraction was performed by nurses and case verification performed by physician review. Discharge medications were obtained and classified by type of medication including statin use. For this analysis, acceptable indications for statin use at discharge included history of coronary artery disease, myocardial infarction, angina, coronary artery bypass and prior ischemic stroke. Academic center was defined as having a neurosurgical or neurology residency program.

Results:
During the period 7/08 to 12/09, 403 cases of ICH were enrolled of which 110 died during the hospitalization and 36 were discharged to hospice. Of the remaining 257 cases, 75 (29%) were on statins at the time of admission of which 12 had their statins stopped prior to discharge. Of the remaining 63 patients, 33 (52%) were discharged on statins without a proper indication. Of 182 ICH patients not on statins at the time of admission, 13 were discharged on statins, of whom 6 (46%) had no compelling indication for a statin. A total of 39 (15%) surviving ICH patients were discharged on statins without a clear indication. No difference in discharge on statins was observed for academic vs. community hospitals.

Conclusions:
While statin use is appropriate after ischemic stroke, there is no evidence that use in ICH prevents recurrence or improves outcomes and evidence suggests that statin use increases the risk of ICH. We found that roughly 1 in 6 ICH patients were discharged on a statin without a justifiable indication given the associated risks. Education of medical providers regarding statins and hemorrhagic stroke may improve stroke care following ICH.
Abstract 3752: Performance Of Color ADC Maps As A Prognostic Tool In Comatose Post-cardiac Arrest Patients
Authors: Mlynash Michael , Kleinman Jonathan T , Finley Caulfield Anna , Ventkatasubramanian Chitra , Buckwalter Marion , Eyngorn Irina , Bammer Roland , Moseley Michael , Wijman Christine A
Published: July 2021

Background:
Predicting outcome for comatose post-cardiac arrest survivors is challenging and compounded by the use of therapeutic hypothermia and sedative agents in recent years. Previous studies suggest that brain abnormalities on MRI are predictive for poor outcome. MRI based predictive factors are attractive because they are not affected by drugs or metabolic derangements; however, most of the methods proposed require image post-processing with specialized software. We assessed the prognostic value of color apparent diffusion coefficient (ADC) maps in a prospective study.

Methods:
Consecutive patients who remained comatose after cardiac arrest were prospectively enrolled. Color ADC maps were created by assigning computed ADC values to 8 colors of spectrum ranging from red to blue (
Figure
). The color ADC maps were not available to the clinical teams caring for the patient. Two raters (a neurocritical care/stroke neurologist and a medical student) independently and blinded reviewed the color ADC maps and predicted 3 month outcome as poor (Glasgow Outcome Scale (GOS) 1 or 2), impaired (GOS=3) or good (GOS of 4 or 5). Both raters were “trained” by viewing 4 examples of patients with good, impaired and poor outcomes. A 3 month GOS of 3-5 was considered a favorable outcome. The agreement between raters and the predictive performance of the color ADC maps were assessed.

Results:
112 color ADC maps of 94 patients (56% with poor, 12% with impaired, and 32% with good outcome) were reviewed: age 59±15 years, 36% females, 69% underwent therapeutic hypothermia, median (IQR) arrest duration 20min (14-30), and time between the arrest and MRI 82hours (60-141). Kappa with quadratic weighting for agreement on predicting all 3 levels of outcomes was 0.74, while kappa for favorable vs. unfavorable outcome was 0.76. For the two reviewers, the sensitivity for predicting poor outcome was 0.85 (95%CI 0.73-0.92) and 0.78 (0.66-0.87), the specificity 0.81(0.66-0.90) and 0.74(0.59-0.86), and the true positive predictive rate 86% (74-93%) and 81% (69-89%), respectively. After excluding early (≤24 hours) and late (>120 hours) scans (ADC changes are time dependent and most apparent after day 1 and before day 6), the specificity improved to 0.87 (0.68-0.96) and 0.77 (0.57-0.89), respectively.

Conclusion:
MRI color ADC maps hold promise as a useful and easy to interpret adjunct for predicting outcome of comatose post-cardiac arrest patients in the first few days after the arrest. Since these maps do not require post-processing and can be created in real-time, they can easily be implemented in the clinical setting.
Abstract 3755: Flow Diversion for Proximal Internal Carotid Artery Aneurysms: Complications and Early Angiographic Results
Authors: Lanzino Giuseppe , Cloft Harry J , Kallmes David F
Published: July 2021

Background:
Flow diversion has been proposed as a valid option for patients with proximal internal carotid artery aneurysms. We analyzed a consecutive series of 38 patients with proximal (to the origin of the posterior communicating artery) internal carotid artery aneurysms treated with flow diversion over a 28-month interval.

Methods:
Clinical information and angiographic follow-up data were prospectively collected in a consecutive series of patients with proximal internal carotid artery aneurysms treated with flow diversion. No patients were lost to follow-up and every eligible patient (with at least 6 months of follow-up) underwent catheter angiography at 6 months.

Results:
The series include 38 patients (37 women and 1 man). Most of the aneurysms were large or giant and with a wide neck. In two patients, we failed to deliver the device to the target segment because of proximal vessel tortuosity; thus 36 patients underwent flow diversion. There were no permanent periprocedural neurological deficits. One patient experienced a transient neurological deficit and another patient suffered slight transient worsening of a third nerve paresis. Complete angiographic occlusion of the aneurysm was observed in 75% of patients at 6 months and in 87% of the eligible patients at one year. One patient was found to have asymptomatic internal carotid occlusion.

Conclusion:
Flow diversion is an effective and safe method to treat internal carotid artery aneurysms not amenable to other endovascular techniques.
Abstract 3773: The Impact Of Reperfusion On Vasogenic Edema Following Middle Cerebral Artery Occlusion In Experimental Ischemia
Authors: Christoforidis Gregory , Rink Cameron , Garg Nitn , Khan Shahid , Sen Chandan
Published: July 2021

Objective:
In order to assess the impact of reperfusion on the degree of subsequent cerebral edema following cerebral ischemia, this work sought to compare 24 hour infarct volume progression between permanent and transient middle cerebral artery occlusion (MCAO) in a canine model.

Methods:
Using a previously published endovascular transient MCAO method, 5 mongrel canines underwent 1-hour transient MCAO and 5 underwent permanent MCAO. Model parameters were altered to result in varying infarct volumes. Magnetic resonanace imaging (MRI) (3T Achieva, Philips) was performed one hour and 24 hours following reperfusion as well as 60 minutes following permanent occlusion. Infarct volumes were calculated using a previously published threshold technique by two observers using 1 hour mean diffusivity (MD) maps and 24hour FLAIR MRI. Reproducibility was assessed using Bland-Altman statistic. Average infarct volumes between the observers were calculated. Bivariate linear fit analysis were used to assess the correlation between immediate and 24 hours infarct volume determinations.

Results:
R square (r2) for linear fit was 0.964 (p=0.0005) for permanent occlusion and 0.971 (p= 0.0022) for transient occlusion (
figure 1
). The infarct volumes measured at 1 hour increased by a factor of 1.42 relative to 24 hour infarct volumes for permanent occlusion and 2.05 for transient occlusion. Bland-Altman statistic indicates that reproducibility using the MD maps (15.9%) and FLAIR images (13.3%) is not substantially different. None of the animals demonstrated hemorrhagic conversion by 24 hours.

Conclusion:
MD maps generated one hour post reperfusion following transient and permanent MCAO in a canine model can serve as a reliable assessment for infarct volume determination. Increase in infarct volume at 24 hours, presumably due to vasogenic edema, was greater in reperfused infarctions than with permanent occlusion.

Figure 1:

Bivariate linear fit analysis comparing immediate and 24-hour infarct volume calculations for permanent and transient occlusions.
Abstract 3790: The TIA Admission Score - A Tool to Determine Observation Versus Inpatient Admission Status for TIA
Authors: Sartor E. Alton , Monlezun Dominique , Sensabaugh Christina , Albright Karen C , Boehme Amelia K , McGwin Gerald , Martin-Schild Sheryl
Published: July 2021

BACKGROUND:
Centers for Medicare and Medicaid Services has criteria for admission to observation vs. inpatient status, one of which is expected discharge within 24 hours. Validated scores predicting the likelihood of stroke after TIA are useful in supporting admission, but do not assist with assigning admission status. We developed a scoring system that predicts which patients presenting with TIA would have a high probability of LOS >23 hours.

METHODS:
Patients presenting to our stroke center from 7/08-12/10 with a diagnosis of TIA were identified from a prospective stroke registry containing demographic and clinical characteristics. A scoring system was created to estimate the probability of a LOS >23hrs based on patient demographics, past medical history, and current medication. Potential predictors of LOS >23hrs with sensitivity ≥65% or (area under the curve) AUC ≥0.6 were evaluated to determine if they demonstrated significant, independent associations with LOS >23hrs using logistic regression, adjusting for weekend admission. Sensitivity and specificity were used to evaluate the score’s ability to predict observation status (LOS ≤23hrs, score ≤2), as well as inpatient status (LOS >23hrs, score ≥4).

RESULTS:
Out of 223 patients with TIA (52% F, 58% AA, median age 62) 110 (49%) had a hospital stay of >23 hours. Patients with LOS >23hrs were older (p=.036), more frequently had a history of coronary artery disease (CAD) (p<.001) and congestive heart failure (p=.059), and more frequently reported taking blood pressure (BP) medications (p=.008). No significant differences were observed in the two groups with regards to the remaining demographic and clinical variables. The TIA admission score ranges from 0-6, consisting of age >70yrs (2 points), presence of CAD (2 points), current use of BP medications (1 point), and being African American (1 point). As shown in
Figure 1
, 85% of patients with a score of 6 had a LOS>23hrs, as compared to 50% in patients with a score of 3, and 29% of patients with a score of 1. A score of ≤2 showed a sensitivity of 68% (specificity 79%) for identifying observation status, whereas a score of ≥4 showed a sensitivity of 79% (specificity 58%) for identifying inpatient status.

CONCLUSIONS:
In our population of TIA patients, clinical characteristics available on presentation identified admission to observation and inpatient status with acceptable sensitivities and specificities. Validation is required in other populations. If validated, this score could assist providers in determining whether TIA patients should be admitted under observation or inpatient status.
Abstract 3802: Retinal Vasoreactivity as a Marker of Impaired Cerebral Function in Diabetes
Authors: Slocomb Julia E , Lott Mary E , Shivkumar Vikram , Bettermann Kerstin
Published: July 2021

The eye and the brain share embryological, anatomic and physiological similarities, which suggest that the retinal microvasculature may be an ideal surrogate marker of cerebrovascular function. This is intriguing, as the cerebral vasculature cannot be directly measured in a non-invasive manner. In epidemiological studies abnormal retinal Arteriovenous Ratios (AVR) are associated with an increased risk of stroke and cerebrovascular disease. However, the association between retinal vasoreactivity measurements and cerebral blood vessel function remains unknown. An attenuated retinal vasoreactivity may indicate endothelial dysfunction in the eye and brain and may prove to be useful as a marker of cerebrovascular disease in high risk populations such as in diabetics.

STUDY GOALS:
To examine 1) the impact of diabetes at different disease stages on measures of cerebrovascular function and 2) the relationship between retinal blood vessel reactivity, retinal AVRs and measures of cerebral small vessel function.

METHODS:
This cohort study included 29 type 2 diabetics, 14 pre-diabetics, and 14 healthy controls (ages: 37 to 75 years). Retinal vasoreactivity was measured with the Dynamic Vessel Analyzer (Imedos, Jena, Germany) following high frequency flicker light stimulation. Cerebrovascular blood flow velocity of the Middle Cerebral Artery (MCA) was assessed by Transcranial Doppler Ultrasound (TCD) (Siemens, USA).

RESULTS:
Progression of diabetes was found to be significantly associated with attenuation of light flicker stimulus response (P=0.0009 artery, P=0.0001 vein, CI 95%), AVR (P=0.0070, CI 95%), PI (P=0.0202, CI 95%), RI (P=0.0033, CI 95%) and hyperventilation-breath hold (P≤0.0001, CI 95%). Across all groups, attenuated retinal arterial and venous diameter responses to the light flicker stimulus were associated with an increase in MCA RI (P=0.02, r=-0.30 artery, P=0.06, r=-0.24 vein, CI 95%). An attenuated venous diameter response was associated with an increase in PI (P=0.02, r=-0.29 vein, CI 95%). In addition, attenuated retinal diameter responses were also associated with a decrease in MCA mean flow velocities following hyperventilation-breath hold (P=0.05, r=0.26 artery, P=0.01, r=0.34 vein, CI 95%). Attenuated retinal responses were also correlated with a reduction in AVR (P=0.05, r=0.26 artery, P=0.15, r=0.19 vein, CI 95%).

CONCLUSION:
Impairment of retinal vasoreactivity is associated with cerebrovascular dysfunction across the continuum of diabetes, possibly indicating that the eye reflects changes in cerebral blood vessel function and stroke risk.
Abstract 3836: Efficacy And Safety Evaluation Of Endovascular Revascularization Devices In The A Rabbit CCA Occlusive Model
Authors: Mehra Manik , Nogueira Raul G , Finol Ender A , Migliuolo Michele , Jahrmarkt Scott , Yang Yi , Gounis Matthew J
Published: July 2021

Background:
Intra-arterial recanalization strategies targeting acute ischemic stroke (AIS) are a focus of increased interest, since their use results in a faster and a higher grade of recanalization. We evaluated different treatment strategies in a dedicated rabbit CCA model of thromboembolic occlusion. The response to Alteplase in rabbits is similar to humans; making this model ideal for thrombolytic evaluation.

Method:
New Zealand White rabbits were anesthetized, the CCA was exposed and a luminal stenosis created bilaterally with 3-0 silk suture. Allogenic clot was injected through a 6F catheter, which lodged consistently at the site of the stenosis. Allowing 45 minutes for clot-vessel wall interaction, the stenosis was released. The clot adhered to the vessel wall and did not migrate distally. The occlusion was treated with either intra-arterial Alteplase (n=4), balloon angioplasty (n=3), balloon infusion wire (NIT Therapeutics, PA; n=3) which in its embodiment mechanically disrupts and adjuvantly delivers Alteplase within the clot or partial stent deployment as a temporary bypass with (n=2) and without Alteplase (n=5). The control vessel (n=4) received no treatment. The primary efficacy endpoint was the final thrombolysis in cerebral infarction (TICI) score. The primary safety endpoint was the vascular safety of the device, which was assessed on luminal scanning electron microscopy (SEM) and hematoxylin and eosin staining.

Results:
Thromboembolic occlusion was created successfully with TICI 0 flow at the CCA in all animals. Partial stent deployment resulted in transient revascularization, however on resheathing, the vessel reoccluded. Use of partial stent deployment with adjuvant Alteplase resulted in revascularization in the high dose (4mg) group, however it failed to recanalize when using a lower (2mg) dose. Use of balloon angioplasty alone or intra-arterial Alteplase alone often failed to revascularize the vessel. The use of the balloon infusion wire resulted in a higher grade of recanalization (TICI 2B) consistently at a lower dose of Alteplase. Histomorphometric and SEM data revealed an acceptable level of disruption for endovascular devices, with endothelial denudation and exposure of the internal elastic lamina.

Conclusion:
With incorporation of newer endovascular treatment strategies to treat AIS, it is imperative to test their safety and efficacy in valid preclinical models, which simulates the thrombolytic and mechanical device- clot interaction as experienced in humans.
Abstract 3842: Angiographic Assessment Of Leptomeningeal Collateral Perfusion Parameters Following Experimental Transient Middle Cerebral Artery Occlusion
Authors: Theyel Brian , Benayoun Marc , Rink Cameron , Sen Chandan , Christoforidis Gregory
Published: July 2021

Objectives:
This work aims to develop and validate an angiographically based quantitative assessment of leptomeningeal collateral perfusion (QLCP) in experimental reversible middle cerebral artery occlusion (MCAO).

Methods:
Pial collaterals were assessed during MCAO using an angiographically based transient MCAO model in eight mongrel dogs (20-30 kg). Angiographic images were analyzed using a custom-made MATLAB program which measured contrast density over time. Using bivariate linear fit analysis relative cerebral blood volume (rCBV), relative transit time (rTT) and relative cerebral blood flow (rCBF) derived from regions of interest (ROI) from the normal and abnormal hemispheres were extracted and compared to one hour post reperfusion MRI based infarct volume calculations and leptomeningeal collateral scoring using previously published methods.

Results:
QLCP was reproducibly assessed but variably predictive of infarct volume on one hour post reperfusion mean diffusivity maps using rCBV (p<0.0001; r2=0.937), rTT (p = 0.05, r2 = 0.494), and rCBF (p=0.0024, r2=0.807). Leptomeningeal collateral scoring variably correlated with rCBV (p<0.0001, r2 = 0.948), rTT (p=0.0285, r2= 0.578) and rCBF (p0.0021, r2= 0.817).

Conclusion:
QLCP was validated in an experimental MCAO model based on correlation with a leptomeningeal collateral scoring system. QLCP assessment of rCBV is a better predictor for infarct volume than rTT or rCBF in a transient MCAO model. It is noteworthy that an angiographically based assessment of rCBV, rTT and rCBF differs from CT and MRI based assessments. In particular , the time frame used and the relative density of the vasculature on the derived color maps differ (
figure
1).
figure
1: QLCP derived cerebral blood volume map. The boxes indicate regions of interest for analysis.
Abstract 3892: Brooklyn AWAReness of StrokE in Diabetes Mellitus
Authors: Panichpisal Kessarin , Tan Benedict , Moradiya Yogesh , Memon Hasan , Vulkanov Volodymyr , Ghody Pranav , Ozkok Derya , Berlin Dmitry , Miller Aisha Y , Lacaille Sherard , Dardis Christopher , Baird Alison E
Published: July 2021

OBJECTIVE:
Diabetes mellitus (DM) is a common risk factor for stroke. Hence stroke awareness is very critical in diabetic patients. In order to design effective educational strategies for stroke intervention and prevention in this high risk group, we assessed the current status of knowledge about stroke symptoms, risk factors and activation of emergency medical services in individuals with DM.

METHOD:
A hospital-based survey was conducted between February and August 2011. Subjects who have DM were interviewed at 2 sites by trained Internal medicine, Neurology residents and medical students using a structured, closed-ended questionnaire.

RESULTS:
Two hundred and thirty subjects were interviewed, 64% female and 71% Caribbean-American and African-American. Seventy five percent of subjects had hypertension. Only sixty percent of subjects knew that they were high risk of stroke and only 46% had been informed by their primary care physician about this risk. More than 75% did not know their hemoglobin a1c and cholesterol levels. Stroke and diabetic ketoacidosis were the least recognized medical complications of DM (29%) while diabetic foot ulcer and diabetic nephropathy were the most recognized complications (54%). Hypertension was the most identified stroke risk factor (66%). Eighty-nine percent of respondents identified two or more stroke symptoms. Only 58% of respondents would call 911 for a stroke scenario. Subjects having DM > 10 years (p=0.02) and graduating from high school (p=0.002) were more likely to call 911, while people who had a history of kidney disease were less likely to call 911 (p=0.024). The two most common sources of information about stroke that DM patients received were from their primary care physicians (43%) and family and friends (35%).

CONCLUSION:
Stroke is one of the least recognized medical complications in DM patients. Primary care physicians play a very important role of stroke education in this high risk population.
Abstract 3942: Mild Controlled Hypothermia Induction is Safe and Feasible for the Treatment of Intracranial Hypertension in Patients with Aneurysmal Subarachnoid Hemorrhage.
Authors: Ibrahim Mohammad , Moussavi Mohammad , Wirkowski Elzbieta , Hanna Adel , Carlowicz Cecilia , Ahmed Younus , Gizzi Martin , Kirmani Jawad F
Published: July 2021

Introduction
Hypothermia has been increasingly used for cerebral resuscitation in comatose survivors of cardiac arrest. A large number of studies have been undertaken in patients with traumatic brain injury to asses the efficacy of hypothermia for reduction of intracranial hypertension. Hypothermia has also been shown to reduce mortality and increase functional outcome if used for longer duration in patients with severe traumatic brain injury. Due to the risk of rebound cerebral edema during re-warming, medical complications and other factors, hypothermia has not been widely utilized for other neurologic catastrophes. To determine the safety and feasibility of hypothermia to treat intracranial hypertension in patients with aneurysmal subarachnoid hemorrhage (SAH), we performed this study.

Methods
Retrospective analysis was performed on 11 consecutive patients with poor grade (Hunt and Hess IV and V) SAH who had high intracranial pressure that was either non responsive or poorly responsive to conventional methods (head of bed at 30 degrees, sedation, CSF drainage and osmotherapy). All patients had intracranial pressure (ICP) monitoring via an external ventriculostomy drain (EVD) catheter. Hypothermia was induced non-invasively via surface cooling pads (Artic Sun Temperature Management System). Intravenous sedation and paralysis was used via intravenous infusion to control shivering. Hypothermia (target temperature of 32 to 34 degree C) was maintained until ICP normalized.

Results
Duration of hypothermia ranged from 79 hours to 190 hours. One patient required re-induction due to rebound increase in ICP during re-warming. Modified rankin scale was recorded at 3 month after the ictus. Eight patients (72%) survived with good recovery, one patient (9%) survived with severe disability and two patients (18%) died. The most common side effect was electrolyte imbalance seen in seven patients (63%), thrombocytopenia in three patients (27%), and pneumonia in four patients(36%). All complications were successfully treated and major consequences of complications (bleeding diathesis, septic shock syndrome and death) were not observed in any of these patients. Two patients had decompressive hemicraniectomy prior to hypothermia induction. Out of nine patients who did not undergo hemi-craniectomy, two died and seven did not require surgical intervention after induction of hypothermia.

Conclusions
Mild hypothermia induction for 72 hours or more for the treatment of intracranial hypertension refractory to other conventional methods in patients with SAH appears safe and feasible. Hypothermia may potentially be an earlier treatment option than currently recommended. This study serves as a template for future efficacy trials.
Abstract 3954: Does the Volume of Stroke/TIA Admissions Relate to Clinical Outcomes in the Ontario Stroke System?
Authors: Hall Ruth , Fang Jiming , Hodwitz Kathryn , Bayley Mark
Published: July 2021

Background:
Previous research has found decreased mortality rates among hospitals that treat high volumes of patients for specific surgical and medical conditions. The degree of association between mortality and volume varies substantially by condition and procedure, and while this relationship has been examined for many surgical procedures and medical conditions, few studies have looked at stroke We examine the volume-outcome relationship among Ischemic stroke patients. Knowledge of how to guide access to care for people with stroke is of increasingly concern given expected growing costs of medical care.

Methods:
All ischemic stroke separations at 128 acute hospitals in the province of Ontario from 2003 to 2009 were analyzed using administrative databases. Spline plots were used to establish small, medium and high volume-based categories. Mulivariate hierarchical modeling was used to evaluate the volume outcome relationship. The outcome of interest was 30-day mortality.

Results:
From 2003 through 2009, 71,856 hospitalizations for stroke/TIA occurred in 128 hospitals. The mean (+/- SD) number of annual hospitalizations for stroke/TIA was 43(30) for small volume hospitals, 157(55) for medium volume hospitals and 278(73) for high volume hospitals. Patient Characteristics: Patients admitted to high volume hospitals were younger, 54% of patients are 75 years of age or older compared to 61% at small volume hospitals (p <0.0001). Patients at small volume hospitals were similar with respect to prevalence of comordid conditions with exception of hypertension, cancer, diabetes, old AMI and renal disease where patients at small volume hospitals had lower prevalence (p < 0.01). Hospital Characteristics: Approximately 15% were specialized stroke centres and 7% had the capacity to provide neurosurgical services. Large volume hospitals were more likely to be specialized stroke centres and or teaching hospitals compared to medium or small hospitals. Overall 30-day risk-adjusted ischemic stroke mortality over the seven year period was 17%. Patients cared for in low volume hospitals have a 30% higher mortality rate compared to patients cared for in a high volume hospital. There was no statistically significant difference in 30-day mortality between medium and high volume hospitals.

Conclusions:
Similar to procedure-based volume outcome relationships, there does appear to be an association between acute hospital stroke volume and 30-day mortality among ischemic stroke patients in Ontario. Hospitals that have average annual stroke volumes greater than 15 but less than 45 per year have 30 day mortality rates 30% higher than hospitals that see on average 278 stroke/TIA patients per year.itals. The critical threshold is about 150 patients per year. This could be explained by higher likelihood of admission to stroke units or to the expertise developed by regularly caring for stroke patients.
Abstract 3984: Neurological Deterioration And Stroke Recurrence In The Acute Phase Of Ischemic Stroke In The Deep Perforating Artery Territory ∼ Fukuoka Stroke Registry ∼
Authors: Fujimoto Shigeru , Sugimori Hiroshi , Jinnouchi Juro , Mezuki Satomi , Ishitsuka Takao , Kitazono Takanari
Published: July 2021

Background & Purpose:
A neurological deterioration in the acute phase can be associated with a bad outcome even in the minor stroke. We investigated the predictive factors for an acute neurological deterioration or stroke recurrence in the deep perforating artery territory stroke.

Subjects &Methods:
Among the consecutive 3062 stroke patients who were admitted to the 7 stroke centers in Fukuoka prefecture Japan within 7 days after the onset, 1141 patients with infarcts supplied by deep perforating artery with the initial NIH stroke scale score of 7 or less and preclinical modified Rankin scale of 0 or 1 were included in the present study. We observed a neurological deterioration (a NIH stroke scale score worsening of ≥1-point), stroke recurrence, or any death during the first 21 hospital days.

Results:
A neurological deterioration with or without stroke recurrence was observed in 196 (17.2%) patients. Baseline NIH stroke scale score was not different between patients with and without a neurological deterioration (2.7±1.9 vs 2.7±1.7). With regard to the TOAST classification, a neurological deterioration was most frequent in Large-artery atherosclerosis (27.8%), and was least frequent in Small-vessel occlusion (12.3%). The site of ischemic lesions was not associated with a neurological deterioration. A preexisting warfarin use was less frequent (7% vs 11%, p=0.0472), dyslipidemia (62% vs 53%, p=0.0182) and a stenosis of ≥50% in the major brain artery (26% vs 16%, p=0.0009) were more frequent, the values of low density lipoprotein (LDL) cholesterol was higher (124.6±36.3 vs 119.4±33.8 mg/dl, p=0.0495) and high density lipoprotein (HDL) was lower (50.7±14.1 vs 53.8±14.4 mg/dl, p=0.0056) in patients with than without a neurological deterioration. Diabetes mellitus was relatively more frequent in patients with than without a neurological deterioration (43% vs 36%, p=0.0669). On multivariate analysis, a stenosis of ≥50% in the major brain artery (OR, 2.44; 95%CI 1.44∼4.17) had a positive association with a neurological deterioration. Initial HDL values (OR, 0.99; 95%CI, 0.97∼1.00) and preexisting warfarin use (OR, 0.38; 95%CI, 0.13∼1.11) tended to be negatively associated with a neurological deterioration.

Conclusions:
The major brain artery stenotic lesion was a significant predictor for an acute neurological deterioration or stroke recurrence in the deep perforating artery territory stroke. A preexisting warfarin use and high HDL value might decrease the risk of a neurological deterioration.
Abstract 54: Mapping of Cerebral Vascular Territories Using Whole Brain Perfusion CT Imaging: A New Method
Authors: Christensen Soren , O'Brien Bill , Menon Bijoy , Bivard Andrew , Campbell Bruce , Desmond Patricia , Davis Stephen , Parsons Mark
Published: July 2021

Introduction:
The nature and endurance of the collateral blood supply in acute stroke is speculated to play a key role in tissue survival, yet research in this area is limited by the lack of appropriate imaging modalities to characterize and quantify collateral flow. We present the first results of a novel post-processing technique that can label and quantify the extent of the major vascular territories, including the predominant source of collateral supply into the hypo-perfused regions, using a 320 slice whole brain perfusion CT acquisition.

Hypothesis:
We hypothesized that the perfusion territories determined by the algorithm would be anatomically consistent with what would be expected from the site of occlusion as determined on CTA.

Methods:
We retrospectively selected data from a cohort of 19 acute stroke patients imaged within 6 h of stroke onset on a Toshiba Aquilion One CT system. We applied an algorithm that uses subtle changes in bolus shape across voxels to infer the pathway of flow from the proximal vessels towards the periphery. Labels were assigned to each of the 6 feeding vessels and the vascular territory maps were generated. Each voxel is color coded by its dominant source of flow.

Results:
We were able to generate images in 15 of 19 cases [4 excluded due to head motion and poor signal enhancement during the bolus passage]. In general, the estimated distributions of vascular territories in the non affected hemisphere were in agreement with text book distribution patterns. In the affected hemisphere, the vascular territory of the occluded vessel was either diminished or absent and the tissue instead supplied by adjacent territories. In 2/15 cases the estimated collateral territory appeared questionable. The
figure
shows two typical cases: In patient 1 with a distal M1 occlusion, the MCA territory is partially taken over by the ACA and PCA territories. In patient 2, the PCA collateralisation recedes following partial reperfusion of the M2 branch occlusion.

Conclusion:
This perfusion CT post-processing technique opens a window to visualization and measurement of vascular supply territories using a routine perfusion CT scan, an application previously limited to arterial spin labelling MRI. This technique is complementary to standard perfusion maps, and we speculate that integration of collateral supply information may enhance the utility of perfusion imaging and ultimately lead to more accurate selection of treatment responders. This new post-processing method has the potential to characterise and quantify collateral circulation with no need for additional hardware or higher radiation doses.
Abstract 86: Does Exercise Post Stroke have a Beneficial Effect on Post-Stroke Depression: A Meta-Analysis
Authors: Salter Katherine L , Mahon Hannah , McClure James A , Foley Norine C , Teasell Robert
Published: July 2021

Given the high prevalence and negative personal and social consequences of post-stroke depression (PSD), identification and application of safe and effective treatments is imperative. While recent publications examining the evidence regarding the impact of physical activity on depression suggest that, in the general population, exercise is associated with significant benefit in terms of reduction of depressive symptomatology, it is not clear that physical activity has the same benefit for individuals who have experienced stroke.

Objective:
To examine the effectiveness of exercise or physical activity on depressive symptomatology following stroke.

Methods:
We undertook a literature review to identify stroke-specific clinical trials examining the effectiveness of exercise or exercise programs when compared to a control condition that included longitudinal assessment of depression as a primary or secondary study outcome. Identified studies were evaluated for methodological quality using the PEDro scale and, where possible, results entered into a pooled, random effect analysis based on reported means and standard deviations from repeated assessments. Pre-post test correlations were estimated using published test/re-test reliability coefficients.

Results:
Eight studies were identified for inclusion; total PEDro scores ranged from 4 to 8. Depression was assessed at baseline and post-intervention using 4 self-report and 1 interview-based assessment tool(s). Participants were community-dwelling individuals; mean age ranged from 56 to 87. Only two trials reported significant between group differences for the outcome of depression, although several noted significant improvement within the intervention group only. Of the 8 identified studies, 6 reported sufficient data for inclusion in pooled analysis. Based on data from 276 participants, there was a moderate reduction in self-reported symptoms of depression associated with post-stroke exercise (ES=0.576; 95% CI 0.22, 0.93). No significant publication bias was identified (Egger’s intercept = 1.21, p=0.64).

Conclusions:
Although previous trials have reported a positive trend toward improvement of the self-reported symptoms of depression associated with exercise, the impact of exercise on depression has not been clear. On pooled analysis, however, it is apparent that participation in exercise is associated with a moderate and significant reduction in self-reported depressive symptomatology in older, community-dwelling individuals with stroke. Since physical impairments may limit participation in exercise programs for many individuals following stroke, additional research is required to examine exercise frequency and/or intensity required to demonstrate benefit.