bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract W P370: Is Local Hypoperfusion the Basis of Transient Neurological Deficits After STA-MCA Bypass in Moyamoya Disease?
Authors: Mukerji Nitin , Cook Douglas J , Steinberg Gary K
Published: March 2022

Object:
Hyperperfusion is believed to be the cause of transient neurological deficits in patients who have undergone an STA-MCA bypass for Moyamoya disease (MMD). We evaluated this on the basis of cerebral blood flow data from thermal diffusion probes used at our center.

Methods:
We studied postoperative cerebral perfusion in 31 patients with MMD who underwent a direct STA-MCA bypass. A Hemedex Q500 flow probe (Hemedex, Inc, Cambridge, MA) with a Bowman cerebral perfusion monitor was placed in the frontal lobe adjacent to the bypass, and flow data was analysed using JMP 8.0.2 (SAS Inc., Cary, NC). Seven patients experienced a transient neurological event (TNE) after the left-sided operation, manifesting as dysphasia around 24 hours postoperative and improving by 48 hours. The patterns of median cerebral blood flows with respect to time were plotted for the 3 groups (left side with TNE, the left side with no TNE and the right side) with smoothing by the moving average method. Observations were divided into time blocks (1 = 0-8 hours, 2 = 8-16 hours, 3 = 16-24 hours, 4 = 24-32 hours, 5 = > 32 hours). Differences in median blood flow between various time blocks and between groups were also analysed to evaluate any significant differences. These were correlated with the clinical picture.

Results:
An average of 20 hours (IQR 10-32 hours) of postoperative flow data was available for each patient. A detailed analysis of 64980 minute-by-minute flow observations shows that the initial post-bypass flow was higher on the left side where TNEs occurred, followed by a widely fluctuating pattern and a sharp drop in the perfusion corresponding with a deficit (p < 0.001, mean difference of flow, t-test) when compared to the other groups where deficits were not observed.

Conclusion:
Based on our observations we demonstrate a pattern of blood flow that suggests local hypoperfusion as the cause of the deficit on the backdrop of impaired autoregulation and a fluctuating blood flow, contrary to the traditional view that attributes these to hyperperfusion.
Abstract W P38: Rates of ADC and Flair Signal Maturation Depend on Depth of Ischemia and Time: Helpful for Determining Time of Onset?
Authors: Ford Andria L , An Hongyu , Modir Shanechi Amir , Khoury Naim , Vo Katie D , Powers William J , Lin Weili , Lee Jin-Moo
Published: March 2022

Background:
Imaging biomarkers may be useful to estimate time of stroke onset when it is unknown. We studied FLAIR and ADC signal maturation in acute ischemic stroke patients to understand how the severity of ischemia may influence the rate of signal change.

Methods:
Ischemic stroke patients with witnessed onset were sequentially imaged with FLAIR, ADC, and PWI (MTT) at 3, 6, and 24 hr after onset. FLAIR and ADC signal intensity (SI) was normalized to the contralesional hemisphere (nFLAIR and nADC). White matter disease was excluded. Regions of stable ischemia between 3-6hr and 6-24hr were stratified based on 6 increments of MTT prolongation (pMTT) ranging from mild to severe ischemia. Rates of nFLAIR and nADC change between 2 time-points (units= /hr and x10-6 mm2/s /hr, respectively) were measured between 3-6hr and 6-24hr for each pMTT increment. % of patients with FLAIR positivity (defined as nFLAIR > 1.15) at 3 and 6 hr was calculated for each pMTT increment.

Results:
37 patients were imaged at 2.6, 6.2, and 24 hr after stroke onset. Between 3 and 6 hr (Fig A, blue), rates of SI change for nFLAIR and nADC progressively increased with increasing severity of ischemia (p<0.0001; Kruskal-Willis). Between 6 and 24 hr (Fig A, green), nFLAIR rates of change decreased but continued to depend on ischemic severity, (p=0.0002). However, during this later time period nADC did not change with ischemic severity (p=0.36). The % of patients with FLAIR positivity increased between 3 and 6 hr and with increasing severity of ischemia (p=0.34 and p=0.0003, respectively; Chi-Square); Fig B.

Conclusions:
Rates of FLAIR and ADC change and FLAIR positivity were influenced by time from stroke onset and severity of ischemia. While FLAIR signal continued to demonstrate perfusion-dependent change beyond 6 hrs, ADC signal matured at 6 hrs, showing little change beyond. Understanding the factors influencing rates of FLAIR and ADC change may help refine an imaging biomarker for determining the time of stroke onset.
Abstract W P39: Internal Cerebral Vein Asymmetry on Follow-Up Brain CT after Intravenous Thrombolysis in Acute Anterior Circulation Ischemic Stroke is Associated With Poor Outcome
Authors: Paliwal Prakash , Yeo Leonard L , Chan Bernard P , teoh hock luen , Seet Raymond C , Sharma Vijay
Published: March 2022

Background and aim:
Identifying early predictors of functional outcome after acute ischemic stroke (AIS) is important for planning rehabilitation strategies. Internal cerebral veins (ICV) drain deep parts of brain, run parallel to each other and consistently seen on CTA. Even minor asymmetry in their filling can be identified. We hypothesized that venous drainage would be impaired in patients with acute occlusion of ICA or MCA. Since systemic thrombolysis can alter the vascular findings, we evaluated the relationship between ICV asymmetry on follow-up CTA and functional outcome.

Methods:
Consecutive AIS patients treated with intravenous thrombolysis between 2007 and 2010 were included. ICV asymmetry was assessed by 2 independent blinded stroke neurologists/ neuroradiologists. Functional outcome was assessed by modified Rankin Scale (mRS) at 3-months, dichotomized as good (0-1) and poor (2-6). Data were analyzed for predictors of functional outcome.

Results:
Of 2238 patients with AIS, 226 (10.1%) anterior circulation AIS patients received intravenous thrombolysis. Median age 65yrs (range 19-92), 44% males and median National Institute of Health Stroke Scale (NIHSS) 16-points (range 4-32). Hypertension was the commonest risk factor in 173 (76.5%) while 78 (34.5%) had atrial fibrillation. ICV asymmetry on follow-up CTA was assessed in 103 (45.5%) patients. Admission NIHSS score (OR1.07;95%CI 1.079-1.201,p=0.046), change in NIHSS score during first 24 hours (OR 0.737; 95%CI 0.672-0.807,p<0.0001) and ICV asymmetry on follow-up CTA (OR 20.3;95%CI 4.67-52.07,p <0.0001) independently predicted poor outcome at 3-months.

Conclusion:
ICV asymmetry on follow-up CTA after intravenous thrombolysis is an early predictor of poor functional outcome.
Abstract W P40: Assessing Criteria for Intra-Arterial Therapy: Inter-Rater Reliability of Clinical-Diffusion Mismatch Among Stroke Clinicians
Authors: George Pravin , Katzan Irene , Gebel James , Uchino Ken
Published: March 2022

Background:
Optimal patient selection strategy for intra-arterial therapy (IAT) in acute ischemic stroke remains uncertain. Clinical-diffusion mismatch (CDM) and perfusion-diffusion mismatch (PDM) on MRI are two selection methods used in practice. PDM can be radiologically defined and its analysis automated but this requires additional time and contrast administration. CDM is less technically challenging, however, there is variation in its definition and its inter-rater reliability has not been reported.

Hypothesis:
CDM has a higher inter-rater variability than PDM among vascular neurologists.

Methods:
Fellowship-trained vascular neurologists from our high-volume stroke center were surveyed on ten cases. For each case, they were first shown diffusion-weighted and apparent diffusion coefficient imaging and NIHSS score components and were asked if they felt a CDM existed. Based on the CDM alone, they were next asked if they would pursue IAT in the presence of a persistent large vessel occlusion. A perfusion image was then shown and the participants were asked if they felt a PDM existed. A final slide was shown giving the age, co-morbidities and pre-morbid disability, and location of arterial occlusion, after which they were again asked if they would pursue IAT. Kappa statistics were used to assess agreement.

Results:
Ten vascular neurologists participated in this study. The average inter-rater kappa for CDM was 0.35, 95% CI (0.28, 0.43) across the 10 cases. The average inter-rater kappa to take a patient for IAT based on CDM alone was 0.37, 95% CI (0.28, 0.46). The average inter-rater kappa for PDM was 0.61, 95% CI (0.53, 0.69). The average inter-rater kappa for final decision to take the patient to IAT was 0.30, 95% CI(0.22,0.37). The rate of IAT over the 10 cases varied from 10% to 70% among the vascular neurologists.

Conclusions:
This study suggests that vascular neurologists have a marginal inter-rater reliability for determining CDM. Inter-rater reliability for PDM was good although this did not have an effect on the reliability of final decision to take a patient for IAT. Further multi-center studies are needed to assess the variability of decision making for IA therapy.
Abstract W P42: Ischemic Lesions Grow, but NIHSS Scores Improve Over 48 Hours After Stroke: Implications for Clinical Trials
Authors: Silva Gisele S , Singhal Aneesh B ,   on behalf of Partner's Spotrias Investigators
Published: March 2022

Background:
DWI lesion growth is often used as a surrogate outcome measure in early-phase stroke clinical trials. Several studies have shown that admission DWI volumes and 3-mth clinical outcomes are strongly correlated, and that DWI volumes and NIHSS scores correlate at various times after stroke. However, there are few quantitative data comparing the dynamic changes of NIHSS scores to DWI lesion growth in acute ischemic stroke.

Methods:
We analyzed data from a phase II clinical trial of normobaric oxygen therapy (NBO) in acute ischemic stroke. Patients ineligible for tPA with imaging-confirmed ischemic stroke <9h and NIHSS>4 were randomized to NBO or Medical Air, delivered for 8h. There was no upper limit for age, NIHSS or stroke volume. NIHSS and DWI scans were obtained at 0 h, 4h (during therapy), 24h, and 48h. In this trial NBO had no significant effect on NIHSS change or DWI growth, hence data from NBO and Air groups were combined for this analysis.

Results:
Serial DWI and NIHSS were obtained in 60 subjects (mean age 72 yrs, 53% male). Mean DWI lesion volumes increased over time (baseline, 44 cc; 24 hrs, 68 cc and 48 hrs, 76 cc, p=0.1 ) but median NIHSS scores decreased over time (baseline, 12; 24 hrs, 10; 48 hrs, 9; p=0.1 ). There was no significant correlation between 0-24 hour change in NIHSS scores and 0-24 hour % DWI growth (r square=0.01, p=0.38), or absolute DWI growth (r square=0.033, p=0.21). There was no significant correlation between 0-48 hour change in NIHSS scores and 0-48 hour % DWI growth (r square 0.005, p=0.63), and only a mild correlation with absolute DWI growth (r square=0.11, p= 0.03). Stroke etiology affected these correlations: there was a significant correlation between NIHSS change and DWI growth at 48 hrs for cardio-embolic strokes, but not for large-artery strokes. Linear regression analysis adjusting for age, gender, mismatch and arterial recanalization status, showed that change in NIHSS was not associated with DWI growth neither at 24 ( p=0.41) nor at 48 hours (p=0.16).

Conclusion:
While the dynamic relationship between clinical deficits and lesion growth differs according to stroke mechanism, on average, infarcts grow but neuro deficits improve in the first few days after ischemic stroke. The mechanisms underlying this paradox require further study.
Abstract W P53: Extracranial Traumatic Aneurysms Due to Blunt Cerebrovascular Injury
Authors: Foreman Paul , Griessenauer Christoph J , Harrigan Mark R
Published: March 2022

Background and Purpose:
Traumatic aneurysms occur in about 10% of extracranial blunt traumatic cerebrovascular injuries (TCVI). The clinical consequences and optimal management of traumatic aneurysms are poorly understood.

Methods:
A prospective systematic study of TCVI at a Level I trauma center identified seven patients with 19 extracranial carotid or vertebral artery aneurysms. An additional six patients with seven traumatic aneurysms were followed outside of the prospective study. All patients were treated with aspirin 325 mg daily and underwent clinical follow up and imaging beyond the initial hospitalization. Endovascular treatment was reserved for aneurysms demonstrating significant enlargement on follow-up imaging. Ischemic complications, aneurysm symptoms, and aneurysm appearance on follow-up CT angiography (CTA) were assessed.

Results:
The seven patients with traumatic aneurysms identified in the prospective cohort comprised 10.3% of all patients with TCVI. Two patients (15.4%) patients had an ischemic stroke. No patient experienced an ischemic stroke or new symptom following the initiation of antiplatelet therapy. Clinical and radiographic follow-up with CTA averaged 22.0 months (range 6.6-55.7 months). Ten of 26 (38.5%) aneurysms were not visualized on last follow up CTA, 10/26 (38.5%) were smaller, 1/26 (3.8%) were unchanged, and 5/26 (19.2%) were larger. Saccular aneurysms were more likely to enlarge than fusiform aneurysms (33.3 vs 11.8%). Two aneurysms (both > 15 mm in size) were treated with stenting.

Conclusion:
The majority of traumatic aneurysms can be managed with an antiplatelet regimen of aspirin 325 mg daily and serial imaging. Saccular aneurysms have a greater tendency to grow when compared to fusiform aneurysms.
Abstract W P55: The Degree of Cerebral Blood Flow Augmentation by External Counterpulsation Correlates With Clinical Outcome After Acute Ischemic Stroke
Authors: Xiong Li , Han Jinghao , Lin Wenhua , Chen Xiangyan , Leung Thomas , Soo Yannie , Wong Ka-sing
Published: March 2022

Background and Purpose:
External counterpulsation (ECP) is a novel noninvasive method used to augment cerebral blood flow which may benefit ischemic stroke patients. We aimed to explore the association between the degree of cerebral blood flow augmentation by ECP and clinical outcome after acute ischemic stroke.

Methods:
Acute ischemic stroke patients within 7 days of symptom onset were recruited into this study. On admission, bilateral middle cerebral arteries of subjects were monitored using transcranial Doppler (TCD). Flow velocity changes before, during, and after ECP were, respectively, recorded for 3 minutes. Cerebral augmentation index (CAI) was the increase in percentage of middle cerebral artery mean flow velocity during ECP compared with baseline. TCD data were analyzed based on ipsilateral or contralateral to the infarct side. Modified Rankin Scale (mRS) was evaluated 3 months, 6 months and 1 year after ischemic stroke onset. We stratified the patients into two groups (good outcome: mRS 0~2; poor outcome: mRS 3~6) at each measurement time point.

Results:
72 patients were recruited (mean age, 63.8±10.7 years; 87.5% males). At month 6 and year 1 after stroke onset, univariate analysis showed that admission National Institutes of Health Stroke Scale (NIHSS) was significantly lower and ECP therapy duration was longer in good outcome group; while the ipsilateral CAI was significantly lower in good outcome group than those in poor outcome group (3.71±4.94 versus 7.73±7.66, P=0.044; 3.50±4.73 versus 8.58±7.72, P=0.015 respectively). Multivariate logistic regression showed that ipsilateral CAI and baseline NIHSS were independent predictors for a favourable outcome at these two measurement points.

Conclusions:
The degree of cerebral augmentation on ipsilateral to the infarct side by ECP is found to be an important predictor for long-term good outcome in acute ischemic stroke patients, in addition to the well-known prognostic factors such as NIHSS.
Abstract W P56: Negative FLAIR-based Intravenous Thrombolysis in Acute Stroke Patients With Unknown Onset Time
Authors: Aoki Junya , Kimura Kazumi , Shibazaki Kensaku , Nagai Koichiro , Saji Naoki , Uemura Jyunichi , Sato Takahiro , Ebata Takuya
Published: March 2022

BACKGROUND AND PURPOSE:
Approximately 25% of acute stroke patients were excluded from intravenous thrombolysis using tPA because of the unknown onset time. We previously reported that patients with unknown onset time would be able to receive tPA when showing no ischemia on the FLAIR (negative FLAIR). We assessed the safety and efficacy of tPA for those patients with ICAO and MCAO. METHODS:From June 2009 to June 2013, we prospectively treated stroke patients with unknown onset time using tPA who satisfied following criteria: negative FLAIR, anterior-circulation stroke, presence of major arterial occlusion, and the DWI-ASPECTS ≥5. tPA therapy was performed within 3 h from the first found abnormal time. Early recanalization was defined as new appearance of at least one of the distal branches within 1 h after tPA therapy on MRA. Dramatic recovery at day 7 was defined as ≥ 10-point reduction in the total NIHSS score or score of 0 or 1. A favorable outcome at 3 months was defined as a mRS score of 0-2. RESULTS:Subject comprised 24 patients (median age, 83 [68-90] years; 8 [33%] males). Eight (33%) patients had the ICAO (ICAO group), and 16 (67%) had the MCAO (MCAO group). NIHSS score was slightly higher in the ICAO group than the MCAO group (18 [17-20] vs. 16 [10-20], p=0.085). Median interval between the last seen normal time and admission was similar between patients in the ICAO group and the MCAO group (5.9 h [5.0-12.4] vs. 5.6 h [4.2-12.9], p=0.602). DWI-ASPECTS on admission tended to be higher in the ICAO and the MCAO groups (9 [8-10] vs. 8 [6-9], p=0.086). During the 7 days after stroke, none of the patients with ICAO and the MCAO groups experienced symptomatic cerebral hemorrhage (p=1.000). Regarding efficacy outcome, only 1 (13%) of the 8 patients in the ICAO group and 7 (44%) of the 16 patients in the MCAO group had early recanalization. Thus, the rate of dramatic recovery at day 7 was lower in the ICAO group than the MCAO group (13% vs. 63%, p=0.033). Among 17 patients with pre-morbid mRS 0-2, none (0%) of the 4 patients with ICAO group and 8 (62%) of the 13 patients achieved favorable outcome (p=0.082).

Conclusions:
Acute MCAO patients with unknown onset time may benefit from tPA therapy when showing no ischemia on FLAIR. Yet, tPA therapy for patients with the ICAO should be ineffective.
Abstract W P58: Thromboelastography Can Detect the Anticoagulant Effect of Factor Xa Inhibitors in Patients Who Might Be Eligible for Tissue Plasminogen Activator Treatment for Acute Ischemic Stroke
Authors: Bowry Ritvij , Fraser Stuart , Archeval-Lao Joancy M , Parker Stephanie A , Cai Chunyan , Rahbar Mohammad H , Grotta James C
Published: March 2022

Background:
Factor Xa inhibitors are approved for stroke prevention in patients with atrial fibrillation. The management of such patients is challenging if they are candidates for intravenous tPA since there is no rapidly available test to detect their anticoagulant effect. Thromboelastography (TEG) analyzes the dynamics of coagulation (Figure 1) and has previously demonstrated a hypercoagulable state in acute stroke patients. We sought to determine whether TEG can detect the anticoagulation effect of Factor Xa inhibitors in stroke patients.

Methods:
Venous blood from seven subacute cardioembolic stroke patients prescribed Rivaroxaban was analyzed before (baseline) and 2, 4, 6 hours after drug administration with four patients also analyzed at 18 hours. Comparison of TEG parameters at various time intervals were assessed by repeated measures analysis of variance. Generalized Estimating Equations with an autoregressive correlation matrix was applied to account for the correlation within patients.

Results:
Baseline TEG results required approximately 11 minutes to obtain. Higher R values were seen from baseline upto 18 hours, along with increased K values lasting upto 6 hours. Lower G, MA, and alpha-angle values were seen from baseline till 4 hours (Table 2). Together these results indicate slower and less strong clotting, and that the anti-coagulation effects of the drug peak at about 4-6 hours, with a trend towards normalization by 18 hours.

Conclusion:
TEG can detect the anticoagulant effect of Factor Xa inhibitors in stroke patients, and might be useful for guiding emergency management of those eligible for tPA.
Abstract W P62: Rapidly Improving Stroke Symptoms (RISS): A Prospective, Pilot Study
Authors: Balucani Clotilde , Law Susan , Ramkishun Charles , Ramkishun Charles , Szarek Michael , Rojas-Soto Diana , Vulkanov Volodymyr , Khandelwal Priyank , Tan Benedict , Tariq Sara , Bulic Sebina , Steinberg Leah , Levine Steven R
Published: March 2022

Background:
“Rapidly Improving Stroke Symptoms” (RISS) is a controversial exclusion criterion for tPA treatment for acute ischemic stroke (AIS). Prior studies suggest 20-30% of those excluded from tPA solely because of RISS have poor outcomes.

Objectives:
(1) To estimate frequency and magnitude of RISS using prespecified RISS definitions; (2) To explore how different RISS definitions predict clinical outcome.

Methods:
A prospective, observational, pilot study of AIS patients presenting within 4.5 hours of symptoms. After informed consent, subjects were administered serial NIH Stroke Scales (NIHSS) by certified examiners every 20 (±5) minutes until a treatment decision (tPA vs no-tPA) was made by the treating physician, independently from the study. RISS was calculated as baseline NIHSS (bNIHSS) - treatment decision NIHSS (tdNIHSS). Definitions of RISS (based on prior literature and expert consensus) were: (1) change in NIHSS score ≥ 4 point improvement (IMP) or (2) % change in NIHSS score (a) ≥ 25% or (b) ≥ 50% IMP. Good outcome was defined as modified Rankin Scale (mRS)=0-1 at 3-month post stroke. Logistic regression was used to determine if definition(s) of RISS predicted good outcome.

Results:
Fifty AIS: mean age 65 yrs (±15 SD); male 56%; black 78%; prior stroke/TIA 28%; median bNIHSS score 8(IQR 2,11); before treatment decision was made, 2 serial NIHSS scores were obtained for the entire cohort, 3 scores in 26/50 (52%); median tdNIHSS score 5 (IQR 2,9); treated with tPA 23/50(46%). Frequency of RISS varied based on definition used: 10% for ≥ 4 point IMP, 22% for ≥ 25% IMP, and 12% for ≥ 50% IMP. In the overall cohort, 42% of patients had good outcomes: 17/27 (63%) not treated with tPA (bNIHSS 3; IQR 2,5) vs 6/23 (26%) treated with tPA (bNIHSS 9;IQR 5,15), p=0.02. There was a difference in tdNIHSS between those not given tPA (2;IQR 1,4) and those given tPA (8;IQR 6,13), p<0.0001. None of the 3 definitions of RISS was independently associated with good outcome.

Conclusions:
Our prospective, pilot data suggest that a serial NIHSS assessment prior to treatment decision is feasible and may help determine the frequency and magnitude of RISS for larger studies. In our cohort, AIS patients improved approximately 3 points on the NIHSS from baseline to tPA treatment decision.
Abstract W P64: DRAGON Score Outperforms 7 Other Hemorrhagic Transformation Scores in Ischemic Stroke Patients Treated With IV r-tPA
Authors: Asuzu David T , Nystrom Karin V , Chi Nai Fang , Greer David M , Halliday Janet R , Wira Charles , Sschindler Joseph L , Sheth Kevin N
Published: March 2022

Introduction:
Hemorrhagic transformation (HT) is a major complication of IV r-tPA therapy following ischemic stroke. At least 8 scores have been proposed to predict HT in patients undergoing IV thrombolytic therapy; however, studies comparing these 8 scores in an independent dataset are missing.

Hypothesis:
We tested the hypothesis that stroke metrics can predict adverse outcome after r-tPA therapy.

Methods:
Clinical data was analyzed from consecutive patients (n = 187) receiving IV r-tPA therapy from January 2009 until May 2013 at the Yale New Haven Stroke Center. 8 stroke metrics were calculated for each patient: DRAGON, ASTRAL, Stroke-TPI, HAT score, MSS, SITS-ICH, SEDAN and SPAN-100. Adverse outcome was assessed by presence of symptomatic intracerebral hemorrhage (sICH). The NINDS trial defined a hemorrhage as symptomatic if it was not seen on a previous CT scan and there had subsequently been either a suspicion of hemorrhage or any decline in neurologic status. Univariate logistic regression was performed using each stroke metric as an independent variable and sICH as the dependent variable. Receiver Operating Characteristic (ROC) analysis was used to test goodness of fit by the DeLong method.

Results:
18 patients (9.6%) had a symptomatic intracerebral hemorrhage after IV rt-PA treatment. Only 4 scores showed good agreement with sICH (ROC area > 0.7): DRAGON (0.76 ± 0.12), ASTRAL (0.73 ± 0.11), Stroke-TPI (0.72 ± 0.11) and HAT score (0.71 ± 0.13) with odds ratios as follows: DRAGON (1.73 ± 0.47), ASTRAL (1.10 ±0.06), Stroke-TPI (1.04 ± 0.03) and HAT score (2.0 ± 0.67).

Conclusions:
The DRAGON score yielded the highest combination of ROC area and odds ratios, and thus performed best at predicting sICH in our independent dataset. While the HAT score yielded a higher odds ratio, it yielded a lower ROC area and was therefore less robust at predicting sICH. Our results demonstrate the potential utility of the DRAGON score as a predictor of adverse clinical outcome in patients undergoing IV r-tPA. Further studies are warranted to assess its discriminatory ability in a large prospective cohort.
Abstract W P67: High Resolution C-arm Ct and Metal Artifact Removal Software; A Novel Imaging Modality to Analyze Aneurysms Treated With Stent Assisted Coil Embolization
Authors: Yuki Ichiro , Kanbayashi Yukinao , Kan Issei , Ikemura Ayako , Ishibashi Toshihiro , Arakawa Hideki , Irie Koreaki , Takao Hiroyuki , Nishimura Kengo , Murayama Yuichi , Mohamed Ashraf
Published: March 2022

Purpose:
Stent assisted coil embolization recently became a common treatment strategy for the wide neck aneurysms. Normal digital subtraction angiography (DSA), however, does not allow visualization of the deployed stents. The combination of high resolution C-arm CT (HR C-arm CT) and a novel Metal Artifact Removal software (MAR) enables the visualization of the coil mass, stent, and contrast material with high spatial resolution as well as significant reduction of metal artifacts produced by the platinum coils. In this study, experimental aneurysms were treated with stent assisted coil embolization and image analysis was performed using the HR C-arm CT and MAR. I.V. injection of the contrast to obtain the images was also performed.

Methods:
A total of 9 experimental aneurysms were created in 5 swine. Endovascular treatment using a stent was performed after the aneurysm creation. HR C-arm CT was performed immediately after the treatment and obtained images were processed with MAR. Intra arterial injection of the diluted contrast (10%) was performed in every swine and intra venous injection (non-diluted) was also performed in 3 swine. Visualization of the residual aneurysms as well as coil loops protruded into the stent lumen was evaluated.

Results:
Coil loops protruded into the stent lumen, which were not visible before the MAR due to the significant metal artifact, were well visualized after the MAR. Likewise, Contrast filling into the residual aneurism was observed after the MAR in every aneurysm. Intravenous injection of the contrast material reproduced similar image quality as compared to the intra arterial injections.

Conclusions:
The combination of the HR-Carm CT and MAR enables the differentiation of the coil mass, stent and contrast material by markedly reducing the metal artifact produced by the coils. This novel image modality may contribute to the evaluation of aneurysms treated with stent assisted coil embolization.
Abstract W P7: Difficulty of Catheter Access to Occluded Target Vessel Predicts Worse Recanalization and Poor Outcomes
Authors: Ribo Marc , Sugg Rebecca , Foster Lydia D , Molina Carlos A , Jovin Tudor G , Tomsick Tom , Broderick Joseph P ,   Interventional Management of Stroke (IMS) III Investigators
Published: March 2022

During endovascular procedures for acute ischemic stroke, catheter access to occlusion site may be technically difficult or impossible. We aim to study the impact of difficult catheter access to target occluded artery on clinical outcome in patients who received endovascular treatment in the IMS III trial.

Methods:
From 434 patients randomized to receive endovascular therapy in the IMS III trial, we excluded patients with no groin puncture (11) or no treatable occlusion on initial angiogram (89). Patients were divided in four groups according to time from groin puncture to initiation of intra-arterial therapy (TGT) quartiles. Recanalization (TICI 2b-3) and favorable outcome (mRS 0-2 at 3 months) were defined.

Results:
We included 334 patients that finally received transfemoral endovascular treatment: mean age 65.9±12.7 years, median NIHSS 17(IQR:14-21) and median time from stroke onset to groin puncture 204 minutes (IQR:170-236). In 23 patients (6.9%) occlusion was not accessible with microcatheter. In all patients distribution of TGT by quartiles was: Q1: 2-28 minutes, Q2: 29-40minutes, Q3: 41-57 minutes and Q4: 58-143 minutes. Rate of favorable outcome decreased as TGT increased: Q1:46.9%, Q2:39.5%, Q3:29.4%, Q4:29.9%. A longer TGT was associated with less favorable outcome (Q1-2:
43.2%
Vs Q3-4:
29.5%; p=0.01). Patients in Q4 had a lower rate of recanalization (Q1-3: 42.75% Vs Q4: 29.2%; p=0.04)

Conclusion:
In acute stroke patients receiving transfemoral endovascular therapies the time spent in accessing occlusion site is frequently longer than 30 minutes. Since longer access times are associated with worse outcome, strategies to reduce this time or alternative access should be studied to shorten procedural times and improve outcomes.
Abstract W P70: What Cfd Parameter is Different Between Growing and No Growing Aneurysm
Authors: Takao Hiroyuki , Kadokura Shou , Suzuki Takashi , Kanbayashi Yukinao , Masuda Shunsuke , Shinohara Kouichi , Mohamed Ashraf , Yamamoto Makoto , Ishibashi Toshihiro , Vinuela Fernando , Murayama Yuichi
Published: March 2022

Background & Purpose:
Research has not yet identified the growth mechanism of cerebral aneurysms. We investigated the values of CFD-derived parameters in cases of growing and non- growing aneurysms.

Methods:
We extracted 30 growing and 30 non- growing aneurysm cases randomly from our database. Commercially available software (ANSYS ICEM CFD14.0) was used for both mesh generation and fluid simulation. The aneurysm geometries were extracted from CTA and analyzed using a mathematical formula for fluid flow under pulsatile blood flow conditions. Simulations were performed before and after growth, and hemodynamic parameters were compared between the two growing and no-growing groups.

Result:
In the growing aneurysms group, The the “growth” area is was different from the bloodstream inflow “impact” area. There was no statistically significant difference in velocity, WSS and OSI between growing and no growing cases. Pressure, however, was significantly different between the two groups(P<0.05).

Conclusion:
CFD-derived pressure values in the aneurysm dome may predict growth of aneurysms and therefore may also predict rupture.
Abstract W P77: In-Depth Comparison of Short-Term Total Hospital Costs and Current Primary Cost Drivers of Coiling vs Clipping for Unruptured Intracranial Aneurysms.
Authors: Duan Yifei , Bambakidis Nicholas , Nelson Jeffrey
Published: March 2022

Objective:
The goal of our study is to perform an in-depth cost comparison between index hospitalizations of patients with unruptured intracranial aneurysms (UIA’s) treated with either endovascular coil embolization or surgical clipping to identify the current primary drivers of costs of either management approach.

Methods:
We obtained detailed breakdowns of index hospitalization costs associated with 125 cases of UIA’s treated with either endovascular coil embolization or surgical clipping from 2010 to 2012 at University Hospitals Case Medical Center. We obtained patient demographics and aneurysm characteristics from our clinical database. We performed cost comparisons that were stratified based on patient age, patient gender, aneurysm size, and aneurysm location. Using multiple linear regressions, we also identified clinical parameters that significantly contribute to total hospital costs.

Results:
Of the 125 cases we identified, 69 were treated with surgical clipping and 56 were treated with coil embolization. Average total hospital costs for clipping was lower than coiling (p = 0.003). Average fixed direct costs and fixed indirect costs for clipping were higher than coiling (p < 0.001, p < 0.001 respectively). Average variable direct costs for clipping were significantly lower than coiling (p < 0.001). The average proportions of total hospital costs accounted for by variable direct costs for clipping and coiling were 50.5% and 68.6% respectively (p < 0.001). Average length of stay for clipping was longer than coiling (p < 0.001).

Our regression results demonstrate that for surgical clipping, patient length of stay (p < 0.001), aneurysm size (p = 0.01), and patient age (p = 0.02) were significant contributors to total hospital costs. For coil embolization, only length of stay (p < 0.001) was a significant contributor to total hospital costs.

Conclusion:
Although surgical clipping of UIA’s is associated with longer hospitalizations, the total index hospitalization costs associated with clipping are lower than those associated with coiling. Length of stay, patient age, and aneurysm size were all significant drivers of total costs for clipping. Variable direct cost is the main driver of total costs for coiling.
Abstract W P81: Echocardiographic Evidence of Intrinsic Aortopathy in Patients With Intracranial Aneurysm
Authors: Shin Yong-Won , Jung Keun-Hwa , Kim Jeong-Min , Cho Young Dae , Kang Hyun-Seung , Han Moon Hee , Roh Jae-Kyu
Published: March 2022

Background:
Intracranial aneurysms (IA) are outpouches of weakened arterial walls encompassing around 3% of general population. Until now, pathophysiology of formation, growth and rupture of the aneurysm is not fully understood, but former studies have shown that intrinsic arterial wall defect contribute to the aneurysmal pathogenesis. Prevalence of IA in patients with coarctation of aorta or bicuspid aortic valve is significantly higher than general population, which suggests common pathophysiology between IA and aortopathy. However, the relationship is difficult to generalize because of the rarity of coarctation of aorta and bicuspid aortic valve. We used common echocardiographic marker, aortic root dimension (ARD), to show the association.

Methods:
We reviewed all patients with IA and performed echocardiography (n=260) who admitted to our institution for coil embolization or for management of ischemic stroke. Patients aged <55 years and had at least one of rupture presentation, size ≥7mm, and multiple aneurysms were classified into eccentric group, and the others were categorized into non-eccentric group. We compared demographics, clinical features, and echocardiographic findings in these two groups.

Results:
Non-eccentric group had more cerebrovascular risk factors such as hypertension (p <0.001), diabetes mellitus (p = 0.009), hyperlipidemia (p <0.021), and more patients had a history of stroke or coronary artery disease (p = 0.013). Multivariate analysis revealed that eccentric group were younger (p <0.001) but had more dilated aortic root (p = 0.015). Subgroup analysis with patients aged <55 years showed similar result in ARD (p = 0.03), and hypertension was more associated with non-eccentric group (p = 0.005). Intriguingly, patients with short stature had a tendency to belong to the eccentric group, although it didn’t reach statistical significance (p=0.063).

Conclusion:
ARD was significantly large in eccentric group compared with non-eccentric group. In patients with IA, common intrinsic arterial wall defect exist between intracranial artery and ascending aorta, and it may be attributable to genetics or developmental process.
Abstract W P82: Natural History Simulation Models: Aneurysms Larger Than 9.5 mm and Aneurysms Growing Faster Than 0.36 mm/year Require Intense Clinical Care
Authors: Patel Suraj V , Chien Aichi
Published: March 2022

Introduction:
It is hard to understand aneurysm growth and rupture due to the difficulty of long-term follow-up studies. There are several Markov models which simulate long-term aneurysm growth and rupture, and our study aims to compare two such models and choose the ideal model for our aneurysm database. By understanding the prognosis of the aneurysms, we can identify which aneurysms require invasive treatment.

Hypothesis:
We hypothesized that there is an ideal model which can accurately simulate the growth and rupture behavior of untreated aneurysms over time.

Method:
Based on longitudinal data, 290 aneurysms were analyzed in 29 males and 177 females. The mean aneurysm size was 4.5±3.45 mm, and the mean age was 61±13.22 years. We tested Growth Model I and Growth Model II to simulate the growth rate and yearly rupture rate for the next 30 years. For both models, growth and rupture were functions of aneurysm volume. At five-year intervals, we calculated the odds ratio (OR) and used the One-Way ANOVA and Independent T-Test to measure differences in rupture rate for the initial aneurysm diameter and the amount of growth.

Results:
After 30 years, the mean aneurysm size was 9.18±2.37 mm for Growth Model I and 7.80±6.44 mm for Growth Model II. The mean 30-year rupture rate was 13.93±12.89% for Growth Model I and 14.15±21.96% for Growth Model II. For both models, there was a significantly (p<0.05) higher rupture rate for larger aneurysms and rapidly growing aneurysms at most five-year intervals. Over 30 years, aneurysms larger than 9.5 mm had a 60-80% rupture rate, and aneurysms between 3.5-9.5 mm had a 10-20% rupture rate. Aneurysms growing more than 0.36 mm/year had a 20-35% rupture rate. For aneurysms larger than 9.5 mm, the 30-year OR was 16.04 in Growth Model I and 91.43 in Growth Model II, and for aneurysms growing more than 0.36 mm/year, the 30-year OR was 2.01 in Growth Model I and 7.31 in Growth Model II.

Conclusion:
In conclusion, any aneurysm larger than 9.5 mm may need immediate surgical treatment. For aneurysms between 3.5-9.5 mm, early surgical intervention is recommended if the growth rate exceeds 0.36 mm/year. Growth Model I is the better model because although both simulations yield similar rupture rates, Growth Model II produces a few unrealistically large aneurysm sizes.
Abstract W P83: Intra-aneurysmal Flow Disruption with the Web Device: Midterm Anatomical Follow-up in a Series of 51 Patients
Authors: Pierot Laurent , Klisch Joachim , Liebig Thomas , Leonardi Marco , Nunzi Nunzio Paolo , Szikora Istvan , Lubicz Boris
Published: March 2022

Purpose:
The objective of intra-saccular flow disruption is the modification of aneurysmal flow by placing a device in the aneurysm sac. Preliminary reports have shown the efficacy of this technique, bit its mid-term efficacy has not yet been evaluated.

Materials and Methods:
Clinical, procedural, and anatomical data were collected in 9 European centers treating intracranial aneurysms with WEB for more than one year. Clinical and procedural data included age, gender, modalities of treatment, treatment complications, and clinical outcome at hospital discharge and 1 year were collected with a follow-up of at least 1 year.

Preoperative, postoperative, intermediate (3-6 months), and mid-term (12-18 months) follow-up DSA or MRA were collected and independently and anonymously evaluated by an experienced interventional neuroradiologist. Occlusion at intermediate and midterm follow-up was separately evaluated using a 4-grades scale (A: total occlusion, AB: opacification of the proximal recess; B: neck remnant, C: aneurysm remnant). Occlusion at midterm was also visually compared to intermediate follow-up and classified as improved, stable, or worsened.

Results:
49 patients (34F, 15M, aged 35-74 years, mean: 57.2) harboring 51 aneurysms were included. Aneurysm location was middle cerebral artery in 23 cases, basilar tip in 10 cases, anterior communicating artery in 9 cases, internal carotid artery in 7 cases, and other in 2 cases. Anatomical results are presented and analyzed according to clinical, procedural, and anatomical characteristics.

Conclusion:
This series is presenting the first analysis of mid-term anatomical results after aneurysm treatment with WEB.
Abstract W P85: Enzymes that Influence Histone Acetylation and DNA Methylation are Altered Following Ischemia in an Age and Sex Specific Manner
Authors: Chisholm Nioka C , Henderson Michael , Sohrabji Farida
Published: March 2022

Background:
In animal models, ischemia results in larger infarcts in middle-aged females as compared to young adult females and several measures important for stroke recovery are impaired in middle-aged animals including growth factor production and neuroinflammatory responses. Middle-aged males however, appear to be similar to their younger counterparts on these measures. This impaired recovery following stroke may be related to epigenetic alterations that occur during aging, including changes in DNA methylation and histone acetylation. The level of acetylation is modulated in part by histone deacetylases (HDACs); whereas DNA methylation is modulated by DNA methyltransferases. We evaluated the hypothesis that ischemia would result in epigenetic alterations and that both sex and age would influence this epigenetic profile.

Methods:
The middle cerebral artery was occluded in adult (6 month) and middle-aged (11+ month) male and female Sprague Dawley rats (n=8/grp). Nuclear proteins were extracted from the ischemic and non-ischemic hemispheres 48 hours after surgery. ELISA based assays were used to measure the amount of HDAC 6 and DNA methyltransferase 1 (DNMT1) as well as the activity of sirtuins and pan-HDACs.

Results:
Following stroke, the ischemic hemisphere had higher levels of HDAC activity (.22±.02 vs .16±.008; p<.05) and a greater amount of HDAC 6 (76.6±5.1 vs 43.3±1.6; p<.05) than the non-ischemic hemisphere. In contrast, sirtuin activity was lower in the ischemic hemisphere (4.9±.5 vs 7.4±.6; p<.05). Importantly, middle-aged males had lower levels of sirtuin activity than adult males (4.7±.4 vs 8.3±.9; p<.05). DNMT1 did not differ between the hemispheres; however, middle-aged females had a greater amount of DNMT1 than adult females (239.6±45.8 vs 125.3±19.8; p<.05).

Conclusions:
Epigenetic modifications are known to influence gene transcription and this study suggests that ischemia alters the activity and availability of enzymes that modulate DNA methylation and histone deacetylation. Importantly, the effects of ischemia are sex and age specific. The differences in epigenetic profiles between the sexes and during aging provide insights into possible mechanisms for the differences in stroke recovery previously documented.
Abstract W P87: Focal Hypothermia Induced by Post-Ischemic Intra-arterial Infusion of Cold Saline Has a Neuroprotective Effect on Cerebral Ischemia Reperfusion Injury
Authors: Kurisu Kota , Abumiya Takeo , Shimbo Daisuke , Kazumata Ken , Nakayama Naoki , Shichinohe Hideo , Houkin Kiyohiro
Published: March 2022

Background and Purpose:
Although the neuroprotective effect of hypothermia on cerebral ischemia is well known, the clinical application of systemic hypothermia is limited because of management problems and complications. We examined whether focal hypothermia induced by post-ischemic intra-arterial infusion of cold saline attenuates cerebral ischemia reperfusion (I/R) injury in the rat transient middle cerebral artery occlusion (MCAO) model.

Methods:
Male Sprague-Dawley rats were subjected to 2-hour MCAO and then were divided into three groups: 1) cold saline group (n=7) infused with 10°C saline (20ml/kg) through the recanalized internal carotid artery for 15 minutes, 2) warm saline group (n=7) infused with 37°C warm saline in the same manner as the cold saline group, and 3) control group subjected to recanalization only (n=7). After 24-hour reperfusion, all rats were tested for neurological score and then sacrificed to examine infarction, brain edema, and Evans blue leakage.

Results:
In the cold saline group, brain temperature at basal ganglia rapidly decreased from 37.7±0.8°C to 35.4±0.7°C and remained significantly lower than pretreatment temperatures (p<0.05) until 30 minutes after the infusion. The cold saline group showed significantly better neurological score compared with the other groups (p<0.01). Infarct volume of cold saline group (13.7±11.3%) was significantly less than that of control (42.5±8.1%) and warm saline (36.4±8.8%) group (p<0.01). Brain edema and Evans blue leakage of cold saline group was also significantly less than those of the other groups (p<0.01).

Conclusions:
The results of the present study suggest that focal hypothermia induced by post-ischemic intra-arterial infusion of cold saline has a neuroprotective effect on I/R injury. This therapeutic strategy is promising because of its feasibility in the clinical situation of endovascular approach.
Abstract W P91: Regulating Set-ß’s Subcellular Localization Toggles Its Function Between Inhibiting and Promoting Axon Growth and Regeneration
Authors: Trakhtenberg Ephraim F , Wang Yan , Morkin Melina I , Fernandez Stephanie G , Mlacker Gregory M , Liu Xiongfei , Patel Karan H , Goldberg Jeffrey L
Published: March 2022

The failure of the adult mammalian central nervous system (CNS) neurons to regenerate axons after stroke remains a major problem. Manipulation of various cell-autonomous factors along with overcoming the inhibitory adult CNS environment only partially restores regeneration. Transcriptional regulators like Set-β are well-positioned to regulate intrinsic axon regeneration capacity, which declines developmentally in maturing CNS neurons. Set-β also functions at the cellular membranes and its subcellular localization is disrupted in Alzheimer’s disease, but many of its biological mechanisms have not been explored in neurons. We found that Set-β was upregulated postnatally in CNS neurons. Remarkably, nuclear Set-β suppressed whereas Set-β localized to cytoplasmic membranes promoted neurite growth in primary CNS neurons. Furthermore, mimicking serine 9 phosphorylation blocked the ability of nuclear Set-β to suppress neurite growth. Finally, recruitment of Set-β to cellular membranes through gene therapy promoted optic nerve axons regeneration in vivo. Thus, Set-β differently regulates axon growth and regeneration depending on subcellular localization and phosphorylation, suggesting a novel mode of regulation of cellular behavior through disparate activities in different cellular compartments, which could be clinically relevant for treating stroke injury in CNS.