bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP450: Angiotensin II-induced Hypertension is Associated With Parenchymal Arteriole and Posterior Cerebral Artery Remodeling and Reduced Cerebral Perfusion
Authors: Diaz-Otero Janice M , Downs Kelsey , Sarno Erika , Jackson William F , Dorrance Anne M
Published: March 2022

Hypertension can cause inward artery remodeling, artery rarefaction, increased vascular resistance and blood brain barrier (BBB) breakdown. These conditions increase the risk of stroke and dementia. The differential effects of Ang II-induced hypertension on the posterior cerebral artery (PCA) and parenchymal arterioles (PAs) have not been investigated. The PAs serve as bottlenecks for the perfusion of the cortex and are important in determining the outcome of stroke. We hypothesized that Ang II-induced hypertension would cause inward remodeling of the PAs and PCAs, artery rarefaction, and blood brain barrier breakdown. PAs and PCAs were collected from 20-week-old male C57Bl/6 mice to assess structure by pressure myography. Data collected at an intraluminal pressure of 60mmHg are presented as mean ± SEM; Sham (n=5) vs. Ang-II (n=5; 800ng/kg/day for 4 weeks). Ang II increased systolic (148 ± 4 vs 176 ± 6mmHg) and diastolic (115 ± 4 vs. 144 ± 6mmHg) blood pressures (p < 0.05). In the PAs, the lumen diameter (37 ± 3 vs. 22 ± 3μm), wall area (830 ± 118 vs. 632 ± 53μm2) and wall stress (199 ± 24 vs 98 ± 22dynes/cm2) were reduced in hypertensive mice (p<0.05). Preliminary studies suggest that Ang II-induced hypertension also impairs myogenic tone and endothelium-dependent dilation in the PAs. In the PCAs, hypertension decreased the lumen diameter (130 ± 5 vs. 97 ± 7μm, p < 0.05). The wall/lumen ratio was increased (0.08 ± 0.01 vs 0.14 ± 0.03) while wall stress (362 ± 28 vs 264 ± 33dynes/cm2) was reduced (p < 0.05). The decreased cerebral perfusion (836 ± 50 vs. 596 ± 83 perfusion units; p < 0.05) is due primarily to artery remodeling and not to artery rarefaction (10.8 ± 0.9 vs 9.5 ± 0.9 number of vessels/area; p > 0.05). Ang II-induced artery remodeling was not associated with increased BBB permeability (2 ± 1 vs 3 ± 1 % extravasation Evans Blue; p > 0.05). Our results suggest that Ang II-induced hypertension results in remodeling of the PCA and PAs associated with decreased cerebral perfusion; this could have detrimental effects on neuronal function increasing the risk of vascular dementia and stroke.
Abstract TP452: Systemic Inflammation Reverses Stroke-induced Changes in Astrocytic Aquaporin-4 Expression
Authors: Sun Ye , Howe Matthew D , Spychala Monica , Rosow Rachael , McCullough Louise D
Published: March 2022

Introduction:
Aquaporin-4 (AQP4) is a perivascular water channel that plays a key role in regulating the blood-brain barrier (BBB). Stroke acutely reduces expression and polarization of AQP4 on astrocytic endfeet, and these vascular changes might persist chronically and evolve with systemic inflammation. Reduced polarization of AQP4 after traumatic brain injury (TBI) leads to impaired perivascular clearance of debris and cognitive decline in mice, and if similar changes occur after stroke, then they may also contribute to post-stroke dementia.

Hypothesis:
Stroke will cause lasting changes in vascular organization, reducing astrocytic AQP4 expression and polarization in the area of injury.

Methods:
Thirty male Balb/cJ mice were subjected to distal middle cerebral artery ligation, allowed to survive for 28 days, and sacrificed 24 hours after injection with lipopolysaccharide (LPS, 0.33 mg/kg i.p.) or saline to model systemic inflammation. Three sequential coronal sections (20 μm) near the site of infarct (0.25 mm from Bregma) were stained with lectin, AQP4, and glial fibrillary acidic protein (GFAP) to evaluate BBB organization. Vessel density was evaluated with AngioTool. AQP4 expression was evaluated by Western blot.

Results:
Stroke increased vascular density in the injured hemisphere (11 ± 0.8% vs 7.6 ± 0.8% in sham mice, p < 0.05). Decreased AQP4 expression and polarization near the site of the infarct was observed, which were reversed with LPS (Figure 1). LPS increased AQP4 protein levels in stroke (2.5 ± 0.37 fold-increase, p < 0.05), but not sham mice.

Conclusions:
Stroke caused a chronic increase in vascular density, with peri-infarct vessels displaying decreased expression and changed polarity of AQP4. However, with systemic inflammation, this is reversed, potentially contributing to neuroinflammation and worsened cognitive outcomes in stroke patients who encounter infections via increased permeability of these abnormal vessels.
Abstract TP458: Is There “Crosstalk” Between Intracranial Arterial Pathologies and Small Vessel Disease??
Authors: Boulouis Gregoire , Charidimou Andreas , Auriel Eitan , Haley Kellen E , van Etten Ellis S , Fotiadis Panagiotis , Reijmer Yael D , Riley Grace A , Vashkevich Anastasia , Gomes Thomas M , Ayres Alison , Schwab Kristin M , Martinez-Ramirez Sergi , Goldstein Joshua N , Viswanathan Anand , Greenberg Steven M , Gurol Mahmut E
Published: March 2022

Background:
Interactions between intracranial arterial pathologies (IAP) and cerebral small vessel disease (SVD) are an increasingly debated topic.

Hypothesis:
We analyzed associations between the type/severity of SVD and two IAPs, the intracranial arterial calcifications (ICAC) and intracranial stenosis (ICS) in intracerebral hemorrhage (ICH) patients.

Methods:
Consecutive ICH patients from a prospective cohort were included. Patients were divided into those meeting Boston criteria for cerebral amyloid angiopathy (CAA) and those with strictly deep hypertensive ICH consistent with hypertensive SVD (HTN-SVD). White matter hyperintensity volume (WMH) and microbleed count (MB) were quantitatively measured on MRI as markers of SVD severity. Head CT angiography was rated for presence of ICAC and for presence of >50% intracranial arterial stenosis (ICS). Associations of IAPs with the type of SVD (CAA vs HTN) as well as imaging markers of SVD severity were analyzed in multivariate models. We also explored the association between IAPs and presence of pre-ICH dementia.

Results:
The cohort included 253 CAA patients and 90 HTN-SVD. CAA patients were older (73.5 vs 64.8, p<0.001), demonstrating higher WMH (25ml vs 16ml, p<0.001) but lower prevalence of hypertension than HTN-ICH. In univariate comparisons between CAA and HTN-SVD, the presence of ICACs (74% vs 72%, p=0.7) and ICS (7% vs 7.8%, p=0.8) were not different. ICS was not related to the type of SVD in multivariate models either. Using multivariate logistic regression, HTN-SVD was independently associated with presence of ICAC (adjusted OR = 2.56 [95% CI 1.1-6.2, p=0.002), as well as older age, male gender and hypercholesterolemia. We found no association between IAPs and parenchymal markers of SVD severity (WMH and MB) (all p>0.2) and no association with presence of dementia before ICH (p>0.2).

Conclusions:
HTN-SVD is associated with increased ICAC in multivariate models, suggesting either shared risk factors or direct interactions between SVD and IAP. There is no association of intracranial large artery pathologies (ICAC, ICS) with parenchymal (WMH, MB) or clinical (dementia) consequences of cerebral small vessel diseases.
Abstract TP46: A Score to Detect Proximal Artery Occlusion in Patients With Acute Ischemic Stroke of the Anterior Circulation Based on NIHSS and Non-contrast Brain CT: the PAO Score
Authors: Martins Filho Rui Kleber V , Camilo Millene R , Libardi Milena C , Santos Renata S , Alessio-Alves Frederico F , Dias Francisco A , Afonso Luis Henrique C , Cougo-Pinto Pedro T , Barreira Clara M , Rocha Leticia J , Abud Daniel G , Pontes-Neto Octavio M
Published: March 2022

Introduction:
After the results of the new endovascular trials that demonstrated a robust effect of endovascular treatment for acute ischemic stroke (AIS), early detection of proximal artery occlusion (PAO) has become a fundamental task during the initial assessment of acute stroke patients at the emergency department. Nevertheless, an accurate identification of PAO may be particularly challenging in smaller hospitals and in developing countries, areas with restricted assess to vascular neuroimaging modalities such as CTA and MRA.

Hypothesis:
Algorithms based on NIHSS and non-contrasted CT (NCCT) findings can be accurately used to detect PAO in patients with AIS of the anterior circulation.

Method:
We retrospectively evaluated 194 consecutive patients with AIS of the anterior circulation from a prospective stroke registry of patients admitted to an academic tertiary emergency unit in Brazil during 2014 that had a NCCT and a CTA at admission. NIHSS scores and attenuation of major intracranial arteries of the anterior circulation on NCCT were collected by two experienced investigators that were blind to the CT angiography findings. We used a ratio between two ROIs (rVA) that were drawn on NCCT blinded to CT angiography: (i) on the region of highest vessel attenuation ipsilateral to the involved hemisphere and (ii) mirror ROI on the corresponding vessel segment of the contralateral hemisphere. We used ROC curve analysis and C-statistics to predict CT angiography PAO.

Results:
NIHSS and vessel attenuation values were highly associated with the PAO with an area under the curve (AUC) of 0.88 (p < 0,001) and 0.83 (p < 0,001), respectively. An NIHSS of 10 at admission had a sensitivity, and negative predictive value of 97% and 97%, respectively. The rVA ≥ 1.50 had a specificity and positive predictive value 96% and 85%, respectively. The POA score was then built by logistic regression from NIHSS and rVA and showed even higher accuracy for the presence of POA on CTA, with an AUC of 0.93 (p < 0,001).

Conclusion:
The PAO score based on admission NIHSS and proximal vessel attenuation on NCCT can be accurately used to detect PAO in patients with AIS of the anterior circulation. Further studies are necessary to validate this score in a multicenter setting.
Abstract TP461: Carotid Intima-Media Thickness and Cognition: The Northern Manhattan Study
Authors: Caunca Michelle R , Gardener Hannah , Gervasi-Franklin Palma , Cheung Ying Kuen , Elkind Mitchell S , Sacco Ralph L , Rundek Tatjana , Wright Clinton B
Published: March 2022

Background/Objective:
Carotid artery intima media thickness (cIMT) may be a marker of cerebral atherosclerotic disease and therefore related to cognitive status in the elderly. We hypothesized that those with greater cIMT would exhibit worse cognition at baseline and have greater cognitive decline over time.

Methods:
A sample of 1166 stroke-free community participants from the Northern Manhattan Study (NOMAS) underwent carotid ultrasound and repeated neuropsychological (NP) testing. cIMT was imaged with a standardized B-mode ultrasound protocol and analyzed by a trained sonographer. We used multivariable linear regression to examine cIMT as a correlate of domain-specific NP Z-scores cross-sectionally and over time; we investigated possible effect modification by APOE ε4 allele, adjusting for demographics and vascular risk factors.

Results:
The mean age of participants was 71±9 years, 60% were women, 15% white, 18% black, 67% Hispanic, and mean cIMT was 0.93 ± 0.09 mm. NP testing was performed among 1166 participants at baseline and among 826 participants with NP follow-up at a mean of 6.2 years apart. Participants with greater cIMT exhibited worse episodic memory at baseline after adjustment for demographics and vascular risk factors (beta=-0.60, P=0.04). APOE ε4 allele presence was a significant effect modifier, and after stratification, APOE ε4 carriers with greater cIMT exhibited worse episodic memory (beta=-1.26, P=0.04), semantic memory (beta=-1.35, P=0.01), and processing speed (beta=-1.22, P=0.02) at baseline. In longitudinal analysis, participants with greater cIMT at baseline did not exhibit cognitive decline after adjustment for demographics and vascular risk factors, but APOE ε4 allele presence was a significant effect modifier. After stratification, APOE ε4 non-carriers with greater cIMT at baseline exhibited greater declines in executive function (beta=-1.03, P=0.05).

Conclusions:
cIMT may be associated with worse cognition and greater cognitive decline in multiple domains among those at high risk for Alzheimer disease, and with worsening executive function in APOE ε4 non-carriers. Interventions that target early stages of atherosclerosis may modify the course of cognitive aging and prevent cognitive decline.
Abstract TP463: TLR2 Knockout Prevents Diabetes-induced Increase in Cerebral Perfusion and Decreases Fear Response
Authors: Hardigan Trevor , Hernandez Caterina , Ergul Adviye
Published: March 2022

Objective:
It is increasingly recognized that vascular cognitive impairment may be a new complication of the disease in both type 1 and type 2 diabetes. We have shown that diabetic Goto-Kakizaki rats present with cognitive deficits and vascular dysfunction, especially impaired relaxation that can be ameliorated by Toll-like receptor-2 (TLR2) inhibition. Since brain function heavily depends on constant perfusion, and decreased cerebral blood flow (CBF) precedes development of inflammation and cognitive deficits, we hypothesized that TLR2 knockout would confer a protection from diabetes mediated cognitive decline.

Methods and Results:
Wild-type (WT) and TLR2 knockout (KO) control and diabetic mice were used. Diabetes was induced by streptozotocin (STZ) injection. 14 weeks after, cerebral perfusion was measured by MRI and cognitive function was assessed by a battery of tests including Y-maze and fear conditioning. There was no difference in cerebral perfusion in WT and TLR2 KO mice (CBF ml/100gxmin:141.1± 5.374 vs. 156.3± 6.727, p >0.05). Diabetic WT mice exhibited an increase in perfusion vs. WT control (185.3± 9.018*, p<0.05), while diabetic TLR2 KO mice did not increase significantly vs. TLR KO control (159.0± 3.038). In Y maze, % novel arm entries were not different amongst all groups. In fear conditioning, WT, WT STZ, and TLR2 KO STZ mice did not differ from each other significantly (% freezing time: WT: 25.5± 6.1, WT STZ: 31.3± 4.9, TLR2 KO STZ: 35.1±7.9). TLR2 mice had significantly decreased freezing % compared to other groups (12.2± 2.7, p<0.05).

Conclusions:
Diabetes induced by STZ mediates an increase in whole brain perfusion in WT mice, an effect that is not observed in TLR2 mice. The lack of difference in percent novel arm entries is likely a result of the relative increase in exploratory behavior in the STZ groups. TLR2 KO mice were protected from the development of fear and anxiety as indicated by the low %freezing time during fear conditioning tests. This could be due to alterations in perfusion. These findings suggest that TLR2 is involved in the development of diabetic cerebrovascular disease and potentially in vascular cognitive impairment.
Abstract TP47: Inverse PWI/DWI Mismatch is a Typical Feature of Acute Subcortical Ischemic Stroke
Authors: Villringer Kersten , Khalil Ahmed A , Brunecker Peter , Nolte Christian , Villringer Arno , Fiebach Jochen
Published: March 2022

Introduction / Hypothesis:
Diffusion/perfusion mismatch (MM) is commonly used to assess tissue at risk in stroke patients. In small subcortical infarcts (SSI) the reverse pattern i.e. “inverse mismatch” (IM) has been shown [1]. We aimed to evaluate the frequency and characteristics of IM in a larger cohort using two different perfusion diffusion analysis approaches.

Methods:
We enrolled 129 patients with SSI within 24 hours of symptom onset (1000+ study, NCT00715533) comprising 44 infarcts of the thalamus, 9 located juxtacortically, 58 in the anterior choroidal artery, 18 in the lenticulostriate territory. Lesion volumes were assessed on DWI images using AnToNIa software. To evaluate perfusion maps a time-shift insensitive technique using a block-circulant matrix for deconvolution (oSVD) [2] was employed. Perfusion lesions were evaluated on MTT and Tmax (delay >2s and >6s) maps. A perfusion/diffusion ratio of 0.7 was used to define IM and 1.3 to define mismatch (MM).

Results:
Results are summarized in table1. For all types of data analysis and all time points, IM was the by far most frequent pathophysiological pattern. Obviously, IM was seen most often at Tmax>6s, but it was still clearly observed with looser thresholds (Tmax>2s, MTT). At earlier time of onset IM occurred less often, but was still the most frequent pattern (p=0.0026). No significant association between infarct location and perfusion pattern was observed

Conclusion:
IM is the most common pathophysiological constellation in SSI. We hypothesize that this is due to a lack of collateral circulation in these “endstream infarcts” and that the diffusion changes in areas without perfusion deficit reflect cytotoxic mechanisms.

1. Doege CA et al. AJNR 2003;24:1355-63

2. Wu O et al. Magn Reson Med 2003;50:164-174
Abstract TP5: Long Term Experience Using the ADAPT Technique for the Treatment of Acute Ischemic Stroke
Authors: Vargas Jan , Spiotta Alejandro , Turner Raymond , Chaudry M. Imran , Turk Aquilla
Published: March 2022

Introduction:
The ADAPT technique has been introduced as a simple and fast method for achieving good angiographic and clinical outcomes using large bore aspiration catheters. We present a single center’s long term experience with the ADAPT technique.

Methods:
Retrospective analysis from a prospectively maintained database was gathered on patients undergoing stroke thrombectomy with the ADAPT technique at the Medical University of South Carolina. Specific parameters captured included age, gender, NIHSS score at presentation, time to presentation from last normal, and modified Rankin Scale score at 90 day follow-up. Radiological and angiographic imaging was reviewed to document the location of the vascular occlusion, TICI flow post procedure, and procedural complications.

Results:
175 consecutive patients who suffered an acute ischemic stroke treated with the ADAPT technique were reviewed. 88 were female, and the average age was 66.8 years. Patients presented with a mean NIHSS score of 15.6, and 69 patients received IV tPA. The average time from onset to puncture was 7.75 hours. The average time for recanalization was 40 minutes. TICI 2B or better recanalization was achieved in 166 (94.9%) patients. 90 day mRS on average was 2.7, and 82 (50.31%) patients had an mRS of 0-2 at 90 days. Direct aspiration alone was performed in 130 of cases, and 45 cases required the additional use of a stent retriever. There was no significant difference in presenting NIHSS, average time to presentation, average mRS at 90 days, or 90 day mortality between the two groups. Time to recanalization was 33.8 minutes for direct aspiration, as compared to 58 minutes in cases that required adjunct devices (p= 0.000036). 67 (63.21%) patients who underwent direct aspiration only achieved a good outcome at 90 days (mRS 0-2), compared to 15 (44.12%) who underwent adjunct therapies (p-value=0.021).

Conclusions:
The ADAPT technique is an effective method to achieve good clinical and angiographic outcomes. The ADAPT technique serves as a useful first line method for revascularization.
Abstract TP50: Efficacy of Stent-retriever Thrombectomy in MRI Vs. CT Perfusion Selected Patients in SWIFT PRIME
Authors: Bonafe Alain , Saver Jeffery , Goyal Mayank , Jahan Reza , Diener Hans-Christoph , Levy Elad , Pereira Vitor , Cognard Christophe , Yavagal Dileep , Albers Gregory W
Published: March 2022

Background:
The majority of patients enrolled in SWIFT PRIME had CT perfusion imaging immediately prior to randomization; 34 patients were randomized following a diffusion and perfusion MRI.

Methods:
Patients with MCA (M1) and distal carotid occlusions were randomized to treatment with tPA alone vs. tPA + Solitaire stent retriever. The primary outcome was the distribution of the mRS at 90 days. The same automated software (RAPID) was used for both MRI and CTP patients to identify patients with the Target mismatch profile for enrollment.

Results:
MRI selection was performed in 34 patients; CTP in 139. Mean age was 71 years (MRI) vs. 68 years (CTP), p=0.08; baseline NIHSS was 17 in both groups. Target mismatch profile was present in 95% (MRI) vs. 83% (CTP), p=0.3. Median time from ER arrival to randomization was 69 min (MRI) vs. 67 min (CTP), p=0.61. A higher percentage of the MRI group was transferred from an outside hospital (59% vs. 35%, p=0.02) and therefore the time from stroke onset to randomization was longer in the MRI group (236 minutes vs. 179 minutes, p=0.003.) Baseline median ischemic core volumes were similar in the MRI vs. CTP group (7 ml vs. 5 ml); baseline perfusion lesions were larger in the MRI group (133 ml vs. 97 ml, P=0.01)

Reperfusion rates (> 90%/TICI 3) did not differ in the Solitaire treated patients in the MRI (94%) vs. CTP (85%) groups, p=0.7. The primary efficacy analysis (distribution of mRS at 90 days) demonstrated a statistically significant benefit in both the MRI (p=0.02) and CTP subgroups (p=0.01). Among MRI selected patients, mRS 0-2 at 90 days occurred in 63% of the Solitaire group vs. 33% of the tPA alone group (ARR 30%, p=0.17) and infarct growth was reduced (17 ml vs. 50 ml, p=0.089). CTP selected patients had mRS 0-2 rates at 90 days of 60% in the Solitaire group vs. 40% tPA alone (ARR 20%, p=0.025) and a reduction in infarct growth (14 vs. 27 ml, p=0.047).

Conclusions:
Although MRI selected patients in SWIFT PRIME were slightly older and treated longer after symptom onset, they demonstrated a statistically significant benefit on the primary efficacy endpoint. Reductions in infarct growth and rates of favorable clinical outcomes in the MR subgroup were also comparable to those seen in the CT perfusion subgroup.
Abstract TP58: A Comparison of Automated and Manual Volumetric Analysis of CT Perfusion in Acute Ischemic Stroke Patients
Authors: Donleavy Bailey , Chung Lee , Wang Haimei , Majersik Jennifer , de Havenon Adam
Published: March 2022

Background:
Manual volumetric analysis of CT perfusion (CTP) in acute ischemic stroke (AIS) patients using the OsiriX software is an established and accurate technique.

Hypothesis:
Automated software will produce accurate measurements compared to manual volumetric measurements.

Methods:
We reviewed 120 inpatients from 2010-2014 with AIS and a CTP from the acute setting. We used the automated Olea Sphere software to generate perfusion maps with oscillation index singular value decomposition (oSVD) and Bayesian probabilistic deconvolution. We used the manual OsiriX software to draw regions-of-interest delineating the stroke core on cerebral blood volume (CBV) and penumbra on cerebral blood flow (CBF) maps of the original CTP. For Bayesian analysis we defined stroke core as relative CBF2 seconds, and penumbra as relative mean transit time >135%. For oSVD we defined stroke core as relative CBF2 seconds, and penumbra as absolute Tmax >6 seconds. We compared techniques with a Pearson correlation coefficient and linear regression.

Results:
Both automated techniques had excellent correlation and agreement with the manual measurements (Table 1), but Bayesian deconvolution yielded superior agreement for CBV (Figure 1).

Conclusion:
Automated CTP volumetric analysis in AIS patients is reliable and accurate. Bayesian deconvolution has superior agreement with manual measurements of stroke core. Automated volumetric methods have an inherent appeal in the acute stroke setting given their efficiency.
Abstract TP60: Perfusion Abnormalities in Patients With Anterior Choroidal Artery (AChA) Stroke
Authors: Alqahtani Saeed , Nadareishvili Zurab , Luby Marie , Latour Lawrence , Benson Richard , Hsia Amie , Leigh Richard , Lynch John K
Published: March 2022

Background:
Prognosis after AChA stroke has been associated with NIHSS and lesion size, but there is limited data on the prevalence of perfusion abnormalities. The goal of this study was to determine the association of perfusion abnormalities and outcome in patients with AChA stroke.

Methods:
The study population was derived from ischemic stroke patients admitted to two primary stroke centers between 07/2000 and 07/2014. Patients received an MRI within 24 hours of symptom onset. Patients with ischemic stroke restricted to the AChA territory were included. A perfusion abnormality (MTT or TTP) which corresponded to DWI were categorized by visual assessment. Patients were excluded if DWI or PWI studies were incomplete or uninterpretable (N=58). Lesion size was measured as the largest diameter on DWI. Demographics, stroke risk factors, and discharge status was collected on all patients. Group comparisons were performed among patients with and without perfusion abnormalities with appropriate statistical tests as indicated.

Results:
Overall, 121 patients were included in the study; mean age was 66 (± 15.3 yrs.), 56% were male, and 41% white. Rates of stroke risk factors: hypertension (86%), hyperlipidemia (49%), diabetes (33%), prior stroke (22%) and atrial fibrillation (12%). The median (IQR) admit NIHSS was 5 (2-8), 25% received IV tPA, and 45% were discharged to home. Perfusion abnormalities were identified in 62% of patients. Lesion size (median, IQR) was greater among patients with a perfusion abnormality (1.63; 1.24-2.04) vs. those without (1.26; 0.99-1.6, p<0.005). Patients with a perfusion abnormality were less likely to be discharged to home than those without (35% vs. 63%, p=0.003). Univariate predictors of discharge to a rehabilitation or subacute facility included age (p<0.05), NIHSS on admission (p<0.05), and a perfusion abnormality (p<0.05).

Conclusion:
Two thirds of patients with AChA stroke have a perfusion abnormality. Patients with a perfusion abnormality have a higher NIHSS on admission and are less likely to be discharged home than patients without perfusion abnormalities.
Abstract TP62: The Incidence of Post-treatment Cerebral Microbleeds After Combined Therapy of Endovascular Thrombectomy and tPA
Authors: Kanaya Yuhei , Shiga Yuji , Takeshima Shinichi , Ota Shinzo , Sekihara Yoshinobu , Takamatsu Kazuhiro , Shimoe Yutaka , Tanaka Akio , Ota Taisei , Nishigaki Masakazu , Kuriyama Masaru
Published: March 2022

Introduction:
Cerebral microbleeds (CMBs) are considered as a risk factor for stroke. The incidence of post-tPA microbleeds have been reported in recent studies, however, it is not clear that whether hybrid procedure (the combination of tPA and endovascular thrombectomy) for ischemic stroke would increase risk of post-treatment CMBs more than treatment with tPA or endovascular thrombectomy alone. Objective of this study is to compare the incidence of post-treatment CMBs and symptomatic exraischemic hemorrhage by treatments: hybrid procedure, tPA alone, and endovascular thrombectomy alone.

Hypothesis:
Combined therapy of endovascular thrombectomy and tPA for ischemic stroke have higher incidence of post-treatment CMBs than tPA or endovascular thrombectomy alone.

Methods:
We retrospectively reviewed pre- and post-T2*-weighted MRI of ischemic stroke patients who received above treatments in our hospital during 2010 to 2014. The presence and number of CMBs were assessed according to the Brain Observer Microbleeds Scale. We compared the number of pre-treatment CMBs, incidence of newly-occurred post-treatment CMBs and symptomatic extraischemic hemorrhage within a year after treatments among hybrid procedure, tPA alone, and endovascular thrombectomy alone.

Results:
A total of 147 (hybrid procedure n=17, tPA alone n=90, endovascular thrombectomy alone n=40) patients’ pre- and post-treatment MRIs were reviewed. The average number of pre- treatment CMBs was 1.4±4.0 and there was no difference among treatments. The incidence of post-treatment CMBs was significantly higher in hybrid procedure (n=5, 29.4%) and tPA alone (n=18, 20.0%) than endovascular thrombectomy (n=1, 2.5%). However, there was no difference between hybrid procedure and tPA alone. Symptomatic extraischemic hemorrhage was found only one patient who received endovascular thrombectomy alone.

Conclusion:
The incidence of CMBs after treatments was increased in treatments using tPA. However, there was no difference in post-treatment incidence between hybrid procedure and tPA alone. This result suggests that additional thrombectomy after tPA would not increase the risk of CMBs.
Abstract TP70: Short-term Outcomes Among Patients With Delayed Arrival or Uncertain Onset Who are not Treated With Iv Tpa Compared to Those With Guideline-based Tpa Treatment
Authors: Siddiqui Khawja A , Wu Ona , Boulouis Gregoire , Schwamm Lee H
Published: March 2022

Intro:
Unclear onset time with delayed arrival is a common reason for non-treatment with tPA. The MR-WITNESS trial is studying if arrival 4.5 h from last known well, favorable clinical factors and FLAIR signal intensity ratios can safely select patients for IV tPA. We performed a retrospective analysis to compare patient outcomes between tPA patients treated within 4.5 h vs. potential MR WITNESS candidates who did not receive tPA.

Methods:
Using our local GWTG-Stroke database we identified 515 patients from 1/2009 through 6/2015 who met study criteria. Patients were defined as potential candidates for MR WITNESS based on a subset of the trial inclusion criteria that were available in our dataset: they met onset time criteria (arrived >= 4.5 but <24 h from last known well, <4.5 h from symptom discovery), did not receive on-label IV tPA or thrombectomy, had NIHSS<=25, blood glucose 50-400 mg/dL and no current oral anticoagulant treatment. Because they did not get acute MR, imaging criteria could not be evaluated. Univariate and multivariable testing were performed to identify predictors of discharge home.

Results:
In univariate testing compared to tPA patients, potential MR WITNESS candidates were less likely to arrive by EMS, more likely to have carotid stenosis, dyslipidemia and prior stroke/TIA, and had lower median NIHSS. Despite lower NIHSS, they were less likely to ambulate independently at discharge or be discharged home. On multivariable analysis, only potential MR Witness eligibility (aOR=0.37 (0.23,0.59); p-value=0.001) and lower NIHSS (aOR=0.86 per point (0.83,0.90); p-value<0.001) were independently associated with discharge home.

Conclusion:
Patients who may be potential candidates for extended window IV tPA per MR WITNESS protocol have poor outcomes when untreated compared to patients who present early and are treated with IV tPA. Further research is warranted to determine if tPA treatment in this cohort can improve outcomes.
Abstract TP76: Role of Surgery in Patients With Cerebral Venous Sinus Thrombosis With Visual Impairment
Authors: Kulkarni Girish B , Sanehalli Manjunath , Ramakrishna Subasri , Mustare Veerendrakumar
Published: March 2022

Introduction:
Almost 30-70% of patients with CVT have papilledema and raised ICP majority improving with antiedema measures, but few will have progressive visual failure. The utility of CSF diversion surgeries in them is unexplored

Methods:
It was a retrospective study of all patients admitted in a stroke ward with CVT confirmed on CT/MRI/MRV. These patients were treated with standard measures and in those patients with progressive visual loss an option of thecoperitoneal shunt (TPS) or optic nerve fenestration (ONF) was suggested and they underwent the procedure after informed consent.

Results:
Among 350 CVT patients seen over 5 years, 8 patients had progressive visual worsening.. Mean age was 27.12+10.1 with M:F:: 3:5. Six underwent the TPS and two ONF. The presenting features were headache with papilledema with vomiting with progressive vision loss in all. Presentation was acute-4, subacute-2, and chronic-2. On imaging superior sagittal and lateral sinus was involved in all patients and deep sinuses in one. Among the two patients undergoing ONF one patient improved in vision and another patient remained status quo. None of them developed any complications of surgery. Among 6 patients who underwent TPS all of them improved in vision and it stabilised over mean follow up period of 12 months with withdrawal of the antiedema measure. Two of them developed features of excessive CSF drainage postural headache which subsided with bed rest. All the patients had non-programmable shunts.

Conclusions:
Shunt surgeries especially TPS is helpful in stabilising and improving the progressive vision loss despite adequate antiedema measures in selective patients of CVT. Programmable shunts may be considered to prevent excessive CSF drainage.
Abstract TP78: When Non-revascularized Transfer Patients Come A-Knocking at a Stroke Center
Authors: Sands Kara A , Albright Karen C , Donnelly John P , Jones Benjamin A , Kaur Manmeet , Sisson April , Shiue Harn , Lyerly Michael , Gropen Toby
Published: March 2022

Background:
Guidelines recommend acute ischemic stroke (AIS) patients be transported rapidly to the closest certified stroke center (SC). The impact of SC care on transfer patients who do not receive acute revascularization therapy is not well understood. We sought to compare patient characteristics, adverse events (AEs), and short term functional outcomes in patients directly presenting to and transferred into a comprehensive stroke center (CSC).

Methods:
We conducted a retrospective review of consecutive AIS patients transferred to our CSC from March 2014-April 2015. We excluded patients who received tPA or endovascular therapy. Demographic and clinical data were collected. We compared AEs (hemorrhagic transformation [HT], DVT, PE, urinary tract infection [UTI], pneumonia [PNA], bacteremia) and poor short term functional outcome, as defined by modified Rankin scale (mRS) score 3-6, among patients directly admitted to our CSC and patients transferred to our CSC.

Results:
Of 589 patients who did not receive revascularization therapy, 24.4% were transfers. Transfers were disproportionately white (76.4 vs 57.8%, p<0.001), had higher median NIHSS (5 vs 4, p=0.028), were less often privately insured (40.1 vs 46.4%), and had less desirable ASPECTS scores on initial head CT (8-10; 22.9 vs 44.0, p<0.001). Transfers had higher odds of having AEs (crude OR 2.134, 95% 1.353-3.365). This association remained after adjusting for age, stroke severity, and admission glucose (OR 2.103, 95% CI 1.276-3.466.004). Transfers more frequently developed HT on repeat imaging (17.5 vs 7.0%, p<0.001), clinical seizure during inpatient stay (4.9 vs 1.6%, p=0.024), and PNA (7.6 vs 3.8%, p=0.061). However, transfer status was not associated with poor short-term functional outcome (crude OR 1.453, 95% CI 0.986-2.141; adjusted OR 1.200, 95% CI 0.703-2.046).

Conclusion:
Despite having more severe strokes and higher frequency of adverse events, patients transferred into our CSC for a higher level of care did not have worse short term functional outcomes. This highlights the importance of specialized inpatient care provided in NICUs and stroke units by experienced multidisciplinary teams.
Abstract TP80: Pre-mixing tPA: Moving Past Gestalt
Authors: McCarthy Kathryn , Caputo Lisa M , Whaley Michelle , Fanale Christopher V , Bar-Or David
Published: March 2022

Introduction:
Target:Stroke recommends pre-mixing intravenous tPA before brain imaging for high likelihood acute ischemic stroke (AIS) patients, allowing the drug to be available immediately after the decision to treat is made. However, premixing tPA is rarely practiced despite potential benefits of improving door-to-needle time.

Hypothesis:
We describe our experience developing criteria to eliminate avoidable wasting of the drug by identifying patients most likely to benefit from pre-mixed tPA and compare rates of wasted tPA before and after criteria development. We hypothesized this would result in a substantial reduction in wasted tPA.

Methods:
On 4/1/14, our Comprehensive Stroke Center instituted a series of interventions to reduce door-to-needle times, including pre-mixing tPA for AIS patients presenting within the tPA treatment window. Seven vials of pre-mixed tPA were wasted over the next five weeks, revealing the need for specific criteria to guide the medical decision to order tPA prior to brain imaging. A multi-disciplinary team examined cases of wasted pre-mixed tPA through peer review and determined four would have been avoided if criteria identified patients ineligible for tPA pre-mixing. Revised criteria were implemented for ordering pre-mixed tPA on 6/1/14.

Results:
Our revised criteria restricted pre-mixing tPA for patients taking anticoagulants, or presenting with a decreased level of consciousness, elevated blood pressure, headache, nausea, vomiting, or advanced stage cancer. Between 6/1/14-6/1/15, there has been one case of non-avoidable wasting, and no cases of avoidable tPA wasting.

Conclusions:
While pre-mixing tPA does not incur financial risk as drug manufacturers replace unused vials without cost, stroke centers remain wary of wasting the drug. We believe succinct criteria can reduce avoidable tPA waste, allowing health care providers to remain fiscally responsible while ensuring AIS patients are treated as fast as possible.
Abstract TP86: Predicting Aneurysm Occlusion After Flow Diversion
Authors: Cebral Juan , Mut Fernando , Chung BongJae , Kadirvel Ramanathan , Kallmes David , Bleise Carlos , Scrivano Esteban , Lylyk Pedro
Published: March 2022

Introduction:
Predicting the course of aneurysms after treatment with flow diverters is important to prognosticate long term outcomes and optimize interventions.

Hypothesis:
Aneurysm occlusion after flow diversion can be predicted using post-treatment flow information.

Methods:
Flows in experimental aneurysms in rabbits (n=15) and clinical cases (n=23) were evaluated with computational fluid dynamics. Subject-specific models were created from 3D angiographies. Flow conditions were measured with ultrasound in the rabbits, and derived from measurements in normal subjects in the clinical cases. Models of the devices were virtually deployed into the anatomical models. Experimental aneurysms were assigned to either a “complete” occlusion group if completely occluded at 4 weeks follow up, or to an “incomplete” occlusion group if still open at 8 weeks. Similarly, clinical cases were classified as “complete” occlusions if completely occluded at 3 months, or as “incomplete” occlusions if still patent at 6 months. Flow variables were then statistically compared between these groups for both the experimental and clinical series, and the predictive power of different variables to discriminate between aneurysms in each group was assessed by calculating the area under the receiving operating characteristics curves.

Results:
In the clinical (experimental) series, the aneurysm inflow rate was 4.02 (3.29) times larger in the incomplete occlusion group than in the completely occluded group, p=0.0210 (0.0239). Similarly, the mean aneurysm velocity was 2.75 (2.29) times larger, p=0.0044 (0.0582), and the shear rate was 1.57 (1.78) times larger, p=0.0210 (0.0722). Inflow rate could discriminate complete and incomplete occlusions with a 77% (90%) accuracy in the clinical (experimental) series. Similarly, mean velocity had a predictive power of 84% (83%) and shear rate of 76% (76%) in the clinical and experimental series.

Conclusions:
Flow conditions created immediately after treatment, in particular aneurysm inflow rate and mean aneurysm velocity, can prognosticate the future occlusion of aneurysms treated with flow diverters.
Abstract TP88: Phase I Experience of Safety of Eptifibatide in Select Patients With Elective Cerebral Aneurysm Embolization
Authors: Brar Jaskiran , Moussavi Mohammad , Mehta Siddhart , Korya Daniel , Chahal Harina , Daniel Joshua , Samaan Mena , Song Yong-Bum (Peter) , Hussain Mohammed , Kirmani Jawad
Published: March 2022

Background:
Literature has reported the application of oral Aspirin and/or Clopidogrel in significantly reducing thromboembolic complications after aneurysmal coiling. There is a lack of data on intravenous Eptifibatide use as the choice of antiplatelet agent in the setting of elective cerebral aneurysmal embolization. Previously we reported on safety outcomes on 19 patients that received intravenous Eptifibatide while undergoing elective embolization of cerebral aneurysms. We now report on more patients to further assess safety outcome with the aim of further corroborating our previous findings.

Methods:
Of all the patients that underwent elective cerebral aneurysmal embolization from 2010-2015 at our university affiliated comprehensive stroke center, patients that received Eptifibatide after aneurysmal embolization were reviewed. Eptifibatide was administered intra-arterially as a 135-μg/kg single-dose bolus, and then continued on intravenous infusion of 0.5-μg/kg/min post-procedurally. Inclusion criteria included clinically assessed risk of clot formation or propagation based on angiographic characteristics. Charts were reviewed for all patients to assess for medical/procedural complications including symptomatic and asymptomatic hemorrhages, groin hematoma, epistaxis and gross hematuria.

Results:
A total of 30 patients (mean age 61, 22% male [n=7]) received Eptifibatide for a mean duration of 19 hours (range 4-29 hours). The aneurysmal size ranged from 2.4 to 23 mm and 83% [n=25] were located in anterior circulation. None of the patients demonstrated symptomatic/asymptomatic hemorrhage. One patient had a groin hematoma without need of transfusion.

Conclusion:
IV Eptifibatide may represent another safe option for rapid and reversible antiplatelet therapy for reduction of thromboembolic complication associated with aneurysmal embolization in select patient population.
Abstract TP92: Prevalence of Aortic Aneurysms in Patients With Intracranial Aneurysms: A Retrospective Analysis
Authors: Lure Allison C , Jiang Boxiang , Chee Christina , Tandy Thomas K , Southerland Andrew M , Worrall Bradford B
Published: March 2022

Introduction:
Intracranial (IA) and aortic aneurysms (AA) share genetic and environmental risks. In a retrospective review of clinical data, we identified those presenting with IA (+/- subarachnoid hemorrhage), who also had abdominal or thoracic imaging.

Method:
In the University of Virginia (UVA) Clinical Data Repository we searched for patients with IA by ICD-9 diagnosis codes and CPT treatment codes. We used three strategies to identify those with aortic imaging: 1) ICD-9 diagnosis codes for AA, 2) CPT and billing codes for abdominal or thoracic imaging (aortogram, ultrasound, angiography, magnetic resonance, and computerized tomography), and 3) CPT and billing codes for AA treatment (endovascular, stent, graft, wrap, or screening). We reviewed all charts to identify those with confirmed IA and imaging. We performed a multivariable logistic regression analysis accounting for sex, age, hypertension, diabetes mellitus, smoking status, and IA size, multiplicity, and location to look for associations with AA.

Results:
Among individuals seen at UVA hospital from 2004 to 2015, we identified 13245 cases with a possible IA, of whom 1017 potential aortic imaging. Our review of charts revealed that 720 did not having an IA. Of the remaining 287 cases, 51 lacked appropriate aortic imaging. We recorded information from the remaining 236 cases - 94/236 (39.8%) had an AA identified. In our multivariable analysis, only female sex was significantly associated with a co-prevalent AA (Odds Ratio: 0.20, 95% confidence interval 0.09 - 0.45). In the table, we provide descriptive statistics for those with and without AA as well as the subsets with thoracic aortic aneurysms (TAA) and abdominal aortic aneurysms (AAA).

Conclusion:
The co-prevalence of AA in a clinical population known to have IA and with aortic imaging was 39.8%. Men had higher risk for AA. This indicates a shared risk for aneurismal disease in the aorta and brain warranting prospective investigation on the mechanisms of risk.
Abstract WMP11: Arterial Occlusive Lesion Location Does Not Impact Functional Outcome in Patients with Endovascular Reperfusion
Authors: Kim Sun , Christensen Soren , Mlynash Michael , Tsai Jenny P , Federau Christian , Kemp Stephanie M , Mishra Nishant , Frankel Michael , Dehkharghani Seena , Devlin Thomas G , Yavagal Dileep R , Akhtar Naveed , Tudor Jovin , Nogueira Raul , Bammer Roland , Straka Matus , Zaharchuk Greg , Albers Greg W , Marks Michael , Lansberg Maarten
Published: March 2022

Introduction:
The relationship between clinical outcome and arterial occlusive lesion (AOL) location in patients after endovascular therapy is not fully determined. We aimed to investigate if the location of the arterial occlusive lesion (AOL) is an independent predictor of good functional outcome.

Hypothesis:
AOL location impacts clinical outcome with distal lesions having higher rates of good functional outcome (GFO) in reperfused patients.

Methods:
Using data from the CTP to predict Response to recanalization in Ischemic Stroke Project (CRISP), a multi-center, NIH-sponsored prospective cohort study, we analyzed the effect of AOL location on clinical outcome. Patients were included if they had documented reperfusion on early follow-up MR or CT perfusion imaging (>50% reduction in Tmax>6s lesion volume) or on angiography (TICI 2b or 3). Good functional outcome was defined as mRS score 0-2 at day 90. AOL location was categorized as proximal ICA, distal ICA, MCA-M1, or MCA-M2. Fully automated perfusion software (RAPID) was used to calculate CTP infarct core volume (rCBF<30%) and critically hypoperfused tissue volume (Tmax>6s). We assessed whether age, NIHSS score, infarct core, critically hypoperfused tissue, and AOL are associated with GFO using univariate and multivariate analyses.

Results:
The analysis included 167 of 201 patients (proximal ICA=21, distal ICA=32, M1=99, M2=15). Median NIHSS score (IQR) for groups were respectively: 18(14-22), 18(15-23), 17(11-20), 15( 13-19). Mean core volumes (mL) (IQR) were: 24.2(1.1-22.9), 13.0(0.0-17.7), 16.5(0.0-26.2), 10.6(1.1-13.0). Significant independent predictors of GFO were age (OR 0.82 for every 5 year increment, 95% CI 0.72-0.94), NIHSS score (OR 0.86, 95% CI 0.79-0.93), and core volume (OR 0.78 for every 10 mL increase, 95% CI 0.62-0.94), whereas AOL location (p=0.8-0.9) and the volume of critically hypoperfused tissue (p=0.5) were not significant in univariate and multivariate analyses.

Conclusion:
Baseline symptom severity, infarct core volume, and age drive functional outcomes in stroke patients with successful endovascular reperfusion. These variables, but not AOL location and volume of critically hypoperfused tissue, should be used for prognostication in the acute setting.
Abstract WMP114: Imaging of
68
Ga-prgd2 Pet/ct for Integrin αvß3 in Cerebral Small Vascular Disease
Authors: Shu Shi , Zhu Zhaohui , Zhu Yicheng , Ni Jun , Zhou Lixin , Yao Ming , Cui Liying , Li Fang , Peng Bin
Published: March 2022

Background:
Angiogenesis was identified in severe intracranial artery stenosis/occlusion patient. The purpose of this study was to identify endogenous angiogenesis in SVD patients.

Methods:
We measured expression of integrin αvß3 using
68
Ga-S-2-(isothiocyanatobenzyl)-1, 4, 7-triazacyclononane-1, 4, 7-triacetic acid-PEG3-E[c(RGDyK)]2 (
68
Ga-PRGD2) PET in 9 patients with SVD. Additionally, all patients underwent
18
F-FDG PET and
13
N-Amonia PET to evaluate the metabolism and cerebral blood flow. 8 patients underwent Mini-Mental State Examination (MMSE). All patients were given informed consent.

Results:
68
Ga-PRGD2 uptake was indentified around white matter lesion and subcortical infarcts as punctiform in 9 patients, and the maximum standardized uptake values (SUVmax) of
68
Ga-PRGD2 around lesions were significantly higher than those in the normal brain (0.18±0.067 vs 0.06±0.029, mean±SD, P<0.001). Cerebral blood flow has a positive correlation with cerebral metabolism and negative correlation with MMSE score, no significant correlation with
68
Ga-PRGD2 uptake (r=-0.368,
P=
0.092)

Conclusion:
The present study shows that there is angiogenesis in human cerebral SVD for the first time. No significant correlation between CBF and angiogenesis suggests complicated mechanisms of angiogenesis in SVD, which needs further investigation.

Figure 1.
MRI FLAIR showed diffuse white matter lesions( A)..
68
Ga-PRGD2 uptake was identified as punctiform around the WMLs (B.).
13
N-Amonia PET image(C) ,
18
F-FDG PET image(D).

Figure 2.
Correlation between
68
Ga-PRGD2,
18
F-FDG and
13
N-Amonia