bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract TP566: Reasons Pre-Existing Mild Cognitive Impairment May Influence Physician Recommendations for Stroke and Heart Attack Treatments
Authors: Reale Bailey K , Zahuranec Darin B , Langa Kenneth M , Forman Jane , Giordani Bruno , Plassman Brenda L , Kollman Colleen , Blair Emilie , Levine Deborah A
Published: January 2019

Background:
Mild cognitive impairment (MCI) is common, affecting up to 1 in 5 adults 65 or older. Although it is known that physicians recommend fewer treatments for stroke and acute myocardial infarction (AMI) to patients with pre-existing dementia, it is unknown how pre-existing MCI influences physician recommendations for stroke and AMI treatments.

Methods:
Qualitative study based on in-depth, semi-structured, in-person interviews with physicians from 2 academic medical centers. We interviewed neurologists (n=7), primary care physicians (n=7), and cardiologists (n=7) using a standard guide. Qualitative content analysis was used to identify unifying and recurrent themes. Participants were asked to reflect on data from a pilot study suggesting that physicians recommended fewer treatments for stroke and AMI to older adults with MCI. Responses between specialties were compared.

Results:
Participants postulated reasons that fewer stroke and AMI treatments were recommended to MCI patients (Table 1). The most common reasons were that physicians may assume patients with MCI have a poor prognosis, quality of life, or will soon progress to dementia (71%), that treatments are risky or harmful (67%), and that patients with MCI won’t comply with treatment (52%). Neurologists more frequently assumed that patients with MCI benefit less from stroke treatments. Whereas, cardiologists often thought that patients with MCI face greater risks from AMI treatments. All three specialties felt that physicians made assumptions that patients with MCI are not able to comply with treatment.

Conclusion:
Physicians may think that patients with MCI are more likely to have a poor prognosis, benefit less from treatments, and/or face greater risks from treatments than cognitively normal patients. Such beliefs may lead physicians to recommend fewer treatments for stroke and AMI to patients with MCI.
Abstract TP567: Identification of Il-17/Cxcl5 as a Novel Regulator of Endothelial-Oligodendrocyte Signaling in Ischemic White Matter Disease
Authors: Xiao Guanxi , Kumar Rosie , Hinman Jason D
Published: January 2019

Introduction:
Cardiovascular risk factors including obesity accelerate the rate of ischemic white matter lesions through unknown mechanisms. Disruption of the normal signaling between endothelial cells and oligodendrocytes may drive the acceleration of white matter lesions. Here, we performed gain and loss of function studies of the IL-17/CXCL5 signaling cascade in white matter endothelia and determined the effect on oligodendrocytes.

Methods:
Obesity-induced activation of IL-17 receptor b was blocked using function-blocking anti-IL-17B antibodies injected systemically q3d for 6 weeks. Over-expression of CXCL5 in white matter endothelia was achieved using FLEX lentiviral administration in Tie2-Cre:tdTomato transgenic mice. Endothelial CXCL5 levels, oligodendrocyte number, and maturation were determined using 3D confocal microscopy. Focal white matter ischemic stroke was induced using stereotactic injection of the irreversible eNOS inhibitor L-Nio.

Results:
IL-17Rb and CXCL5 levels are significantly increased at RNA and protein levels in white matter endothelial cells in obese mice. Endothelial expression of CXCL5 is further increased after focal white matter stroke. Administration of function-blocking anti-IL-17B antibodies to high fat diet mice reduced the level of endothelial CXCL5 by 60.4% without changing endothelial IL-17Rb levels. The total number and mean distance of vessel-associated oligodendrocyte precursor cells (OPCs) was not different in control vs. anti-IL-17B treated animals. In normal weight Tie2-Cre:tdTomato mice, forced over-expression of CXCL5 resulted in an increased number of vessel-associated OPCs compared to control. In obese mice, stroke-responsive OPCs are increased 37% at 7d after focal white matter stroke and remyelination of focal white matter lesions at 28d is impaired.

Conclusions:
Chronic cardiovascular risk factors such as obesity promote changes in white matter endothelia including activation of IL-17/CXCL5 signaling. Up-regulation of CXCL5 in white matter endothelia attracts OPCs to vessels and exaggerates the injury response to focal white matter stroke. Endothelial-oligodendrocyte signaling may provide novel therapeutic targets for ischemic white matter disease.
Abstract TP568: Predictors of Long-Term Impaired Processing Speed After Stroke
Authors: Mahon Susan , Krishnamurthi Rita , Prah Philip , Jones Kelly , Feigin Valery
Published: January 2019

Background and Aims:
Impaired Processing Speed (IPS) affects up to 50 to 70 % of stroke survivors and has a major influence on post-stroke cognitive dysfunction, affecting quality of life and increased dependence on others. Few studies have examined predictors of IPS after stroke, and there is a paucity of data in terms of long-term prevalence. This study examined baseline predictors associated with long-term impaired processing performance in an existing population-based cohort, four years after stroke.

Method:
IPS was assessed using the Symbol Digit Modalities Test (SDMT), at four years after stroke in a sample drawn from an existing population-based study (n=133, mean age =67.0 ± 13.4). Baseline predictors were obtained at time of stroke and/or within two weeks of the acute event. Multivariate linear and logistic models were used to identify baseline predictors (reported as OR with 95%CI) and prevalence of long-term IPS.

Results:
Four years after stroke 62% of survivors had IPS indicated by a mean score < 40 on the SDMT (m = 36.9 ± 11.2). There were significant associations between long-term IPS and the following baseline factors: older age (OR 3.03, 95% CI 0.9-9.3,
p
=0.05), previous stroke (OR 2.74, 95% CI 1.0-7.4,
p
=0.05), cholesterol (OR 2.72, 95% CI 1.3-5.4,
p
=0.01), hypertension (OR 1.82, 95% CI 0.9-3.6,
p
=0.05), coronary artery disease (OR 3.35, 95% CI 1.6-9.6,
p
=0.01), and arrhythmia (OR 4.40, 95% CI 1.5-12.4,
p
=0.01).

Conclusion:
IPS remains highly prevalent long after stroke. Early identification of those who are at higher risk of IPS is vital to target rehabilitation interventions, improving overall outcomes.
Abstract TP570: Cerebrovascular Risk Factors in Elderly Patients With Alzheimer’s Disease
Authors: Nagata Ken , Yamazaki Takashi , Takano Daiki
Published: January 2019

Background:
Since disease modifying therapy is not yet available in our current medical practice against dementia including Alzheimer’s disease (AD), the management of vascular risk factors (VRFs) is regarded as the most practical way in the prevention and treatment of dementias. In this paper, the influence of VRFs including cerebrovascular lesions were analysis in relation to the cognitive function in elderly AD patients.

Subjects and Methods:
The present study was conducted based on 111 Japanese patients (37 men and 74 women) with probable AD who visited our memory clinic. None of them experience stroke events. Their mean age was 75.7 years, and the mean MMSE was 19.0. All subjects underwent 1.5 Tesla MRI, neuropsychological evaluation and laboratory tests including brain natriuretic peptide (BNP) and APOE status. Hypertension, diabetes, obesity, dyslipidemia, heart failure, coronary artery disease, atrial fibrillation (AF) and frailty were regarded as VRFs.

Results:
The mean MMSE score was highest in 4 cases who had no VRF, whereas that was lowest in 11 cases (9.1%) who had 4 or more VRFs. On MRI, 56 cases (50.5%) showed old lacunar infracts, and 18 cases (16.2%) had old microbleeds. The mean MMSE score was 17.5 in those with thalamic infarcts, whereas that was 19.3 in those without thalamic lesions. Severe white matter lesions and AF were also associated lower cognitive score. The mean MMSE was 18.5 in the underweight cases (BMI<20), whereas that was 20.5 in overweight subjects. Those with the lowest BNP quartile showed the highest MMSE score, whereas the highest BNP quartile had lowest MMSE score. For both systolic and diastolic blood pressure, those in the lowest tertile showed lower MMSE score as compared with those in the highest tertile.

Conclusion:
The cerebrovascular risk factors including thalamic infarcts, severe white matter lesions, heart failure, AF, and frailty influenced on the clinical presentation in elderly AD patients.
Abstract TP571: Coated-Platelets, RANTES and IL-7 Correlate With Silent Brain Infarction in Carotid Stenosis
Authors: Khattab Mohamad , Vincent Andrea , Prodan Calin , Ijaz Sardar , Bajwa Muhammad , Dale George , Kirkpatrick Angelia
Published: January 2019

Background:
Silent brain infarction (SBI) is associated with both cognitive decline and recurrent stroke. While cortical SBI may have an embolic source, the etiology of subcortical SBI (80% of SBI) is less clear. We now examine the association between coated-platelets (procoagulant platelets observed upon dual agonist stimulation with collagen and thrombin), soluble mediators of inflammation, cell adhesion, angiogenesis and coagulation and SBI in carotid stenosis patients.

Methods:
Asymptomatic patients with ≥50% carotid stenosis were enrolled, coated-platelets assayed, and plasma obtained for measurement of 58 plasma biomarkers. Presence and location of SBI, defined as a focal, ≥ 3mm cavitary lesion with T1 hypointensity and T2 hyperintensity features on MRI within 12 months of enrollment, were recorded. Variables correlating (p<0.10) with SBI were included for multiple regression and retained if p<0.05.

Results:
Thirty-two subjects were analyzed. Cardiac ejection fraction (r= -0.34, p=0.0325), coated-platelets (r=0.5471, p=0.0014) and IL-7 (r=0.35, p=0.0498) correlated with overall SBI number. Antiplatelet use (r= -0.63, p=0.0001), coated-platelets (r=0.43, p=0.0152) and RANTES (r=0.39, p=0.0283) correlated with cortical SBI number. Beta blocker use (r= -0.40, p=0.0238) and coated-platelets (r=0.52, p=0.0030) correlated with subcortical SBI number, with a trend for correlation between IL-7 and subcortical SBI number (r=0.35, p=0.0518). Multivariate analysis revealed coated-platelet levels ≥40.5% and lack of beta blocker use were associated with subcortical SBI (OR=35.22, p=0.0057 and OR=10.74, p=0.0347 respectively).

Discussion:
Our results demonstrate a strong association between coated-platelets and SBI regardless of anatomic location. We have also identified two inflammatory mediators associated with cortical (RANTES) and subcortical (IL-7) SBI location. Our findings suggest protective effects of antiplatelet use for cortical SBI and beta blocker use for subcortical SBI. Altogether, these data support a thrombotic mechanism of SBI with differing auxiliary mechanisms for cortical and subcortical SBI that may involve alternate inflammatory pathways.
Abstract TP577: Prevalence and Associations of Ischemic Stroke in Pulmonary ArterioVenous Fistulas
Authors: Topiwala Karan , Patel Smit , Tarasaria Karan , Pervez Mubashir
Published: January 2019

Introduction:
Pulmonary arteriovenous fistula (PAVF) is an abnormal intrapulmonary right-to-left shunt. About 1 in 4 patients with untreated PAVF may suffer a paradoxical embolic acute ischemic stroke (AIS) by 65 years of age. Current expert recommendations are to treat all CT scan visible PAVF, even if asymptomatic. The American Heart Association Stroke Guidelines recommend using antiplatelet agents for secondary prophylaxis of AIS related to PAVF.

Objective:
To determine from the Nationwide Inpatient Sample (NIS), the prevelance and management trends of AIS in patients diagnosed with PAVF.

Methods:
Using the NIS from 2001-2014, patients carrying a secondary diagnosis of PAVF (ICD-9 CM code: 417.0) and a subsequent hospitalization with AIS were identified. SAS 9.4 was used for data analysis with categorical and continuous variables tested using the Chi-Square test of proportions and Student’s t-test, respectively. Cox proportional hazard regression was used to adjust for confounders.

Results:
A total of 4430 (weighted) patients (>18 years) were diagnosed with PAVF at a mean age of 55.6 years (SE±0.7). About 7% (n=312, p<0.0001) patients with PAVF were admitted with AIS at a mean age of 58.5 years (SE ±2.5). From 2001 to 2014, there was a two-fold increase in the prevalence of PAVF (204 vs. 455) as well as AIS related admissions (5% vs. 12%). On univariate analysis, epistaxis (p= 0.0184 OR 5.7), migraine (p= 0.0007, OR 5.7), patent foramen ovale (PFO) (p=0.0002, OR 3.2) and cannabis use (p= 0.009, OR 5.8) were significantly associated with AIS. Migraine (p=0.0062, OR 4.17) and PFO (p=0.0004, OR 3.68) retained significance on multivariate analysis. None of the ischemic strokes received reperfusion therapy. Only about 8% (n=24) were on long-term antiplatelet therapy. Approximately 3.2% (n= 141) of all patients with PAVF had a percutaneous embolization of their fistula.

Conclusion:
In a nationally representative sample, the prevalence of AIS in patients with PAVF has roughly doubled from 2001 to 2014. Utilization of reperfusion therapy and secondary stroke prophylaxis with antiplatelet agents is low. Consensus guidelines and randomized control trials are need to establish the role of fistula embolization in these patients.
Abstract TP578: Comparison of Demographic, Clinical, and Angiographic Characteristics Between Pediatric and Adult HHT Patients With Brain AVMs
Authors: Gautam Ayushi , Nelson Jeffrey , Kim Helen , Hetts Steven
Published: January 2019

Introduction:
Hereditary Hemorrhagic Telangiectasia (HHT) is an autosomal-dominant disorder that affects 1 in 5,000 people, and is caused by heterozygous mutations in ENG, ACVRL1, and SMAD4. Diagnosis of HHT is either by genetic testing or by the presence of 3 of 4 Curacao clinical criteria: telangiectasia, recurrent nosebleeds, AVMs, or an affected first-degree relative. Approximately 5 to 23% of HHT patients are affected by brain AVMs. While characteristics of sporadic brain AVMs have been well-outlined in the literature, the angiographic features of brain AVMs in HHT patients are not as well understood on whether characteristics differ by age. The purpose of this study was to compare the clinical and angiographic characteristics in pediatric and adult HHT patients with brain AVM.

Methods:
Patients with a confirmed diagnosis of HHT and evidence of brain AVM on imaging (n=49) were queried from the UCSF Center for Cerebrovascular Research database. These patients were all enrolled in the multicenter Brain Vascular Malformation Consortium HHT Project at the UCSF HHT Center of Excellence. We assessed whether differences in demographic, clinical, and angiographic data existed between pediatric and adult patients; pediatric patients were defined as <18 years old at enrollment or imaging. Fisher's exact test was used to test patient-level comparisons, and logistic mixed-effect models were used to assess lesion-level characteristics. P-value<0.05 was considered statistically significant.

Results:
Adult HHT patients were significantly more likely to have telangiectasia, and were more likely to have pulmonary AVM and anemia, but not significantly so. Deep venous drainage was significantly more common in lesions from pediatric patients, as well as a trend for lesions with diffuse bAVM borders, venous stenosis, and venous ectasia. Larger sample sizes are needed to determine if these features are significantly different in bAVMs of pediatric and adult HHT patients.
Abstract TP58: Experimental Comparison of Physical Properties Depending on the Unsheathing Level of Stent: Solitaire versus Trevo Retriever Stents
Authors: Jeon Hong Jun , Ahn Jun Hyong , Lee Jong Young
Published: January 2019

Purpose:
This study compared the physical properties depending on the unsheathing level of Solitaire and Trevo stent and provided experimental information about the controlling of STR over small vessels.

Materials and Methods:
The following stents were tested in five section based on the degree of microcatheter’s unsheathing: Trevo 4/20 and Solitaire 4/20 mm. Experimental silicone models such as 1.5 / 2 / 3 / 4 mm were applied to check the frictional force and continuously flushed with 37° C saline. Radial force repeatedly measured 10 times for each segment and friction force of the segments compared into individual silicon tubes along the straight and U-curved paths.

Results:
Trevo demonstrated higher radial forces than solitaire in overall physical changes (Unloading: 1.5 vs 0.75 N/mm, deploying: 1 vs 0.5 N/mm, Loading: 1.75 vs 1 N/mm,
p
<0.05). According to the decreased section of unsheathing level, maximal deploying and loading radial force was gradually decreased in each stent, but the physiological force difference between two portions was lesser in Trevo stent (
p<
0.05). Depending on those sections, friction force of each stent was also gradually reduced less than 3mm tube. Under a 2mm tube, trevo stent appeared a relatively low force than Solitaire in all unsheathing sections (
p<
0.05), but Solitaire showed the highest force at the peak of the U-curved path (
p<
0.05).

Conclusion:
Even though radial and frictional force could be controlled as reducing the unsheathing level of both stents, handling of trevo stent may be a safe than solitaire in a small vessel less than 2mm.
Abstract TP581: Maternal and Fetal Outcomes in Women With Brain Arteriovenous Malformation Rupture During Pregnancy
Authors: Yan Kimberly , Ko Nerissa U , Hetts Steven , Abla Adib A , Lawton Michael T , Kim Helen
Published: January 2019

Background:
Intracranial hemorrhage (ICH) is often the initial presenting symptom for patients with brain arteriovenous malformations (bAVM), which is further complicated in the setting of pregnancy. There are no standard guidelines for management of pregnant women with bAVM, and few studies have reported on maternal and fetal outcomes in those with bAVM ICH. The purpose of this descriptive study was to review our case series for maternal and fetal outcomes in women with bAVM ICH during pregnancy.

Methods:
We conducted a retrospective review of our database for women between the ages of 15-50 years who presented with a bAVM ICH during pregnancy between 2000-2017. Demographics, angiographic characteristics, gestational age/trimester at ICH, mode and timing of AVM treatment, and maternal (e.g. modified Rankin Scale, mRS) and fetal outcomes (e.g. healthy or intrauterine fetal death) were recorded from the medical records.

Results:
We identified 16 bAVM cases who were pregnant at the time of ICH. Mean age of cases was 27±6.7 years, 56% were non-Caucasian, and 81% presented with an ICH during the second or third trimester. Of 16 patients, 2 terminated pregnancies in the 1
st
trimester, 1 miscarried immediately after ICH, and 13 patients carried to term (69% delivered cesarean and 23% vaginal). Of 13 patients with live births, 77% received emergent AVM treatment (embolization+resection or resection only) at time of ICH, while 3 deferred treatment until after birth. The majority of bAVMs were Spetzler-Martin grade 2 or 3 (87%), 56% had deep venous drainage, and mean AVM size was 2.5±1.2cm. At 2-year follow-up, 85% of women had good outcomes (mRS 0-2). Only one patient did worse after AVM treatment due to a permanent neurological deficit. All cases had healthy fetal outcomes at time of delivery and at 2-yr follow-up.

Conclusion:
Our case series suggest good fetal and maternal outcomes in ruptured bAVM patients presenting during pregnancy, the majority of which were treated before delivery. Treatment of ruptured AVMs during pregnancy should be tailored to the needs of each specific patient in close consultation with the obstetrics and neurosurgery teams.
Abstract TP583: Consideration on Surgical Treatment of Arteriovenous Fistula at the Craniocervical Junction
Authors: Oda Jumpei , Nakahara Ichiro , Matsumoto Shoji , Ganaha Tsukasa , Hasebe Akiko , Suzuki Takeya , Omi Tatsuo , Tanabe Jun , Watanabe Sadayoshi , Suyama Kenichiro , Moriya Shigeta
Published: January 2019

Objective:
Management of arteriovenous fistula at the craniocervical junction (CCJ-AVF) is challenging, because CCJ-AVF is quite rare, most cases are difficult to treat by the endovascular treatment only, and difficult to understand its complicated anatomy preoperatively. The aim of this presentation is to propose several tips and pitfalls regarding the surgical strategy for CCJ-AVF, particularly focused on anatomical relationships with shunting point and key structures.

Methods:
We experienced 9 cases of CCJ-AVF during about 4 years since April 2015. These patients presented by as follows, 3 subarachnoid hemorrhage, 2 hematomyelia, 1 cerebellar hemorrhage, and 3 incindentally. We performed surgical ligation for 8 cases and endovascular treatment for 2 cases, including combined therapy for one case in each. Direct surgery was usually performed as follows: general anesthesia, park-bench position, transcondylar fossa approach and C1 laminectomy, cut the dentate ligament with MEP/SEP and NIM monitoring and ICG video angiography repeatedly.

Results:
Postoperative DSA showed a complete cure in every case. One case treated by surgical ligation had a transient neurological deficit, while another case treated by endovascular treatment showed deterioration of preoperative motor dysfunction.

Conclusions:
For CCJ-AVFs, we prefer direct surgical ligation, because this lesion has a dangerous anastomoses between radiculo-meningeal and pial supply which cannot be detect preoperatively. Our approach can provide a suitable operative field to ensure understanding of its complicated structure. In our series, the patients who underwent surgical ligation had a good result except one patient with transient neurological deficit caused by postoperative excessive venous thrombosis of the drainer which required temporary anticoagulation.
Abstract TP586: Rates and Predictors of Stroke in Medically Managed Patients With Unruptured Arteriovenous Malformations in ARUBA (A Randomized Trial of Unruptured Brain Arteriovenous Malformations)
Authors: Qureshi Adnan I , Saeed Omar , Sahito Sindhu
Published: January 2019

Background:
Primary endovascular embolization has been advocated for treatment of brain arteriovenous malformations (BAVM) in recent trials. We performed this analysis to identify the rate and predictors of incident stroke in a cohort of unruptured BAVM patients recruited in a multicenter trial.

Methods:
We analyzed adult patients (≥18 years) with an unruptured BAVM were enrolled into Randomised trial of Unruptured Brain Arteriovenous malformations (ARUBA) at 39 clinical sites in nine countries who were randomized to medical treatment. We identified the rates of stroke ascertained by in-person neurological follow-up visits were performed at 6 month intervals during the first 2 years and annually, with telephone contacts every 6 months thereafter. The effect of baseline clinical and neuroimaging characteristics on incident stroke were determined.

Results:
A stroke event had occurred for 11 (10·1%) of the 109 patients randomized to medical management with a mean follow-up 33·3 months [SD 19·7]) with an annual incidence of 10.1%. Patients with unrelated intracranial aneurysms and higher systolic blood pressure were at higher risk. The mean systolic blood pressure was significantly higher among patients with stroke event (mean 142.3 ± SD 20.3 versus 124.8 ± 14.8, p=.03). There was a linear increase in the risk of stroke event with increasing systolic blood pressure in the logistic regression model (OR 1.1, 95% 1.0 - 1.11, p=.047) There was a trend towards lower incidence of stroke events in BAVM located in the occipital lobe (p=.099). Patient’s age, initial lesion size, and Spetzler Martin grade were not associated with stroke events.

Conclusions:
A low rate of stroke events was seen in patients with unruptured BAVM with the potential preventive role of aggressive systemic blood pressure treatment.
Abstract TP588: Underlying Mechanisms Of Preconditioning Against Stroke: Lack Of Ischemic Neuroprotectant Sirt1 Increases Long-term Potentiation Induction In Mice
Authors: Escobar Iris , Stegelmann Samuel D , Perez-Pinzon Miguel A
Published: January 2019

Sirt1 has been implicated to play a major role in ischemic preconditioning (IPC)—a phenomenon whereby a sublethal episode of ischemia induces tolerance to a subsequent prolonged ischemic insult, such as stroke. Both IPC and pharmacological mimetics (i.e. resveratrol) upregulate Sirt1 activity and expression. Since Sirt1 is thought to regulate the expression of proteins involved in synaptic plasticity, neuroprotection afforded by Sirt1 may be explained by changes in these processes. For this reason, we investigated the effects of Sirt1 deficiency on long-term potentiation (LTP). Using inducible, neuronal-specific
Sirt1
knockout mice, acute brain slices were prepared and extracellular field recordings were taken in the CA1 region of the hippocampus. Sirt1 deficiency significantly increased LTP induction (2.08 ± 0.065 fold change relative to a 1.46 ± 0.054 change in wild-type mice; n = 10-11,
p
= 0.022), suggesting Sirt1 may function to repress the transcription of genes associated with LTP. Paired-pulse facilitation was also significantly increased, where neuronal
Sirt1
knockout mice had a 2.10 ± 0.047 fold increase in the paired-pulse response after LTP compared to that of the wild-type control (1.60 ± 0.040; n = 10-11,
p
= 0.001). These changes were indicative of presynaptic involvement. To test whether similar changes in plasticity occur during the late phase of preconditioning, wild-type mice were treated with resveratrol or a vehicle control and subjected to electrophysiological recordings
ex vivo
48 hours later. However, no differences in LTP induction or paired-pulse facilitation were observed. Thus, it is unclear whether protection mediated by resveratrol preconditioning involves changes in synaptic plasticity. Since Sirt1 is capable of deacetylating many histone and non-histone proteins, its effects on transcription and gene expression may vary depending on its activity and period of activation. It is probable that during the extended window of ischemic tolerance, Sirt1 may exert different effects than that of the early or classical late phase. Thus, future studies investigating the effects of Sirt1 on plasticity across different time windows of IPC may shed light on new, more direct targets that can mimic or facilitate preconditioning.
Abstract TP59: Experience With Endovascular Therapy in Acute Ischemic Stroke Patients Presenting With Low National Institute of Health Stroke Scale Scores
Authors: Osteraas Nicholas D , Schacter Daniel , Conners James , Vargas Alejandro , Cherian Laurel , Song Sarah , Dafer Rima M
Published: January 2019

Background:
Endovascular thrombectomy (ET) is indicated for select patients with anterior circulation large vessel occlusion (ACLVO) with NIHSS
>
6. Safety and efficacy of ET in patients with NIHSS <6 and ACLVO is an area of clinical equipoise; we present our experience with this population.

Methods:
Internal ischemic stroke database was queried for patients with admission NIHSS <6 from 1/2015 to 6/2018. NIHSS on presentation, cortical signs, use of ET (on arrival or after clinical decline) and outcomes were retrospectively collected. Outcomes were compared between patients taken directly for ET and those observed using Mann Whitney U.

Results:
Of 173 admissions with NIHSS <6 upon arrival, 15 patients had ACLVO. Of those, all had cortical signs; 8 patients were admitted and monitored, 7 patients went directly to ET . Of the 8 monitored patients, 3 (38%) received IVtPA, 6 (75%) underwent rescue ET after clinical decline, all with favorable aspects . Arrival mean NIHSS was 3.3 (4.6), NIHSS at time of ET was 10.6 (7.4). Occlusions were located in the first branch of the middle cerebral artery (M1) in 3 cases, with one case each of M2, internal carotid artery (ICA) and tandem occlusion. A symptomatic intracerebral hemorrhage occurred in a patient with re-occlusion, stent placement and IV antiplatelet use. Five patients (63%) were discharged to an acute rehab facility, the remaining 27% were discharged to home, with NIHSS of 7.7 (7.2) on discharge and mRS of 1.75 (1.5) at 90-day follow-up. Of the 7 patients who proceeded directly to ET, arrival NIHSS was 2.3 (2.2), 43% received IVtPA, occlusions were present in the terminal ICA in all cases, with tandem occlusions additionally present in 3 (43%). One patient clinically worsened and was found to have vasospasm. This same patient was discharged to rehab, the remainder (85.8%) were discharged to home. Discharge stroke scale (mean 1.4, SD 2.2) approached significance (U=11, p=0.052) compared to the observation group, discharge location (chi 3.6, p=0.58) and discharge mRS did not (U=12, p=0.28).

Discussion:
Despite the low sample size, there was a trend toward significance in discharge NIHSS in favor of patients that were taken directly for ET. Further study regarding management of patients with low NIHSS and LVO is merited.
Abstract TP61: Could Fazekas Score Serve as a Predictor of Functional Outcomes in ELVO Patients Undergoing Mechanical Thrombectomy?
Authors: Hooper Destiny , McCane David , Lee Jason , Chiu David , Gadhia Rajan
Published: January 2019

Objective:
To evaluate the association between cerebral small vessel disease (CSVD) burden and degree of disability based on modified Rankin Score at 90 days, in patients presenting with emergent large vessel occlusion (ELVO) within 6 hours of last known well.

Methods:
We conducted a retrospective analysis of all patients presenting with an ELVO between May 2016 and July 2018. Patients with a TICI score of 2b or 3 were included and evaluated for CSVD burden as quantified by white matter hyperintensities in the non-affected hemisphere, on T2-FLAIR MRI using the Fazekas score (0-3). 90-day modified Rankin Scale scores (mRS, range 0-6) and patient information was collected from the Houston Methodist Hospital Outcomes Based Prospective Endpoints in Stroke (HOPES) registry.

Results:
138 patients were evaluated, TICI 2b/3 was achieved in 114, and 84 patients were able to undergo MRI. Factors excluding patients from MRI included: medical instability, implantable devices, and death. All 84 patients were successfully re-evaluated at 90 days and divided into two cohorts, functionally independent (mRS 0-2) and functional dependent/deceased (mRS 3-6). Among the 84 patients, 37 (mean age 69.4y [SD, 14.5]; 54% female) were determined to be functionally independent (14, mRS 0; 19, mRS 1; 4, mRS 2) with the average Fazekas score for each subclass and the cohort; (mRS 0, 1.07; mRS 1, 0.89; mRS 2, 1; 0.97). The remaining 47 patients (mean age 71.1y [SD, 15.8]; 55% female) were determined to have a significant degree of disability, or were deceased (8, mRS 3; 10, mRS 4; 15, mRS 5; 14, mRS 6). Average Fazekas scores were (mRS 3, 1.75; mRS 4, 1.90; mRS 5, 2.13; mRS 6, 1.93; 1.96). Potentially confounding variables, including the use of intravenous alteplase (78% vs. 76%), and door to groin puncture time (204m [SD, 74m] vs. 206m [SD, 54m]) were found to be non-significant contributors.

Conclusion:
Based on our analytical cohort of ELVO patients undergoing thrombectomy, CSVD burden, classified by Fazekas score on T2-FLAIR MRI, was found to correlate with worse 90-day mRS. These results may be explained by potentially poor cerebrovascular reserve and diminished collateral blood flow in patients with greater CVSD burden.
Abstract TP63: Hypoperfusion Volume Immediately After Endovascular Reperfusion Therapies: A Highly Accurate Early Predictor of Clinical Outcome After Recanalization
Authors: Garcia-Tornel Alvaro , Ribo Marc , Rodriguez-Luna David , Boned Sandra , Muchada Marian , Hernandez David , Pagola Jorge , Juega Jesus , Rodriguez Noelia , Tomasello Alejandro , Molina Carlos A , Rubiera Marta
Published: January 2019

Despite successful recanalization after endovascular treatment (EVT), a proportion of patients will not experience favorable outcome. We hypothesize that an early computed tomography perfusion (CTP-AFT) immediately after EVT may improve clinical outcome prediction.

Methods:
Consecutive patients with large vessel occlusion (LVO) who achieved partial (TICI 2a) or complete (TICI 2b/3) recanalization after EVT underwent CTP-AFT within 30 minutes. Different CTP parameters were measured with the Rapid software. Clinical data were recorded including dramatic recovery (DR: ≥8 points decrease from baseline NIHSS or NIHSS 0-2 at 24 hours)

Results:
Forty-six LVO were included, median baseline NIHSS was 18 (P25-75 13-22). Final recanalization grades were: TICI 2a, 5 patients (10.8%); TICI 2b, 19 (41.6%); and TICI 3, 22 (47.8%). Median 24h infarct volume was 7.5 cc (0-19). Median NIHSS decrease after 24h was 8 (1-16). Twenty-seven (58%) patients experienced DR. The volume with Tmax>6 seconds was the only CTP parameter that correlated with degree of recanalization: TICI 2a: 102cc (60-138); TICI 2b: 15cc (0-37); and TICI 3: 0cc (0-5), p<0.005. Lower Tmax>6s volume was associated with lower 24h-infarct volume (p<0.01), lower 24h NIHSS (p<0.01) and higher probability of DR (p<0.01). A ROC curve identified a Tmax>6s volume <5.5cc as the best cut-off point to predict DR (sens 73.7%, specif 70.4%, AUC 0.74). A logistic regression analysis adjusted by age, baseline NIHSS, ASPECTS, occlusion location and time and degree of recanalization showed that the only predictor of DR was a Tmax>6s volume <5.5cc (OR 21.6, CI 2.7-173.2, p<0.01).

Conclusion:
CTP maps performed immediately after EVT correlated with degree of recanalization. However, a low Tmax>6s volume predicted clinical outcome better than post-procedural TICI scores.
Abstract TP66: Optimizing CT Perfusion Thresholds for Identification of Ischemic Core in Hyperacute Stroke
Authors: Legault Catherine , Lansberg Maarten , Heit Jeremy , Albers Greg
Published: January 2019

Objective:
CT perfusion (CTP) estimates of infarct core are typically based on identifying regions of very low CBF (typically <30% of normal). These thresholds were optimized in patient populations that typically did not include patients scanned in the hyper-acute phase (< 60 minutes from stroke onset). Our aim was to determine if these thresholds apply to the hyper-acute phase.

Methods:
We conducted a retrospective review (2012 to 2017) of patients who met the following inclusion criteria: acute ischemic stroke due to an ICA or M1 occlusion, baseline CTP core (rCBF <30%) >20ml, and underwent endovascular therapy with TICI2b/3 reperfusion. Baseline ischemic core volumes were compared to final infarct volumes, measured on follow-up CT or MRI obtained >24 hours after stroke onset.

Results:
In 7 of 21 included patients, the ischemic core assessed on baseline CTP overestimated the final infarct by at least 10 ml. Five of these patients had witnessed onset and two were unwitnessed. The mean time from stroke onset to CTP was 0.96 hours for the seven patients with core overestimation and 3.4 hours in the 14 patients without core overcall. 6 of the 7 patients with core overcall had good outcomes (mRS of 0 to 2 at 90 days) compared to 4/14 without core overcall (p-value 0.01). For patients with core overcall, 2 additional CTP thresholds (rCBF <20% and <15%) were assessed. rCBF<20% produced core volume estimates that most closely matched the final infarct volume and did not overcall the final infarct volume. The median difference between baseline core and final infarct volume with the <20% threshold was 27 ml compared to 35 ml with <30%.

Conclusion:
A rCBF threshold of <30% tends to overestimate the ischemic core in patients imaged within 60 minutes of symptom onset. A threshold of <20% may be more appropriate for patients imaged in the hyper-acute phase of stroke.
Abstract TP67: Acute Blood Pressure Changes Aggravate Ischemic Lesion Growth After Large Vessel Occlusion
Authors: Jeong Han-Gil , Kim Beom Joon , Kim Hyeran , Jung Cheolkyu , Park Seong-Ho , Han Moon-Ku , Bae Hee-Joon
Published: January 2019

Backgrounds:
Penumbral perfusion dynamically changes with alterations of collateral flow and systemic blood pressure. We investigated the association between acute changes of systolic blood pressures and infarct growth within penumbral area.

Method:
We included ischemic stroke patients <24h after onset from Jan 2015 to Mar 2018 with the following criteria; initial NIHSS score ≥ 6-point, internal carotid or middle cerebral artery occlusion, no recanalization treatment, baseline penumbral volume >15 mL, and mismatch ratio >1.8. Perfusion quantification, 3D voxel-registration and image segmentation were done by Olea 3.0 and Analyze 12.0. Penumbra was defined as Tmax >6s lesion without infarct. Infarct growth within penumbra was defined by the infarct volume at a follow-up image. Hypoperfusion intensity ratio (HIR) was defined by the proportion of Tmax >10s within penumbra. Blood pressure change integral (BPCI) was defined by an integration of SBP initial - SBP trajectory over 24 h (Figure A). BP
dropmax
was defined by a maximum decrease of SBP between successive measurements.

Results:
Among 25 patients included (age, 71.3±13.5; male, 56%), median baseline NIHSS score was 13 (interquartile range [IQR], 8-18). Median volume of initial infarct within Tmax >6s was 16 mL (IQR, 6-58), penumbra was 80 mL (IQR, 29-138), HIR was 46% (IQR, 31-63), and infarct growth within penumbra was 26% (IQR, 11-48). Median BPCI was 157.4 mmHg·h (IQR, -76.8-566.2) and BP
dropmax
was 34 mmHg (IQR, 25-43). Median infarct growth was linearly associated with BPCI (β=0.022;
p
-value=0.03; Figure B), BP
dropmax
(β=0.77;
p
-value=0.048; Figure C), and HIR (β=0.69;
p
-value<0.01). High dichotomized BPCI and BP
dropmax
increased infarct growth rate (Figure D).

Conclusions:
Acute decline of systemic blood pressure may aggravates penumbral perfusion and thus increase infarct growth within penumbral tissue in emergent large vessel occlusion patients without recanalization.
Abstract TP68: Visual Assessment of Diffusion-Weighted-Imaging Infarct Volume Lacks Accuracy and Reliability
Authors: FAHED Robert , Khoury Naim , Guenego Adrien , Smajda Stanislas , Redjem Hocine , Ciccio Gabriele , Escalard Simon , Desilles Jean-Philippe , Mazighi Mikael , Blanc Raphael , Piotin Michel
Published: January 2019

Introduction:
Patients screened by MRI in the extended window (6-24hr) for mechanical thrombectomy (MT) might require the treating physician to visually estimate the DWI infarct volume at institutions where the RAPID software is not available. We aimed to assess the accuracy of DWI volume estimation compared with RAPID, as well as the interrater and intrarater agreement among physicians.

Methods:
Eighteen raters (all physicians involved on daily stroke management) assessed over two independent sessions 32 MR scans from a prospective MT database. Raters generated a visual estimate of the DWI infarct volume and were asked whether they would recommend MT for the assessed patient or not. Sensitivity, specificity and accuracy of the estimated volumes were compared with the available RAPID measurements for various volume cut-points. Interrater and intrarater agreement was measured using Fleiss’ kappa statistics.

Results:
Raters mean accuracy was <90% for all volume cut-points (
A
). Interrater agreement was below substantial for each DWI infarct volume cut-point (
B
). Intrarater agreement was substantial for 55-83% of raters, depending on the selected cut-point (
C
). Raters recommended MT for a mean of 77% of patients, including a mean of 56% of patients with an estimated infarct volume≥71ml.

Conclusion:
The visual assessment of DWI infarct volume lacks accuracy when RAPID measurements are the reference values. Less-than-substantial reproducibility of the volume estimates was demonstrated among physician raters who recommended MT for large infarct volumes despite the absence of rigorous scientific evidence.
Abstract TP69: Three-Phase Helical Computed Tomographic Angiography Perfusion Maps Predict Final Infarction in the Acute Ischemic Stroke Setting
Authors: McDougall Connor C , Maxwell Erin , Reaume Noaah , Gupta Sah Rani , d'Esterre Christopher D , Barber Philip A
Published: January 2019

Background:
Three-phase helical CTA can provide information on parenchymal hemodynamics distal to the occlusion, similar to CT perfusion (CTP). Helical CTA is a less expensive and a more widely available modality. We propose two perfusion map algorithms applied to three-phase helical CTA, providing optimal thresholds for prediction of final infarct volume

Methods:
44 stroke patients with occlusion visible on CTA were acutely imaged with three-phase CTA (temporal sampling was 8 seconds). MR diffusion weighted imaging (DWI) between 24-48 hours were used to measure final infarct volume. The three-phase helical CTA perfusion maps were denoted “Delay” and “Flow Average” (see Figure 1). The maps were filtered using a 3D Gaussian blurring technique. The maps were generated for all patients, then a receiver operating characteristic (ROC) curve was generated for the merged patient data, comparing infarct vs. normal tissue. Thresholds were determined using ROC curves by optimizing sensitivity and specificity.

Results:
The “Delay” map generated an ROC curve with an Area-Under-Curve (AUC) of statistical significance. The “Flow Average” map generated an ROC curve with an Area-Under-Curve (AUC) of statistical significance.

Conclusion:
The proposed “Delay” and “Flow Average” perfusion maps applied to three-phase CTA predicted final infarct volume to a high degree of accuracy, close to CTP accuracies from the literature. These results show the capability of three-phase helical CTA to generate quantitative perfusion maps which will be useful for non-tertiary centers that do not have access to expensive post-processing software.
Abstract TP7: Isolated Basal Ganglia Strokes Undergoing Thrombectomy Have High Rates of Good Clinical Outcomes
Authors: Bouslama Mehdi , Haussen Diogo , Grossberg Jonathan , Rodrigues Gabriel , Barreira Clara , Frankel Michael , Nogueira Raul
Published: January 2019

Background and Purpose:
Isolated basal ganglia strokes are thought to have worse clinical outcomes as compared to mixed and cortical infarcts.

Methods:
Review of a prospectively collected database of endovascular patients with anterior circulation Large vessel occlusion strokes from January 2014-June 2018. Only patients with an ASPECT score of 6 to 9 were included. Patients were dichotomized into 2 groups according to ASPECT region involvement: (i) isolated basal ganglia and (iBG) (ii) other stroke patterns. Baseline characteristics and Clinical outcomes were compared.

Results:
465 patients qualified for the study of which 324 (70%) were iBG strokes. Baseline characteristics were comparable between the 2 groups except for higher rates of hypertension (73.8%vs63.8%,p=0.03) and larger CTP core infarct (3.6 cc[0-13] vs 3[0-10.85], p<0.001) in the iBG group. There were no differences between groups in rates of successful reperfusion (mTICI 2b-3) (97.2% for iBG vs96.5%, p=0.66), any parenchymal hematomas (9.4%vs11.4%, p=0.49) and rates of good outcomes (mRS 0-2) (53.7% vs 50.4%, p=0.55). iBG patients had lower 90-day mortality rates (13.1%vs23.3, p=0.01). This persisted as non-statistically significant trend after adjusting for potential confounders (OR 0.54 95%CI [0.277-1.03],p=0.06)

Conclusions:
iBG strokes carry similar procedural and clinical outcomes as other stroke patterns with a trend towards lower mortality.
Abstract TP71: Time Burden of Perfusion Imaging
Authors: Shoirah Hazem , Stein Laura , Wheelwright Danielle , Mocco J , Tuhrim Stanley , Fifi Johanna
Published: January 2019

Background:
Perfusion imaging currently plays a crucial role in patient selection for endovascular thrombectomy (EVT) in the extended time window i.e. last known well (LKW) to treatment time is 6-24 hours. There is insufficient data about the treatment delays perfusion imaging may pose, especially in the real world.

Methods:
We retrospectively reviewed all patients who underwent EVT between August 2016 and July 2018 in a large tertiary network. The stroke triage algorithm in our network specifies CT perfusion (CTP) only for patients who present with LKW time 6-24 hours prior to presentation or when otherwise clinically indicated. Patients were classified in two cohorts based on the acquisition of CTP. We compared baseline characteristics, in addition to pre-specified time metrics of post-arrival workflow. Our aim was to compare hospital arrival to GP between CTP and non-CTP cohorts.

Results:
A total of 284 patients were included; 82 (28.9%) in the CTP and 202 (71.1%) in the non-CTP cohort. Patients in the CTP cohort had longer time from LKW to hospital arrival (521.3 ±434.2 mins vs 249.7 ±233.9 mins, p = 0.0001). There was no difference between the cohorts in EMS arrival versus transfers from other hospitals, or time from arrival to CT. More patients had undergone CTA at the receiving hospital in the CTP cohort (18.9% difference, 95% CI 6.6-29.7, p = 0.003). Similarly, image acquisition time was longer in the CTP cohort (33 ±46mins vs 6 ±21 mins, p = 0.0001). In the CTP cohort, 90.2% (95% CI 81.7-95.7) had Alberta Stroke Program Early CT Score (ASPECTS) ≥6. Time from hospital arrival to groin puncture (GP) was longer in the CTP cohort (126.6 ±121.4 vs 88.3 ±111.0, p = 0.01).

Conclusions:
While CTP was a determining factor for patient selection in extended time window trials, real world practice is hindered by longer image acquisition and interpretation times of CTP, resulting in significant treatment delay. The majority of patients undergoing EVT after CTP evaluation, would be candidates for treatment based on CT criteria for selection in less than 6h window (i.e. ASPECTS ≥6). Future studies should evaluate using CT for patient selection in extended time window, reserving CTP only for patients who would otherwise be excluded.