bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WP419: Visualization and Evaluation of Human Lenticulostriate Arteries Using High-resolution Black-blood T1-weighted Turbo-spin Echo (TSE) at 3T and 7T
Authors: Ma Samantha J , Yan Lirong , Wang Danny J
Published: October 2018

Purpose:
Cerebral small vessel disease (SVD) leads to cognitive decline and is the most common vascular cause of dementia. Small arteries, particularly the lenticulostriate arteries (LSAs), are known to be involved in silent strokes. We aim to image the LSAs using a high-resolution 3D black blood T1 weighted (T1w) turbo-spin echo (TSE) sequence with variable flip angles (VFA) at both 3T and 7T.

Methods:
Four healthy volunteers (1 female, 26±3 years) were scanned on both Siemens 3T Prisma and 7T Terra MRI systems using a 32-channel head coil. A 3D T1w TSE sequence with VFA was chosen for small vessel imaging with inherent excellent contrast between vessels and tissue due to good blood suppression properties. Black blood images were acquired with optimized imaging parameters at 3T (voxel size = 0.26x0.26x0.5 mm
3
interpolated, slices=166, TE/TR = 12/1000 ms, ETL=41, scan time = 9:05 min) and 7T (voxel size = 0.5 mm
3
isotropic, slices=288, TE/TR = 13/1430 ms, ETL = 40, scan time = 11:55 min). Contrast to noise ratio (CNR) was calculated to compare image quality between 3T and 7T.

Results and Discussion:
Fig. 1 displays the LSAs using minimum intensity projection across 25 mm slices from a subject at 3T and 7T. Improved delineation of LSAs, especially distal regions, can be appreciated at 7T compared to 3T. Comparison of CNR for blood in the LSAs vs. the adjacent white matter between 3T and 7T (CNR: 9.1 vs. 15.5, 6.7 vs. 15.4, and 4.3 vs. 8.9 for the stem, middle, and distal regions, respectively) further demonstrated that LSAs imaged at 7T have better contrast in general and especially in the distal regions as noted by the colored arrows.

Conclusion:
This preliminary study demonstrated the feasibility for visualizing LSAs in the human brain using high-resolution T1w TSE at 3T and 7T. Specifically, TSE at 7T provides better delineation of LSAs with better contrast between vessels and tissue. Our findings suggest this 7T TSE technique could be a promising imaging marker of cerebral small vessel diseases.
Abstract WP42: Factors Affecting Care Withdrawal After Acute Ischemic Stroke Treatment: A Comparison Between Standardized Treatment Modalities
Authors: Saleem Muhammad A , Shaikh Suhail , Mohsin Saad , Khan Safi U , Potter Kelly , Horton James
Published: October 2018

Background:
A higher percentage of acute ischemic stroke patients resort to care withdrawal after standardized treatments have been instituted.

Objective:
We aimed at identifying the factors responsible for care withdrawal among patients with acute ischemic stroke receiving various standardized treatment modalities in a clinical trial setting.

Design and Methods:
We analyzed data from Interventional Management of Stroke (IMS) III; a multicenter, double-blinded, randomized clinical trial. The patients who had resorted to care withdrawal during the course of trial were identified and divided into three groups based on the type of acute stroke treatment: IV-thrombolysis only, IA-thrombectomy only, and combined IA-thrombectomy with IA-thrombolysis. The three groups were compared for their baseline characteristics and major outcomes such as neurologic deterioration within 24-hours of randomization, hemorrhagic complications, and length of hospital stay. Bonferroni adjusted p-value of 0.016 was considered significant.

Results:
Out of 123 patients who had withdrawal of care in the IMS-III trial, 47 (38.2%) received IV-thrombolysis only, 25 (20.3) received IA-thrombectomy only, and 51 (41.5) received combined IA-thrombectomy and IA-thrombolysis. The three groups were similar for age, gender, baseline NIHSS score, stroke etiology, time from stroke onset to randomization, and status prior to stroke. Patients who received IV-thrombolysis only had significantly more mother ship transfers followed by IA-thrombectomy only and combined treatment groups (89.4 vs 68.0 vs 76.5; p=0.006). The combined treatment group had significantly greater rate of asymptomatic intracranial hemorrhage (ICH) followed by IA-thrombectomy only and IV-thrombolysis only treatment arms (41.2% vs 28% vs. 14.9%; p=0.015). Higher rates of patients undergoing IV-thrombolysis only treatment resorted to full palliative care as compared to the other two groups (p=0.07). The three groups did not differ in their rates of neurologic deterioration and length of hospital stay (p=0.84 and p=0.42 respectively).

Conclusions:
Asymptomatic ICH is a major determinant of care withdrawal after treatment of acute ischemic stroke with combined IA-thrombolysis and IA-thrombectomy.
Abstract WP426: Does Intracerebral Hemorrhage in Brain Arteriovenous Malformation Share Genetic Risk Factors With Primary Intracerebral Hemorrhage?
Authors: Nelson Jeffrey , Bendjilali Nasrine , Weinsheimer Shantel M , McCulloch Charles E , Ko Nerissa U , Zaroff Jonathan G , Lawton Michael T , Pawlikowska Ludmila , Kim Helen
Published: October 2018

Introduction:
Sporadic brain arteriovenous malformations (BAVMs) are rare vascular lesions that are a major cause of intracerebral hemorrhage (ICH) in younger persons. Genetic risk factors for ICH in BAVM have not been firmly established. Late-onset primary ICH is more common, with several candidate loci reported. It is not known whether genetic variants associated with primary ICH are also associated with BAVM ICH.

Methods:
We performed a case-control study including 138 Caucasian cases with BAVM ICH and 504 healthy Caucasian controls. We tested 8 candidate variants reported for primary ICH in or near 7 genes (
ACE
,
APOE
,
COL4A2
,
MTHFR
,
PMF1
,
SLC25A44
, and
TRHDE)
. Genotypes were extracted from existing Affymetrix genome-wide array data or from PCR-based assays for 3 variants. Logistic regression was used to determine whether candidate variants (or, when unavailable, proxy variants in high linkage disequilibrium) were associated with BAVM ICH, assuming an additive genetic model and adjusting for age and sex. We considered variants statistically significant if P<0.05 and in the same direction of association (risk allele) as reported for primary ICH.

Results:
No statistically significant associations were observed between BAVM ICH and genetic variants implicated in primary ICH. The strongest finding was for rs9521733 in
COL4A2
(OR=1.26, P=0.13). Further evaluation of the
COL4A2
+/- 5kb locus revealed nine variants associated with BAVM ICH; the strongest association was with rs9521692 (OR=0.49, P=0.001).

Conclusions:
Specific candidate variants implicated in primary ICH were not significantly associated with BAVM ICH, suggesting that genetic risk factors may differ between primary and BAVM ICH. The
COL4A2
locus may contain additional variants associated with BAVM ICH but will require larger studies to validate findings.
Abstract WP53: Improved Prediction of the Final Infarct From Acute Stroke Neuroimaging Using Deep Learning
Authors: Niu Yilin , Gong Enhao , Xu Junshen , Pauly John , Zaharchuk Greg
Published: October 2018

Introduction:
Predicting the final infarct for acute stroke from acute imaging is valuable for triage and prognosis (1). We developed and tested a Deep Learning model, based on a 3D Convolutional Neural Network (CNN) architecture, to predict the lesion based on a 30-90 day scan from acute images.

Method:
The model has 3 advantages compared with traditional CNN (Figure):

1. 3D CNN more efficiently utilizes spatial information across multiple slices.

2. Patches instead of entire images are used as inputs. With a patch-based approach, we avoid the impact of minimally-relevant information from distant voxels. Training on patches also prevents over-fitting by augmenting each image into thousands of samples.

3. Multi-scale structure is used by processing patches with different resolutions. Segmentation based on a single scale image cannot fully capture varying local information and may miss contextual information. We use two scales of patches to learn both local and global context.

The model was trained and tested using the MICCAI ISLES 2017 challenge dataset (2), which consists of 43 cases with acute ADC and PWI maps paired with annotated final infarct segmentations at day 30-90. Dice score coefficient (DSC) and AUC for segmentation were used as quality metrics.

Results:
Using 70% of dataset for training and rest for testing, we achieved a DSC of 0.43±0.18 and 0.90 for AUC. As a comparison, the winning entry for the ISLES 2016 challenge achieved a DSC of 0.31, while several previous research works (threshold based, cluster based, Generalized Linear Model, etc.) achieve up to 0.84 AUC (1).

Conclusion:
We demonstrate that a deep learning approach can predict the final stroke lesion based on acute diffusion and perfusion neuroimaging data. Given its inherent speed, high performance, and capacity for further training, deep learning is a promising method for stroke lesion outcome prediction.

References

1. Rekik et al., Neuroimage Clin 2012;

2.
http://www.isles-challenge.org/
Abstract WP54: Early Alterations in Neurite Orientation Dispersion and Density After Acute Ischemic Stroke
Authors: Wu Ona , Etherton Mark R , Lauer Arne , Boulouis Gregoire , Giese Anne-Katrin , Mills Brittany B , Cloonan Lisa , Donahue Kathleen L , Copen William A , Schaefer Pamela W , Rost Natalia S
Published: October 2018

Background:
Advanced diffusion imaging approaches that model intracellular and extracellular diffusion components such as neurite orientation dispersion and density imaging (NODDI) may provide additional insight into evolution of acute ischemic stroke (AIS) injury over standard diffusion tensor imaging approaches (DTI).

Methods:
NODDI was acquired at discharge in a prospective study of acute ischemic stroke patients with advanced white matter disease (N=36). Neurite density (ND), and orientation dispersion (OD) were calculated along with model-free diffusion parameters: mean kurtosis (MK), axial kurtosis (AK), radial kurtosis (RK), mean diffusivity (MD), axial diffusivity (AD), radial diffusivity (RD) and fractional anisotropy (FA). Follow-up (FU) infarct volumes were drawn on discharge FLAIR. MD, AD, RD, FA, MK, AK, RK, OD and ND values were compared (1-way ANOVA) in infarct core (abnormal acute DWI), Growth (normal acute DWI, abnormal FU) and normal contralateral gray matter (nGM) and white matter (nWM).

Results:
Patient characteristics were: mean±SD age 69±10 y, median [IQR] initial NIH SS score 6 [3-11], time-to-acute MRI 7.3±5.3 h, time-to-FU MRI 2.8±1.2 days, acute DWI lesion 3.1 [0.5-18.8] cm
3
, FU lesion 8.1 [1.2-45.4] cm
3
and 61% men. Figure A shows examples of maps from a single subject. Core and growth values differed significantly (P<0.0001) from nGM and nWM for MD AD, RD, FA, MK, AK, RK, OD and ND. Within the lesion MD, AD, RD and FA were decreased while MK, AK and RK were increased. OD and ND were also increased within the lesion.

Discussion:
Increased OD is expected with tissue infarction due to loss of structural integrity. In contrast, increased ND in the subacute time-frame is paradoxical. One possible mechanism could be that hyperacute ischemia-induced cellular swelling increases tortuosity of water diffusion paths, imposing direction-dependent restrictions upon diffusion, increasing intracellular and extracellular diffusion.
Abstract WP58: Enhancement of Acute Stroke Lesions on Non-Contrast CT Using Relative Signal Intensity Maps
Authors: Srivatsan Aditya , Christensen Soren , Lansberg Maarten G
Published: October 2018

Purpose:
Early ischemic changes on non-contrast CT (NCCT) are often subtle, which makes the detection of early infarct signs challenging. To accentuate early ischemic changes and facilitate the interpretation of the NCCT scan, we aimed to develop a novel, automated post-processing technique that generates NCCT ratio-maps in relative Hounsfield Units to highlight regions that are hypodense.

Materials and Methods:
Relative signal intensities were calculated by dividing the signal intensity of each voxel by the signal intensity of a corresponding region in the contralateral hemisphere. Relative signal intensities were visualized as a heat map ranging from dark blue (for ratios equal to 0.95) to red (for ratios less than or equal to .8). The heat map was overlaid on the NCCT for visual clarity (figure). Voxels with a ratio below 0.95 were designated as infarct. The NCCT ratio-map technique was tested on the first six cases enrolled in the CRISP study at a single center and were compared to the baseline CT perfusion maps and the day 5 follow-up FLAIR scan.

Results:
The median time from symptom onset to CT was 5.2 hours (IQR 3.8-6.6), median NIHSS was 16, and all patients achieved TICI 2b or 3 reperfusion. In all six cases, the territory of early infarct signs on the NCCT ratio-map was more extensive than on the conventional NCCT scan, and corresponded with the region of low CBF on the baseline CT perfusion map and the final infarct on the day 5 FLAIR (figure). In 3 cases, the CT ratio-map identified ischemic tissue that an experienced vascular neurologist did not identify during prospective review of the conventional NCCT. Limitations included false positives on the ratio-map due to asymmetric CSF and white matter disease.

Conclusion:
The NCCT ratio-map markedly increases sensitivity for detection of early infarct signs. This novel method will assist clinicians in the interpretation of the NCCT and serves as a major milestone towards fully automated CT volumetric lesion quantification.
Abstract WP64: Ultra-early Treatment With IV tPA for Large Artery Occlusion Improves Recanalization Rates and Clinical Outcomes
Authors: Di Lorenzo Rodica , Sheikhi Lila , Patel Payal , Donohue Megan , Wisco Dolora , Uchino Ken , Hussain Shazam M
Published: October 2018

Introduction:
Emergent large vessel occlusions (ELVO) cause approximately 45% of ischemic strokes and are associated with poor outcomes. With the advent of intra-arterial therapy (IAT), the role of IV tPA for treatment of ELVO stroke has been questioned. We hypothesized that ultra-early treatment with IV tPA for ELVO stroke improves recanalization rates and clinical outcomes.

Methods:
Retrospective chart review was performed of patients who received IV tPA for ELVO stroke and were treated at our institution between January 2013 and December 2016. We compared patients treated with IV tPA within 60 minutes of being last known well (LKW) with patients treated beyond 60 minutes in regards to (1) recanalization, defined as complete reconstitution of blood flow on arterial imaging, (2) early neurological improvement, defined as National Institute of Health Stroke Scale (NIHSS) of ≤ 1 or decline by ≥ 5 points at 24 hour post-IV tPA, (3) 90 day functional status measured by modified Rankin Scale (mRS), and (4) mortality at 90 days.

Results:
Of 201 patients with ELVO ischemic stroke, 158 patients had adequate post-IV tPA arterial imaging. 25 patients were treated within 60 minutes of LKW, while the remaining 133 patients were treated beyond 60 minutes. Groups did not differ in regards to age, gender, cardiovascular risk factors, NIHSS on presentation, baseline mRS, or occlusion location. The percentage of patients who underwent IAT for persistent occlusion did not differ between the two groups. Recanalization of arterial occlusion following IV tPA without IAT, early neurological improvement, survival, and good clinical outcome were more frequent in patients who received IV tPA within 60 minutes of LKW.

Conclusion:
Our data suggest that ultra-early IV tPA administration for ELVO stroke increases the chance of recanalization and leads to improved clinical outcomes. Prospective studies are needed to verify our findings.
Abstract WP68: The Risk of Hemorrhagic Transformation After Thrombolysis for Acute Ischemic Stroke in Chinese vs. North American Patients: A Comparative Study
Authors: Xu Xiaomeng , Wang Deren , Wang Fang , Liu Xinfeng , Selim Magdy
Published: October 2018

Introduction:
There is a widespread belief that Asian population is more susceptible to bleeding, which limits the use of t-PA in patients with ischemic stroke (AIS) in China because of the fear of hemorrhagic transformation (HT). However, this has not been examined in clinical practice. We undertook the current study to compare the incidence of symptomatic HT (SHT) among thrombolysis-treated AIS patients in 2 academic institutions in China and United States.

Methods:
We compared the clinical and radiological features of 191 consecutive patients treated with IV t-PA within 4.5h of onset ± endovascular therapy from an American (ASC; n = 86) and a Chinese stroke centers (CSC; n = 105). SHT was defined using various definitions based on the NINDS t-PA, ECASS-2, and a modified version of SITS-MOST study (mSITS-MOST) criteria. We used penalized logistic regression to adjust for confounding variables and to identify predictors of SHT.

Results:
ASC patients were older; had higher prevalence of women; diabetes, hypertension, and cardiac disease; and use of anti-thrombotics and statins. They also had higher baseline serum glucose, shorter onset-to-treatment time, and fewer endovascular interventions. However, none of these emerged as independent predictor of SHT. On logistic regression, there was a trend for an association between baseline serum glucose and the risk of SHT in the ACS population (p=0.056), but not the CSC cohort (p=0.119). The rates of SHT were higher in the ASC cohort compared to the CSC cohort, as follows: 18.6% vs. 13.9% based on NINDS definition of SHT; 15.1% vs. 11.9% based on ECASS-2; and 11.6% vs. 5.0% based on mSITS-MOST. Despite higher rates of SHT in the ASC, fatal HT occurred in only 5.9% of cases vs. 7.9% in CSC cases. However, none of these differences were significant (unadjusted and adjusted p values >0.05).

Conclusions:
Contrary to perceived notions that HT is more common in AIS Chinese patients, we found that the rate of SHT after t-PA is equivalent between Chinese and North American stroke patients. Our findings require further confirmation in a larger and multi-institutional cohort of patients. Similar results could have a positive impact on increased use of t-PA for AIS in China and other Asian countries.
Abstract WP70: Aptamer Inhibition of Von Willebrand Factor Ameliorates Ischemic Stroke Burden in a Murine Model of Thromboembolic Stroke
Authors: Dornbos David L , Wheeler Debra G , Harris Hallie , Gnyawali Surya , Huttinger Allyson , Talentino Spencer , Venetos Nicholas , Musgrave Nicholas , Jones Cheyenne , Wilson Jenna , Bratton Camille , Carlisle Kendyl , Zweier Jay L , Sen Chandan K , Rink Cameron , Nimjee Shahid M
Published: October 2018

Introduction:
While recombinant tissue plasminogen activator (rTPA) is the mainstay of ischemic stroke treatment, recanalization is only achieved in 25-50% of patients. With a significant risk of intracranial hemorrhage, its use has been limited to within 4.5 hours of symptom onset. Previous work has demonstrated that aptamer inhibition of Von Willebrand Factor (VWF) effectively restores reperfusion following murine carotid artery occlusion.

Hypothesis:
We tested the hypothesis that VWF aptamer would promote recanalization following thrombotic middle cerebral artery (MCA) occlusion, ameliorating stroke burden with greater efficacy than rTPA.

Methods:
Adult wild-type (C57BL/6J) mice were anesthetized, and the right carotid artery was exposed. A 32-gauge intracranial catheter was advanced within the carotid artery. Murine autologous blood was then mixed with 10 μL 0.9% normal saline and 1 μL murine thrombin and was allowed to stabilize at 37 °C for 15 minutes, after which it was injected through the catheter into the MCA. Laser-doppler flowmetry monitoring measured decreased flow following injection of the embolus. Treatment (vehicle, platelet binding buffer, n=5; VWF aptamer, n=6; rTPA, n=7) was initiated 20 minutes after thrombus injection. An MRI was obtained at 24 hours to assess ischemic stroke volumes.

Results:
None of the mice receiving rTPA survived to 24 hours, while all mice treated with VWF aptamer and vehicle survived to 24 hours and received an MRI. Ischemic stroke volume was significantly decreased in mice treated with VWF aptamer (5.49 ± 5.01 mm
3
) compared to vehicle (35.34 ± 9.57 mm
3
, p<0.05)(Figure 1). No evidence of intracranial hemorrhage was identified in either cohort.

Conclusions:
Treatment with VWF aptamer decreases stroke volume on MRI in a murine model of embolic stroke without the risk of hemorrhagic conversion seen in patients treated rTPA. VWF inhibition represents a promising therapy in stroke treatment.
Abstract WP75: Enhancement of Disturbed Flow is Involved in Recanalization After Complete Endovascular Coil Embolization of Internal Carotid Artery-Posterior Communicating Artery Aneurysms
Authors: FUKUDA Shunichi , Shimogonya Yuji , Imamura Hirotoshi , Matsui Yuichi , Yomemoto Naohiro , Sakai Nobuyuki
Published: October 2018

Background and purpose:
Although it is thought that hemodynamics is closely involved in recanalization after endovascular coil embolization of cerebral aneurysms, details are still not clear. Using computational flow dynamic (CFD) analysis, the aim of this study was to identify hemodynamic predictors specific to recanalization after complete coil embolization.

Methods:
We used patient-specific arterial geometries of 14 internal carotid artery-posterior communicating artery (ICPC) aneurysms after coil embolization. Pulsatile blood flow was simulated using ANSYS-CFX, based on the Navier-Stokes equations for incompressible fluid. As the pulsatile inlet boundary condition, we used a typical flow velocity waveform of internal carotid artery that was scaled based on the patient-specific mean velocity. In order to eliminate the influence due to aneurysm size between both groups, multivariate logistic regression analysis was performed using aneurysm size and each hemodynamic metric as independent variables to find hemodynamic predictors for recanalization after coil embolization.

Results:
With a follow-up of >1 year, 6 aneurysms were recanalized, and 8 cases were stable. Significant hemodynamic risk factors specific to recanalization were high values of metrics in association with disturbed flow, i.e. oscillatory shear index (OSI) [odds ratio (OR), 0.00115; 95% confidence interval (CI), 0.00102-0.00144;
p
= 0.017] and normalized transverse WSS (NtransWSS) (OR, 0.00103; 95%CI, 0.0010-0.00179;
p
= 0.043), but not flow rate of parent artery, aneurysmal mean velocity, or WSS magnitude-based metrics, including WSS and normalized WSS.

Conclusions:
These data suggest that enhanced disturbed flow plays a central role in recanalization after complete coil embolization of ICPC aneurysms. Imaging examinations at shorter intervals may be necessary if strong disturbed flow is observed in the aneurysm before surgery.
Abstract WP80: Microsurgical Clipping of Ophthalmic Artery Aneurysms:Surgical Results and Visual Outcomes With 208 Aneurysms
Authors: Kamide Tomoya , Tabani Halima , Burkhardt Jan-Karl , Lawton Michael T
Published: October 2018

Background:
While most paraclinoid aneurysms can be clipped with excellent results, new visual deficits postoperatively are a concern. Meanwhile, new technology like flow diverters has increased the popularity of endovascular therapy. However, endovascular treatment of paraclinoid aneurysms is not without procedural risks, is associated with higher rates of incomplete aneurysm occlusion and recurrence, and may not address optic nerve compression symptoms that surgical debulking can.

Objective:
The increasingly endovascular management of paraclinoid aneurysms should be justified by comparisons to surgical benchmarks. Therefore, we aimed to define patient, visual, and aneurysm outcomes in the most common paraclinoid aneurysm: ophthalmic artery (OphA) aneurysms.

Methods:
Results from microsurgical clipping of 208 OphA aneurysms in 198 patients were retrospectively reviewed. Patient demographics, aneurysm morphology (size, calcification, etc), clinical characteristics and patient outcomes were recorded and analyzed.

Results:
Despite 20% of these aneurysms being large or giant in size, complete aneurysm occlusion was accomplished in 91% of aneurysms, with patency of OphA preserved in 99.5%. Aneurysm recurrence rate was 3.1% and retreatment rate was 0%. Good outcomes (modified Rankin Scale score: 0-2) were observed in 96.2% of patients overall, and in all 156 patients with unruptured aneurysms. New visual field defects (hemianopsia or quadrantanopsia) were observed in 3.8% (8 patients), decreased visual acuity in 2.4% (5 patients), and monocular blindness in 4.3% (9 patients). Vision improved in 9 of 17 patients (52.9%) with preoperative deficits.

Conclusion:
The most important risk associated with clipping OphA aneurysms is a new visual deficit. Meticulous microsurgical technique is necessary during anterior clinoidectomy, aneurysm dissection, and clip application to optimize visual outcomes. As the results of endovascular therapy and specifically flow diverters become known, they warrant comparison with these surgical benchmarks to determine best practices.
Abstract WP82: Screening Individuals With Intracranial Aneurysms for Abdominal Aortic Aneurysm - the Brain and Aortic Aneurysm Screening (BAAS) Study
Authors: Lescure Tyler N , Rosenbaum Blake L , Rahman Shareena A , Green Ilana E , Berthaud Jimmy V , Carrera Joseph F , Thomas Matthew J , Barrett Kevin M , Southerland Andrew M , Meschia James F , Worrall Bradford B
Published: October 2018

Introduction:
Aneurysm rupture is associated with high mortality and morbidity, including both intracranial aneurysms (IA) and abdominal aortic aneurysms (AAA). Despite potential preemptive treatment in those identified prior to IA or AAA rupture, the evidence for whom to screen remains limited. IA and AAA share both environmental and genetic risk, and prior cost-effectiveness models suggest the potential efficacy of screening in these high-risk individuals. We hypothesized that reciprocal screening in those presenting with IA for AAA would yield positive results.

Methods:
The BAAS study sought to establish the co-prevalence of IA and AAA. In this arm of BAAS, we recruited patients presenting with IA and screened them for AAA using abdominal ultrasound (aU/S) at two sites: Mayo Clinic and the University of Virginia (UVA). All participants underwent a detailed interview to collect demographic, radiographic, and clinical data. At UVA, participants also received genetic counseling.

Results:
At Mayo Clinic, we enrolled and screened 81 consecutive patients with aSAH (3 patients with known AAA were excluded) with 3 (3.7%) positive aU/S for AAA. At UVA, we recruited 195 consecutive patients presenting with ruptured or unruptured IA and completed screening aU/S in 178 (93%). Only one (0.6%) had an AAA.

Conclusion:
The lower positive screening at UVA (0.6%) which enrolled both ruptured and unruptured IA compared to the 3.7% positive results at Mayo suggests that future efforts to identify who with IA might benefit from AAA screening should focus on those with aneurysmal subarachnoid hemorrhage (aSAH).
Abstract WP84: National Inpatient Sample Analysis of Unruptured Intracranial Aneurysms: Trends in Treatment and In-Hospital Complications 2002-2014
Authors: Salahuddin Hisham , Siddiqui Nauman , Zaidi Syed F , Jumaa Mouhammad
Published: October 2018

Introduction:
Our objective was to determine trends in treatment preference and in-hospital complications of patients undergoing elective and non-elective treatment for unruptured intracranial aneurysms (UIA) in the United States over a 12-year period.

Methods:
We identified patients from the National Inpatient Sample database who were electively or non-electively admitted to the hospital with a primary ICD 9 diagnosis of unruptured intracranial aneurysm (437.3) from 2002 to 2014. We identified the method of treatment (surgical clipping or endovascular coiling) and studied in-hospital complications.

Results:
We identified 111,811 patients with UIAs between 2002 to 2014. Of these patients, 89,599 (80.1%) of patients were electively admitted. Approximately 47% (42,112) of patients underwent surgical clipping, while 53% (47,487) of patients underwent endovascular coiling. Of 22,212 patients who were admitted non-electively, 38.6% (8570) patients underwent surgical clipping and 61.4% (13,642) underwent endovascular coiling. There was a significantly higher proportion of patients treated with endovascular coiling for non-electively admitted patients as compared to elective admissions.

For electively treated UIAs there were no significant differences in in-hospital mortality between the two treatment groups. Iatrogenic cerebrovascular accidents and intracranial hemorrhage were significantly less common in the endovascular coiling group throughout the study period.

For non-electively treated UIAs, there was no significant difference in hospital mortality over the 12-year period. The rate of iatrogenic cerebrovascular accidents was generally lower for endovascular coiling with the exception of 2003. Endovascular coiling resulted in a significantly lower rate of iatrogenic cerebrovascular accidents in 2004 and 2008-2012. Intracranial hemorrhage was significantly less common in the endovascular group in 2004 and 2008-2014.

Conclusions:
Endovascular therapy has lower rates of in-hospital iatrogenic cerebrovascular accidents, and similar rates of mortality. The rate of endovascular and surgical therapies has plateaued since approximately 2005.
Abstract WP87: Remote Pre-, Per, and Postconditioning of Cerebral Ischemia in Preclinical Models: Comprehension of Mechanisms for Translation to Clinical Trials
Authors: Thakkar Mrugesh , Chen Gangling , Doré Sylvain
Published: October 2018

Background:
Limb remote ischemic conditioning is a series of mechanical interruptions that alters the hydrodynamics of reperfusion of a remote, distal organ or limb rendering a significantly reduced infarct size. Here, we are providing a first, extensive, and technical review of mechanisms involved in remote pre, per, and postconditioning of stroke in preclinical models to facilitate the translation to a clinical protocol.

Methods:
Three databases were searched using these terms: “remote,” “condition(ing),” “pre,” “per,” “post,” “ischemic,” “stroke,” “brain,” “cerebral,” “stroke,” “rat(s),” “mouse,” “mice,” and “outcomes.” An extensive analysis of each article’s experimental research protocol design was done to gather both quantitative and qualitative data to compose an exhaustive list of mechanisms involved in remote ischemic conditioning. In addition, recommendations are provided on how to improve the studies to maximize clinical application.

Results:
We identified 1,153 articles of which 125 were reviewed in depth to show a decreased infarction size, cerebral edema, and neurologic deficits. Studies showed the following: a range of significantly decreased infarct volume (43 to 26%, p<0.05), reduced cerebral edema (84 to 81%, p<0.05), and most studies included a decreased neurologic deficit test (p<0.05). Of interest, studies revealed the therapeutic window for conditioning can be as late as 3h after reperfusion. The figure depicts systemic and molecular pathways involved.

Conclusion:
As an attractive low-cost, low-risk, and easily-operated therapy, the application of remote ischemic conditioning can be applied to cerebral ischemia in the clinical setting. When carrying out experimental studies, such detailed mechanisms of action and potential biomarkers should be integrated into clinical trial designs to ensure proper translation and ultimately therapeutic efficacy.
Abstract WP91: Chemogenetic Activation of Cholinergic Neurons in the Mouse Nucleus Basalis During Stroke Recovery
Authors: Becker April M , Betz Dene M , Goldberg Mark P
Published: October 2018

The cholinergic projection neurons of the nucleus basalis (NB) mediate learning and cortical plasticity. Artificial activation of NB during tone presentation has been shown to increase the representation of paired frequencies in the auditory cortex, and when NB is stimulated during motor behavior it increases task-relevant representations of the cortical motor map. NB activation during successful movements also increases performance after training. We tested the hypothesis that increased activity of NB neurons during rehabilitative motions can improve the extent of stroke recovery. We injected a cre-dependent Gq DREADD (Designer Receptors Activated by Designer Drugs) or control GFP virus bilaterally into the nucleus basalis of transgenic C57/BL6 mice expressing cre in cholinergic neurons. Photothrombotic stroke was then targeted to sensorimotor representations of the forelimb, and performance in the automated reach task used to assess functional deficits and recovery. From weeks 2-6 after stroke, mice received and injection of the DREADD-activating drug clozapine-N-oxide before rehabilitative sessions, and final drug-free performance was assessed at week 7. We see a biologically significant trend toward greater improvement at week 7 after stroke in the average performance of DREADD-injected mice compared to the control group. Methods for improved replication and increasing effect size will be discussed.
Abstract WP95: Cortical Neurogenesis in the Juvenile Brain Following Ischemic Stroke
Authors: Rodgers Krista M , Patsos Olivia P , Yonchek Joan C , Traystman Richard J , Macklin Wendy B , Herson Paco S
Published: October 2018

Introduction:
Ischemic stroke is a common injury of the CNS, resulting in neuronal death and impaired brain function, likely contributing to long-term disability in adults. The lack of pharmacological interventions for patients with impairments in stroked-injured brain regions signals need for new strategies aimed at restoring function to the post-ischemic brain. Neurogenesis involves the generation of newborn neurons and occurs throughout life in the mammalian brain, making it an appealing target for potential interventions to enhance post-stroke recovery. Stroke-induced neurogenesis in adult mice has been reported to involve vigorous proliferation and migration of neural progenitors, but most cells die rapidly and fail to repopulate damaged areas. We tested the hypothesis that cortical neurogenesis is enhanced in the immature brain.

Methods:
We compared juvenile (P20-25) and adult (P60) mice following 45min transient middle cerebral artery occlusion (MCAo). Neurogenesis was examined with immunohistochemistry, including bromodeoxyuridine (BrdU) labeling and cell-type specific markers at 24hr, 7d, and 30d. Post-ischemic neurobehavioral outcomes were assessed at baseline, 7d, and 30d.

Results and Conclusions:
Despite extensive neuronal cell death in the injured cortex of both age groups at acute time points (24hr and 7d), a remarkable regenerative response was found at 30d, with substantially more mature newborn neurons found in juveniles than adults. Behavioral tests revealed reductions in affected limb use and general motor functioning in MCAo-injured adults and juveniles at 7d, with only the juveniles returning to near baseline levels on most tasks by 30d. When neurogenesis was arrested with ionizing radiation, 30d behavioral recovery was lost. Evidence of cortical neurogenesis is scarce; however, we discovered that newborn neurons in the developing brain not only survive, but post-stroke behavioral outcomes are only improved in non-irradiated juvenile mice. These results provide support for cortical neurogenesis, neuronal replacement, and enhanced functional recovery following stroke, which may have major biological significance for endogenous recovery and repair following CNS damage.
Abstract WP97: A Novel Behavioral Neuroscore Survey Improves Characterization of Experimental Ischemic Stroke in Mice
Authors: Goodman Joseph M , Maniskas Michael , Salmeron Kathleen , Edwards Danielle , Grohs Gillian , Roberts Jill , Fraser Justin , Bix Gregory
Published: October 2018

Stroke remains the fifth leading cause of death in the U.S, highlighting a pressing need to improve the translatability of experimental stroke studies. To more reproducibly mimic clinical assessments in animal stroke models, we developed and tested a novel behavioral Neuroscore assessment designed to serve as an experimental analog to the National Institutes of Health Stroke Scale. Our Neuroscore measured discrepancies in visual, sensorimotor, and fatigue-related performances over five tasks while generating a numerical score ranging from zero to eleven (zero representing normal). Once administered, the resulting score was used as a predictor for determining the severity of stroke. The Neuroscore was designed and administered on C57Bl/6 mice. To mimic the NIH Stroke Scale, the Neuroscore used similar, but mouse-appropriate components over five-minute administrations: Level of Consciousness, Gaze and Visual Field, Sensory-Limb testing in response to stimuli, and a motor component assessed with Paralysis-Paw Hang tasks. Inter-rater reliability assessments were also performed. For this initial experiment, the MCAo model (tandem common carotid/middle cerebral artery occlusion model) was tested. Neuroscore effectively and significantly increased on post-stroke day (PSD) 1 after MCAo (N=36) compared to shams (N=25, p<0.001). Upon analyzing inter-rater reliability, a significant intraclass correlation coefficient of 0.707 was calculated (N=3, p<0.001). In conclusion, we developed a novel Neuroscore evaluation to mimic the NIH Stroke Scale for mice. The Neuroscore appropriately changed after experimental stroke, and significant reliability findings indicated similar scoring across experimenters. Future testing in other stroke models, as well as in rats is indicated to further evaluate this tool as a universal post-stroke translational assessment.
New species of Dugdaleiella, gen. nov., Kozloviella, gen. nov., and Pfitzneriella Viette from upper elevation Andes of Ecuador and Peru (Lepidoptera: Hepialidae)
Authors: GREHAN JOHN R. , MIELKE CARLOS. G. C.
Published: October 2018

Six new Hepialidae species are described from high elevation habitats in the Andes of Peru and Ecuador. One species is assigned to the genus Kozloviella gen. n., K. viazmenskyi sp. n., from Peru, and five to the genus Pfitzneriella Viette, 1951: P. antonkozlovi sp. n., P. olafi sp. n., P. titarenkoi, sp. n., P. yuliyakovalevae sp. n. from Peru and P. rawlinsi sp. n., from Ecuador. Dugdaleiella gen. n., is proposed to accommodate the Ecuadorian species Dugdaleiella monticola (Maassen, 1890) comb. n., formerly placed in Pfitzneriella. The taxonomic (but not the phylogenetic) status of P. lucicola (Maassen, 1890) is unaltered pending future opportunity to examine the type series. Preliminary phylogenetic analysis of the morphological characters supports Kozloviella gen. n., and Pfitzneriella as sister taxa, and separates P. titarenkoi sp. n., from the other species of Pfitzneriella. We suggest that the ancestor of these high elevation genera already occupied a pre-Andean upland habitat across Peru and Ecuador and this ancestor further diverged into the modern genera and species during the Andean orogeny. We consider it likely that there is a considerable diversity of endemic high elevation Hepialidae that remains to be discovered in the eastern Andes between Venezuela and Bolivia.
A review of the Cyana bianca (Walker, 1856) species-group with descriptions of a new species and a new subspecies from Indochina (Lepidoptera, Erebidae, Arctiinae)
Authors: VOLYNKIN ANTON V. , ČERNÝ KAREL , IVANOVA MARIA S.
Published: October 2018

The Cyana bianca (Walker, 1856) species-group is revised. Cyana bianca malayana Bucsek, 2012 is upgraded to the species level. A new species, C. indosinica Volynkin & Černý, sp. nov. (China: Yunnan, Thailand, Laos, Vietnam) and a new subspecies, C. quadripartita vieta Volynkin & Černý, ssp. nov. (Vietnam) are described.
Application of DNA Barcoding in the Classification of Grasshoppers (Orthoptera: Acridoidea)—A Case Study of grasshoppers from Hebei Province, China
Authors: CHEN LI-PING , CHANG YA-GE , LI JIAN , WANG JIAN-MEI , LIU JIN-LIN , ZHI YONG-CHAO , LI XIN-JIANG
Published: October 2018

Grasshoppers (Orthoptera: Acridoidea) are the main pests in agriculture, animal husbandry and forestry, and some species of grasshoppers can cause serious disaster. Taxonomy is the basis of pest control. Traditional morphological identification is time-consuming and laborious. It may be due to the existence of cryptic species or the limited number of morphologists, making the identification extremely unstable. In recent years, with the development of molecular systematics, DNA barcoding technology has been applied to environment, ecology, quarantine and so on. This study focuses on testing the feasibility of DNA barcoding in the species identification for superfamily Acridoidea. Sequences of the cox1 gene were obtained from 245 individuals of 43 species of Acridoidea and one species of Tetrigoidea as outgroup from Hebei Province. Phylogenetic, genetic distance and sequence difference threshold analyses using the Maximum Likelihood (ML), Automatic Barcode Gap Discovery (ABGD) and Molecular Defined Operational Taxonomic Units (MOTU) methods, respectively, were performed for obtained sequences and the 139 additional sequences of 21 species downloaded from GenBank. The results have shown that 40, 33, and 35 species among the 48 species are consistent with the traditional morphological classification based on the phylogenetic tree, ABGD and MOTU results, respectively and the DNA barcoding technology is very efficient and helpful for identifying the species of the superfamily Acridoidea; however, the morphological approach is still playing a key role in the species identifications. It also indicates that the cox1 gene is suitable for the phylogeny of genera and species level, but it is not suitable for the phylogenetic relationship of the advanced taxa such as families.
Review of the Stomodes tolutarius species group (Coleoptera: Curculionidae: Entiminae: Otiorhynchini) from the Balkan Peninsula with description of two new species from Greece
Authors: BOROVEC ROMAN , HLAVÁČ PETER
Published: October 2018

Species of the tolutarius species group of the genus Stomodes Schoenherr, 1826 are revised. A redescription of the genus is provided and all available male and female genitalia are illustrated. Two new species, S. benedikti sp. n. and S. dodocunevi sp. n. from Greece, are described. A lectotype is designated for S. amorei Desbrochers des Loges, 1904. The redescriptions of the following species are provided: S. marocanus Hoffmann, 1956; S. muelleri Lona, 1922; S. leonhardi Wagner, 1912; S. letzneri Reitter, 1889 and S. tolutarius Schoenherr, 1826. S. muelleri is for the first time recorded for Macedonia, Bosnia and Hercegovina and Greece; S. tolutarius for Macedonia, Bulgaria and Turkey. An identification key to species of the tolutarius species group is given.
The Hadley Circulation Regime Change: Combined Effect of the Western Pacific Warming and Increased ENSO Amplitude
Authors: Guo Yi-Peng , Tan Zhe-Min
Published: October 2018

The variation in the interannual relationship between the boreal winter Hadley circulation (HC) and El Niño–Southern Oscillation (ENSO) during 1948–2014 is investigated. The interannual variability of the HC is dominated by two principal modes: the equatorial asymmetric mode (AM) and the equatorial symmetric mode (SM). The AM of the HC during ENSO events mainly results from a combined effect of the ENSO sea surface temperature (SST) anomalies and the climatological background SST over the South Pacific convergence zone. Comparatively, the SM shows a steady and statistically significant relationship with ENSO; however, the interannual relationship between the AM and ENSO is strengthened during the mid-1970s, which leads to a HC regime change—that is, the interannual pulse of the HC intensity and its response to ENSO are stronger after the mid-1970s than before. The long-term warming trend of the tropical western Pacific since the 1950s and the increased ENSO amplitude play vital roles in the HC regime change. Although the tropical eastern Pacific also experienced a long-term warming trend, it has little influence on the HC regime change due to the climatologically cold background SST over the cold tongue region.
Preconditioning and Formation of Maud Rise Polynyas in a High-Resolution Earth System Model
Authors: Kurtakoti Prajvala , Veneziani Milena , Stössel Achim , Weijer Wilbert
Published: October 2018

Open-ocean polynyas (OOPs) in the Southern Ocean are ice-free areas within the winter ice pack that are associated with deep convection, potentially contributing to the formation of Antarctic Bottom Water. To enhance the credibility of Earth system models (ESMs), their ability to simulate OOPs realistically is thus crucial. Here we investigate OOPs that emerge intermittently in a high-resolution (HR) preindustrial simulation with the Energy Exascale Earth System Model, version 0.1 (E3SMv0), an offspring of the Community Earth System Model (CESM). While low-resolution (LR) simulations with E3SMv0 show no signs of OOP formation, the preindustrial E3SMv0-HR simulation produces both large Weddell Sea polynyas (WSPs) as well as small Maud Rise polynyas (MRPs). The latter are associated with a prominent seamount in the eastern Weddell Sea, and their preconditioning and formation is the focus of this study. The steep flanks of the rugged topography in this region are in E3SMv0-HR sufficiently well resolved for the impinging flow to produce pronounced Taylor caps that precondition the region for convection. Aided by an accumulation of heat in the Weddell Deep Water layer, the ultimate trigger of convection that leads to MRPs is the advection of anomalously high upper-ocean-layer salinity. The crucial difference to WSP-producing LR ESM simulations is that in E3SMv0-HR, WSPs are realistically preceded by MRPs, which in turn are a result of the flow around bathymetry being represented with unprecedented detail.
The Nebraska Mesonet: Technical Overview of an Automated State Weather Network
Authors: Shulski Martha , Cooper Stonie , Roebke Glen , Dutcher Al
Published: October 2018

The Nebraska Mesonet was established in 1981 as one of the nation’s first automated state weather networks. “Automated” is defined by the nature of the observations being made and recorded by machine, as opposed to observations made and recorded manually. At the time of inception, the five observing locations were geared toward servicing agricultural production applications. The Nebraska Mesonet has grown to 69 stations (as of 2018) and is now a multipurpose environmental observing network under the Nebraska State Climate Office (NSCO). The network is composed of environmental observation stations, sited using best practices for mesoscale and microscale environment situations. Precise observations are acquired using high-quality instrumentation, following manufacturer recommendations for calibrations and maintenance. Calibrations are performed in the NSCO calibration laboratory. Uses for the data include but are not limited to water management, drought monitoring, energy production, health, environmental research, animal management, and crop pest management. This paper provides a technical overview and history of the network, outlining current practices for station siting, maintenance, data quality assurance, and data utility.