bluuebunny/crossref_metadata_2025 huggingface dataset:
Abstract WMP95: Drip and Ship vs. Mothership: Conditional Probability Modelling for Patients With Suspected Large Vessel Occlusion
Authors: Holodinsky Jessalyn K , Williamson Tyler S , Demchuk Andrew M , Zhao Henry , Zhu Luke , Malik Fizzah , Goyal Mayank , Hill Michael D , Kamal Noreen
Published: October 2018

Introduction:
For patients with suspected large vessel occlusion (LVO) stroke should we bypass alteplase treatment at Primary Stroke Centres (PSC) in favor of endovascular therapy (EVT) at Comprehensive Stroke Centres (CSC) (mothership) or transport the patient to the PSC for alteplase and then transfer to the CSC for EVT (drip and ship)? This is complicated by the inability to definitively diagnose LVO stroke without imaging.

Methods:
The efficacy decay of alteplase and EVT over time and the accuracy of the Los Angeles Motor Scale (LAMS) LVO screening tool were combined with various treatment times to predict the probability of good outcome (mRS 0 - 1 at 90 days) for both transport strategies for patients with LAMS ≥4.

Results:
The results are shown in the Figure. If the patient is closest to the CSC mothership is always superior. If treatment is fast at both centres drip and ship is superior if the centres are far apart and the patient must travel past a PSC to get to a CSC, otherwise the strategies are equivalent (Panel A). Slow treatment at the PSC increases the area where mothership is superior and eliminates drip and ship unless the time from onset to alteplase administration exceeds 4.5 hours in the mothership scenario (Panel B). Slow treatment at both centres decreases the mothership area and expands the drip and ship area (Panel C).

Conclusions:
Due to the uncertainty in patient diagnosis both transport options are equivalent in most scenarios. A triaging tool with greater positive predictive value would increase the size of the mothership areas. However, even with diagnosis uncertainty the importance of fast treatment times is illustrated.
Abstract WP102: Unique Role of CD163 and Haptoglobin in Transient Ischemic Stroke
Authors: Kamat Pradip K , Leclerc Jenna L , Patel Rachna , Doré Sylvain
Published: October 2018

Background:
Ischemic stroke is a devastating neurological deficit that accounts for 87% of all stroke cases in the US. Post ischemic stroke, oxidative stress leads to a production of reactive oxygen species, which cause considerable tissue damage. Inflammation plays an important role in ischemic stroke brain injury by activating resident cells and producing proinflammatory mediators. The scavenger receptor CD163, and the acute-phase plasma glycoprotein Haptoglobin (Hp) alleviate post ischemic damage resulting from toxic oxidative reactions and inflammation. This is the first investigation into the roles of CD163 and Hp in ischemic stroke, specifically in tMCAO.

Methods:
Transient focal cerebral ischemia was induced by MCAO in wildtype (WT), CD163 knockout (CD163-/-), haptoglobin knockout (Hp-/-), and haptoglobin-CD163 double knockout mice (Hp-/-xCD163-/-) using the intraluminal filament protocol. Focal neurological deficit was observed post-surgery daily at 24, 48 and 72h through neurological deficit scoring (NDS). Mice were tested in an open field chamber for basic locomotion and circling behaviors activity in a pretest before surgery and at 24, 48, and 72h post-stroke. Lesion volume and hemispheric enlargement were assessed in a blinded manner using cresyl violet staining. Data is expressed as mean ± SEM and all statistical analysis was performed in JMP Pro 12.

Results:
The Hp-/- and Hp-/-xCD163-/- had better functional and anatomical outcomes. Regression analysis of open field shows better recovery for Hp-/- and Hp-/-xCD163-/-. Hp-/- had 45.2% smaller lesion volume (p=0.0049) and 66.1% reduced hemispheric enlargement (p=0.0174) compared to WT. The Hp-/-xCD163-/- mice had 55.0% smaller lesion volume (0.0210) and 64.5% reduced hemispheric enlargement (p=0.0037) compared to CD163-/- mice.

Conclusion:
These results suggest that there is a significant decrease in neuronal damage post ischemia following the genetic deletion of Hp suggesting a unique role of the haptoglobin-CD163 pathway in stroke.
Abstract WP105: A Novel Mouse Model of Cerebellar Stroke With Hippocampal Deficits
Authors: Moreno-Garcia Myriam , Schmidt Roxanna , Kubesh Molly , Quillinan Nidia
Published: October 2018

Objective:
Each year in the U.S. there are an estimated 20,000 strokes resulting in cerebellar infarction. The neurological impairments observed in these patients include motor coordination and motor learning impairments. Surprisingly, cerebellar stroke patients also exhibit executive and emotional dysfunction. Establishing a model of cerebellar stroke that recapitulates aspects of human cerebellar infarction will allow for us to perform mechanistic studies of brain injury and identify therapeutic targets to improve recovery in stroke patients. The goal of this study was to develop and characterize a photo-thrombotic mouse model of focal cerebellar stroke.

Methods:
Adult male and female mice were head-fixed in a stereotaxic frame, were administered Rose Bengal (150 ug/g) and the superior cerebellar artery was illuminated for 15 minutes with a cold white LED light source. Behavioral testing of motor and memory function was performed in mice subjected to sham procedure or photo-thrombosis at 7 days following surgery. Stereological analysis of lesion volume was performed at 1 and 7 days after surgery. Extracellular field recordings were performed in the CA1 region of the hippocampus to assess long-term potentiation (LTP).

Results:
Cerebellar stroke volumes were larger at 1 day (2.4 mm
3
) than 7 days (0.964 mm
3
), likely due to edema at the earlier time point. Lesion volumes were similar between males and females at both time points. Cerebellar infarction resulted in gait abnormality, motor incoordination and ipsilateral limb impairments. Memory impairments were also observed at 7 days after cerebellar stroke. Memory deficits correlate with contralateral hippocampal long-term plasticity impairments at 7 days after stroke.

Conclusions:
We have developed a reproducible model of cerebellar stroke that results in cerebellar infarction and associated motor impairments. Importantly, we alsoobserve memory deficits and have identified a molecular mechanism that we can target to improve memory function after stroke. This novel model will be a valuable tool for understanding how alterations in the cerebellar network resulting from cerebellar infarction produce motor and non-motor deficits.
Abstract WP108: Interrogating the Role of Contralesional Cortex Activation in Stroke Recovery
Authors: Cheng Michelle Y , Ito Masaki , Levy Sabrina , Smerin Daniel , Chiang Terrance , Steinberg Gary
Published: October 2018

Background:
Functional neuroimaging studies have reported increased activation in the contralesional primary motor cortex (cM1) in both experimental and clinical settings of stroke. However, the cellular resolution of cM1 activity and the role of cM1 activation in post-stroke recovery is unclear. In this study we characterized the time course of neuronal activation in cM1 during post-stroke recovery using activity-dependent markers. Furthermore, we investigated the role of cM1 activation in post-stroke recovery using the chemogenetic approach to silence the neuronal activity in cM1.

Methods:
Adult male C57Bl6 mice (6-7 weeks) were subjected to stereotaxic injection of AAV-CamKIIa-hM4D-mCherry into the cM1. Ischemic stroke was induced by transient MCAO. For time-course study, brains collected at post-stroke days (PD) 3, 5, 14 and 28 were processed for immunostaining using activity-dependent marker pCREB. For cM1 neuronal silencing, clozapine-N-oxide (CNO) was used to induce inhibitory effects via hM4D. Stroke mice received either CNO or saline intraperitoneally during early phase (PD5-14) or late phase (PD15-28). Functional recovery was evaluated using the rotating beam test at pre-stroke baseline and PD 4, 7, 10 and 14, 21 and 28.

Results:
Timecourse analysis showed that pCREB expression was predominantly observed in cM1 when compared to iM1, as early as PD5 and gradually increased at PD14. While neuronal silencing of cM1 during early phase (PD5-14) did not have significant effect on recovery, neuronal silencing of cM1 during late phase (PD 15-28) showed a trend of beneficial effect on recovery (CNO group n=5, SAL group n=4), suggesting a time-dependent role of cM1 activation during post-stroke recovery.

Conclusions:
Our results showed that basal cM1 neuronal activity increased after stroke and interhemispheric imbalance persisted until at least PD14. Chemogenetic neuronal silencing studies suggest that inhibiting cM1 activation during late phase of recovery may be beneficial. Ongoing studies are addressing the time dependent role of cM1 activation, and elucidating the neuronal subtypes (excitatory vs inhibitory) that are activated in cM1 after stroke.
Abstract WP109: Deferoxamine Improves Vascular Repair and Cognitive Outcomes After Embolic Stroke In Diabetic but Not Control Animals: Interaction With tPA
Authors: Li Weiguo , Dong Guangkuo , Menk Paul T , Abdul Yasir , Ward Rebecca , Fagan Susan C , Ergul Adviye
Published: October 2018

Diabetes increases the risk of hemorrhagic transformation (HT) in ischemic stroke, especially with the use of tissue plasminogen activator (tPA). We showed that iron chelation therapy with deferoxamine (DFX) improves functional outcome in male diabetic animals after embolic stroke but its interaction with tPA remained unknown. We also reported that increased HT is associated with loss of cerebrovasculature in the recovery period in diabetic animals. This study tested the hypotheses that DFX treatment initiated after stroke 1) will improve neurological recovery after embolic stroke with tPA, and 2) will prevent cerebrovascular regression in diabetes. Control and type 2 diabetic animals were subjected to embolic middle cerebral artery occlusion. tPA (1 mg/kg) was given at 90 min post-occlusion. DFX (100 mg/kg) or vehicle was given every 12 h for 7 days after stroke. The composite score (Bederson’s score and beam walk), adhesive removal (ART) and novel object recognition (NOR) were assessed at day 3, 7 and 14 after the surgery. Cerebrovascularization indices in the ipsilateral cortex (vascular volume, surface area, and branch density) were measured with 3D imaging. DFX improved sensorimotor deficits in both groups and this effect was more robust in tPA combination. While DFX lowered vascularization indices in control animals, it prevented vasoregression in diabetes. Interestingly, DFX prevented the recovery of cognitive function in controls while improving it in diabetic animals. These results suggest that treatment with DFX may improve long term recovery in diabetes.
Abstract WP112: Association and Discordance Between Magnetic Resonance Angiography and Three-Dimensional Vessel Wall Imaging in Detecting Intracranial Atherosclerosis
Authors: Sun Jie , Gao Haifeng , Balu Niranjan , Hippe Daniel , Yuan Chun , Hatsukami Thomas
Published: October 2018

Background:
Evaluation of intracranial atherosclerosis currently relies on angiography techniques to detect luminal stenosis, among which 3D time-of-flight (TOF) MRA is most widely used. Recently, 3D vessel wall (VW) MRI has allowed direct plaque visualization in major intracranial arteries.

Purpose:
We sought to study the association between luminal stenosis on TOF-MRA and plaque on VW-MRI in major intracranial arteries.

Methods:
Patients with recent cerebral ischemic events and without cardioembolic or rare etiologies were scanned with intracranial TOF-MRA (resolution: 0.53x0.83x1.4 mm
3
) and VW-MRI (0.8x0.8x0.8 mm
3
). Eleven segments were evaluated, including cavernous and supraclinoid internal carotid artery (ICA), anterior cerebral artery (A1), middle cerebral artery (M1), basilar artery, and posterior cerebral artery (P1). TOF-MRA and VW-MRI were analyzed blinded to each other and clinical data. Luminal stenosis on TOF-MRA was categorized as mild (1-49%), moderate (50-69%), severe (70-99% or flow void), and occlusion (100%). Plaque on VW-MRI was defined as focal wall thickening that exceeded twice reference wall thickness, with plaque burden measured as 1 - lumen diameter / outer wall diameter at the level of maximum wall thickness.

Results:
Nineteen patients were recruited (59.4±14.3 years; 68.4% male). TOF-MRA detected stenosis in 28 segments while VW-MRI detected plaque in 88 segments. Sixty-three (71.6%) plaques on VW-MRI did not show luminal stenosis on TOF-MRA, which, compared to those showing luminal stenosis on TOF-MRA, had smaller plaque burden (0.48±0.09 vs. 0.58±0.11; p<0.001) and were more commonly localized in the supraclinoid ICA (p=0.029) and less likely in the A1 segment (p=0.043). Three (2 mild; 1 moderate) stenoses on TOF-MRA did not show plaque on VW-MRI. TOF-MRI and VW-MRI had a weak correlation both in detecting segmental atherosclerosis (Cohen’s kappa: 0.30 [0.20, 0.41]) and in evaluating lesion severity (stenosis vs. plaque burden; Spearman’s rho: 0.44 [0.25, 0.60]).

Conclusions:
In symptomatic patients, segmental atherosclerosis was three times more prevalent on VW-MRI than TOF-MRA. Further studies are warranted to understand the clinical implications of VW-MRI plaques that are undetected on TOF-MRA.
Abstract WP116: The Prevalence of
RNF213
p.R4810K Variant is High in Juvenile–Onset Stroke Patients With Intracranial Arterial Stenosis
Authors: Kamimura Teppei , Okazaki Shuhei , Morimoto Takaaki , Kobayashi Hatasu , Harada Kouji , Tomita Tsutomu , Higashiyama Aya , Takahashi Jun C , Nakagawara Jyoji , Toyoda Kazunori , Koizumi Akio , Ihara Masafumi
Published: October 2018

Background and purpose:
RNF213
is a susceptibility gene for moyamoya disease (MMD) and over 90% of Japanese patients with MMD have the
RNF213
p.R4810K variant. Recent studies have reported that 20 - 25% of East Asian patients with intracranial arterial stenosis also have the p.R4810K variant, while only about 2% of healthy Japanese population have the variant. In this study, we examined the prevalence of this variant in patients with juvenile-onset ischemic stroke.

Methods:
This single-center cross-sectional study was completed at the National Cerebral and Cardiovascular Center, Osaka, Japan. We analyzed 70 Japanese patients who suffered ischemic stroke or TIA with intracranial arterial stenosis before their 60
th
birthday. Patients with cardioembolic stroke or definite/probable MMD were excluded.

Results:
The
RNF213
p.R4810K variant was found in 24.2% of juvenile-onset stroke patients with intracranial arterial stenosis. This variant was found more often in women than in men (38% vs. 16%, OR 3.3, 95% CI 1.1-10.2, p=0.045). The variant was identified in 35% of the patients with stenosis in the M1 segment of the middle cerebral artery or the A1 segment of the anterior cerebral artery (OR 25.0, 95% CI 1.4-437.8, p<0.01), but in only one patient with intracranial posterior circulation stenosis (Table 1). When restricted to patients with multiple M1 or A1 stenoses, the variant prevalence increased to 56%. Conventional risk factors for stroke, such as smoking, hypertension, diabetes mellitus, dyslipidemia, and family history did not differ between patients with and without the variant.

Conclusion:
The
RNF213
p.R4810K variant is common for juvenile-onset ischemic stroke with M1 or A1 stenosis.
Abstract WP117: Neurophysiological Detection of Stroke and Large Vessel Occlusions (LVOs)
Authors: Ziayee Habibullah , Zaker Shahrak Babak , Wechsler Lawrence , Alvi Muhammad , Sherman Jay , Kesinger Matt R , Jadhav Ashutosh
Published: October 2018

Introduction:
Approximately 1.9 million neurons are lost with each passing minute of a cerebral large vessel occlusion (LVO). Proper triage is imperative for transfer to an appropriate center and further care. EEGs and SSEPs are the standard of care for intraoperative detection of stroke. Asymmetric changes in electrographic activity can identify neural ischemia with high accuracy. In this study, we tested the predictive power of a brain functional symmetry index (BFSI) to identify stroke with EEG and SSEP.

Methods:
We conducted a cross-sectional study utilizing ischemic stroke patients admitted to two university hospitals. EEG results were recorded by leads placed on the head. Evoked potentials were acquired via electrodes providing somatosensory stimulations bilaterally to the wrists. Patients were further categorized into LVOs versus non-LVOs. During analysis, measures were taken to also account for small sample size of both stroke and LVO identification. The predictive power of the algorithm to identify stroke and LVO were examined.

Results:
A total of 38 patients were enrolled of which 19 patients had ischemic strokes. Of the strokes, 8 were LVOs. Demographics of control and stroke patients were analyzed using t-test and chi-squared analysis. BFSI correctly classified 17/19 strokes (89%) and 17/19 controls (89%). Similar results were obtained when predicting for larger sample sizes with 84% sensitivity, 79% specificity, 80% positive predictive value, and 83% negative predictive value. Of the LVOs, the BFSI correctly identified all LVOs (100% sensitivity) and produced a specificity of 57%. Again, similar results were demonstrated when accounting for larger sample size with sensitivity of 100% and specificity of 53%.

Conclusion:
The predictive power of BFSI demonstrates high accuracy for ischemic strokes, especially LVOs. These results not only demonstrate a dependable means of detecting stroke in a controlled environment, it also serves as a blueprint for rapid detection of LVOs in the prehospital setting.
Abstract WP118: Incidence and Management of Re-stenosis in Patients Stented for Intracranial Atherosclerotic Disease: A Consecutive Series of 226 Patients
Authors: Alexander Michael J , Barnard Zachary , Schiraldi Michael
Published: October 2018

Introduction:
Angioplasty and stenting for intracranial atherosclerotic disease can re-establish adequate luminal diameter in highly stenotic arteries and improve cerebral blood flow. As in other vascular territories, intracranial stented arteries may develop delayed re-stenosis due to progression of atherosclerotic disease or endothelial hyperplasia. The primary strategies for management of re-stenosis have included aggressive medical therapy, angioplasty only, and repeat angioplasty and stenting.

Materials and Methods:
A total of 226 patients underwent intracranial angioplasty and stenting for symptomatic ICAD from 2000-2017. Patients were treated with balloon expandable coronary stents until 2002, when self-expanding intracranial nitinol stents became available. The series included: 21 balloon expandable coronary stents, 33 Neuroform stents, 37 Enterprise stents, and 135 Wingspan stents. Of this group, 210 patients had delayed follow up intracranial vascular imaging at 6 months, 1 year, and longer. In follow up, 24 of the 210 patients (11.4 %) developed significant re-stenosis, defined as 70% or greater. Eleven of the patients were symptomatic and 13 had no symptoms. A total of 17 patients underwent endovascular treatment of their re-stenosis, and 7 had medical management only.

Results:
The mean time interval for re-stenosis was 8.7 months. Of the 17 patients treated with endovascular therapy for re-stenosis, 4 patients had angioplasty only and 13 patients had angioplasty and stenting. There was one peri-procedural stroke in this group (5.9%) and no other strokes in the follow up period (mean 2.4 years, range 6 months - 7 years). Of the 7 patients who were managed medically, 1 patient had a stroke (14.3%) in the follow up period at 10 months (mean follow up 2.1 years, range 3 months - 5 years).

Discussion:
The preliminary data from this study suggests that patients with severe re-stenosis may be at significant risk of stroke, even if the re-stenosis is currently asymptomatic. As with other vascular territories, re-stenosis can be managed with multiple modalities, but repeat angioplasty and stenting in this series appears to be a low risk and viable option for these patients compared with medical therapy alone.
Abstract WP12: Mechanical Thrombectomy for Basilar Artery Occlusion
Authors: Uno Junji , Kameda Katsuharu , Karashima Satoshi , Otsuji Ryosuke , Ren Nice , Nagaoka Shintaro , Maeda Kazushi , Ikai Yoshiaki , Gi Hidefuku
Published: October 2018

Background and Purpose:
Basilar artery occlusion (BAO) is an infrequent cause of stroke, accounting for 1.1% of acute ischemic stroke cases. The natural history of patients with BAO is devastating, with morbidity rates of up to 80%. No previous randomized controlled studies on the efficacy of recanalization therapy have been reported.

Methods:
In the present single-center study, consecutive BAO patients were treated with mechanical thrombectomy (MT) using the stent retriever and the Penumbra system. Computed tomography perfusion was used for patient evaluation. Clinical outcomes were correlated with demographic, clinical, and radiographic findings.

Results:
Between October 2011 and March 2017, MT was performed in 37 patients with BAO (mean age 70.1±10.9). Mean baseline National Institutes of Health Stroke Scale was 23±11. Recanalization rate (≧thrombolysis in cerebral infarction 2b) was 100%. Mean onset to recanalization time (OTR) was 226.3±117.8minutes. Favorable outcome at 90 days (modified Rankin scale≦2) was 60.6%. Mortality rate at 90 days was 10.8%. In an univariate analysis, IV rt-PA use, and OTR were significantly associated with favorable outcomes. In a multivariate logistic regression model, IV rt-PA use and lower NIHSS score were significantly related to favorable outcomes.

Conclusions:
Multimodal endovascular therapy using the Penumbra system and/or stent retriever demonstrated high recanalization rates and improved outcomes in BAO. Both devices were feasible and effective in the treatment of BAO. An approach combining MT with IV thrombolysis provided better recanalization rates and improved clinical outcomes.
Abstract WP120: Long-Term Survival of Carotid Endarterectomy and Carotid Artery Stenting in Japanese Population
Authors: HOSODA Kohkichi , Fujita Atsushi , Kohta Masaaki , Kimura Hidehito , Imahori Taichiro , Tanaka Jun , Kohmura Eiji
Published: October 2018

Introduction:
According to the current guidelines, treatment for carotid stenosis with carotid endarterectomy (CEA) or carotid artery stenting (CAS) should be limited to patients with life expectancy of >3 to 5 years. We aimed to assess the long-term survival after CEA and CAS in Japanese population.

Methods:
Between August 2006 and June 2015, 262 consecutive carotid revascularizations with either CEA or CAS were performed in our institute. The initial treatment was regarded as the starting point in the cases of the patients who received treatment by bilateral carotid artery stenosis or retreatment. A Kaplan-Meier life table was done and a multivariate Cox hazard model was built for the analysis of the long-term survival-associated risk factors.

Results:
A total of 231 patients (CEA 142, CAS 89; mean age, 72.1 ± 7.4 y.o.), including 106 symptomatic patients, were enrolled in the current study with mean follow-up period of 52.2 months. During follow-up 37 patients (16%) died, being cancer (19%) and pneumonia (19%) the most frequent causes. Cumulative 3- and 5-year survival rates were 92% and 87%, respectively. Kaplan-Meier estimates of the 5-year survival rate were 89.8% for CEA and 81.5% for CAS (P=0.033) (Figure Left). Cox regression model showed independent risk factors related to survival were age (Hazard ratio [HR], 1.08/year [95%CI, 1.03-1.13]; p = 0.003) (Figure Right)and CAS (HR, 2.3 [95%CI, 1.2-14.6]; p = 0.012). Presence of symptom was not associated with the long-term survival. No death due to stroke occurred.

Conclusion:
The life-expectancy of patients in the current study satisfies the current guidelines and the long-term survival was associated with age and CAS. The inclusion of higher risk patients in the CAS group may have been the reason for CAS being a risk factor.
Abstract WP122: A Serial Study of Carotid Web
Authors: Yang Tao , Yoshida Kazumichi , Fushimi Yasutaka , Yamamoto Yu , Ishii Akira , Takagi Yasushi , Miyamoto Susumu
Published: October 2018

Introduction:
Intimal flap-like protrusion of the carotid artery is referred to as a carotid web (also known as carotid diaphragm and atypical fibromuscular dysplasia) that can cause recurrent ischemic stroke. We retrospectively studied the prevalence, demographics, clinical presentation, and imaging features of all patients in a series with defined carotid webs, and describe the treatment and histopathology of two that were symptomatic.

Methods:
This retrospective study analyzed data from a series of 505 patients who underwent head and neck computed tomography angiography (CTA) at Kyoto University Hospital between April 2011 and Oct 2016. Reports have indicated that CTA is reliable for detecting carotid webs, which are defined on images of oblique sagittal sections as a thin intraluminal filling defect along the posterior wall of the carotid bulb. Ultrasonic echo and MRI findings were also matched when available. Carotid webs were finally defined by interpretation of CTA images by a radiologist and an experienced neurosurgeon.

Results:
The prevalence of carotid webs in this series was 1.8% (9 of 505 patients), the mean age was 56 (range, 42 - 67) years, and six patients were women. Two (22.2%) of the nine patients with carotid webs had recurrent stroke and both were treated radically by carotid endarterectomy. The histopathological findings suggested fibromuscular dysplasia accompanied by early atherosclerotic changes.

Conclusions:
The prevalence of carotid webs was low and they tended to occur more frequently among women in the present series. An optimal management strategy has not yet been devised. However, recurrent ischemic stroke might be caused by turbulent blood flow at the point of recess that leads to the formation of thrombus and emboli. We recommend that such patients undergo radical treatment.
Abstract WP123: Timing and Risk Factors for Restenosis Following Carotid Endarterectomy and Angioplasty With Stenting
Authors: Witek Alex M , Howie Benjamin A , Toth Gabor
Published: October 2018

Background:
We sought to determine the incidence of restenosis following carotid endarterectomy (CEA) and carotid angioplasty with stenting (CAS), analyze temporal trends to identify an optimal follow-up schedule, and identify covariates associated with restenosis.

Methods:
Patients undergoing CEA or CAS at our institution between 2009 and 2016 were assessed retrospectively. Temporal trends in peak systolic velocity (PSV) were examined qualitatively. Restenosis was defined as an increase in PSV to >250 cm/s, or as >70% stenosis on CTA or catheter angiography. Rates of restenosis were calculated using the Kaplan-Meier method. Cox proportional hazards regression was used to evaluate for an association between selected covariates and time to restenosis.

Results:
We analyzed 204 CEA and 113 CAS cases, of which 85% had symptomatic disease. Cumulative restenosis rates were 9% at one year and 14% at four years (Figure 1). There was no difference between CEA and CAS procedures (hazard ratio 1.285, p=0.58). Interestingly, there was a trend toward higher risk of restenosis for left-sided procedures, which did not reach statistical significance (hazard ratio 2.401, p=.051). Restenosis was asymptomatic in 96% of occurrences. Univariate regression identified no covariates associated with restenosis at a threshold of p<0.05 .

Conclusions:
The restenosis rate was overall low after CEA and CAS, with the highest risk seen in the first year, and significantly reduced later on. Most restenoses were asymptomatic. We did not identify specific covariates associated with restenosis. Close follow-up with imaging is recommended during the first year after treatment. Due to relatively low incidence of delayed stenosis, follow-up beyond 1 year should be tailored based on individual risk factors.
Abstract WP125: Pathologic Changes in Carotid Artery Lesions in Relation With Intensity of Statins Therapy
Authors: Vázquez Guido , Couto Juan B , Thomson Alejandro , Claverie Carlos S , Raffaelli Hector , Dulbecco Eduardo , Vigliano Carlos A , Klein Francisco R
Published: October 2018

Introduction:
Due to its lipid lowering and pleiotropic effects, statins are part of the standard medical treatment of carotid artery disease. Nevertheless, scarce medical information can be found relating intensity of its use and arterial pathologic changes. The aim of our research was to study the relationship between intensity and temporal patterns of statins therapy (ST) with pathologic changes of carotid lesions (CLs) obtained from carotid endarterectomies (CAE).

Methods:
236 consecutive patients undergoing CAE from 01/01/2012 to 06/30/2017 were retrospectively analyzed. Intensity of the ST was categorized according to the 2013 AHA Guidelines as High (HI); Moderate (MI) or Low (LI). The CLs samples were described blindly by a pathologist with no clinical information. Vulnerability of the CLs were classified according to the AHA Guidelines into types IV; V (Va, Vb ,Vc) and VI (VIa, VIb , VIc). Findings as fibrosis, Myofibroblastic hiperplasia, lipid core, calcification, inflammation, hemorrhage and thrombosis were cuantified as absent, mild, moderate and intense. Angiogenesis was graded in a scale from 0 to 3. Spearman correlation; X
2
, t test and logistic regression were used for statistical significance.

Results:
We studied 236 CAEs (55% right sided) with a mean age of 69,5 years; 41% women; 32,3% symptomatic . In 83% of the cases, statins were being used (HI in 48,4%, MI in 50% and LI in 1.6%; Duration of ST previous to CAE was > 6 months; 63%; < 6 months: 29.8% and <1 month in 7.8%. Complicated plaques (type VI) were shown in 50.8%. An inverse correlation was found between statins dosing and stenosis grading (
p
<.05) and fibrosis scores (
p
=.03). No association between histopathologic changes and ST was found. A correlation between complicated plaques and symptomatic lesions was found. (p=.01).

Conclusions:
No association was found between the pathologic findings of the CLs and the intensity and duration of the statins therapy evn though in our population a low percentage of patients received HI and long duration ST.
Abstract WP129: The Yield of Antiplatelet Resistance in Carotid and Vertebral Artery Stenting
Authors: Muchada Lopez Marian , Rodriguez Noelia , Vert Carla , Requena Manuel , Montoya Anna , Rodriguez-Luna David , Boned Sandra , Hernandez David , Tomasello Alejandro , Ribo Marc , Molina Carlos A , Rubiera Marta
Published: October 2018

Background:
Platelet function measured by Aggregometry tests (AT) are commonly used to measure the response to antiplatelets in patients undergoing intracranial and coronary stenting. However, its relevance in carotid and vertebral stents (CVS) is unsettled. We aimed to determine the yield of antiplatelet resistance (AR) in CVS patients, and its relationship with early restenosis and new ischemic lesions on magnetic resonance imaging (MRI).

Methods:
We studied consecutive patients undergoing CVS. Platelet function was assessed before stenting by means of VerifyNow-assay using Aspirin and P2Y12 cartridges. Antiplatelet reactivity was defined using the cut-off values ARU≥550 as Aspirin resistance (AASR) and PRU≥220 as Clopidogrel resistance (CR). Patients received baseline and 5-day MRI. Periprocedural complications, the new ischemic lesions at 5-day MRI and stent permeability by carotid ultrasound at 24 hours, 5 days and 3 months were analysed.

Results:
A total of 366 patients were screened. Of those, 246 patients were enrolled and tested for platelet function. A total of 135 patients (54.2%) showed AR, 48 AASR (19.5%) and 112 CR (45.5%). Aspirin dose after the test was increased in 21 patients (45.7%). In 22 patients (20%) with CR the daily dose was increased, in 40 patients (37.7%) an extra-loading dose was administrated and in 9 patients (8.4%) we increased both. At 24 hours, one patient showed restenosis >50% and another an occlusion (0.4 and 0.4% respectively). At 5 days, 8 patients had restenosis <50% (13.1%) and in 43 (17.5%) MRI showed new ischemic lesions. At 3 months 9 patients had stenosis >50% (4.5%) and stenting-related recurrence was observed in 3 (1.4%). A larger size lesions at 5-day MRI (OR 0.143; 95%CI 0.028-0.719) and a multi-territorial ischemic pattern (OR 0.143; 95%CI 0.075-0.893) were associated with lack of response to Clopidogrel therapy. No significant differences in AASR were observed across different groups.

Conclusion:
The yield of antiplatelet resistance in our series was 54.2%. Clopidogrel resistance was associated with a larger size and a multi-territorial stroke pattern at 5-day MRI. More studies are needed to elucidate the clinical impact of Aggregometry test and management recommendations.
Abstract WP13: Salvageable Tissue and Endovascular Recanalization for Acute Ischemic Strokes After 6 to 12 Hours From Onset
Authors: Kim Beom Joon , Kim Hyeran , Jeong Han-Gil , Yang Mi Hwa , Jung Chulkyu , Han Moon-Ku , Demchuk Andrew , Bae Hee-Joon
Published: October 2018

Introduction:
Endovascular recanalization (EVT) for acute ischemic stroke patients with sizable penumbral tissues seems plausible even beyond 6 hours from their last seen normal (LSN), provided that there remain salvageable tissues.

Methods:
A total of 111 acute ischemic stroke patients were included in the analysis, who had ICA or MCA occlusion cases with baseline NIHSS score ≥6-point and arrived 6 - 12 hours after LSN. Baseline demographics, stroke information and functional outcomes were prospectively collected during routine clinical practice. Attending physicians made treatment decisions for EVT by current guidelines and institutional protocols. MR image parameters, including volume of diffusion-restrcted lesions (ADC value ≤450) and mapping of hypoperfused area (T
max
delay ≥6 seconds), were quantified using an automated commercial software with minimal manual operations. Binary logistic regression analysis models taking mRS score 0 - 1 at 3 months after stroke as a dependent variable were constructed.

Results:
Of the 111 ICA or MCA occlusion cases who arrived 6 - 12 hours after LSN, 58% had mismatch ratio of ≥1.8 at baseline and 42% had favorable imaging profiles by DEFUSE-2 study. EVT was done in 54% of cases. Three-month mRS score 0 - 1 was found in 19% and mortality in 14%. EVT was associated with significantly increased odds of having mRS score 0 - 1 at 3 months after stroke (adjusted OR, 6.15 [95% CI, 1.12 - 44.10]) after controlling for covariates. Good response to EVT was dependent upon the baseline infarct volume and time delay (Figure) Sensitivity analyses for propensity weighting, location of occlusion, preceding intravenous tPA, size of penumbral tissues showed consistent associations favoring for EVT.

Conclusions:
EVT is feasible and efficacious for anterior circulation occlusion with substantial neurological deficits even 6 - 12 hours after LSN. More research is warranted to target the best candidates of EVT using image parameters.
Abstract WP130: Comparison of VerifyNow System and Thrombelastography for Assessing Asprin Response in Stroke Patients in China
Authors: Han Yan , Lv Huihui , Shi Zhuqing , Zhou Yang , Liu Qianyun
Published: October 2018

Objectives:
The aim of the study was to compare the consistency of VerifyNow System and thrombelastography (TEG) in stroke patients treated with asprin in China.

Methods:
Patients hospitalized in Changhai Hospital and Yueyang Hospital with acute ischemic stroke were randomly enrolled into treatment with a 100-mg daily maintenance dose of asprin. Platelet reactivity was evaluated by VerifyNow System (Accumetrics Inc.) and TEG (Hemonetics Corporation) at the same time on the 5th-7th day of asprin treatment. Patients with asprin low response (ALR) were detected by using the methods and criteria published earlier (ARU ≥550 assayed by VerifyNow System or Inhibition% ≤50% measured by TEG). All patients were followed up for 2 years and clinical endpoint was ischemic events, including major adverse cardiac events (MACE), recurrence of stroke, transient ischemic attack (TIA),and the composite of vascular death.

Results:
Totally 94 patients were enrolled for the study and there were wide varieties in parameters of VerifyNow System and TEG. Results showed a total of 16 and 15 patients, respectively, identified as ALR assessed by VerifyNow System and TEG, but only three patients were detected to be asprin low responders by both tests. The kappa consistency analysis showed poor consistency between VerifyNow System and TEG results in terms of ALR (Kappa = 0.030, p < 0.01). Of the patients recruited, 83 (88.3%) patients were followed up for 2 year and a total of 15 (18.1%) cases of clinical events were observed. There was no correlation between ALR assessed by TEG (TEG-ALR) and the clinical endpoints (P > 0.05), but a significant relevance was found between ALR assessed by VerifyNow System (VerifyNow-ALR) and the ischemic events in 2 years of follow-up (OR
adj
: 3.13; 95%CI: 1.3-7.55; P = 0.011). Among the risk factors for cerebrovascular disease, we only found stroke history was related to the clinical endpoints (P = 0.005).

Conclusions:
There was poor correlation between VerifyNow System and TEG in platelet function detection. VerifyNow-ALR and stroke history were risk factors for ischemic events, and VerifyNow System may be available to guide individualized antiplatelet therapies in stroke patients in China.
Abstract WP134: Quantitatively Monitoring Regression or Progression in Intracranial Atherosclerotic Plaques Using 3D Vessel Wall Imaging and Deep-learning-based Vessel Wall Analysis
Authors: Fan Zhaoyang , Yang Qi , Shi Feng , Miao Huijuan , Yang Yujiao , Schlick Konrad , Gonzalez Nestor , Maya Marcel , Song Haiqing , Li Debiao , Guo Xiuhai , Song Shlee
Published: October 2018

Introduction:
Intracranial atherosclerotic disease (ICAD) is one of the most common causes of ischemic stroke worldwide. Despite aggressive medical management, the rate of recurrent stroke is 13% at 1 year. Intracranial vessel wall imaging (VWI) is a noninvasive,
“looking-beyond-the-lumen”
imaging method that can directly characterize the geometric and signal features of ICAD lesions. The present work sought to assess the feasibility of quantitatively monitoring regression or progression of ICAD plaques using VWI-based methods.

Methods:
Eight ischemic stroke patients (1F, 7M; age 27-66 ys) treated with intensive medical therapy underwent initial (4 days - 4 months of onset) and follow-up 3D VWI (6-13 months). Images were randomized and reviewed by two neuroradiologists to determine the culprit lesion in each subject. A custom-designed deep-learning-based intracranial vessel analysis method was used to segment vessel wall boundaries and quantify the following features of the culprit lesion, including peak normalized wall index (NWI), plaque volume, pre-contrast plaque-wall contrast ratio (CR), and post-contrast plaque enhancement ratio (ER).

Results:
No subjects except for subject #4 had a recurrent stroke during the follow-up period. The four plaque features exhibited different change patterns as shown in
Figure
. Subject #1 and #4 demonstrated an increase in plaque ER, volume, and peak NWI; subject #7 demonstrated an increase in plaque CR, volume and peak NWI. Other patients had a decrease or no change in these features.

Conclusions:
In this work, the interrogated plaque features demonstrated regression in most of patients after intensive medical therapy. Elevated values in some of these features appeared positively associated with stroke recurrence. Temporal changes in these features may have a strong indication on culprit lesions’ response to medical therapy. In conclusion, it is feasible to quantitatively monitor plaque-level treatment response.
Abstract WP136: Twisted Carotid Bifurcation is the Right Side Dominant Phenomenon Even in the Impartial Population
Authors: Kudo Kentaro
Published: October 2018

Background:
The internal carotid artery (ICA) runs usually posterolateral to the external carotid artery (ECA) at their bifurcation. But some ICA is positioned medially to the ECA, so called twisted carotid bifurcation (TCB). Some reports have shown TCB to be more likely to occur on the right side in the patients with internal carotid stenosis (ICS), but the reason is not established. We evaluate the frequency of TCB sides.

Methods:
From January 2013 to the present, 584 consecutive patients (mean age, 65.2±11.5) who underwent cerebral angiography were reviewed. We evaluate their common carotid arteriography in the anteroposterior view. We defined the term TCB as the center of the ICA locates medially to the center of the ECA.

Result:
We evaluated a total number of 742 sides of the carotid bifurcation, and the TCB was found in 62 sides (8.4%). Among the 62 sides, 54 were on the right side (87%) and eight were on the left side (13%). The mean age of the TCB group was 72.0±9.0, while the non TCB group was 65.2±11.5. Male vs female sides were 25 vs 37 in the TCB group, and 350 vs 330 in the non TCB group. There were 43 sides of patients with hypertension in the TCB group (69.3%), while 301 sides in the non TCB group (44.3%).

Discussion:
TCB not only sometimes brings difficulty in performing carotid endarterectomy (CEA), but also may lead various symptoms. There are some reports which reveal the TCB has right side dominancy. However, most of those reports targeted patients with ICS, and have small cases. Our study showed TCB tend to occur on the right side, even in the more impartial population. There were no significant differences between the TCB group and the non TCB group in the demographic characteristics such as hypertension (p value = 0.48), male to female gender ratio (p value = 0.087), except for the mean age (p value = 0.027). Although some insist that the TCB is a congenital abnormality, our study showed TCB is related to age.

Conclusion:
The TCB is a right side dominant phenomenon, not only in the ICS patients, but also in the more impartial population. Further evaluation such as hemodynamics or investigating more demographic characteristics will be of our interest in the future to assume the basis of dominancy.
Abstract WP138: Effect of Duration Between Stroke Onset and Admission to Inpatient Rehabilitation Facilities on Improvement in Activities of Daily Living During Hospitalization
Authors: Nariaki Shiraishi , Matsumoto Daisuke , Suzuki Yusuke , Jeong Seungwon , Sugiyama Motoya , Takahiro Hayashi , Kondo Katsunori
Published: October 2018

Objective:
This study aimed to determine whether early admission of stroke patients to inpatient rehabilitation facilities (IRFs) resulted in improvement in motor function during hospitalization.

Methods:
Data were extracted from the Japan association of rehabilitation database for 2,177 patients admitted to IRFs at 32 centers. Items surveyed were age; sex; stroke type; length of stay; period from onset to IRF admission (≤7, 8–14, or 15–60 days); motor functional independence measure (mFIM) and cognitive FIM (cFIM) at admission and discharge; and modified Rankin Scale (mRS) score before onset, at admission, and at discharge. In addition, the difference between mFIM at admission and at discharge (mFIM gain) were calculated. For comparative analysis, we stratified patients into mildly, moderately, and severely impaired groups if their mRS scores at admission were 0–2, 3, and 4–5, respectively. We used multiple regression analysis to examine the factors affecting ADL at discharge.

Results:
Mildly impaired patients admitted within 7 days of onset had a higher mFIM score and mFIM gain (estimate=4.75, p=0.032) than those admitted 15–60 days after onset. Meanwhile in moderately impaired patients, no correlation was found between the length of time from onset to admission, and mFIM and mFIM gain. Severely impaired patients admitted within 7 days of onset had a higher mFIM score and mFIM gain (estimate=9.07, p=0.032) than those admitted 15–60 days after onset.

Conclusion:
Mildly and severely impaired stroke patients experience greater improvement in ADL, if admitted to an IRF within 7 days after stroke onset.
Abstract WP139: Transcranial Direct Current Stimulation (tDCS) Generates Electric Fields (EF) at the Level of Deep Nuclei of the Human Brain
in vivo
Authors: Chhatbar Pratik Y , Kautz Steven A , Takacs Istvan , Rowland Nathan C , Revuelta Gonzalo J , George Mark S , Bikson Marom , Feng Wuwei
Published: October 2018

Introduction:
tDCS is an investigational neuromodulatory therapy for stroke recovery and data has been inconsistent and mixed. The general perception for tDCS is that the majority of current gets shunted at the level of scalp and only minor portion penetrates to the superficial cortex. We aimed to detect electrical field (EF) via deep brain stimulation (DBS) leads in human brain.

Hypothesis:
Scalp-applied tDCS generates EF across the brain and forms detectable voltage gradient across DBS leads.

Methods:
We recruited patients undergoing DBS stage 2 procedure (implantable pulse generator or IPG implantation). We connected our recording setup to the IPG end of the DBS lead(s), which is otherwise unavailable except this specific surgical procedure. We applied 2 mA and 4 mA of tDCS using bitemporal and occipitofrontal montage and recorded voltage gradients across electrodes of DBS lead(s), while monitoring the applied voltage, injected current and body resistance through tDCS setup.

Results:
We recruited 3 patients with unilateral or bilateral DBS leads and found that tDCS application results in changed voltage gradient across contact points of the leads. Because of side-by-side orientation of the leads, bitemporal montage induces in voltage gradient in dose-dependent manner, but occipitofrontal montage did not detect any voltage gradient across the DBS leads because of their relatively equidistant positioning from the anode/cathode. Finally, 4 mA of tDCS resulted in lower body resistance (~20-30% less) when compared to 2 mA of tDCS.

Conclusions:
tDCS-generated EF were detected at the level of deep nuclei. Our findings offer insights into the body’s changing resistance to tDCS in a dose-dependent manner that can optimize tDCS simulation models towards improving tDCS efficacy in stroke recovery.