Search

The evolution of quantum computers poses a serious threat to contemporary public-key encryption (PKE) schemes. To address this impending issue, the National Institute of Standards and Technology (NIST) is currently undertaking the Post-Quantum Cryptography (PQC) standardization project intending to evaluate and subsequently standardize the suitable PQC scheme(s). One such attractive approach, called Bit Flipping Key Encapsulation (BIKE), has made to the final round of the competition. Despite having some attractive features, the IND-CCA security of the BIKE depends on the average decoder failure rate (DFR), a higher value of which can facilitate a particular type of side-channel attack. Although the BIKE adopts a Black-Grey-Flip (BGF) decoder that offers a negligible DFR, the effect of weak-keys on the average DFR has not been fully investigated. Therefore, in this paper, we first perform an implementation of the BIKE scheme, and then through extensive experiments show that the weak-keys can be a potential threat to IND-CCA security of the BIKE scheme and thus need attention from the research community prior to standardization. We also propose a key-check algorithm that can potentially supplement the BIKE mechanism and prevent users from generating and adopting weak keys to address this issue.

Introduction The prospective INSIGHT Registry is a multicenter ‘multi‐omic’ analysis of thrombi associated with acute hemorrhagic or ischemic stroke. This updated interim analysis evaluated the performance of Penumbra RED catheters used during aspiration thrombectomy for acute ischemic stroke (AIS). Methods All AIS cases in which Penumbra RED aspiration catheters (RED 62, 68, or 72) were utilized as a frontline treatment were included in the analysis. Retrieved clot fragments were classified based on their gross appearance. Key time metrics and procedural data were also collected, including first‐pass / post‐procedure modified Treatment in Cerebral Ischemia (mTICI) score. Results Of 400 patients enrolled across 25 US centers, 161 underwent thrombectomy with Penumbra RED catheters over ten months (Jul 2021 through Apr 2022). The mean patient age was 70.7 years, and 50.9% were female. The middle cerebral artery first segment (M1) was the most common primary occlusion site (60.4%; 96/159). IV t‐PA was administered before the procedure in 13.7% (22/161) of patients. The median time from stroke onset / last known well to mTICI≥ 2b was 5.0 hrs. [IQR 3‐11], and the median time from a puncture to mTICI≥ 2b was 23.0 mins [IQR 15‐31]. Firm‐red clots represented 45.3% (67/148), while soft‐red clots were found in 37.8% (56/148) of retrieved clots. In turn, firm‐white and soft‐white clots were seen in 11.5% (17/148) and 5.4% (8/148) of cases, respectively. Rates of the first pass and final mTICI≥ 2b scores by clot type are shown in Table 1. Conclusions Aspiration thrombectomy with Penumbra RED catheters resulted in good revascularization rates for all clot types.

Background Delays in endovascular reperfusion for patients with large vessel occlusion stroke are known to worsen outcomes, and the mechanism is believed to be time‐dependent expansion of the ischemic infarction. In this study, we hypothesize that delays in onset to reperfusion (OTR) assert an effect on outcomes independent of effects of final infarct (FI). Methods We performed a subgroup analysis from the prospective multicenter COMPLETE (International Acute Ischemic Stroke Registry With the Penumbra System Aspiration Including the 3D Revascularization Device; Penumbra, Inc) registry for 257 patients with anterior circulation large vessel occlusion who underwent endovascular therapy with successful reperfusion (modified treatment in cerebral infarction score 2b/3). FI was measured by Alberta Stroke Program Early CT score and volume on 24‐ to 48‐hour computed tomography or magnetic resonance imaging. The likelihood of 90‐day good functional outcome (modified Rankin scale 0–2) was assessed by OTR and absolute risk difference (ARD) was estimated using multivariable logistic regressions adjusting for patient characteristics including FI. Results In univariable analysis, longer OTR was associated with a decreased likelihood of good functional outcome (ARD –3% [95% CI –4.5 to –1.0]/h delay). In multivariable analysis accounting for FI, the association between OTR and functional outcome remained significant (ARD –2% [95% CI –3.5 to –0.4]/h delay) with similar ARD. This finding was maintained in the subset of patients with FI imaging using CT only, using Alberta Stroke Program Early CT Score or volumetric FI measurements, and also in patients with larger versus smaller FIs. Conclusions The impact of OTR on outcomes appears to be mostly through a mechanism that is independent of FI. Our findings suggest that although the field has moved toward imaging infarct core definitions of eligibility for endovascular treatment, time remains an important predictor of outcome, independent of infarct core.

© 2018 Elsevier B.V. As we progress in into a digital era where most aspects of our life depend upon a network of computers, it is essential to focus on digital security. Each component of a network, be it a physical network, virtual network or social network requires security when transmitting data. Hence the dynamic wireless mesh network must also deploy high levels of security as found in current legacy networks. This paper presents a secure Geo-Location Oriented Routing (Secure-GLOR) protocol for wireless mesh networks, which incorporates a hybrid encryption scheme for its multilevel security framework. The hybrid encryption technique improves the network's overall performance compared to the basic encryption by using a combination of symmetric key as well as asymmetric key encryption. Using the combination of the two encryption schemes, the performance of the network can be improved by reducing the transmitted data size, reduced computational overhead and faster encryption–decryption cycles. In this paper discussed multiple encryption schemes for both symmetric and asymmetric encryption, compare their performance in various experimental scenarios. Proposed security scheme achieves better performance based on the results obtained with most viable options for our network model.

Introduction: Understanding clot composition and associated genomic, epigenomic, and proteomic signatures could provide insight into thrombus biology and etiology, and aid in prognosis in stroke. We report preliminary analysis of histology evaluations in subjects enrolled in the INSIGHT Registry, a multicentered ‘multi-omic’ analysis of thrombi associated with acute hemorrhagic and ischemic stroke this multi-omic clot collection registry. Our aim was to determine potential histology differences in thrombi as a consequence of infarct time (time from last known normal to thrombectomy). Material and Methods: Subjects age ≥18 years, treated frontline with the Penumbra System for thrombectomy are included in this analysis. Patient demographics, medical history, radiographic, and procedural information are collected in conjunction with extracted clot and concurrent extracranial arterial blood. Enrollment, data collection, and data monitoring are ongoing for the INSIGHT registry. While the protocol includes analysis for proteomics and transcriptomics, for this analysis we used automated histology. An MSB Trichrome stain was used to evaluate the tissue. Composition was determined by automated pixel analysis, with the values representing ratios of the overall clot. Results: Samples from 60 subjects who were enrolled from 10 sites between 02/2021 and 07/2021. Analysis of the thrombi successfully determined the relative portions of fibrin, red blood cells (RBCs), and platelets (PLT). The median percentage of fibrin in the thrombi was 44.0% (IQR 29.0 - 57.6; N=60). The median time interval from Last Known Well to recanalization was 4.0 hours (IQR 2.9-12.8 hours; N=55). There was no correlation between the time interval of stroke and the percent of fibrin in the thrombus (Pearson correlation coefficient -0.01, p 0.94). Conclusion: These preliminary results demonstrate a lack of relationship between time interval of the stroke and clot histology composition with relation to fibrin. Thrombus fibrin composition is likely more related to other factors, and not predominantly related to time. We are currently investigating potential relationships to demographics and co-morbidities.

This meeting abstract was removed due to the OA licensing requirements of this journal. The full abstract is listed here : https://www.svin.org/files/SVIN_2021_Abstracts_for_Web.pdf

Background and Purpose— Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry. Methods— The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT. Results— A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P =0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P =0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P =0.29) and mortality (42.9% versus 44.7%; P =0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P =0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P =0.02). Conclusions— Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

Edge computing is an emerging research area to incorporate cloud computing into edge network devices. An Edge datacenter, also referred to as EDC, processes data streams and user requests in real-time and is therefore used to decrease the latency and congestion in the network. EDC is usually setup as a distributed system and is accordingly placed between the cloud datacenter and the data source. These EDCs work as an intermediate layer in the fog hierarchy between IoT and Cloud datacenter. EDC’s are aided by load balancers, responsible for distributing the workload amongst multiple EDC, in order to optimize resource utilization and response time. The load balancers make sure that the workload is equally divided amongst the available EDCs to avoid over loading of some EDCs while other remain idle as this directly impacts the user response and real-time event detection. Given the fact that EDCs are deployed in remote environments, the need for secure authentication is of major importance. In this paper we propose a novel load balancing technique that enables EDC authentication as well as identification of idle EDCs for better load balancing. The proposed load balancing technique is also compared with existing approaches and proves to be more efficient in locating EDC’s with less workload. In addition to the improved efficiency, the proposed scheme also strengthens the security of the network by incorporating destination EDC authentication.

Introduction: Despite advanced imaging and rapid recanalization, the majority of patients with large vessel occlusion (LVO) acute ischemic stroke (AIS) do not achieve functional independence at 90 days. Here, we explore the hypothesis that prolonged ischemia worsens clinical outcome beyond changes reflected in final infarct size, particularly in elderly patients. Methods: From the prospective, multicenter COMPLETE (Penumbra, Inc) registry, patients were included if they underwent endovascular therapy (EVT) for anterior circulation LVO, achieved TICI 2b/3 reperfusion, and EVT began within 90 minutes of imaging. Final infarct volumes (FIV) were measured on 24-48h post-EVT scans using ASPECTS. Multivariable logistic regression was used to determine the effect of stroke onset to hospital arrival time (OTA) on likelihood of functional independence (mRS 0-2) at 90 days, adjusting for age, NIHSS, occlusion location, pre-morbid mRS and final infarct. The effect of OTA on outcome was evaluated in older vs. younger patients using propensity score matching. Data are presented as median [IQR] or OR [95% CI]. Results: Among 302 patients, median age was 71 [61-79], NIHSS was 15 [10-20], 56% were female, median OTA was 154 [75-320]. Median FIV ASPECTS was 7 [6-8]. In multivariable analysis adjusting for FIV, longer OTA was associated with decreased likelihood of functional independence (OR 0.74 [0.57-0.96]). FIV-independent worsening with prolonged OTA was more pronounced with advanced age (Figure). Using propensity score matching, elderly patients (age > 70) matched by age, NIHSS, occlusion location and FIV were less likely to have functional independence with prolonged OTA (Coef -0.2, p Conclusions: In patients with LVO AIS who achieve successful reperfusion, delays in EVT reduce the likelihood of good clinical outcomes independent of FIV. This effect is more pronounced with advanced age.

Data processing in real-time brings better business modeling and an intuitive plan of action. Internet of things (IoT), being a source of sensitive data collected and communicated through either public or private networks, requires better security from end to end to uphold integrity, quality, and acceptability of data. Designing an adaptive solution plays a vital role where IoT is deployed for the sensing-as-a-services in the critical infrastructure and near real-time decision making by deploying data analysis in the edge datacenters. Again, securing the system with user's demand and device specifications is a challenging and open research problem. This paper proposed a decision tree based user-centric security approach named DecisionTSec that provides a secure channel for communication in IoT networks, combining edge datacenters in the network edges. Further, the proposed DecisionTSec is validated by experimenting with the real-time testbed for the system performance along with the theoretical security validation.

The current era of technology is flooded with hundreds of Internet of Things (IoT) applications with billions of IoT objects. One of the primary applications is healthcare systems, where body area network (BAN)-sensing healthcare devices (such as leg movement sensor, heart-rate sensing, etc.) collect the user's real-time data (such as heart rate, step counts, and many more). These real-time users’ data are vulnerable to various attacks related to authentication. It may also create scope for further attacks exploiting authentication. Therefore it requires a proper authentication mechanism and should be transmitted securely without compromising the privacy of the user's healthcare information. Moreover, these devices are very much computationally resource constrained. This chapter emphasizes the afore-mentioned threats and constraints, and proposes a secure, lightweight authentication protocol between a healthcare wearable device and its user. The scheme uses a cryptographic hash function and X-OR functionalities only. It is tested by a well-known formal security verification tool, AVISPA, to show its robustness against various attacks related to authentications. The secure establishment of a shared secret key is also shown by the well-known BAN authentication logic. Furthermore, the computational cost of the scheme is also computed and compared with other work to prove its efficiency.

Background and Purpose— In acute ischemic stroke, fast and complete recanalization of the occluded vessel is associated with improved outcomes. We describe a novel measure for newer generation devices: the first pass effect (FPE). FPE is defined as achieving a complete recanalization with a single thrombectomy device pass. Methods— The North American Solitaire Acute Stroke Registry database was used to identify a FPE subgroup. Their baseline features and clinical outcomes were compared with non-FPE patients. Clinical outcome measures included 90-days modified Rankin Scale score, National Institutes of Health Stroke Scale score, mortality, and symptomatic intracranial hemorrhage. Multivariate analyses were performed to determine whether FPE independently resulted in improved outcomes and to identify predictors of FPE. Results— A total of 354 acute ischemic stroke patients underwent thrombectomy in the North American Solitaire Acute Stroke registry. FPE was achieved in 89 out of 354 (25.1%). More middle cerebral artery occlusions (64% versus 52.5%) and fewer internal carotid artery occlusions (10.1% versus 27.7%) were present in the FPE group. Balloon guide catheters were used more frequently with FPE (64.0% versus 34.7%). Median time to revascularization was significantly faster in the FPE group (median 34 versus 60 minutes; P =0.0003). FPE was an independent predictor of good clinical outcome (modified Rankin Scale score ≤2 was seen in 61.3% in FPE versus 35.3% in non-FPE cohort; P =0.013; odds ratio, 1.7; 95% confidence interval, 1.1–2.7). The independent predictors of achieving FPE were use of balloon guide catheters and non-internal carotid artery terminus occlusion. Conclusions— The achievement of complete revascularization from a single Solitaire thrombectomy device pass (FPE) is associated with significantly higher rates of good clinical outcome. The FPE is more frequently associated with the use of balloon guide catheters and less likely to be achieved with internal carotid artery terminus occlusion.

© 2012 IEEE. In the continuous evolution of the computer age, the next big step in security is being achieved by embracing quantum cryptography. As the unit of information shifts from the currently used bit to the quantum bit (qubit), a new realm of untapped features is offered that can be used to ensure the confidentiality of the information being shared among participants. This system confidentiality is ensured by the use of a quantum channel for exchanging secret keys, which are then used to encrypt the data being shared. The system is a combination of cryptography and quantum computing that is aided by the laws of physics.

© 2002-2012 IEEE. The Internet of Things (IoT) is an emerging technology that has gained a huge user base by facilitating Internet-connected devices being used in numerous applications including smart vehicular infrastructure. In this context, we focus on the traditional vehicular ad hoc network that has evolved into a new perception called the Internet of Vehicles (IoV), and is expected to soon transform into the Internet of Autonomous Vehicles (IoAV). IoAV hopes to facilitate smart vehicular infrastructure and autonomous driving without the need for human involvement. However, as the number of connected vehicles keeps increasing, so does the need for autonomous decision making. Hence, the IoAV must provide robust, secure, seamless, and scalable communication among the vehicles as well as the roadside units. This article provides an overview of autonomous vehicle communication layers, its associated properties, and security threats. Further, this article also briefly discusses the current research trends and future research issues.

Background and Purpose- Mechanical thrombectomy (MT) devices have led to improved reperfusion and clinical outcomes in acute ischemic stroke patients with emergent large vessel occlusions; however, less than one-third of patients achieve complete reperfusion. Use of intraarterial thrombolysis in the context of MT may provide an opportunity to enhance these results. Here, we evaluate the use of intraarterial rtPA (recombinant tissue-type plasminogen activator) as rescue therapy (RT) after failed MT in the North American Solitaire Stent-Retriever Acute Stroke registry. Methods- The North American Solitaire Stent-Retriever Acute Stroke registry recruited sites within North America to submit data on acute ischemic stroke patients treated with the Solitaire device. After restricting the population of 354 patients to use of RT and anterior emergent large vessel occlusions, we compared patients who were treated with and without intraarterial rtPA after failed MT. Results- A total of 37 and 44 patients was in the intraarterial rtPA RT and the no intraarterial rtPA RT groups, respectively. Revascularization success (modified Thrombolysis in Cerebral Infarction ≥2b) was achieved in more intraarterial rtPA RT patients (61.2% versus 46.6%; P=0.13) with faster times to recanalization (100±85 versus 164±235 minutes; P=0.36) but was not statistically significant. The rate of symptomatic intracranial hemorrhage (13.9% versus 6.8%; P=0.29) and mortality (42.9% versus 44.7%; P=0.87) were similar between the groups. Good functional outcome (modified Rankin Scale score of ≤2) was numerically higher in intraarterial rtPA patients (22.9% versus 18.4%; P=0.64). Further restriction of the RT population to M1 occlusions only and time of onset to groin puncture ≤8 hours, resulted in significantly higher successful revascularization rates in the intraarterial rtPA RT cohort (77.8% versus 38.9%; P=0.02). Conclusions- Intraarterial rtPA as RT demonstrated a similar safety and clinical outcome profile, with higher reperfusion rates achieved in patients with M1 occlusions. Prospective studies are needed to delineate the role of intraarterial thrombolysis in MT.

Background: Various techniques are used to enhance the results of mechanical thrombectomy with stent-retrievers, including proximal arrest with balloon guide catheter (BGC), conventional large bore proximal catheter (CGC), or in combination with local aspiration through a large-bore catheter positioned at the clot interface (Aspiration-Retriever Technique for Stroke [ARTS]). We evaluated the impact of ARTS in the North American Solitaire Acute Stroke (NASA) registry. Summary: Data on the use of the aspiration technique were available for 285 anterior circulation patients, of which 29 underwent ARTS technique, 131 CGC, and 125 BGC. Baseline demographics were comparable, except that ARTS patients are less likely to have hypertension or atrial fibrillation. The ARTS group had more ICA occlusions (41.4 vs. 22% in the BGC, p = 0.04 and 26% in CGC, p = 0.1) and less MCA/M1 occlusions (44.8 vs. 68% in BGC and 62% in CGC). Time from arterial puncture to reperfusion or end of procedure with ARTS was shorter than with CGC (54 vs. 91 min, p = 0.001) and was comparable to the BGC time (54 vs. 67, p = 0.11). Final degree of reperfusion was comparable among the groups (TICI [modified Thrombolysis in Cerebral Infarction] score 2b or higher was 72 vs. 70% for CGC vs. 78% for BGC). Procedural complications, mortality, and good clinical outcome at 90 days were similar between the groups. Key Messages: The ARTS mechanical thrombectomy in acute ischemic stroke patients appears to yield better results as compared to the use of CGCs with no significant difference when compared to BGC. This early ARTS technique NASA registry data are limited by the earlier generation distal large bore catheters and small sample size. Future studies should focus on the comparison of ARTS and BGC techniques.

Background and Purpose— Failure to recanalize predicts mortality in acute ischemic stroke. In the North American Solitaire Acute Stroke registry, we investigated parameters associated with mortality in successfully recanalized patients. Methods— Logistic regression was used to evaluate baseline characteristics and recanalization parameters for association with 90-day mortality. A multivariable model was developed based on backward selection with retention criteria of P P ≤0.10), then refit to minimize the number of excluded cases (missing data). Results— Successfully recanalized patients had lower mortality (25.2% [59/234] versus 46.9% [38/81] P P =0.205). However, mortality was significantly higher in patients with symptomatic intracranial hemorrhage (72% [23/32] versus 26% [73/281]; P P P c index=0.72), proximal occlusion, initial National Institutes of Health Stroke Scale≥18, and use of rescue therapy remained significant independent predictors of 90-day mortality. Conclusions— Failure to recanalize and presence of symptomatic intracranial hemorrhage resulted in increased mortality. Despite successful recanalization, proximal occlusion, high National Institutes of Health Stroke Scale, and need for rescue therapy were predictors of mortality.

Background and Purpose— The Solitaire With the Intention for Thrombectomy (SWIFT) and thrombectomy revascularization of large vessel occlusions in acute ischemic stroke (TREVO 2) trial results demonstrated improved recanalization rates with mechanical thrombectomy; however, outcomes in the elderly population remain poorly understood. Here, we report the effect of age on clinical and angiographic outcome within the North American Solitaire-FR Stent-Retriever Acute Stroke (NASA) Registry. Methods— The NASA Registry recruited sites to submit data on consecutive patients treated with Solitaire-FR. Influence of age on clinical and angiographic outcomes was assessed by dichotomizing the cohort into ≤80 and >80 years of age. Results— Three hundred fifty-four patients underwent treatment in 24 centers; 276 patients were ≤80 years and 78 were >80 years of age. Mean age in the ≤80 and >80 cohorts was 62.2±13.2 and 85.2±3.8 years, respectively. Of patients >80 years, 27.3% had a 90-day modified Rankin Score ≤2 versus 45.4% ≤80 years ( P =0.02). Mortality was 43.9% and 27.3% in the >80 and ≤80 years cohorts, respectively ( P =0.01). There was no significant difference in time to revascularization, revascularization success, or symptomatic intracranial hemorrhage between the groups. Multivariate analysis showed age >80 years as an independent predictor of poor clinical outcome and mortality. Within the >80 cohort, National Institutes of Health Stroke Scale (NIHSS), revascularization rate, rescue therapy use, and symptomatic intracranial hemorrhage were independent predictors of mortality. Conclusion— Greater than 80 years of age is predictive of poor clinical outcome and increased mortality compared with younger patients in the NASA registry. However, intravenous tissue-type plasminogen activator use, lower NIHSS, and shorter revascularization time are associated with better outcomes. Further studies are needed to understand the endovascular therapy role in this cohort compared with medical therapy.

© 2017 IEEE. With the dawn of a new era, digital security has become one of the most essential part of any network. Be it a physical network, virtual network or social network, the demand for secure data transmission is ever increasing. Wireless mesh networks also stand the same test of security as the legacy networks. This paper presents a secure version of the Geo-Location Oriented Routing (GLOR) protocol for wireless mesh networks, incorporating a multilevel security framework. It implements authentication using the new features of the network model and enables encryption throughout the network to provide high levels of security.

Affordance perception comprises the evaluation of whether our given bodily capabilities and properties of the environment allow particular actions. Typical impairments after left brain damage in motor cognition as well as after right brain damage in visuo-spatial abilities may affect the evaluation of whether interactions with objects are possible. Further it is unclear whether deficient motor function is accounted for when deciding upon action opportunities. For these purposes we developed a paradigm with two tasks that differ in their type of demands on affordance perception and tested it in healthy young adults ( Randerath and Frey, 2016 ). Here, we applied one of these two tasks in stroke patients and age matched healthy participants. A sample of 34 stroke patients with either left (LBD) or right brain damage (RBD) and 29 healthy controls made decisions about whether their hands would fit through a defined horizontal aperture presented in various sizes, while they remained still. Data was analyzed using a detection theory approach and included criterion, perceptual sensitivity and diagnostic accuracy as dependent variables. In addition we applied modern voxel based lesion analyses to explore neural correlates. Compared to controls, both patient groups demonstrated lower perceptual sensitivity. As predicted, increased motor cognitive deficiencies after left brain damage and visuo-spatial deficits after right brain damage were associated with worse performance. Preliminary lesion analyses demonstrated that next to lesions in ventro-dorsal regions, damage in the cortex-claustrum-cingulate pathway may affect perceptual sensitivity. Results were similar for left and right brain damage suggesting a bilateral network. Accordingly, we propose that perceptual sensitivity for affordance based judgments is a capability depending on motor-cognitive and visuo-spatial processing, which frequently is deficient after left or right brain damage, respectively. Further research on diagnostics and training in affordance perception after brain damage is needed.

© 2016 IEEE. Wireless Mesh Network is an emerging technology with great potential to become a Self-Sustained Network. Unlike the traditional networks that dominate the current communication system and rely on a large and expensive setup of wired/wireless access points to provide connection between users, the Wireless Mesh Network is formed by the user devices (referred as Nodes) which connect to each other to form a network. However, due to the use of legacy/traditional network models for mesh networks, there exist various limitations towards its implementation. This paper presents a new approach towards the Wireless Mesh Network, incorporating a new routing scheme based on the Geo-Location of the devices. It puts forward the structure, working principle and its performance during the first implementation.

Background and Purpose— Previous work that predated the availability of the safer stent-retriever devices has suggested that general anesthesia (GA) may have a negative impact on outcomes in patients with acute ischemic stroke undergoing endovascular therapy. Methods— We reviewed demographic, clinical, procedural (GA versus local anesthesia [LA], etc), and site-adjudicated angiographic and clinical outcomes data from consecutive patients treated with the Solitaire FR device in the investigator-initiated North American SOLITAIRE Stent-Retriever Acute Stroke (NASA) Registry. The primary outcomes were 90-day modified Rankin Scale, mortality, and symptomatic intracranial hemorrhage. Results— A total of 281 patients from 18 centers were enrolled. GA was used in 69.8% (196/281) of patients. Baseline demographic and procedural factors were comparable between the LA and GA groups, except the former demonstrated longer time-to-groin puncture (395.4±254 versus 337.4±208 min; P =0.04), lower National Institutes of Health Stroke Scale (NIHSS; 16.2±5.8 versus 18.8±6.9; P =0.002), lower balloon-guide catheter usage (22.4% versus 49.2%; P =0.0001), and longer fluoroscopy times (39.5±33 versus 28±22.8 min; P =0.008). Recanalization (thrombolysis in cerebral infarction ≥2b; 72.94% versus 73.6%; P =0.9) and rate of symptomatic intracranial hemorrhage (7.1% versus 11.2%; P =0.4) were similar but modified Rankin Scale ≤2 was achieved in more LA patients, 52.6% versus 35.6% (odds ratio, 1.4 [1.1–1.8]; P =0.01). In multivariate analysis, hypertension, NIHSS, unsuccessful revascularization, and GA use (odds ratio, 3.3 [1.6–7.1]; P =0.001) were associated with death. When only anterior circulation and elective GA patients were included, there was a persistent difference in good outcomes in favor of LA patients (50.7% versus 35.5%; odds ratio, 1.3 [1.01–1.6]; P =0.04). Conclusions— The NASA Registry has demonstrated that clinical outcomes and survival are significantly better in patients treated with LA, without increased symptomatic intracranial hemorrhage risk. Future trials should prospectively evaluate the effect of GA on outcomes.

Background and purposeEndovascular techniques are frequently employed to treat large artery occlusion in acute ischemic stroke (AIS). We sought to determine the predictors and clinical impact of intracranial hemorrhage (ICH) after endovascular therapy.MethodsRetrospective analysis of consecutive patients presenting to 13 high volume stroke centers with AIS due to proximal occlusion in the anterior circulation who underwent endovascular treatment within 8 h from symptom onset. Logistic regression was performed to determine the variables associated with ICH, hemorrhagic infarction (HI), and parenchymal hematomas (PHs), as well as 90 day poor outcome (modified Rankin Scale score ≥3) and mortality.ResultsThere were a total of 363 ICHs (overall rate 32.3%; HI=267, 24%; PH=96, 8.5%) among the 1122 study patients (mean age 67±15 years; median National Institutes of Health Stroke Scale score 17 (IQR 13-20)). Independent predictors for HI included diabetes mellitus (OR 2.27, 95% CI (1.58 to 3.26), p

Cerebral air embolism is a dreaded complication of invasive medical procedures. The mainstay of therapy for patients with cerebral air embolism has been hyperbaric oxygen therapy, high flow oxygen therapy, and anticonvulsants. We present a novel therapeutic approach for treatment of cerebral air embolism causing large vessel occlusion, using endovascular aspiration. Our patient developed a cerebral air embolism following sclerotherapy for varicose veins. This caused near total occlusion of the superior division of the M2 segment of the right middle cerebral artery. Symptoms included unilateral paralysis, unintelligible speech, and hemianopia; National Institutes of Health Stroke Scale (NIHSS) on presentation was 16. The air embolism was treated using a distal aspiration technique. Angiography following aspiration showed Thrombolysis in Cerebral Infarction 2B reperfusion. Following aspiration, the patient was re-examined; NIHSS at that time was 4. At 1 month follow-up, the modified Rankin Scale score was 1 and NIHSS was 1. Treatment of cerebral air embolism is discussed.

BackgroundTime to reperfusion following endovascular treatment (ET) predicts outcomes after acute ischemic stroke (AIS).ObjectiveTo assess the time–outcome relationship within reperfusion grades in the North American Solitaire Acute Stroke registry.MethodsWe identified patients given ET for anterior circulation ischemic stroke within 8 h from onset and in whom reperfusion was achieved. Together with clinical and outcome data, site-adjudicated modified Thrombolysis in Cerebral Ischemia (TICI) was recorded. We assessed the impact of time to reperfusion (onset to procedure completion time) on good outcome (modified Rankin Scale 0–2 at 3 months) in patients who achieved TICI 2 or higher reperfusion in multivariable models. We further assessed this relationship within strata of reperfusion grades. A pResultsIndependent predictors of good outcome at 3 months among those achieving TICI ≥2a reperfusion (n=188) were initial National Institutes of Health Stroke Scale score (adjusted OR=0.90, 95% CI 0.85 to 0.95), symptomatic hemorrhage (adj. OR=0.16, 95% CI 0.05 to 0.60), TICI grade (TICI 3: adj. OR=11.52, 95% CI 3.34 to 39.77; TICI 2b: adj. OR=5.14, 95% CI 1.61 to 16.39), and time to reperfusion per 30 min interval (adj. OR=0.91, 95% CI 0.82 to 0.99). There was an interaction between final TICI grade and 30 min time to reperfusion intervals (p=0.001) such that the effect of time was strongest in TICI 2a patients.ConclusionsTime to reperfusion was a strong predictor of outcome following ET for AIS. However, the effect varied by TICI grade such that its greatest effect was in those achieving TICI 2a reperfusion.

© Springer International Publishing AG 2016. Wireless Mesh Network is an emerging technology with great potential for evolving into a self-sustained network. The traditional networks, which dominate the present day communication systems, rely on large and expensive setups of wired/wireless access points for connection between users. Unlike the traditional networks, a Wireless Mesh Network is formed by the user devices which connect to each other to form a network. The security of such networks is however very low as each data packet passes through multiple devices making it susceptible to vulnerabilities. This paper discusses a new network model that implements a strong security framework over a new routing technique. The new network model, unlike any other, features a new addressing scheme that is no longer limited by the drawbacks of the legacy systems and can hence implement better security measures.

BACKGROUND: Reperfusion therapy for acute ischemic stroke (AIS) is rapidly evolving, with the development of multiple endovascular modalities that can be used alone or in combination. OBJECTIVE: To determine which pharmacologic or mechanical modality may be associated with increased rates of recanalization. METHODS: A cohort of 1122 patients with AIS involving the anterior circulation treated at 13 stroke centers underwent intra-arterial (IA) therapy within 8 hours of symptom onset. Demographic information, admission National Institutes of Health Stroke Scale (NIHSS), mechanical and pharmacologic treatments used, recanalization grade, and hemorrhagic complications were recorded. RESULTS: The mean age was 6 7 ± 16 years and the median NIHSS was 1 7. The sites of arterial occlusion before treatment were M1 middle cerebral artery (MCA) in 561 (50%) patients, carotid terminus in 214 (19%) patients, M2 MCA in 171 (15%) patients, tandem occlusions in 141 (13%) patients, and isolated extracranial internal carotid artery occlusion in 35 (3%) patients. Therapeutic interventions included multimodal therapy in 584 (52%) patients, pharmacologic therapy only in 264 (24%) patients, and mechanical therapy only in 274 (24%) patients. Patients treated with multimodal therapy had a significantly higher Thrombolysis in Myocardial Infarction 2 or 3 recanalization rate (435 patients [74%]) compared with pharmacologic therapy only (160 patients, [61%]) or mechanical only therapy (173 patients [63%]), P < .001. In binary logistic regression modeling, independent predictors of Thrombolysis in Myocardial Infarction 2 or 3 recanalization were use of IA thrombolytic OR 1.58 (1.21-2.08), P < .001 and stent deployment 1.91 (1.23-2.96), P < .001. CONCLUSION: Multimodal therapy has significantly higher recanalization rates compared with pharmacologic or mechanical therapy. Among the individual treatment modalities, stent deployment or IA thrombolytics increase the chance of recanalization.

Object The authors evaluated the prognostic significance of blood glucose level at admission (BGA) and change in blood glucose at 48 hours from the baseline value (CG48) in nondiabetic and diabetic patients before and after endovascular therapy for acute ischemic stroke (AIS). Methods The BGA and CG48 data were analyzed in 614 patients with AIS who received endovascular therapy at 7 US centers between 2006 and 2009. Data reviewed included demographics, stroke risk factors, diabetic status, National Institutes of Health Stroke Scale (NIHSS) score at presentation, recanalization grade, intracranial hemorrhage (ICH) rate, and 90-day outcomes (mortality rate and modified Rankin Scale score of 3–6 [defined as poor outcome]). Variables with p values < 0.2 in univariate analysis were included in a binary logistic regression model for independent predictors of 90-day outcomes. Results The mean patient age was 67.3 years, the median NIHSS score was 16, and 27% of patients had diabetes. In nondiabetic patients, BGA ≥ 116 mg/dl (≥ 6.4 mmol/L) and failure of glucose level to drop > 30 mg/dl (> 1.7 mmol/L) from the admission value were both significant predictors of 90-day poor outcome and death (p < 0.001). In patients with diabetes, BGA ≥ 116 mg/dl (≥ 6.4 mmol/L) was an independent predictor of poor outcome (p = 0.001). The CG48 was not a predictor of outcome in diabetic patients. A simplified 6-point scale including BGA, Thrombolysis in Myocardial Infarction (TIMI) Grade 2–3 Reperfusion, Age, presentation NIHSS score, CG48, and symptomatic ICH (BRANCH) corresponded with poor outcomes at 90 days; the area under the curve value was > 0.79. Conclusions Failure of blood glucose values to decrease in the first 48 hours after AIS intervention correlated with poor 90-day outcomes in nondiabetic patients. The BRANCH scale shows promise as a simple prognostication tool after endovascular therapy for AIS, and it merits prospective validation.

How are relationships between corporate clients and law firms evolving? Drawing on interview and survey data from 166 chief legal officers of S&P 500 companies from 2006–2007, we find that—contrary to standard depictions of corporate client-provider relationships—(1) large companies have relationships with ten to twenty preferred providers; (2) these relationships continue to be enduring; and (3) clients focus not only on law firm platforms and lead partners, but also on teams and departments within preferred providers, allocating work to these subunits at rival firms over time and following “star” lawyers, especially if they move as part of a team. The combination of long-term relationships and subunit rivalry provides law firms with steady work flows and allows companies to keep cost pressure on firms while preserving relationship-specific capital, quality assurance, and soft forms of legal capacity insurance. Our findings have implications for law firms, corporate departments, and law schools.

Background and Purpose— Patients undergoing intra-arterial therapy (IAT) for acute ischemic stroke receive either general anesthesia (GA) or conscious sedation. GA may delay time to treatment, whereas conscious sedation may result in patient movement and compromise the safety of the procedure. We sought to determine whether there were differences in safety and outcomes in GA patients before initiation of IAT. Methods— A cohort of 980 patients at 12 stroke centers underwent IAT for acute stroke between 2005 and 2009. Only patients with anterior circulation strokes due to large-vessel occlusion were included in the study. A binary logistic-regression model was used to determine independent predictors of good outcome and death. Results— The mean age was 66±15 years and median National Institutes of Health Stroke Scale score was 17 (interquartile range, 13–20). The overall recanalization rate was 68% and the symptomatic hemorrhage rate was 9.2%. GA was used in 44% of patients with no differences in intracranial hemorrhage rates when compared with the conscious sedation group. The use of GA was associated with poorer neurologic outcome at 90 days (odds ratio=2.33; 95% CI, 1.63–3.44; P P Conclusions— Patients placed under GA during IAT for anterior circulation stroke appear to have a higher chance of poor neurologic outcome and mortality. There do not appear to be differences in hemorrhagic complications between the 2 groups. Future clinical trials with IAT can help elucidate the etiology of the differences in outcomes.

Our paper contributes to the studies on the relationship between workers' human capital and their decision to become self-employed as well as their probability to survive as entrepreneurs. Analysis from a panel data set of research analysts in investment banks over 1988-1996 reveals that star analysts are more likely than non-star analysts to become entrepreneurs. Furthermore, we find that ventures started by star analysts have a higher probability of survival than ventures established by non-star analysts. Extending traditional theories of entrepreneurship and labor mobility, our results also suggest that drivers of turnover vary by destination: (a) turnover to entrepreneurship and (b) other turnover. In contrast to turnover to entrepreneurship, star analysts are less likely to move to other firms than non-star analysts.

This paper examines the portability of star security analysts' performance. Star analysts who switched employers experienced an immediate decline in performance that persisted for at least five years. This decline was most pronounced among star analysts who moved to firms with lesser capabilities and those who moved solo, without other team members. Star analysts who moved between two firms with equivalent capabilities also exhibited a drop in performance, but only for two years. Those who switched to firms with better capabilities and those who moved with other team members exhibited no significant decline in short-term or long-term performance. These findings suggest that firm-specific skills and firms' capabilities both play important roles in star analysts' performance. In addition, we find that firms that hire star analysts from competitors with better capabilities suffered more extreme negative stock-market reactions than those that hire from comparable or lesser firms. These findings suggest that hiring stars may be perceived as value destroying and may not improve a firm's competitive advantage.

The World Wide Web serves as a huge repository of information that is highly dynamic, diverse and growing at an exponential rate in a lightening speed. In order to speed-up and further improve tasks like information search and retrieval, personalization etc; it is highly important to develop techniques to classify text documents more accurately and efficiently than before. This paper is an effort in that direction, where the effectiveness of Extreme Learning Machines(ELM) in the domain of text classification is studied and compared with many of the existing relevant techniques like Support Vector Machines(SVM), which are currently one of the most popular and effective techniques for classifying text documents. Ours is one of the few works that highlight the high performance of ELM in the field of text classification, by implementing classifiers based on different interpretations of ELM, analyzing their performance, and studying which feature selection techniques are most suited to improve their accuracy. In our multi-class classification problem, we studied a single ELM classifier based on the one-against-all scheme, and a multi-layer ELM classifier inspired from deep networks, and then perform extensive experiments on different datasets to demonstrate the applicability and effectiveness of our approach. Results show that ELM based classifiers can outperform many of the traditional classification techniques including the most powerful state-of-the-art technique such as SVM.

Background: Time to reperfusion following endovascular treatment (ET) strongly predicts outcomes after acute ischemic stroke (AIS). However, the impact of time may vary depending on the grade of reperfusion. We sought to assess time-outcome relationship within grades of reperfusion in the North American Solitaire Acute Stroke (NASA) registry. Methods: The investigator-initiated NASA registry recruited 24 clinical sites within North America to submit demographic, clinical, site-adjudicated angiographic, and clinical outcome data on consecutive patients treated with the Solitaire Flow Restoration device. We identified patients treated with anterior circulation ischemic stroke treated within 8 hours. The modified Thrombolysis in Cerebral Ischemia (TICI) was used wherein TICI 2 was divided in TICI 2a (< 50% reperfusion) and TICI 2b (> 50% reperfusion). We assessed the impact of time to reperfusion (onset to procedure completion time) on good outcome (modified Rankin Scale 0-2 at 3 months) in those who achieved at least TICI 2a reperfusion, independent of other relevant covariates using logistic regression analysis. We further assessed this relationship within strata of reperfusion grade. Results: Among 265 eligible patients, 209 (78.9%) had complete data (mean age 68.4 years, median NIHSS score 18). Reperfusion grade was as follows: TICI 3: 35.4%; TICI 2b: 39.7%, TICI 2a: 14.8%; TICI 0-1: 10.0%. Independent predictors of outcome at 3 months among those achieving TICI 2-3 reperfusion were: initial NIHSS score, intravenous tissue plasminogen activator use, symptomatic hemorrhage, and time to reperfusion. For each 30 minutes, the adjusted OR for time to reperfusion was 0.874 (95% CI 0.797-958). There was a significant interaction between final TICI grade and 30-minute time to reperfusion intervals (P=0.001) such that the effect of time was strongest in TICI 2a patients. Conclusions: Time to reperfusion is a strong predictor of outcome following ET for AIS with 13% decreased odds of good outcome per 30-minute delay in achieving TICI 2-3 reperfusion. However, the effect varied by TICI grade such that its greatest effect was in those achieving TICI 2a reperfusion.

Despite approaching a 90 % rate of recanalization, good clinical outcomes are only seen in about 50 % of the patients who undergo stroke intervention. This discrepancy indicates that the recanalization of the artery does not always result in good clinical outcome. Also a subset of patients will not have any significant clinical improvement despite achieving early or late recanalization (Broderick et al., N Engl J Med 368:893–903, 2013; Kidwellet al., N Engl J Med 368:914–923, 2013). Therefore, there is a need to more accurately identify patients who will benefit from early or late recanalization using interventional therapy. Clinical assessment scales like National Institutes of Health Stroke Scale (NIHSS) and Houston Intra-arterial Therapy (HIAT) score can help identify patients with moderate to severe strokes, who may benefit from interventional therapies. The evolution of CT and MR imaging in conjunction with clinical assessment may allow us to further refine our ability to identify subgroups of patients who benefit from stroke intervention. These clinical and imaging criteria for patient selection are the focus of discussion in this chapter.

BackgroundMechanical thrombectomy with stent-retrievers results in higher recanalization rates compared with previous devices. Despite successful recanalization rates (Thrombolysis in Cerebral Infarction (TICI) score ≥2b) of 70–83%, good outcomes by 90-day modified Rankin Scale (mRS) score ≤2 are achieved in only 40–55% of patients. We evaluated predictors of poor outcomes (mRS >2) despite successful recanalization (TICI ≥2b) in the North American Solitaire Stent Retriever Acute Stroke (NASA) registry.MethodsLogistic regression was used to evaluate baseline characteristics and recanalization outcomes for association with 90-day mRS score of 0–2 (good outcome) vs 3–6 (poor outcome). Univariate tests were carried out for all factors. A multivariable model was developed based on backwards selection from the factors with at least marginal significance (p≤0.10) on univariate analysis with the retention criterion set at p≤0.05. The model was refit to minimize the number of cases excluded because of missing covariate values; the c-statistic was a measure of predictive power.ResultsOf 354 patients, 256 (72.3%) were recanalized successfully. Based on 234 recanalized patients evaluated for 90-day mRS score, 116 (49.6%) had poor outcomes. Univariate analysis identified an increased risk of poor outcome for age ≥80 years, occlusion site of internal carotid artery (ICA)/basilar artery, National Institute of Health Stroke Scale (NIHSS) score ≥18, history of diabetes mellitus, TICI 2b, use of rescue therapy, not using a balloon-guided catheter or intravenous tissue plasminogen activator (IV t-PA), and >30 min to recanalization (p≤0.05). In multivariable analysis, age ≥80 years, occlusion site ICA/basilar, initial NIHSS score ≥18, diabetes, absence of IV t-PA, ≥3 passes, and use of rescue therapy were significant independent predictors of poor 90-day outcome in a model with good predictive power (c-index=0.80).ConclusionsAge, occlusion site, high NIHSS, diabetes, no IV t-PA, ≥3 passes, and use of rescue therapy are associated with poor 90-day outcome despite successful recanalization.

In this paper, we propose a novel graph-based approach for modeling the browsing data of Web users in order to understand their interests and their relationship with other users in the network. The aim was to identify users who are more influential while recommending pages to a network of users with similar interests. We call these users influential users and assign them an influence score that indicates the extent to which similar users follow their recommendations. By monitoring the browsing activity of influential users, we can identify their interest profiles as well as relevant pages quickly, and recommend these pages to users with similar interests. We call our proposed graph-based model a recommendation network. In this graph, nodes represent users and an edge between users u and v expresses the fact that u and v have similar interests, in particular the weight of the edge is the degree to which the user interest profiles match. Based on the graph, we build a recommendation system for Web pages, taking into account the influence of users in a network. Experimental results that measure the precision, with which recommended Web pages are visited by users, indicate that our system performs significantly better than traditional collaborative filtering-based recommender systems.

The increasing abundance of content on the web has made information filtering even more important in helping users find information related to their interests. Personalization of web search is one such effort, that aims at improving the efficiency with which a user finds results relevant to his query. This is done by keeping track of a user's individual interests, and taking it into account while returning search results. We propose a robust user modeling technique that implicitly creates a Dynamic Category Interest Tree (DCIT), using a general ontology of the web and a set of web pages collected over time that give an insight into a user's interests. The DCIT is designed to use a fuzzy classification technique to keep track of what topics a user is interested in, his amount of interest in a topic, as well as reflect his changing interests overtime. The DCIT consists of a general ontology of the web, where each node represents a topic and consists of keywords that are usually used to describe that topic or category. Additional keywords that the user frequently associates with a topic, such as names of important people, organizations, or a specialized terminology, etc. Are also incorporated into the relevant topic. We use the Apriori Algorithm to extract these associated words from the user's web history in order to more accurately define the user's categories of interest. The DCIT is initially created by a content based approach using only the browsing history of the user, and is later further enhanced through collaborative filtering using the k-nearest neighbour-based algorithm. We propose a technique to re-rank the results from a search engine according to their relevance to a user, based on his implicitly learned DCIT. According to experimental results, our DCIT based ranking often outperforms search engines such as Google when it comes to retrieving web pages that are more relevant to a user's interest.

Background and Purpose: Previous work has suggested that general anesthesia (GA) may have a negative impact on outcomes in acute ischemic stroke (AIS) patients undergoing endovascular therapy, however, those data predated the availability of the safer and possibly more effective stentriever devices. Methods: The investigator-initiated NASA Registry recruited North American sites to submit demographic, clinical, procedural (including use of GA versus local anesthesia [LA]), and site-adjudicated angiographic and clinical outcome data on consecutive patients treated with the Solitaire™ FR device. The primary outcomes were mRS at 90-days, mortality, and sICH. Results: A total of 281 patients from 18 centers were enrolled in this sub-study. GA was utilized in 69.8% (196/281) of patients. Baseline demographics were comparable between the LA and GA groups, except the former demonstrated a longer time to groin puncture (395.4±254 versus 337.4±208min, p=0.04) and slightly lower NIHSS (16.2±5.8 versus 18.8±6.9, p=0.002). Procedural factors were also similar, although lower balloon-guide catheter usage (22.4% versus 49.2%, p=0.0001) and longer fluoroscopy times (39.5±33 versus 28±22.8min, p=0.008) were seen in the LA versus GA cohorts, respectively. Recanalization (TICI≥2a) success (91.8 versus 86.8%, p=0.3) and the rate of sICH (7.1% versus 11.2%, p=0.4) were similar between the LA and GA patients, respectively. The primary outcome of mRS≤2 was achieved in 52.6% and 35.6% (OR 1.4[1.1-1.8], p=0.01) of LA and GA patients, respectively. In a multivariate analysis, hypertension, NIHSS, unsuccessful revascularization, and GA use (OR 3.3(1.6-7.1), p=0.001) were associated with death. To account for potential confounders, when only anterior circulation patients and patients who were electively intubated were included, there was a persistent difference in good outcomes in favor of the LA patients (50.7% versus 35.5%, OR 1.3[1.01-1.6], p=0.04). Conclusions: The NASA Registry has demonstrated that clinical outcomes and survival are significantly better in patients treated without GA without any increase in sICH. Future AIS trials should prospectively evaluate the effect of GA on outcomes.

Background and Purpose— Efficient and timely recanalization is an important goal in acute stroke endovascular therapy. Several studies demonstrated improved recanalization and clinical outcomes with the stent retriever devices compared with the Merci device. The goal of this study was to evaluate the role of the balloon guide catheter (BGC) and recanalization success in a substudy of the North American Solitaire Acute Stroke (NASA) registry. Methods— The investigator-initiated NASA registry recruited 24 clinical sites within North America to submit demographic, clinical, site-adjudicated angiographic, and clinical outcome data on consecutive patients treated with the Solitaire Flow Restoration device. BGC use was at the discretion of the treating physicians. Results— There were 354 patients included in the NASA registry. BGC data were reported in 338 of 354 patients in this subanalysis, of which 149 (44%) had placement of a BGC. Mean age was 67.3±15.2 years, and median National Institutes of Health Stroke Scale score was 18. Patients with BGC had more hypertension (82.4% versus 72.5%; P =0.05), atrial fibrillation (50.3% versus 32.8%; P =0.001), and were more commonly administered tissue plasminogen activator (51.6% versus 38.8%; P =0.02) compared with patients without BGC. Time from symptom onset to groin puncture and number of passes were similar between the 2 groups. Procedure time was shorter in patients with BGC (120±28.5 versus 161±35.6 minutes; P =0.02), and less adjunctive therapy was used in patients with BGC (20% versus 28.6%; P =0.05). Thrombolysis in cerebral infarction 3 reperfusion scores were higher in patients with BGC (53.7% versus 32.5%; P P =0.002) and good clinical outcome at 3 months were superior in patients with BGC compared with patients without (51.6% versus 35.8%; P =0.02). Multivariate analysis demonstrated that the use of BGC was an independent predictor of good clinical outcome (odds ratio, 2.5; 95% confidence interval, 1.2–4.9). Conclusions— Use of a BGC with the Solitaire Flow Restoration device resulted in superior revascularization results, faster procedure times, decreased need for adjunctive therapy, and improved clinical outcome.

This paper proposes a theory to analyze the specialization of banking activities based upon the different functions that banks perform when rendering a variety of financial services. The functional difference in the services performed by banks is based upon two dimensions: the degree of information asymmetry involved in providing the service, and the degree of verifiability of the value of the service rendered. This has implications for the length of banking relationships and also determines whether banks develop the right degree of skill specialization and resource intensity for the existing task mix. Costly overspecialization occurs in certain deal type transactions and underspecialization occurs in relationship type transactions. The paper examines how bank-client relationships are structured and proposes an explanation for phenomena such as bank syndication. First-mover advantages and monopoly skills are also shown to be natural outcomes of the model. The analysis has implications for banking regulation, such as for the Glass–Steagall Act, in the sense that it analyzes the effects of this specialization, first enacted within the spirit of the Act.

BackgroundLimited post-marketing data exist on the use of the Solitaire FR device in clinical practice. The North American Solitaire Stent Retriever Acute Stroke (NASA) registry aimed to assess the real world performance of the Solitaire FR device in contrast with the results from the SWIFT (Solitaire with the Intention for Thrombectomy) and TREVO 2 (Trevo versus Merci retrievers for thrombectomy revascularization of large vessel occlusions in acute ischemic stroke) trials.MethodsThe investigator initiated NASA registry recruited North American sites to submit retrospective angiographic and clinical outcome data on consecutive acute ischemic stroke (AIS) patients treated with the Solitaire FR between March 2012 and February 2013. The primary outcome was a Thrombolysis in Myocardial Ischemia (TIMI) score of ≥2 or a Treatment in Cerebral Infarction (TICI) score of ≥2a. Secondary outcomes were 90 day modified Rankin Scale (mRS) score, mortality, and symptomatic intracranial hemorrhage.Results354 patients underwent treatment for AIS using the Solitaire FR device in 24 centers. Mean time from onset to groin puncture was 363.4±239 min, mean fluoroscopy time was 32.9±25.7 min, and mean procedure time was 100.9±57.8 min. Recanalization outcome: TIMI ≥2 rate of 83.3% (315/354) and TICI ≥2a rate of 87.5% (310/354) compared with the operator reported TIMI ≥2 rate of 83% in SWIFT and TICI ≥2a rate of 85% in TREVO 2. Clinical outcome: 42% (132/315) of NASA patients demonstrated a 90 day mRS ≤2 compared with 37% (SWIFT) and 40% (TREVO 2). 90 day mortality was 30.2% (95/315) versus 17.2% (SWIFT) and 29% (TREVO 2).ConclusionsThe NASA registry demonstrated that the Solitaire FR device performance in clinical practice is comparable with the SWIFT and TREVO 2 trial results.

Purpose. Arteriovenous malformations (AVMs) in the basal ganglia and thalamus have a more aggressive natural history with a higher morbidity and mortality than AVMs in other locations. Optimal treatment—complete obliteration without new neurological deficits—is often challenging. We present a patient with a large bilateral basal ganglia and thalamic AVM successfully treated with hypofractionated stereotactic radiosurgery (HFSRS) with intensity modulated radiotherapy (IMRT).Methods. The patient was treated with hypofractionated stereotactic radiosurgery to 30 Gy at margin in 5 fractions of 9 static fields with a minimultileaf collimator and intensity modulated radiotherapy.Results. At 10 months following treatment, digital subtraction angiography showed complete obliteration of the AVM.Conclusions. Large bilateral thalamic and basal ganglia AVMs can be successfully treated with complete obliteration by HFSRS with IMRT with relatively limited toxicity. Appropriate caution is recommended.

Background and Purpose: Endovascular techniques are frequently employed to treat large artery occlusion in acute ischemic stroke (AIS). We sought to determine the predictors and clinical impact of intracranial hemorrhage (ICH) after endovascular therapy. Methods: Retrospective analysis of consecutive patients presenting to 13 high-volume stroke centers with AIS due to proximal occlusion in the anterior circulation who underwent endovascular treatment within 8 hours from symptom onset. Logistic regression was performed to determine the variables associated with ICH, hemorrhagic infarction (HI), and parenchymal hematomas (PH) as well as 90-day poor outcome (mRS≥3), and mortality. Results: A total of 1122 patients (mean age, 67±15 years; median NIHSS, 17 [IQR13-20]) were studied. Independent predictors for HI included diabetes mellitus (OR 2.27, 95%CI [1.58-3.26], p Conclusions: In AIS patients undergoing endovascular therapy, diabetes mellitus, longer time to treatment, and Merci thrombectomy appear to be associated with a higher risk for HI while atrial fibrillation appears to result in a higher risk for PH. While both HI and PH are associated with poor outcomes only PH is associated with higher mortality.