Recognition Of Ischemic Stroke Research Articles

Abstract TP87: Discrete-event Simulation Of The Prehospital Stage Of The Acute Ischemic Stroke

Introduction: It is critical to treat Acute Ischemic Stroke (AIS) patients quickly; however, treatment eligibility is dependent on the arrival time to the nearest stroke center by Private Vehicle (PV) or Emergency Medical Services (EMS). The duration in the prehospital stage is defined as the period from stroke onset to arrival at a non-stroke center, primary stroke center or comprehensive stroke center. This study aims to detail the prehospital stage of suspected AIS patients in order to identify opportunities for process improvements. Methods: Discrete-event simulation (DES) is a powerful decision-making tool and robust methodology for evaluating treatment processes and allows for improvements to be tested before implementing changes using real resources. A DES is developed using ARENA software to model the prehospital stage of suspected AIS patients. The process steps include two treatment pathways, PV and EMS. The pathways differ because those patients arriving via EMS allow for the activation of the code stroke protocol prior to hospital arrival. The drive times from the stroke scene to the hospital were kept constant at 40 min assuming a suburban transport. The model assumes 60% recognition of ischemic stroke using EMS stroke screening tools and large vessel occlusion screening tools and a 90% probability that the paramedics correctly screen for a potential stroke and bypass to a stroke center. The primary outcome measure is median onset-to-door time, defined as the time from onset of stroke symptoms to arrival to the hospital. The Mann-Whitney U test is used for evaluating statistical significance among the outputted median onset-to-door time for all scenarios. Results: The following process improvement scenarios were run: reducing the waiting time for EMS on average from 7 min to 5 min and reducing delays on-scene on average from 20 min to 15 min, and the median onset-to-door time reductions were from a median of 57.53 min to a median of 51.41 min (p<0.0001). Conclusions: Reduction in onset to arrival times is possible by reducing waiting time for the EMS and delay on-scene of the stoke.

Abstract P583: Comparison of FAST-S to BEFAST-S for Pediatric Stroke: A Comprehensive Stroke Center Retrospective Analysis

Objective: To assess the demographic characteristics and presenting symptoms in a cohort of pediatric patients with ischemic stroke and develop a tool to improve recognition of ischemic stroke at the institution and in the community. Methods: We conducted a retrospective review of children aged 1 month to 18 years with radiologically confirmed ischemic stroke admitted to the University of Kentucky between January 2013 and June 2020. Characteristics such as age, sex, and diagnosis were recorded. The FAST (Face, Arms, Speech) and BEFAST (Balance, Eyes, Face, Arms, Speech) mnemonics were applied to all patients. We then applied the FAST-S tool and used the novel BEFAST-S. FAST-S adds new onset seizure to the previously validated tool. Results: For the study period, we identified 158 cases. Most patients were ≥ 3 years of age (n=113) and most were male (n=96). About one third (31%, n=50) of presentations concerning for stroke had diagnosed ischemic stroke at time of discharge; the majority were ≥ 3 years of age (n=31). Strokes were commonly associated with trauma (24%, n=12) and infection (22%, n=11). Common mimics for stroke included seizure in the absence of stroke (30%, n=33), migraine (18%, n=20), and conversion disorder (13%, n=14). FAST and BEFAST each identified the same 30 patients as having ischemic stroke (60%), with 26 patients being ≥ 3 years of age. Inclusion of new onset seizures (FAST-S/BEFAST-S) correctly identified one additional patient ≥ 3 years of age (87%, n=27) and nine additional patients under 3 (n=19, 78% versus n=4, 21%). New onset seizure reduced the number of missed strokes regardless of age from 40% (n=20) to 16% (n=8). Conclusions: Although BEFAST improves the sensitivity of identification of ischemic strokes in adults, it did not identify additional strokes beyond FAST in our pediatric population. Inclusion of new onset seizure in addition to either FAST or BEFAST, however, reduced the number of missed strokes by at least half, particularly in children < 3 years of age. Thus, education of FAST-S or BEFAST-S may be useful for providers and emergency services.

Selection of appropriate architecture and parameters of neural network for images recognition and classification

In this article the image recognition and classification problem is considered. Further, there will be suggestion of the new way of using a convolutional neural network to solve the considering problem in an example of a particular task, such as the recognition of ischemic stroke on magnetic resonance images. Moreover, it is considering reasons of choosing the image classification and making arguments obtained by a literary analysis of studies affecting the task. Authors have investigated different neural networks architectures and the accuracy depending on training speed, numbers of layers, numbers of epochs and mini sample size. Experiments result is presented in the table form. During the studying, magnetic resonance images of different diseases having same signals with a considering pathology in diffusion-weighted images format has been selected for the training of the convolutional neural network and for getting the most favourable result. In the result, a suitable architecture with defined parameters has been selected to get the highest accuracy.

Why were the benefits of tPA exaggerated?

News magazine US News and World Report began an article aboutthrombolytic treatment of acute stroke with the following anecdote: One Wednesday morning in January, 36-year-old Laurie Lucas was rushingabout, dressing her daughters for school and talking on the phone, when astrange confusion swept over her. She felt woozy. Her right arm flailed aboutand her right leg went weak. Paramedics arriving at Lucas's Sanford, Florida,home thought she was having epileptic seizures, but brain scans revealed ablockage of an artery that supplies the brain with blood. Lucas, a physicallyfit former professional cheerleader, had suffered a massive stroke... If Lucashad been stricken a year ago, before a new treatment was developed, she almostcertainly would havedied.1(p62) This story is interesting but misleading. It is not plausible thatphysicians could accurately conclude that Laurie Lucas “almost certainlywould have died” without treatment. Nor is it true that“massive” strokes are likely to benefit from thrombolytictreatment.2 Inaddition to several anecdotes, the US News and World Report articleincludes “expert” testimony in which prominent physiciansexaggerate the efficacy and effectiveness of the new treatment. Such exaggerations also appear in medical journals and other professionalvenues. Specialists have announced “the decade of thebrain,”3 a“new era of proactive rather than reactive stroketherapy,”4 and“transformation from a realm of fatalism to a field of therapeuticopportunities.”5Landis and associates write, “With the tools in hand, recognition ofischemic stroke as a medical emergency and application of prudent thrombolytictechniques will have a major impact on stroke morbidity andmorality.”6(p226)Some commentators even warn of lawsuits if thrombolytic agents are not givento eligible strokepatients.7 Theseclaims are without scientificbasis.8,9,10Yet, robust exaggerations and effusive sentiments of this sort appear notmerely in the literature concerning acute stroke but on other topics as well.They are a serious problem because they exhibit interpretation bias, which maylead to errors in clinical judgment and to unrealistic patientexpectations.11