Computer-assisted analysis of routine EEG to identify hidden biomarkers of epilepsy: A systematic review.

Background: Computational analysis of routine electroencephalogram (rEEG) could improve the accuracy of epilepsy diagnosis. We aim to systematically assess the diagnostic performances of computed biomarkers for epilepsy in individuals undergoing rEEG. Methods: We searched MEDLINE, EMBASE, EBM reviews, IEEE Explore and the grey literature for studies published between January 1961 and December 2022. We included studies reporting a computational method to diagnose epilepsy based on rEEG without relying on the identification of interictal epileptiform discharges or seizures. Diagnosis of epilepsy as per a treating physician was the reference standard. We assessed the risk of bias using an adapted QUADAS-2 tool. Results: We screened 10 166 studies, and 37 were included. The sample size ranged from 8 to 192 (mean=54). The computed biomarkers were based on linear (43%), non-linear (27%), connectivity (38%), and convolutional neural networks (10%) models. The risk of bias was high or unclear in all studies, more commonly from spectrum effect and data leakage. Diagnostic accuracy ranged between 64% and 100%. We observed high methodological heterogeneity, preventing pooling of accuracy measures. Conclusion: The current literature provides insufficient evidence to reliably assess the diagnostic yield of computational analysis of rEEG. Significance: We provide guidelines regarding patient selection, reference standard, algorithms, and performance validation.

Diagnostic accuracy of ancillary tests for death by neurologic criteria: a systematic review and meta-analysis.

PURPOSE: Ancillary tests are frequently used in death determination by neurologic criteria (DNC), particularly when the clinical neurologic examination is unreliable. Nevertheless, their diagnostic accuracy has not been extensively studied. Our objective was to synthesize the sensitivity and specificity of commonly used ancillary tests for DNC. SOURCE: We performed a systematic review and meta-analysis by searching MEDLINE, EMBASE, Cochrane databases, and CINAHL Ebsco from their inception to 4 February 2022. We selected cohort and case-control studies including patients with 1) clinically diagnosed death by neurologic criteria or 2) clinically suspected death by neurologic criteria who underwent ancillary testing for DNC. We excluded studies without a priori diagnostic criteria and studies conducted solely on pediatric patients. Accepted reference standards were clinical examination, four-vessel conventional angiography, and radionuclide imaging. Data were directly extracted from published reports. We assessed the methodological quality of studies with the QUADAS-2 tool and estimated ancillary test sensitivities and specificities using hierarchical Bayesian models with diffuse priors. PRINCIPAL FINDINGS: Overall, 137 records met the selection criteria. One study (0.7%) had a low risk of bias in all QUADAS-2 domains. Among clinically diagnosed death by neurologic criteria patients (n = 8,891), ancillary tests had similar pooled sensitivities (range, 0.82-0.93). Sensitivity heterogeneity was greater within (σ = 0.10-0.15) than between (σ = 0.04) ancillary test types. Among clinically suspected death by neurologic criteria patients (n = 2,732), pooled ancillary test sensitivities ranged between 0.81 and 1.00 and specificities between 0.87 and 1.00. Most estimates had high statistical uncertainty. CONCLUSION: Studies assessing ancillary test diagnostic accuracy have an unclear or high risk of bias. High-quality studies are required to thoroughly validate ancillary tests for DNC. STUDY REGISTRATION: PROSPERO (CRD42013005907); registered 7 October 2013.

RéSUMé: OBJECTIF: Les examens auxiliaires sont fréquemment utilisés dans la détermination du décès selon des critères neurologiques (DCN), en particulier lorsque l'examen neurologique clinique n'est pas fiable. Néanmoins, leur précision diagnostique n'a pas été étudiée de manière approfondie. Notre objectif était de synthétiser la sensibilité et la spécificité des examens auxiliaires couramment utilisés pour la DCN. SOURCES: Nous avons réalisé une revue systématique et une méta-analyse en effectuant des recherches dans les bases de données MEDLINE, EMBASE, Cochrane et CINAHL Ebsco de leur création jusqu'au 4 février 2022. Nous avons sélectionné des études de cohorte et cas témoins incluant des patients présentant 1) un décès selon des critères neurologiques diagnostiqué cliniquement ou 2) un décès selon des critères neurologiques soupçonné cliniquement qui ont été soumis à des examens auxiliaires pour un DCN. Nous avons exclu les études sans critères diagnostiques a priori et les études menées uniquement auprès de patients pédiatriques. Les normes de référence acceptées étaient l'examen clinique, l'angiographie conventionnelle à quatre vaisseaux et l'imagerie nucléaire. Les données ont été directement extraites de comptes rendus publiés. Nous avons évalué la qualité méthodologique des études avec l'outil QUADAS-2 et estimé les sensibilités et les spécificités des examens auxiliaires à l'aide de modèles hiérarchiques bayésiens avec des distributions préalables diffuses. CONSTATATIONS PRINCIPALES: Au total, 137 études répondaient aux critères de sélection. Une étude (0,7 %) présentait un faible risque de biais dans tous les domaines de QUADAS-2. Parmi les patients ayant reçu un diagnostic clinique de décès selon des critères neurologiques (n = 8891), les examens auxiliaires présentaient des sensibilités combinées similaires (intervalle de 0,82 à 0,93). L'hétérogénéité de sensibilité était plus grande au sein (σ = 0,10-0,15) plutôt qu'entre (σ = 0,04) les types d'examens auxiliaires. Parmi les patients cliniquement soupçonnés de décès selon des critères neurologiques (n = 2732), les sensibilités combinées des examens auxiliaires variaient entre 0,81 et 1,00 et les spécificités entre 0,87 et 1,00. La plupart des estimations comportaient une grande incertitude statistique. CONCLUSION: Les études évaluant la précision diagnostique des examens auxiliaires présentent un risque de biais incertain ou élevé. Des études de haute qualité sont nécessaires pour valider en profondeur les examens auxiliaires pour la DCN. ENREGISTREMENT DE L'éTUDE: PROSPERO (CRD42013005907); enregistrée le 7 octobre 2013.

Computer-assisted analysis of routine electroencephalogram to identify hidden biomarkers of epilepsy: protocol for a systematic review.

INTRODUCTION: The diagnosis of epilepsy frequently relies on the visual interpretation of the electroencephalogram (EEG) by a neurologist. The hallmark of epilepsy on EEG is the interictal epileptiform discharge (IED). This marker lacks sensitivity: it is only captured in a small percentage of 30 min routine EEGs in patients with epilepsy. In the past three decades, there has been growing interest in the use of computational methods to analyse the EEG without relying on the detection of IEDs, but none have made it to the clinical practice. We aim to review the diagnostic accuracy of quantitative methods applied to ambulatory EEG analysis to guide the diagnosis and management of epilepsy. METHODS AND ANALYSIS: The protocol complies with the recommendations for systematic reviews of diagnostic test accuracy by Cochrane. We will search MEDLINE, EMBASE, EBM reviews, IEEE Explore along with grey literature for articles, conference papers and conference abstracts published after 1961. We will include observational studies that present a computational method to analyse the EEG for the diagnosis of epilepsy in adults or children without relying on the identification of IEDs or seizures. The reference standard is the diagnosis of epilepsy by a physician. We will report the estimated pooled sensitivity and specificity, and receiver operating characteristic area under the curve (ROC AUC) for each marker. If possible, we will perform a meta-analysis of the sensitivity and specificity and ROC AUC for each individual marker. We will assess the risk of bias using an adapted QUADAS-2 tool. We will also describe the algorithms used for signal processing, feature extraction and predictive modelling, and comment on the reproducibility of the different studies. ETHICS AND DISSEMINATION: Ethical approval was not required. Findings will be disseminated through peer-reviewed publication and presented at conferences related to this field. PROSPERO REGISTRATION NUMBER: CRD42022292261.

Infratentorial Brain Injury Among Patients Suspected of Death by Neurologic Criteria: A Systematic Review and Meta-analysis.

BACKGROUND AND OBJECTIVES: There is a paucity of data on the frequency and prognosis of infratentorial brain injury among patients suspected of death by neurologic criteria (DNC), which likely contributes to scientific uncertainty regarding the role of isolated brainstem death in DNC determination. Our aim was to synthesize the prevalence, characteristics, and evolution of infratentorial brain injury, including isolated brainstem death, among patients suspected of DNC. METHODS: We conducted a systematic review by searching Medline, Embase, EBM Reviews, CINAHL Complete, and the gray literature from inception to March 26, 2021. We selected cohort and cross-sectional studies, case reports, and case series that included patients suspected of DNC. Two study investigators independently performed study selection, data collection, and risk of bias assessment. Our primary outcomes were the respective prevalence of infratentorial brain injury and isolated brainstem death, which we meta-analyzed using mixed-effects Bayesian hierarchical models with diffuse priors. Our secondary outcomes were the characteristics and evolution of patients with infratentorial brain injury and isolated brainstem death. RESULTS: Twenty-one studies met the selection criteria, most of which were of moderate to high risk of bias. Among patients suspected of DNC, the prevalence of infratentorial brain injury ranged from 2% to 16% (n = 3,602, mean prevalence: 6.3%, 95% highest density interval [2.4%-14.2%]), whereas the prevalence of isolated brainstem death ranged from 1% to 4% (n = 3,692, mean prevalence: 1.5%, 95% highest density interval [0.5%-3.9%]). A total of 38 isolated brainstem death cases with data on clinical characteristics and/or evolution were included. All had infratentorial strokes. Twenty patients had EEG background activity in the α or θ frequencies, 19 had preserved cerebral blood flow, 2 had preserved supratentorial cerebral perfusion, 2 had cortical responses to visual evoked potentials, and 1 had cortical responses to somatosensory evoked potentials. At the latest follow-up, 28 had progressed to whole-brain death. DISCUSSION: Studies with moderate to high risk of bias suggest that infratentorial brain injury is relatively uncommon among patients suspected of DNC. Isolated brainstem death is rarer and seems to carry a high risk of progression to whole-brain death. These findings require further high-quality investigation.

Prospective Evaluation of a Two-Scale Protocol for Prehospital Large Vessel Occlusion Detection.

Background and purposes: Stroke severity scales may expedite prehospital large vessel occlusion (LVO) stroke detection, but few are validated for paramedic use. We evaluated the feasibility of introducing the Cincinnati Stroke Triage Assessment Tool (C-STAT) in the field and its capacity to detect LVO stroke.Methods: We performed a prospective paramedic-based study assessing C-STAT in the field on patients currently redirected to two comprehensive stroke centers (CSC), based on a Cincinnati Prehospital Stroke Scale (CPSS) score of 3/3. C-STAT was administered by on-site paramedics with telephone guidance from trained centralized clinical support paramedics.Results: Between October 2018 and November 2019, C-STAT scores were obtained in 188/218 (86.2%) patients, among which 118/188 (62.8%) were positive. Paramedics reported performing the C-STAT in less than 5 minutes on 170/188 (90.4%) patients and noted no difficulties administering the scale in 151/188 (80.3%). A positive C-STAT identified 51/68 (75%) LVO strokes in the cohort, demonstrating a 43% (95% CI: 38%-48%) positive and 76% (95% CI: 66%-83%) negative predictive value for LVO stroke diagnosis. In a cohort of 100 patients with CPSS 3/3, requiring a positive C-STAT for redirection would decrease CSC patient volume by 37 but miss 9 of 36 LVO strokes.Conclusion: Prehospital administration of the C-STAT was feasible, using a model of minimal paramedic training and real-time telephone guidance. A protocol based on both a CPSS 3/3 and a positive C-STAT would decrease CSC redirected patient volume by one-third but would miss one-quarter of LVO strokes when compared to a CPSS-based protocol.

Three-month functional outcomes following endovascular thrombectomy during the first wave of the COVID-19 pandemic: a Canadian single-center cohort study.

BACKGROUND: The COVID-19 pandemic has disrupted acute stroke care logistics, including delays in hyperacute management and decreased monitoring following endovascular therapy (EVT). We aimed to assess the impact of the pandemic on 90-day functional outcome among patients treated with EVT. METHODS: This is an observational cohort study including all patients evaluated for an acute stroke between March 30, 2020 and September 30, 2020 (pandemic cohort) and 2019 (reference cohort) in a high-volume Canadian academic stroke center. We collected baseline characteristics, acute reperfusion treatment and management metrics. For EVT-treated patients, we assessed the modified Rankin score (mRS) at 90 days. We evaluated the impact of the pandemic on a 90-day favourable functional status (defined as mRS 0-2) and death using multivariable logistic regressions. RESULTS: Among 383 and 339 patients included in the pandemic and reference cohorts, baseline characteristics were similar. Delays from symptom onset to evaluation and in-house treatment were longer during the early first wave, but returned to reference values in the subsequent months. Among the 127 and 136 EVT-treated patients in each respective cohort, favourable 90-day outcome occurred in 53/99 (53%) vs 52/109 (48%, p=0.40), whereas 22/99 (22%) and 28/109 (26%, p=0.56) patients died. In multivariable regressions, the pandemic period was not associated with 90-day favourable functional status (aOR 1.27, 95% CI 0.60 to 2.56) or death (aOR 0.74, 95% CI 0.33 to 1.63). CONCLUSION: In this single-center cohort study conducted in a Canadian pandemic epicenter, the first 6 months of the COVID-19 pandemic did not impact 90-day functional outcomes or death among EVT-treated patients.

Clinical evaluation and ancillary testing for the diagnosis of death by neurologic criteria: a cross-sectional survey of Canadian intensivists.

PURPOSE: Trust in the deceased organ donation process relies on the expectation that the diagnosis of death by neurologic criteria (DNC) is accurate and reliable. The objective of this study was to assess the perceptions and approaches to DNC diagnosis among Canadian intensivists. METHODS: We conducted a self-administered, online, cross-sectional survey of Canadian intensivists. Our sampling frame included all intensivists practicing in Canadian institutions. Results are reported using descriptive statistics. RESULTS: Among 550 identified intensivists, 249 (45%) completed the survey. Respondents indicated they would be comfortable diagnosing DNC based on clinical criteria alone in cases where there is movement in response to stimulation (119/248; 48%); inability to evaluate upper/lower extremity responses (84/249; 34%); spontaneous peripheral movement (76/249; 31%); inability to evaluate both oculocephalic and oculo-caloric reflexes (40/249; 16%); presence of high cervical spinal cord injury (40/249; 16%); and within 24 hr of hypoxemic-ischemic brain injury (38/247; 15%). Most respondents agreed that an ancillary test should always be conducted when a complete clinical evaluation is impossible (225/241; 93%); when there is possibility of a residual sedative effect (216/242; 89%); when the mechanism for brain injury is unclear (172/241; 71%); and if isolated brainstem injury is suspected (142/242; 59%). Sixty-six percent (158/241) believed that ancillary tests are sensitive and 55% (132/241) that they are specific for DNC. Respondents considered the following ancillary tests useful for DNC: four-vessel conventional angiography (211/241; 88%), nuclear imaging (179/240; 75%), computed tomography (CT) angiography (156/240; 65%), and CT perfusion (134/240; 56%). CONCLUSION: There is variability in perceptions and approaches to DNC diagnosis among Canadian intensivists, and some practices are inconsistent with national recommendations.

RéSUMé: OBJECTIF: La confiance dans le processus de don d'organes de donneurs décédés repose sur l'attente que le diagnostic de décès déterminé par des critères neurologiques (DDN) soit précis et fiable. L'objectif de cette étude était d'évaluer les perceptions et les approches du diagnostic de DDN chez les intensivistes canadiens. MéTHODE: Nous avons mené un sondage transversal auto-administré et en ligne auprès des intensivistes canadiens. Notre base d'échantillonnage comprenait tous les intensivistes exerçant dans des établissements canadiens. Les résultats sont présentés à l'aide de statistiques descriptives. RéSULTATS: Parmi les 550 intensivistes identifiés, 249 (45 %) ont répondu au sondage. Les répondants ont indiqué qu'ils seraient à l'aise de diagnostiquer un DDN en fonction de critères cliniques seulement dans les cas où il y a : un mouvement en réponse à une stimulation (119/248; 48 %); une incapacité à évaluer les réponses des membres supérieurs et inférieurs (84/249; 34 %); un mouvement périphérique spontané (76/249; 31 %); une incapacité à évaluer à la fois les réflexes oculo-céphaliques et vestibulo-oculaires (40/249; 16 %); la présence de lésions médullaires cervicales hautes (40/249; 16 %); et dans les 24 heures suivant une lésion cérébrale hypoxémique-ischémique (38/247; 15 %). La plupart des répondants étaient d'accord pour dire qu'un test auxiliaire devrait toujours être réalisé lorsqu'une évaluation clinique complète est impossible (225/241; 93 %); lorsqu'il y a possibilité d'un effet sédatif résiduel (216/242; 89 %); lorsque le mécanisme de la lésion cérébrale n'est pas clair (172/241; 71 %); et si une lésion isolée du tronc cérébral est suspectée (142/242; 59 %). Soixante-six pour cent (158/241) des répondants étaient d'avis que les tests auxiliaires étaient sensibles et 55 % (132/241) qu'ils étaient spécifiques pour le DDN. Les répondants ont jugé utiles les tests auxiliaires suivants pour le DDN : l'angiographie conventionnelle des quatre vaisseaux (211/241; 88 %), l'imagerie nucléaire (179/240; 75 %), l'angiographie par tomodensitométrie (TDM) (156/240; 65 %) et la perfusion en TDM (134/240; 56 %). CONCLUSION: Les perceptions et les approches du diagnostic de DDN varient parmi les intensivistes canadiens, et certaines pratiques ne sont pas conformes aux recommandations nationales.

Assessment of Canadian Public Automated External Defibrillator Registries.

BACKGROUND: Public automated external defibrillator (AED) registries aim to increase layperson defibrillation for victims of out-of-hospital cardiac arrest. This study aims to characterize Canadian AED registries and the process by which these databases are updated and used. METHODS: A survey was administered to representatives from each eligible AED registry. Collected data included information on registry management, AED validation process, linkage to emergency medical dispatch (EMD), and number of AEDs per registry. Three unregistered AEDs in each region were then located and registered into their respective registry. The primary endpoint was the proportion of AEDs that became visible in the registry within 1 month. RESULTS: Of the 9 Canadian provinces that have registries, 7 are provincial, whereas 2 contain smaller independent registries. The survey was completed by 90% of contacted registries. The number of AEDs per registry ranged from 21 to 443 per 100,000 persons. Six registries are managed by a provincial government, 6 use a standardized validation process, and 8 are linked to EMD. Of the 21 AEDs registered by our study personnel in 7/10 registries, 9 (43%) were made available to the public within 1 month of registration. Only 1 registry employed an AED validation process that included direct contact with AED managers. CONCLUSIONS: Canadian public AED registries demonstrate significant differences in their governance and administrative processes. A majority of registries are integrated with EMD for out-of-hospital cardiac arrest, but not all registries use a standardized validation process to ensure accuracy of AED information submitted by the public.

INTRODUCTION: Les registres publics de défibrillateurs externes automatiques (DEA) ont pour objectif d'accroître la défibrillation par des non-professionnels aux victimes d'arrêt cardiaque extra-hospitalier. La présente étude a pour objectif de décrire les registres canadiens de DEA et le processus par lequel ces bases de données sont actualisées et utilisées. MÉTHODES: Les représentants de chaque registre admissible de DEA ont répondu à une enquête. Les données recueillies étaient les suivantes : les renseignements sur la prise en charge du registre, le processus de validation des DEA, la liaison avec la répartition médicale d'urgence (RMU) et le nombre de DEA par registre. Trois DEA non enregistrés dans chaque région ont ensuite été localisés et inscrits dans leur registre respectif. L'issue principale était la proportion de DEA qui étaient visibles au registre en un mois. RÉSULTATS: Dans les neuf provinces canadiennes qui ont des registres, sept ont des registres provinciaux, alors que deux comptaient des registres indépendants plus petits. Quatre-vingt-dix pour cent des représentants des registres ont rempli l'enquête. Le nombre de DEA par registre allait de 21 à 443 par 100 000 personnes. Six registres sont gérés par les autorités provinciales, six utilisent un processus de validation standardisé et huit sont liés à la RMU. Parmi les 21 DEA enregistrés par notre personnel d'étude dans 7/10 registres, neuf (43 %) ont été mis à la disposition du public un mois après leur enregistrement. Seul un registre utilisait un processus de validation des DEA qui consistait en un contact direct avec les gestionnaires de DEA. CONCLUSIONS: Les registres publics canadiens de DEA démontrent des différences significatives dans leurs processus administratifs et de gestion. La majorité des registres sont intégrés à la RMU pour la gestion des arrêts cardiaques extra-hospitaliers, mais ce ne sont pas tous les registres qui utilisent un processus de validation standardisé pour garantir l'exactitude des renseignements sur les DEA soumis par le public.

Early Impact of the COVID-19 Pandemic on Acute Stroke Treatment Delays.

This is an observational cohort study comparing 156 patients evaluated for acute stroke between March 30 and May 31, 2020 at a comprehensive stroke center with 138 patients evaluated during the corresponding time period in 2019. During the pandemic, the proportion of COVID-19 positive patients was low (3%), the time from symptom onset to hospital presentation was significantly longer, and a smaller proportion of patients underwent reperfusion therapy. Among patients directly evaluated at our institution, door-to-needle and door-to-recanalization metrics were significantly longer. Our findings support concerns that the current pandemic may have a negative impact on the management of acute stroke.

Central neurogenic hyperventilation in conscious patients due to CNS neoplasm: a case report and review of the literature on treatment.

BACKGROUND: Central neurogenic hyperventilation (CNH) is increasingly reported in conscious patients with a CNS neoplasm. We aimed to synthesize the available data on the treatment of this condition to guide clinicians in their approach. METHODS: We describe the case of a 39-year-old conscious woman with CNH secondary to glioma brainstem infiltration for whom hyperventilation was aborted with hydromorphone, dexamethasone, and brainstem radiotherapy. We then performed a review of the literature on the treatment of CNH in conscious patients due to a CNS neoplasm. RESULTS: A total of 31 studies reporting 33 cases fulfilled the selection criteria. The underlying neoplasm was lymphoma in 15 (45%) and glioma in 13 (39%) patients. Overall, CNH was aborted in 70% of cases. Opioids and sedatives overall seemed useful for symptom relief, but the benefit was often of short duration when the medication was administered orally or subcutaneously. Methadone and fentanyl were successful but rarely used. Chemotherapy was most effective in patients with lymphoma (89%), but not glioma (0%) or other neoplasms (0%). Patients with lymphoma (80%) and other tumors (100%) responded to radiotherapy more frequently than patients with glioma (43%). Corticosteroids were moderately effective. Subtotal surgical resection was successful in the 3 cases for which it was attempted. CONCLUSION: Definitive treatment of the underlying neoplasm may be more successful in aborting hyperventilation. Variable rates of palliation have been observed with opioids and sedatives. Treatment of CNH is challenging but successful in a majority of cases.

Automated External Defibrillator Geolocalization with a Mobile Application, Verbal Assistance or No Assistance: A Pilot Randomized Simulation (AED G-MAP).

OBJECTIVE: Shockable rythms are common among victims of witnessed public out-of-hospital cardiac arrest (OHCA), but bystander defibrillation with a public automated external defibrillator (PAED) is rare. Instructions from the emergency medical dispatcher and mobile applications were developed to expedite the localization of PAEDs, but their effectiveness has not been compared. METHODS: Participants were enrolled in a three-armed randomized simulation where they witnessed a simulated OHCA on a university campus, were instructed to locate a PAED and provide defibrillation. Participants were stratified and randomized to: (1) no assistance in finding the PAED, (2) assistance from a geolocalization mobile application (AED-Quebec), or (3) verbal assistance. Data collectors tracked each participant's time elapsed and distance traveled to shock. RESULTS: Of the 52 volunteers participating in the study (46% male, mean age 37), 17 were randomized to the no assistance group, 18 to the mobile application group and 17 to the verbal group. Median (IQR) time to shock was, respectively, 10:00 min (7:49-10:00), 9:44 (6:30-10:00), and 5:23 (4:11-9:08), with statistically significant differences between the verbal group and the other groups (p ≤ 0.01). The success rate for defibrillation in <10 minutes was 35%, 56% and 76%. Multivariate regression of all participants pooled showed that knowledge of campus geography was the strongest predictor of shock in <10 minutes (aOR =14.3, 95% CI 1.85-99.9). Among participants without prior geographical knowledge, verbal assistance provided a trend towards decreased time to shock, but the differences over no assistance (7:28 vs. 10:00, p = 0.10) and over the mobile app (7:28 vs. 10:00, p = 0.11) were not statistically significant. CONCLUSION: In a simulated environment, verbally providing OHCA bystanders with the nearest PAED's location appeared to be effective in reducing the time to defibrillation in comparison to no assistance and to an AED geolocalizing mobile app, but further research is required to confirm this hypothesis, ascertain the external validity of these results, and evaluate the real-life implications of these strategies.

Stroke Mimics Transported by Emergency Medical Services to a Comprehensive Stroke Center: The Magnitude of the Problem.

BACKGROUND: Despite the use of validated prehospital stroke scales, stroke mimics are frequent among patients transported by Emergency Medical Services to the Emergency Department. We aimed to describe the frequency and characteristics of neurological and non-neurological mimics transported to a comprehensive stroke center for acute stroke evaluation. METHODS: This was a retrospective analysis of a database consisting of all consecutive patients with suspected stroke transported to the Emergency Department of a comprehensive stroke center during an 18-month period. Hospital charts and neuroimaging were utilized to adjudicate the final diagnosis (acute stroke, stroke mimic, and specific underlying diagnoses). RESULTS: Nine hundred fifty patients were transported with suspected stroke, among whom 405 (42.6%) were stroke mimics (age 66.9 ± 17.1 years; 54% male). Neurological mimics were diagnosed in 223 (55.1%) patients and mimics were non-neurological in 182. The most common neurological diagnoses were seizures (19.7%), migraines (18.8%), and peripheral neuropathies (11.2%). Cardiovascular (14.6%) and psychiatric (11.9%) diagnoses were common non-neurological mimics. Patients with neurological mimics were younger (64.1 ± 17.3 years versus 70.5 ± 16.1 years, P < .001) and had less vascular risk factors than non-neurological mimics. The proportion of non-neurological mimics remained high (38%) despite the use of a prehospital stroke identification scale. CONCLUSIONS: Stroke mimics are common among patients transported by Emergency Medical Services to a comprehensive stroke center for suspected stroke, with a considerable proportion being non-neurological in origin. Studies refining triage and transport of suspected acute stroke may be warranted to minimize the number of mimics transported by to a comprehensive stroke center for acute stroke evaluation.

Is Distance to the Nearest Registered Public Automated Defibrillator Associated with the Probability of Bystander Shock for Victims of Out-of-Hospital Cardiac Arrest?

Introduction Rapid access to defibrillation is a key element in the management of out-of-hospital cardiac arrests (OHCAs). Public automated external defibrillators (PAEDs) are becoming increasingly available, but little information exists regarding the relation between the proximity to the arrest and their usage in urban areas. METHODS: This study is a retrospective, observational, cross-sectional analysis of non-traumatic OHCA during a 24-month period in the greater Montreal area (Quebec, Canada). Using logistic regression, bystander shock odds are described with regards to distance from the OHCA scene to the nearest PAED, adjusted for prehospital care arrival delay and time of day, and stratifying for type of location. RESULTS: Out of a total of 2,443 OHCA victims identified, 77 (3%) received bystander PAED shock, 622 (26%) occurred out-of-home, and 743 (30%) occurred during business hours. When controlling for time (business hours versus other hours) and minimum response delay for prehospital care arrival, a marginal negative association was found between bystander shock and distance to the nearest PAED in logged meters (aOR=0.80; CI, 0.64-0.99) for out-of-home cardiac arrests. No significant association was found between distance and bystander shock for at-home arrests. Out-of-home victims had significantly higher odds of receiving bystander shock up to 175 meters of distance to a PAED inclusively (aOR=2.52; CI, 1.07-5.89). CONCLUSION: For out-of-home cardiac arrests, proximity to a PAED was associated with bystander shock in the greater Montreal area. Strategies aiming to increase accessibility and use of these life-saving devices could further expand this advantage by assisting bystanders in rapidly locating nearby PAEDs. Neves Briard J , de Montigny L , Ross D , de Champlain F , Segal E . Is distance to the nearest registered public automated defibrillator associated with the probability of bystander shock for victims of out-of-hospital cardiac arrest? Prehosp Disaster Med. 2018;33(2):153-159.