Design and Validation of a Prehospital Stroke Scale to Predict Large Arterial Occlusion

Emergency Care of Patients with Acute Ischemic Stroke

Stroke is a leading cause of morbidity and mortality and a major cause of long-term disability. Management of acute ischemic stroke in the first hours is critical to patient outcomes. This review provides an overview of acute ischemic stroke management, with a focus on the golden hour. Additional topics discussed include prehospital considerations and initial evaluation of the patient with history, examination, and imaging as well as treatment options, including thrombolysis and endovascular therapy.

A Novel Combination of Blood Biomarkers and Clinical Stroke Scales Facilitates Detection of Large Vessel Occlusion Ischemic Strokes

Acute ischemic stroke caused by large vessel occlusions (LVOs) is a major contributor to stroke deaths and disabilities; however, identification for emergency treatment is challenging. We recruited two separate cohorts of suspected stroke patients and screened a panel of blood-derived protein biomarkers for LVO detection. Diagnostic performance was estimated by using blood biomarkers in combination with NIHSS-derived stroke severity scales. Multivariable analysis demonstrated that D-dimer (OR 16, 95% CI 5–60; p-value < 0.001) and GFAP (OR 0.002, 95% CI 0–0.68; p-value < 0.05) comprised the optimal panel for LVO detection. Combinations of D-dimer and GFAP with a number of stroke severity scales increased the number of true positives, while reducing false positives due to hemorrhage, as compared to stroke scales alone (p-value < 0.001). A combination of the biomarkers with FAST-ED resulted in the highest accuracy at 95% (95% CI: 87–99%), with sensitivity of 91% (95% CI: 72–99%), and specificity of 96% (95% CI: 90–99%). Diagnostic accuracy was confirmed in an independent cohort, in which accuracy was again shown to be 95% (95% CI: 87–99%), with a sensitivity of 82% (95% CI: 57–96%), and specificity of 98% (95% CI: 92–100%). Accordingly, the combination of D-dimer and GFAP with stroke scales may provide a simple and highly accurate tool for identifying LVO patients, with a potential impact on time to treatment.

Prehospital Stroke Management Optimized by Use of Clinical Scoring vs Mobile Stroke Unit for Triage of Patients With Stroke: A Randomized Clinical Trial

Importance

Transferring patients with large-vessel occlusion (LVO) or intracranial hemorrhage (ICH) to hospitals not providing interventional treatment options is an unresolved medical problem.

Objective

To determine how optimized prehospital management (OPM) based on use of the Los Angeles Motor Scale (LAMS) compares with management in a Mobile Stroke Unit (MSU) in accurately triaging patients to the appropriate hospital with (comprehensive stroke center [CSC]) or without (primary stroke center [PSC]) interventional treatment.

Design, Setting, and Participants

In this randomized multicenter trial with 3-month follow-up, patients were assigned week-wise to one of the pathways between June 15, 2015, and November 15, 2017, in 2 regions of Saarland, Germany; 708 of 824 suspected stroke patients did not meet inclusion criteria, resulting in a study population of 116 adult patients.

Interventions

Patients received either OPM based on a standard operating procedure that included the use of the LAMS (cut point ≥4) or management in an MSU (an ambulance with vascular imaging, point-of-care laboratory, and telecommunication capabilities).

Main Outcomes and Measures

The primary end point was the proportion of patients accurately triaged to either CSCs (LVO, ICH) or PSCs (others).

Results

A predefined interim analysis was performed after 116 patients of the planned 232 patients had been enrolled. Of these, 53 were included in the OPM group (67.9% women; mean [SD] age, 74 [11] years) and 63 in the MSU group (57.1% women; mean [SD] age, 75 [11] years). The primary end point, an accurate triage decision, was reached for 37 of 53 patients (69.8%) in the OPM group and for 63 of 63 patients (100%) in the MSU group (difference, 30.2%; 95% CI, 17.8%-42.5%; P < .001). Whereas 7 of 17 OPM patients (41.2%) with LVO or ICH required secondary transfers from a PSC to a CSC, none of the 11 MSU patients (0%) required such transfers (difference, 41.2%; 95% CI, 17.8%-64.6%; P = .02). The LAMS at a cut point of 4 or higher led to an accurate diagnosis of LVO or ICH for 13 of 17 patients (76.5%; 6 triaged to a CSC) and of LVO selectively for 7 of 9 patients (77.8%; 2 triaged to a CSC). Stroke management metrics were better in the MSU group, although patient outcomes were not significantly different.

Conclusions and Relevance

Whereas prehospital management optimized by LAMS allows accurate triage decisions for approximately 70% of patients, MSU-based management enables accurate triage decisions for 100%. Depending on the specific health care environment considered, both approaches are potentially valuable in triaging stroke patients.

Trial Registration

ClinicalTrials.gov identifier: NCT02465346.

Potential accuracy of prehospital NIHSS-based triage for selection of candidates for acute endovascular stroke therapy

OBJECTIVE

Whether patients with acute stroke and large vessel occlusion (LVO) benefit from prehospital identification and diversion by emergency medical services (EMS) to an endovascular stroke therapy (EST)-capable center is controversial. We sought to estimate the accuracy of field-based identification of potential EST candidates in a hypothetical best-of-all-worlds situation.

METHODS

In Kaiser Permanente Northern California, all acute stroke patients arriving at its 21 stroke centers between 7:00 am and midnight from January 2016 to December 2019 were evaluated by teleneurologists on arrival. Initial National Institutes of Health Stroke Scale (NIHSS) score, presence of LVO, and referral for EST were obtained from standardized teleneurology notes. Factors associated with LVO were evaluated using generalized estimating equations accounting for clustering by facility.

RESULTS

Among 13,377 patients brought in by EMS with potential stroke, 7168 (53.6%) were not candidates for acute stroke interventions. Of the remaining 6089 cases, 2,573 (42.3%) had an NIHSS score >10, the cutoff with a higher association for LVO. Only 703 patients (27.3% with NIHSS score >10) were ultimately diagnosed with LVO and referred for EST. Across all NIHSS scores, only 884 (6.6%) suspected acute stroke patients had LVO and EST referral.

CONCLUSIONS

Even if field-based tools were as accurate as NIHSS scoring and predictions by stroke neurologists, only about 1 in 4 acute stroke patients diverted to EST-capable centers would benefit by receiving EST. Depending on geography and stroke center performance on door-to-needle time, many systems may be better served by focusing on expediting evaluation, treatment with intravenous thrombolysis, and transfer to EST-capable centers.

Effects of state-wide implementation of the Los Angeles Motor Scale for triage of stroke patients in clinical practice

BACKGROUND

The prehospital identification of stroke patients with large-vessel occlusion (LVO), that should be immediately transported to a thrombectomy capable centre is an unsolved problem. Our aim was to determine whether implementation of a state-wide standard operating procedure (SOP) using the Los Angeles Motor Scale (LAMS) is feasible and enables correct triage of stroke patients to hospitals offering (comprehensive stroke centres, CSCs) or not offering (primary stroke centres, PSCs) thrombectomy.

METHODS

Prospective study involving all patients with suspected acute stroke treated in a 4-month period in a state-wide network of all stroke-treating hospitals (eight PSCs and two CSCs). Primary endpoint was accuracy of the triage SOP in correctly transferring patients to CSCs or PSCs. Additional endpoints included the number of secondary transfers, the accuracy of the LAMS for detection of LVO, apart from stroke management metrics.

RESULTS

In 1123 patients, use of a triage SOP based on the LAMS allowed triage decisions according to LVO status with a sensitivity of 69.2% (95% confidence interval (95%-CI): 59.0-79.5%) and a specificity of 84.9% (95%-CI: 82.6-87.3%). This was more favourable than the conventional approach of transferring every patient to the nearest stroke-treating hospital, as determined by geocoding for each patient (sensitivity, 17.9% (95%-CI: 9.4-26.5%); specificity, 100% (95%-CI: 100-100%)). Secondary transfers were required for 14 of the 78 (17.9%) LVO patients. Regarding the score itself, LAMS detected LVO with a sensitivity of 67.5% (95%-CI: 57.1-78.0%) and a specificity of 83.5% (95%-CI: 81.0-86.0%).

CONCLUSIONS

State-wide implementation of a triage SOP requesting use of the LAMS tool is feasible and improves triage decision-making in acute stroke regarding the most appropriate target hospital.

Management of Acute Ischemic Stroke

Objectives:

Concise “synthetic” review of the state of the art of management of acute ischemic stroke.

Data Sources:

Available literature on PubMed.

Study Selection:

We selected landmark studies, recent clinical trials, observational studies, and professional guidelines on the management of stroke including the last 10 years.

Data Extraction:

Eligible studies were identified and results leading to guideline recommendations were summarized.

Data Synthesis:

Stroke mortality has been declining over the past 6 decades, and as a result, stroke has fallen from the second to the fifth leading cause of death in the United States. This trend may follow recent advances in the management of stroke, which highlight the importance of early recognition and early revascularization. Recent studies have shown that early recognition, emergency interventional treatment of acute ischemic stroke, and treatment in dedicated stroke centers can significantly reduce stroke-related morbidity and mortality. However, stroke remains the second leading cause of death worldwide and the number one cause for acquired long-term disability, resulting in a global annual economic burden.

Conclusions:

Appropriate treatment of ischemic stroke is essential in the reduction of mortality and morbidity. Management of stroke involves a multidisciplinary approach that starts and extends beyond hospital admission.

Mean Platelet Volume as a Potential Marker of Large Vessel Occlusion and Predictor of Outcome in Acute Ischemic Stroke Patients Treated with Reperfusion Therapy

(1) Background: An early diagnosis of a large vessel occlusion (LVO) is crucial in the management of the acute ischemic stroke (AIS). The laboratory predictors of LVO and a stroke outcome remain unknown. We have hypothesized that high MPV—a surrogate marker of the activated platelet—may be associated with LVO, and it may predict a worse AIS outcome. (2) Methods: This was a retrospective study of 361 patients with AIS who were treated with thrombolysis (tPA, 65.7%) and/or mechanical thrombectomy (MT, 34.3%) in a tertiary Stroke Center between 2011 and 2019. (3) Results: The mean MPV in the cohort was 9.86 ± 1.5 fL (1st–4th quartiles: <8.8, >10.80 fL). Patients in the 4th quartile compared to the 1st had a significantly (p < 0.01) more often incidence of an LVO related stroke (75% vs. 39%) and a severe stroke manifestation with a higher RACE score (5.2 ± 2.8 vs. 3.3 ± 2.4), NIHSS at baseline (mean ± SD, 14 ± 6.5 vs. 10.9 ± 5.2), and NIHSS at discharge (6.9 ± 7 vs. 3.9 ± 3.6). A multivariate analysis revealed that quartiles of MPV (OR 1.4; 95%CI 1.2–1.8) significantly predicted an LVO stroke, also after the adjustment for RACE < 5 (OR 1.4; 95%CI 1.08–1.89), but MPV quartiles did not predict a favorable stroke outcome (mRS ≤ 2) (OR 0.89; 95%CI 0.7–1.13). (4) Conclusion: Our data suggest that MPV is an independent predictor of LVO in patients with an acute ischemic stroke.

Reliability of Field Assessment Stroke Triage for Emergency Destination Scale Use by Paramedics: Mobile Stroke Unit First-Year Experience

[Figure: see text].

Design and validation of a recognition instrument-the stroke aid for emergency scale-to predict large vessel occlusion stroke

Background and purpose: Rapidly recognizing patients with large-vessel occlusion stroke (LVOS) and transferring them to a center offering recanalization therapy is crucial of maximizing the benefits of early treatment. We therefore aimed to design an easy-to-use recognition instrument for identifying LVOS.

Methods: Prospective data were collected from emergency departments of 12 stroke-center hospitals in China during a 17-month study period. The Stroke Aid for Emergency (SAFE) scale is based on consciousness commands, facial palsy, gaze, and arm motor ability. Receiver operating characteristic analysis was used to obtain the area under the curve for the SAFE scale and previously established scales to predict LVOS.

Results: The SAFE scale could accurately predict LVOS at an accuracy rate comparable to that of the National Institutes of Health Stroke Scale (c-statistics: 0.823 versus 0.831, p = 0.4798). The sensitivity, specificity, positive predictive value, and negative predictive value for the SAFE scale were 0.6875, 0.8577, 0.6937, and 0.8542, respectively, with a cutoff point of 4. The SAFE scale also performed well in a subgroup analysis based on the patients’ ages, occluded vessel locations, and the onset-to-door times.

Conclusions: The SAFE scale can accurately recognize LVOS at a rate comparable to those of other, similar scales.

Swiss guidelines for the prehospital phase in suspected acute stroke

Acute stroke treatment has advanced substantially over the last years. Important milestones constitute intravenous thrombolysis, endovascular therapy (EVT), and treatment of stroke patients in dedicated units (stroke units). At present in Switzerland there are 13 certified stroke units and 10 certified EVT-capable stroke centers. Emerging challenges for the prehospital pathways are that (i) acute stroke treatment remains very time sensitive, (ii) the time window for acute stroke treatment has opened up to 24 h in selected cases, and (iii) EVT is only available in stroke centers. The goal of the current guideline is to standardize the prehospital phase of patients with acute stroke for them to receive the optimal treatment without unnecessary delays. Different prehospital models exist. For patients with large vessel occlusion (LVO), the Drip and Ship model is the most commonly used in Switzerland. This model is challenged by the Mothership model where stroke patients with suspected LVO are directly transferred to the stroke center. This latter model is only effective if there is an accurate triage by paramedics, hence the patient may benefit from the right treatment in the right place, without loss of time. Although the Cincinnati Prehospital Stroke Scale is a well-established scale to detect acute stroke in the prehospital setting, it neglects nonmotor symptoms like visual impairment or severe vertigo. Therefore we suggest “acute occurrence of a focal neurological deficit” as the trigger to enter the acute stroke pathway. For the triage whether a patient has a LVO (yes/no), there are a number of scores published. Accuracy of these scores is borderline. Nevertheless, applying the Rapid Arterial Occlusion Evaluation score or a comparable score to recognize patients with LVO may help to speed up and triage prehospital pathways. Ultimately, the decision of which model to use in which stroke network will depend on local (e.g. geographical) characteristics.

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.

Novel flat-panel cone-beam CT compared to multi-detector CT for assessment of acute ischemic stroke: A prospective study

PURPOSE

Cone beam CT (CBCT) imaging assessment of acute ischemic stroke (AIS) patients with large-vessel occlusion (LVO) in the angiosuite may improve stroke workflow and decrease time to recanalization. In order for this workflow to gain widespread acceptance, current CBCT imaging needs further development to improve image quality. Our study aimed to compare the image quality of a new CBCT protocol performed directly in the angiosuite with imaging from multidetector CT as a gold standard.

METHODS

AIS patients with an LVO who were candidates for endovascular treatment were prospectively included in this study. Following conventional multidetector CT (MDCT), patients underwent unenhanced cone beam CT (XperCT, Philips) imaging in the angiosuite, using two different protocols: a standard 20.8 s XperCT and/or an improved 10.4 s XperCT protocol. Images were evaluated using both qualitative and quantitative methods.

RESULTS

We included 65 patients in the study. Patients received CBCT imaging prior to endovascular treatment; 18 patients were assessed with a standard 20.8 s protocol scans and 47 with a newer 10.4 s scan. The quantitative analysis showed that the mean contrast-to-noise ratio (CNR) was significantly higher for the newer 10.4 s protocol compared with the 20.8 s protocol (2.08 +/- 0.64 vs. 1.15 +/- 0.27, p < 0.004) and the mean image noise was significantly lower for the 10.4 s XperCTs when compared with the 20.8 s XperCTs (6.30 +/- 1.34 vs. 7.82 +/- 2.03, p=<0.003). Qualitative analysis, including 6 measures of image quality, demonstrated that 74.1 % of the 10.4 s XperCT scans were ranked as 'Acceptable' for assessing parenchymal imaging in AIS patients(scoring 3-5 points on a 5-point Likert-scale), compared with 32.4 % of the standard 20.8 s XperCT and 100 % of the MDCT scans. Compared to the MDCT studies, 83 % of the 10.4 s XperCT scans were deemed sufficient image quality for a direct-to-angiosuite selection, compared to only 11 % for the standard 20.8 s scans. The largest image quality improvements included grey/white matter differentiation (59 % improvement), and reduction of image noise and artefacts (63 % & 50 % improvement, respectively).

CONCLUSIONS

Continued advances in cone-beam CT allow marked improvements in image quality for the assessment of brain parenchyma, which supports a direct-to-angiosuite approach for AIS patients eligible for thrombectomy treatment.

Blood Biomarkers to Differentiate Ischemic and Hemorrhagic Strokes

OBJECTIVE

To validate a panel of blood biomarkers to differentiate between ischemic stroke (IS) and intracerebral hemorrhage (ICH) in patients with suspected stroke.

METHODS

Patients with suspected stroke admitted within 4.5 hours after onset were enrolled. Blood samples were collected at hospital admission. Glial fibrillary acid protein (GFAP), retinol binding protein 4 (RBP-4), N-terminal proB-type natriuretic peptide (NT-proBNP), and endostatin were measured by immunoassays. Cutoff points were obtained for 100% specificity for IS. A high-sensitivity assay to measure GFAP and rapid point-of-care tests (POCTs) to measure RBP-4 and NT-proBNP were used in subsets of patients. Biomarker panels were evaluated in another cohort of 62 stroke mimics.

RESULTS

A total of 189 patients (154 IS and 35 ICH) were enrolled. Patients with IS had higher RBP-4, NT-proBNP, and endostatin and lower GFAP levels than patients with ICH. The best biomarker combination for the identification of IS was RBP-4+NT-proBNP, which was able to identify 29.7% of patients with IS with 100% specificity. In the subset of patients for whom GFAP was measured with the high-sensitivity assay, RBP-4, NT-proBNP, and GFAP identified 51.5% of patients with IS with 100% specificity. When stroke mimics were included, specificities were reduced to 98.4 and 96.8%, respectively. POCTs of RBP-4 and NT-proBNP showed results similar results to those of conventional ELISAs.

CONCLUSIONS

A biomarker panel including RBP-4, NT-proBNP, and GFAP provided moderate but potentially useful sensitivity rates at 100% specificity for IS diagnosis. If confirmed in future studies, this strategy might allow prehospital treatment in selected patients.

CLASSIFICATION OF EVIDENCE

This study provides Class I evidence that a biomarker panel including RBP-4, NT-proBNP, and GFAP distinguishes IS from ICH with moderate accuracy.

Prehospital Triage Accuracy in Patients With Stroke Symptoms Assessed Within 6 to 24 Hours or With an Unknown Time of Onset

BACKGROUND AND PURPOSE

The Stockholm Stroke Triage System, implemented in 2017, identifies patients with high likelihood of large vessel occlusion (LVO) stroke. A previous report has shown Stockholm Stroke Triage System notably reduced time to endovascular thrombectomy (EVT). As the indication for EVT now includes patients up to 24 hours, we aimed to assess Stockholm Stroke Triage System triage accuracy for LVO stroke and EVT treatment for patients presenting late (within 6-24 hours or with an unknown onset), put in contrast to triage accuracy within 0 to 6 hours.

METHODS

Between October 2017 and October 2018, we included 2905 patients with suspected stroke, transported by priority 1 ground ambulance to a Stockholm Region hospital. Patients assessed 6 to 24 hours from last known well or with unknown onset were defined as late-presenting; those within <6 hours as early-presenting. Triage positivity was defined as transport to comprehensive stroke center because of suspected stroke, hemiparesis and high likelihood of EVT-eligible LVO per teleconsultation.

RESULTS

Overall triage accuracy was high in late-presenting patients (90.9% for LVO, 93.9% for EVT), with high specificity (95.7% for LVO, 94.5% for EVT), and low to moderate sensitivity (34.3% for LVO, 64.7% for EVT), with similar findings in the early-presenting group.

CONCLUSIONS

Our results may support using the Stockholm Stroke Triage System for primary stroke center bypass in patients assessed by ambulance up to 24 hours from time of last known well.

Integrated Stroke System Model Expands Availability of Endovascular Therapy While Maintaining Quality Outcomes

BACKGROUND AND PURPOSE

The optimal endovascular stroke therapy (EVT) care delivery structure is unknown. Here, we present our experience in creating an integrated stroke system (ISS) to expand EVT availability throughout our region while maintaining hospital and physician quality standards.

METHODS

We identified all consecutive patients with large vessel occlusion acute ischemic stroke treated with EVT from January 2014 to February 2019 in our health care system. In October 2017, we implemented the ISS, in which 3 additional hospitals (4 total) became EVT-performing hospitals (EPHs) and physicians were rotated between all centers. The cohort was divided by time into pre-ISS and post-ISS, and the primary outcome was time from stroke onset to EPH arrival. Secondary outcomes included hospital and procedural quality metrics. We performed an external validation using data from the Southeast Texas Regional Advisory Council.

RESULTS

Among 513 patients with large vessel occlusion acute ischemic stroke treated with EVT, 58% were treated pre-ISS and 43% post-ISS. Over the study period, EVT procedural volume increased overall but remained relatively low at the 3 new EPHs (<70 EVT/y). After ISS, the proportion of patients who underwent interhospital transfer decreased (46% versus 37%; P<0.05). In adjusted quantile regression, ISS implementation resulted in a reduction of time from stroke onset to EPH arrival by 40 minutes (P<0.01) and onset to groin puncture by 29 minutes (P<0.05). Rates of postprocedural hemorrhage, modified Thrombolysis in Cerebral Infarction (TICI) 2b/3, and 90-day modified Rankin Scale were comparable at the higher and lower volume EPHs. The improvement in onset-to-arrival time was not reflective of overall improvement in secular trends in regional prehospital care.

CONCLUSIONS

In our system, increasing EVT availability decreased time from stroke onset to EPH arrival. The ISS provides a framework to maintain quality in lower volume hospitals.

Using ESN-Smartphone Application to Maximize AIS Reperfusion Therapy in Alexandria Stroke Network: A Stroke Chain of Survival Organizational Model

Background: In developing countries like Egypt, the clinical workflow of stroke management is poorly established due to the lack of awareness of the stroke patients concerning their need of therapeutic intervention and the poor identification of facilities equipped to treat stroke. Hence, establishing a stroke system of care in developing countries that can efficiently and rapidly triage patients to the appropriate reperfusion therapy center is imperative to improving stroke management and outcomes.

Aims: To evaluate a pilot experience in stroke hospital identification and expediting decision-making in AIS treatment through the Alexandria stroke network and Egyptian Stroke Network (ESN)-app.

Methods: Between 2017 and 2019, seven hospitals registered themselves on the AS-Network as pilot hospitals. The ESN-application was used to detect stroke type, tele-connect stroke teams and hospitals, track triage of patients to equipped facility in real time, and streamline stroke workflow. The quality of and time required for stroke management were compared between 84 patients with acute ischemic stroke (AIS) whose treatment involved the ESN-app and 276 patients whose treatment did not.

Results: During this pilot study, 360 AIS cases received reperfusion therapy, 84 of which were indicated by the ESN-app. The use of the application was associated with the significant drop in time metrics for the reperfusion AIS-patients (door-in-door-out time; 56 ± 34 min vs. 96 ± 45 min, door-to-groin puncture time; 50 ± 7 min vs. 120 ± 25 min, door-to-needle time; 55 ± 12 min vs. 78 ± 16 min with p < 0.0001). Its use was also associated with higher rates of excellent outcomes at the 90-day follow-up (without ESN-app vs. with ESN-app, 67.9 vs. 47.1%, p = 0.001) but no difference in 90-day mortality or symptomatic intracerebral hemorrhage (without ESN-app vs. with ESN-app, 9.5 vs. 11.2% and 4.8 vs. 5.1%, p > 0.05).

Conclusion: Our pilot experience demonstrated that the use of the ESN-app expedited the stroke treatment workflow and facilitated tele-connection between registered stroke facilities. Additionally, its use might be associated with achieving higher rates of excellent outcomes at 90 days, where a larger scale study is needed for more confirmation.

Portable Neuromonitoring Device Detects Large Vessel Occlusion in Suspected Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Early detection of large vessel occlusion (LVO) stroke optimizes endovascular therapy and improves outcomes. Clinical stroke severity scales used for LVO identification have variable accuracy. We investigated a portable LVO-detection device (PLD), using electroencephalography and somatosensory-evoked potentials, to identify LVO stroke.

METHODS

We obtained PLD data in suspected patients with stroke enrolled prospectively via a convenience sample in 8 emergency departments within 24 hours of symptom onset. LVO discriminative signals were integrated into a binary classifier. The National Institutes of Health Stroke Scale was documented, and 4 prehospital stroke scales were retrospectively calculated. We compared PLD and scale performance to diagnostic neuroimaging.

RESULTS

Of 109 patients, there were 25 LVO (23%), 38 non-LVO ischemic (35%), 14 hemorrhages (13%), and 32 stroke mimics (29%). The PLD had higher sensitivity (80% [95% CI, 74-85]) and similar specificity (80% [95% CI, 77-83]) to all prehospital scales at their predetermined high probability LVO thresholds. The PLD had high discrimination for LVO (C-statistic=0.88).

CONCLUSIONS

The PLD identifies LVO with superior accuracy compared with prehospital stroke scales in emergency department suspected stroke. Future studies need to validate the PLD's potential as an LVO triage aid in prehospital undifferentiated stroke populations.

D-Dimer as Predictor of Large Vessel Occlusion in Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Improving prehospital triage of large vessel occlusion (LVO) would reduce time to reperfusion therapies. We aimed to study early predictors of LVO in acute ischemic stroke to identify candidates for endovascular treatment.

METHODS

The Stroke-Chip was a prospective observational study conducted at 6 Stroke Centers in Catalonia. Blood samples were obtained in the first 6 hours from symptom onset of consecutive patients. Stroke severity was evaluated with National Institutes of Health Stroke Scale (NIHSS) and LVO was assessed. Independent association of multiple blood biomarkers with LVO was evaluated using logistic regression models adjusted by covariates. Sensitivity, specificity, and predictive values were assessed for NIHSS and the combination of NIHSS and selected serum biomarkers levels.

RESULTS

One thousand three hundred eight suspected strokes were enrolled for a 17-month period. LVO was not assessed in 131 patients. One thousand one hundred seventy-seven patients were selected for analysis (mean age 69.3 years, 56% men, median baseline NIHSS of 6, and median time to blood collection 2.5 hours). LVO was detected in 262 patients. LVO patients were older, had higher baseline NIHSS, history of atrial fibrillation, and lower time from stroke onset to admission. After logistic regression analysis, D-dimer remained an independent predictor of LVO (odds ratio, 1.59 [1.31-1.92]). Specificity and positive predictive value to exclude or detect LVO were higher when using combined D-dimer levels and NIHSS score assessment rather than NIHSS alone.

CONCLUSIONS

Early D-dimer levels are an independent predictor of LVO and may be useful to better optimize prehospital patient transport to the appropriate stroke center.

Comparison of Prehospital Scales for Predicting Large Anterior Vessel Occlusion in the Ambulance Setting

Importance

The efficacy of endovascular thrombectomy (EVT) for symptomatic large anterior vessel occlusion (sLAVO) sharply decreases with time. Because EVT is restricted to comprehensive stroke centers, prehospital triage of patients with acute stroke codes for sLAVO is crucial, and although several prediction scales are already in use, external validation, head-to-head comparison, and feasibility data are lacking.

Objective

To conduct external validation and head-to-head comparisons of 7 sLAVO prediction scales in the emergency medical service (EMS) setting and to assess scale feasibility by EMS paramedics.

Design, Setting, and Participants

This prospective cohort study was conducted between July 2018 and October 2019 in a large urban center in the Netherlands with a population of approximately 2 million people and included 2 EMSs, 3 comprehensive stroke centers, and 4 primary stroke centers. Participants were consecutive patients aged 18 years or older for whom an EMS-initiated acute stroke code was activated. Of 2812 acute stroke codes, 805 (28.6%) were excluded, because no application was used or no clinical data were available, leaving 2007 patients included in the analyses.

Exposures

Applications with clinical observations filled in by EMS paramedics for each acute stroke code enabling reconstruction of the following 7 prediction scales: Los Angeles Motor Scale (LAMS); Rapid Arterial Occlusion Evaluation (RACE); Cincinnati Stroke Triage Assessment Tool; Prehospital Acute Stroke Severity (PASS); gaze-face-arm-speech-time; Field Assessment Stroke Triage for Emergency Destination; and gaze, facial asymmetry, level of consciousness, extinction/inattention.

Main Outcomes and Measures

Planned primary and secondary outcomes were sLAVO and feasibility rates (ie, the proportion of acute stroke codes for which the prehospital scale could be reconstructed). Predictive performance measures included accuracy, sensitivity, specificity, the Youden index, and predictive values.

Results

Of 2007 patients who received acute stroke codes (mean [SD] age, 71.1 [14.9] years; 1021 [50.9%] male), 158 (7.9%) had sLAVO. Accuracy of the scales ranged from 0.79 to 0.89, with LAMS and RACE scales yielding the highest scores. Sensitivity of the scales ranged from 38% to 62%, and specificity from 80% to 93%. Scale feasibility rates ranged from 78% to 88%, with the highest rate for the PASS scale.

Conclusions and Relevance

This study found that all 7 prediction scales had good accuracy, high specificity, and low sensitivity, with LAMS and RACE being the highest scoring scales. Feasibility rates ranged between 78% and 88% and should be taken into account before implementing a scale.

Prehospital EMS Triage for Acute Stroke Care

Acute stroke has had major advances over the last two decades due to the introduction of pharmacologic and endovascular revascularization, which can improve functional outcome. Stroke systems of care have been developed to provide faster, more efficient care for stroke patients. A major part of these care pathways is prehospital care, when patients are triaged to appropriate levels of care. It is essential that prehospital scales are used accurately and effectively by emergency medical services to assist them with the triage process. New technologies including mobile stroke units, telemedicine, and wearable technology have been introduced as options for optimization of this emergent process.

Design and Derivation of the Austrian Prehospital Stroke Scale (APSS) to Predict Severe Stroke with Large Vessel Occlusion

Objectives: Prediction of large vessel occlusion (LVO) is highly relevant for accurate prehospital transportation triage. The Austrian Prehospital Stroke Scale (APSS) score for LVO prediction was developed using critical synthesis of previously published LVO-scores. The aim of this study was to investigate the accuracy of the APSS and compare it to other LVO-scores. Methods: APSS consists of 5 items: "facial palsy," "motor arm," "language," "motor leg" and "gaze deviation." The score ranges from 0 to 9 points. Data from 741 consecutive stroke patients with acute vessel imaging admitted to an independent comprehensive stroke center was used to test the predictive performance of the APSS in context of other LVO-scores (CPSS, FAST-ED, G-FAST, sNIHSS-EMS and RACE). Results: In the prediction of treatable LVO the APSS showed the highest area under the curve (0.834) with significant difference to CPSS (p = 0.010) and G-FAST (p = 0.006) and showed highest sensitivity (69%) as compared to other LVO scores. Specificity (85%), positive predictive value (75%), negative predictive value (81%) and accuracy (79%) were comparable to other LVO scores. Receiver operating curve analysis revealed an optimal cutoff for LVO prediction at APSS equal to 4 points. Conclusions: The easy assessable 5-item APSS score tended to outperform other LVO scores. Real-life prospective evaluation in prehospital setting is ongoing.

Acute ischemic stroke endovascular therapy

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

Triage and systems of care in stroke

There has been increasing adoption of endovascular stroke treatment in the United States following multiple clinical trials demonstrating superior efficacy. Next steps in enhancing this treatment include an analysis and development of stroke systems of care geared toward efficient delivery of endovascular and comprehensive stroke care. The chapter presents epidemiological data and an overview of the current state of stroke delivery and potential improvements for the future in the light of clinical data.

External validation of prehospital stroke scales for emergent large vessel occlusion

BACKGROUND

It is suggested that a prehospital scale should be utilized to identify patients with emergent large vessel occlusion (ELVO). We aimed to perform external validation of nine ELVO scales.

METHODS

This single center retrospective observational study included patients with ischemic stroke visiting the emergency department (ED) within 6 h of symptom onset. Participants were excluded if individual items of the National Institute of Health Stroke Scale scores were not recorded or they did not receive brain computed tomography angiography or magnetic resonance imaging before intravenous thrombolysis or endovascular thrombectomy, and within 24 h of ED admission. The first definition of ELVO was emergent occlusion of the internal carotid artery (ICA) and middle cerebral artery segment 1 (M1). The second definition was emergent occlusion of ICA, M1, basilar artery, middle cerebral artery segment 2, anterior cerebral artery segment 1, and posterior cerebral artery segment 1. Area under the receiver operating characteristic curve (AUROC) was constructed to examine discrimination. The sensitivity, specificity, positive predictive value, and negative predictive value of the nine scales under the two ELVO definitions were calculated.

RESULTS

A total of 1231 patients were included in the study. No significant differences were observed in the AUROC under the two ELVO definitions. However, sensitivity values of these scales were largely different, ranging from 44.56% to 93.68% under the first ELVO definition. The sensitivity values among scales were also different under the second ELVO definition.

CONCLUSION

Stakeholders in the community should choose suitable scales according to their own system conditions.

Different Stroke Scales; Which Scale or Scales Should Be Used?

BACKGROUND

There has been a considerable development in the clinometric of stroke. But researchers are concerned that some scales are too generic, inherently and the insight may not be provided. The current study was conducted to determine which scale or scales should be used in stroke survivors.

METHODS

We selected 67 studies which were published between January 2010 and December 2018 from Up to date, CINAHL, ProQuest, Scopus, PubMed, Embase, Medline, Elsevier and Web of Science with MeSH terms. Inclusion criteria were: clinical trials, prospective studies, retrospective cohort studies, or cross-sectional studies; original research in adult human stroke survivors. We excluded the following articles: non-adult population; highly selected studies or treatment studies without incidence data; commentaries, single case reports, review article, editorials and non-English articles or articles without full text available.

RESULTS

Face Arm Speech Test and Cincinnati Pre-Hospital Stroke Scale scales because it was easy to learn and rapidly administer the recommended dose to use in pre-hospital, but there are not gold standard in stroke diagnosis in Pre-Hospital. National Institutes of Health Stroke Scale valuable in the acute stage for middle cerebral artery, not chronic or long term post stroke outcome. The Barthel Index scores for approximately three weeks could predict activities of daily living disabilities in 6 months.

CONCLUSION

Every scale has an advantage and a disadvantage and we were not able to introduce the gold standard for each item, but some special scales were used more in the studies, preferred for comparing with other studies to match the research results.

Gaze Deviation and Paresis Score (GPS) Sufficiently Predicts Emergent Large Vessel Occluding Strokes

OBJECTIVES

The prognosis of patients with acute ischemic stroke (AIS) essentially depends on both prompt diagnosis and appropriate treatment. Endovascular stroke therapy (EST) proved to be highly efficient in the treatment of emergent large vessel occluding (ELVO) strokes in the anterior circulation. To achieve a timely diagnosis, a robust combination of few and simple signs to identify ELVOs in AIS patients applicable by paramedics in the prehospital triage is worthwhile.

MATERIALS AND METHODS

This retrospective single-center study included 904 AIS patients (324 ELVO, 580 non-ELVO) admitted between 2010 and 2015 in a tertiary stroke center. We re-evaluated two symptoms based on NIHSS items, gaze deviation and hemiparesis of the limbs ("Gaze deviation and Paresis Score, GPS") for the pre-hospital prediction of ELVO.

RESULTS

A positive GPS AIS in patients predicted ELVO with a sensitivity of 0.89, specificity = 0.97, positive predictive value (PPV) = 0.95, negative predictive value (NPV) = 0.94 and diagnostic odds ratio (DOR) = 34.25 (CI: 20.75-56.53). The positive Likelihood-ratio (LR⁺) was 29.67, the negative Likelihood ratio (LR^-) 0.11. NIHSS of patients with positive GPS (gaze palsy NIHSS ≥ 0, Motor arm NIHSS ≥2 and Motor leg NIHSS ≥2) was markedly higher compared to negative GPS patients (p < 0.001).

CONCLUSIONS

The GPS proved to be similarly accurate in detecting ELVO in the anterior circulation of AIS patients and even more specific than other published clinical scores. Its simplicity and clarity might enable non-neurological medical staff to identify ELVO AIS patients with high certainty in a preclinical setting.

Number of Patients with Ischemic Stroke did not Decline in a Regional Stroke Unit After the Implementation of Mechanical Thrombectomy

OBJECTIVES

Since the implementation of mechanical thrombectomy (MT) in 2015 for patients with ischemic stroke and large-vessel occlusion, the question arose as to whether patients should be primarily admitted to the nearest regional stroke unit (SU) for prompt intravenous thrombolysis (IVT) or to a more distant supraregional SU performing MT, to avoid secondary-transfer delays in MT. Although an evidence-based answer is still lacking, a discrepant discussion with potential consequences for the regional flow of stroke patients arose. We aimed to assess if MT implementation was associated with the number and characteristics of patients with stroke/transient ischemic attack (TIA) admitted to a regional SU not offering endovascular treatment.

MATERIALS AND METHODS

Patients with acute stroke/TIA treated at the Klinikum Main-Spessart Lohr, Germany, in 2013/2014 or 2017/2018 were included in this retrospective study. Data were derived from the clinical information system and mandatory stroke quality assessment. We assessed the catchment area using a region-based approach. For each region, the number of patients treated in our hospital, including data regarding clinical severity, demographic characteristics, and changes over time, were analyzed.

RESULTS

The number of patients with acute stroke/TIA increased from 890 (2013/2014) to 1016 (2017/2018). Aggregated demographic and clinical data of the whole catchment area showed no differences between 2013/2014 and 2017/2018 (P > 0.05) besides duration of hospitalization (P < 0.01), IVT rate (P < 0.01), and secondary transfer for MT. A region-based analysis revealed an increase in younger and more severely affected patients admitted from the periphery of the catchment area between 2013/2014 and 2017/2018.

CONCLUSION

Despite the implementation of MT in the supraregional SUs around our regional SU (not offering MT), more patients with stroke/TIA were admitted to our hospital, especially younger and more severely affected patients, from the border regions of the catchment area.

Usefulness of a single-parameter tool for the prediction of large vessel occlusion in acute stroke

BACKGROUND

In acute stroke, large vessel occlusion (LVO) should be promptly identified to guide patient's transportation directly to comprehensive stroke centers (CSC) for mechanical thrombectomy (MT). In many cases, prehospital multi-parameter scores are used by trained emergency teams to identify patients with high probability of LVO. However, in several countries, the first aid organization without intervention of skilled staff precludes the on-site use of such scores. Here, we assessed the accuracy of LVO prediction using a single parameter (i.e. complete hemiplegia) obtained by bystander's telephone-based witnessing.

PATIENTS AND METHODS

This observational, single-center study included consecutive patients who underwent intravenous thrombolysis at the primary stroke center and/or were directly transferred to a CSC for MT, from January 1, 2015 to March 1, 2020. We defined two groups: patients with initial hemiplegia (no movement in one arm and leg and facial palsy) and patients without initial hemiplegia, on the basis of a bystander's witnessing.

RESULTS

During the study time, 874 patients were included [mean age 73 years (SD 13.8), 56.7% men], 320 with initial hemiplegia and 554 without. The specificity of the hemiplegia criterion to predict LVO was 0.88, but its sensitivity was only 0.53.

CONCLUSION

Our results suggest that the presence of hemiplegia as witnessed by a bystander can predict LVO with high specificity. This single criterion could be used for decision-making about direct transfer to CSC for MT when the absence of emergency skilled staff precludes the patient's on-site assessment, especially in regions distant from a CSC.

Management of acute stroke. Specific nursing care and treatments in the stroke unit

OBJECTIVE

This study provides a series of updated, evidence-based recommendations for the management of acute stroke. We aim to lay a foundation for the development of individual centres' internal protocols, serving as a reference for nursing care.

METHODS

We review the available evidence on acute stroke care. The most recent national and international guidelines were consulted. Levels of evidence and degrees of recommendation are based on the Oxford Centre for Evidence-Based Medicine classification.

RESULTS

The study describes prehospital acute stroke care, the operation of the code stroke protocol, care provided by the stroke team upon the patient's arrival at hospital, reperfusion treatments and their limitations, admission to the stroke unit, nursing care in the stroke unit, and discharge from hospital.

CONCLUSIONS

These guidelines provide general, evidence-based recommendations to guide professionals who care for patients with acute stroke. However, limited data are available on some aspects, showing the need for continued research on acute stroke management.

REMOTE Ischemic Perconditioning Among Acute Ischemic Stroke Patients in Catalonia: REMOTE-CAT PROJECT

Rationale: Remote ischemic perconditioning during cerebral ischemia (RIPerC) refers to the application of brief episodes of transient limb ischemia commonly to a limb, it represents a new safe, simple and low-cost paradigm in neuroprotection.

Aim and/or Hypothesis: To evaluate the effects of RIPerC on acute ischemic stroke (AIS) patients, applied in the ambulance, to improve functional outcomes compared with standard of care.

Sample Size Estimates: A sample size of 286 patients in each arm achieves 80% power to detect treatment differences of 14% in the outcome, using a two-sided binomial test at significance level of 0.05, assuming that 40% of the control patients will experience good outcome and an initial misdiagnosis rate of 29%.

Methods and Design: We aim to conduct a multicentre study of pre-hospital RIPerC application in AIS patients. A total of 572 adult patients diagnosed of suspected clinical stroke within 8 h of symptom onset and clinical deficit >0 according to prehospital rapid arterial occlusion evaluation (RACE) scale score will be randomized, in blocks of size 4, to RIPerC or sham. Patients will be stratified by RACE score scale. RIPerC will be started in the ambulance before hospital admission and continued in the hospital if necessary. It will consist of five cycles of electronic tourniquet inflation and deflation (5 min each). The cuff pressure for RIPerC will be 200 mmHg during inflation. Sham will only simulate vibration of the device.

Study Outcome(s): The primary outcome will be the difference in the proportion of patients with good outcomes as defined by a mRS score of 2 or less at 90 days. Secondary outcomes to be monitored will include early neurological improvement rate, treatment related serious adverse event rates, size of the infarct volume, symptomatic intracranial hemorrhage, metabolomic and lipidomic response to RIPerC and Neuropsychological evaluation at 90 days.

Discussion: Neuroprotective therapies could not only increase the benefits of available reperfusion therapies among AIS patients but also provide an option for patients who are not candidates for these treatments. REMOTE-CAT will investigate the clinical benefit of RIC as a new neuroprotective strategy in AIS.

Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT03375762.

Pathway Design for Acute Stroke Care in the Era of Endovascular Thrombectomy: A Critical Overview of Optimization Efforts

The efficacy of intravenous thrombolysis and endovascular thrombectomy (EVT) for acute ischemic stroke is highly time dependent. Optimal organization of acute stroke care is therefore important to reduce treatment delays but has become more complex after the introduction of EVT as regular treatment for large vessel occlusions. There is no singular optimal organizational model that can be generalized to different geographic regions worldwide. Current dominant organizational models for EVT include the drip-and-ship- and mothership model. Guidelines recommend routing of suspected patients with stroke to the nearest intravenous thrombolysis capable facility; however, the choice of routing to a certain model should depend on regional stroke service organization and individual patient characteristics. In general, design approaches for organizing stroke care are required, in which 2 key strategies could be considered. The first entails the identification of interventions within existing organizational models for optimizing timely delivery of intravenous thrombolysis and/or EVT. This includes adaptive patient routing toward a comprehensive stroke center, which focuses particularly on prehospital triage tools; bringing intravenous thrombolysis or EVT to the location of the patient; and expediting services and processes along the stroke pathway. The second strategy is to develop analytical or simulation model-based approaches enabling the design and evaluation of organizational models before their implementation. Organizational models for acute stroke care need to take regional and patient characteristics into account and can most efficiently be assessed and optimized through the application of model-based approaches.

Prehospital Triage Strategies for the Transportation of Suspected Stroke Patients in the United States

Background and Purpose:

Ischemic stroke patients with large vessel occlusion (LVO) could benefit from direct transportation to an intervention center for endovascular treatment, but non-LVO patients need rapid IV thrombolysis in the nearest center. Our aim was to evaluate prehospital triage strategies for suspected stroke patients in the United States.

Methods:

We used a decision tree model and geographic information system to estimate outcome of suspected stroke patients transported by ambulance within 4.5 hours after symptom onset. We compared the following strategies: (1) Always to nearest center, (2) American Heart Association algorithm (ie, directly to intervention center if a prehospital stroke scale suggests LVO and total driving time from scene to intervention center is <30 minutes, provided that the delay would not exclude from thrombolysis), (3) modified algorithms with a maximum additional driving time to the intervention center of <30 minutes, <60 minutes, or without time limit, and (4) always to intervention center. Primary outcome was the annual number of good outcomes, defined as modified Rankin Scale score of 0–2. The preferred strategy was the one that resulted in the best outcomes with an incremental number needed to transport to intervention center (NNTI) <100 to prevent one death or severe disability (modified Rankin Scale score of >2).

Results:

Nationwide implementation of the American Heart Association algorithm increased the number of good outcomes by 594 (+1.0%) compared with transportation to the nearest center. The associated number of non-LVO patients transported to the intervention center was 16 714 (NNTI 28). The modified algorithms yielded an increase of 1013 (+1.8%) to 1369 (+2.4%) good outcomes, with a NNTI varying between 28 and 32. The algorithm without time limit was preferred in the majority of states (n=32 [65%]), followed by the algorithm with <60 minutes delay (n=10 [20%]). Tailoring policies at county-level slightly reduced the total number of transportations to the intervention center (NNTI 31).

Conclusions:

Prehospital triage strategies can greatly improve outcomes of the ischemic stroke population in the United States, but increase the number of non-LVO stroke patients transported to an intervention center. The current American Heart Association algorithm is suboptimal as a nationwide policy and should be modified to allow more delay when directly transporting LVO-suspected patients to an intervention center.

Test characteristics of a 5-element cortical screen for identifying anterior circulation large vessel occlusion ischemic strokes

OBJECTIVE

Stroke severity screens typically include cortical signs, such as field cut, aphasia, neglect, gaze preference, and dense hemiparesis (FANG-D). The accuracy and reliability of these signs, when assessed by emergency physicians, to identify patients with anterior circulation large vessel occlusion (ACLVO) acute ischemic stroke (AIS) is unknown. We hypothesized that the FANG-D screen applied by emergency physicians would be sensitive and reliable for identifying ACLVO AIS.

METHODS

We conducted a prospective cohort study enrolling consecutive patients with suspected AIS presenting within 4.5 hours of last known well to the emergency department (ED). Emergency physicians performed the FANG-D screen prior to, and blinded to the results of, imaging. The imaging standard was defined as a non-contrast computed tomography (CT) for identifying hemorrhage and CT angiography for identifying large vessel occlusion. ACLVO was defined as an occlusion of the internal carotid artery, the middle cerebral artery, or its first branch. A convenience sample of patients had a duplicate FANG-D screen performed by a second emergency physician to assess interobserver agreement.

RESULTS

We performed 608 FANG-D assessments on 491 patients presenting to the ED, of whom 64 (10%) had an ACLVO. FANG-D had a sensitivity of 91% (confidence interval [CI] = 81%-96%) and a specificity of 35% (CI = 31%-39%) for identifying ACLVO. Interobserver agreement was tested on 133 patients and was found to be substantial, with a Fleiss' kappa of 0.77 (CI = 0.64-0.88).

CONCLUSIONS

The FANG-D screen is a sensitive test for identifying ACLVO when performed by emergency physicians and demonstrates substantial interrater reliability.

Automatic Grading of Stroke Symptoms for Rapid Assessment Using Optimized Machine Learning and 4-Limb Kinematics: Clinical Validation Study

Background

Subtle abnormal motor signs are indications of serious neurological diseases. Although neurological deficits require fast initiation of treatment in a restricted time, it is difficult for nonspecialists to detect and objectively assess the symptoms. In the clinical environment, diagnoses and decisions are based on clinical grading methods, including the National Institutes of Health Stroke Scale (NIHSS) score or the Medical Research Council (MRC) score, which have been used to measure motor weakness. Objective grading in various environments is necessitated for consistent agreement among patients, caregivers, paramedics, and medical staff to facilitate rapid diagnoses and dispatches to appropriate medical centers.

Objective

In this study, we aimed to develop an autonomous grading system for stroke patients. We investigated the feasibility of our new system to assess motor weakness and grade NIHSS and MRC scores of 4 limbs, similar to the clinical examinations performed by medical staff.

Methods

We implemented an automatic grading system composed of a measuring unit with wearable sensors and a grading unit with optimized machine learning. Inertial sensors were attached to measure subtle weaknesses caused by paralysis of upper and lower limbs. We collected 60 instances of data with kinematic features of motor disorders from neurological examination and demographic information of stroke patients with NIHSS 0 or 1 and MRC 7, 8, or 9 grades in a stroke unit. Training data with 240 instances were generated using a synthetic minority oversampling technique to complement the imbalanced number of data between classes and low number of training data. We trained 2 representative machine learning algorithms, an ensemble and a support vector machine (SVM), to implement auto-NIHSS and auto-MRC grading. The optimized algorithms performed a 5-fold cross-validation and were searched by Bayes optimization in 30 trials. The trained model was tested with the 60 original hold-out instances for performance evaluation in accuracy, sensitivity, specificity, and area under the receiver operating characteristics curve (AUC).

Results

The proposed system can grade NIHSS scores with an accuracy of 83.3% and an AUC of 0.912 using an optimized ensemble algorithm, and it can grade with an accuracy of 80.0% and an AUC of 0.860 using an optimized SVM algorithm. The auto-MRC grading achieved an accuracy of 76.7% and a mean AUC of 0.870 in SVM classification and an accuracy of 78.3% and a mean AUC of 0.877 in ensemble classification.

Conclusions

The automatic grading system quantifies proximal weakness in real time and assesses symptoms through automatic grading. The pilot outcomes demonstrated the feasibility of remote monitoring of motor weakness caused by stroke. The system can facilitate consistent grading with instant assessment and expedite dispatches to appropriate hospitals and treatment initiation by sharing auto-MRC and auto-NIHSS scores between prehospital and hospital responses as an objective observation.

An Online Training Intervention on Prehospital Stroke Codes in Catalonia to Improve the Knowledge, Pre-Notification Compliance and Time Performance of Emergency Medical Services Professionals

Strokes are a time-dependent medical emergency. The training of emergency medical service (EMS) professionals is essential to ensure the activation of stroke codes with pre-notification, as well as a rapid transfer to achieve early therapy. New assessment scales for the detection of patients with suspected large vessel occlusion ensures earlier access to endovascular therapy. The aim of this study was to evaluate the impact on an online training intervention focused on the Rapid Arterial oCclusion Evaluation (RACE) scoring of EMS professionals based on the prehospital stroke code in Catalonia from 2014 to 2018 in a pre-post intervention study. All Catalonian EMS professionals and the clinical records from primary stroke patients were included. The Kirkpatrick model guided the evaluation of the intervention. Data were collected on the knowledge on stroke recognition and management, pre-notification compliance, activated stroke codes and time performance of EMS professionals. Knowledge improved significatively in most items and across all categories, reaching a global achievement of 82%. Pre-notification compliance also improved significantly and remained high in the long-term. Increasingly higher notification of RACE scores were recorded from 60% at baseline to 96.3% in 2018, and increased on-site clinical care time and global time were also observed. Therefore, the online training intervention was effective for increasing EMS professionals' knowledge and pre-notification compliance upon stroke code activation, and the wide adoption of a new prehospital scale for the assessment of stroke severity (i.e., the RACE scale) was achieved.

[Perioperative stroke]

Perioperative stroke is defined as an ischemic cerebrovascular event that occurs during or within 30 days after surgery and is associated with an increased perioperative risk of morbidity and mortality. Depending on the type of surgery stroke is diagnosed in up to 11% of all patients in the perioperative period. Patients with a history of ischemic stroke or transitory ischemic attack have an increased risk for perioperative stroke. Therefore, a critical assessment of indications and the timing of surgery are crucial to prevent recurring stroke in this patient population. Importantly, individualized blood pressure management is essential for optimization of cerebral perfusion during the perioperative period.This article provides a summary of the epidemiology, risk factors, and etiology of perioperative stroke. Moreover, possible preventive strategies relevant for the anesthesiologist are reviewed.

Modeling the Optimal Transportation for Acute Stroke Treatment : Impact of Diurnal Variations in Traffic Rate

Purpose

Prolonged transfer times between the primary stroke center (PSC) and the comprehensive stroke center (CSC) are one of the major causes of treatment delay for endovascular stroke treatment. We aimed to analyze the effect of the diurnal variations in traffic rates at weekdays and weekends on the catchment area size of three transportation paradigms, i.e. mothership, drip-and-ship (DS) and drip-and-drive (DD).

Methods

A conditional probability model that predicts the probability of good outcome for patients with suspected large vessel occlusion was used to analyze the prehospital stroke triage in northwest Germany and produce catchment area maps. Transportation times were calculated during each hour of a weekday and a Sunday using Google Maps. For comparison, real DD transportation times from our CSC in Hamburg-Eppendorf (blinded for review) to a PSC in Lüneburg were prospectively recorded.

Result

On weekdays, the mothership catchment area was the largest (≥40,000 km², 63%) except for a decrease during morning rush hours, when the DD catchment area was highest (30,879 km², 48%). The DS catchment area was higher than the DD catchment area during the afternoon rush hours both during the week as well as on Sundays.

Conclusion

Our study showed a considerable impact of the diurnal variations in traffic rate and direction of travel on optimal stroke transportation. Stroke systems of care should take real time traffic information into account.

Electronic supplementary material

The online version of this article (10.1007/s00062-020-00933-y) contains supplementary material, which is available to authorized users.

Design and validation of prehospital acute stroke triage (PAST) scale to predict large vessel occlusion

BACKGROUND AND AIMS

Acute ischemic stroke patients with large vessel occlusion (LVO) have severe symptoms and poor prognosis. Early recognition of these patients in prehospital setting contributes to rapid triage to comprehensive stroke centers with endovascular therapy conditions. We aimed to develop a simple and efficient scale to identify LVO and compare with other published scales.

METHODS

Medical records of acute ischemic stroke patients within 24 h of stroke onset at Beijing Tiantan hospital were retrospectively collected. The Prehospital Acute Stroke Triage (PAST) scale was designed based on the National Institutes of Health Stroke Scale (NIHSS) items with higher predictive values for LVO. Receiver operating characteristics curves were used to determine and compare the discriminative ability of each scale.

RESULTS

A total of 1313 patients diagnosed with acute ischemic stroke were included in this study. Half of the patients were used to design and the other were used to validate the PAST scale. The PAST scale showed a comparable predictive ability to NIHSS to detect LVO (c-statistics, 0.8607 vs 0.8715, p = 0.1889). A FAST scale ≥2 showed sensitivity of 0.85209, specificity of 0.76301 and accuracy of 0.80518. The PAST scale also showed good performance in subgroup analysis based on the time of onset, infarct location and the type of vascular examination.

CONCLUSIONS

PAST scale is relatively simple and has comparable ability to more complex NIHSS for recognizing large vessel occlusion.

Stroke

Stroke is a major cause of death and disability globally. Diagnosis depends on clinical features and brain imaging to differentiate between ischaemic stroke and intracerebral haemorrhage. Non-contrast CT can exclude haemorrhage, but the addition of CT perfusion imaging and angiography allows a positive diagnosis of ischaemic stroke versus mimics and can identify a large vessel occlusion target for endovascular thrombectomy. Management of ischaemic stroke has greatly advanced, with rapid reperfusion by use of intravenous thrombolysis and endovascular thrombectomy shown to reduce disability. These therapies can now be applied in selected patients who present late to medical care if there is imaging evidence of salvageable brain tissue. Both haemostatic agents and surgical interventions are investigational for intracerebral haemorrhage. Prevention of recurrent stroke requires an understanding of the mechanism of stroke to target interventions, such as carotid endarterectomy, anticoagulation for atrial fibrillation, and patent foramen ovale closure. However, interventions such as lowering blood pressure, smoking cessation, and lifestyle optimisation are common to all stroke subtypes.

Induced neuroprotection by remote ischemic perconditioning as a new paradigm in ischemic stroke at the acute phase, a systematic review

BACKGROUND

Remote ischemic conditioning during cerebral ischemia (remote ischemic perconditioning, RIPerC) refers to the application of several cycles of brief ischemia and reperfusion (I/R) commonly to a limb, and it represents a new paradigm in neuroprotection with multiple mechanisms of action in ischemic stroke (IS) patients during acute phase. Some clinical trials just finished, and a few others are still ongoing; gather the current knowledge and pull it down to influence the present and future studies was the goal of this paper.

METHODS

A systematic review of published research papers and/or registered clinical trials since 2000 was performed.

RESULTS

Nineteen studies were identified and only four studies were completed. All of them have demonstrated that RIPerC is safe, feasible and well tolerated in IS patients. However, a high heterogeneity of clinical trial characteristics was observed: five (26.3%) randomized clinical trials (RCTs) included only thrombolytic-treated patients, three (15.8%) RCTs only thrombectomy-treated patients, and five (26.3%) RCTs required radiological confirmation of IS. Temporal inclusion criteria vary from 4 h to 48 h. Most of the clinical trials used 4 cycles of RIPerC in the upper non-affected limb. Interestingly, only three (16.7%) RCTs applied RIPerC during the transportation in the ambulance. Neuroimaging outputs were the main endpoints when endovascular therapy was applied; functional outcome is also the main endpoint in large-medium size studies.

CONCLUSIONS

This review summarizes the completed and ongoing clinical trials on RIPerC in IS patients, where RIPerC has been used alone or in combination with recanalization therapies. Ongoing clinical trials will provide new information on the best RIPerC intervention strategy and potentially improve the functional outcome of IS patients; definition of new RIPerC strategies would ideally aim at enhancing tissue preservation, promoting neurological recovery, and stratify patients to improve treatment feasibility.

Paramedic utilization of Vision, Aphasia, Neglect (VAN) stroke severity scale in the prehospital setting predicts emergent large vessel occlusion stroke

BACKGROUND

Numerous stroke severity scales have been published, but few have been studied with emergency medical services (EMS) in the prehospital setting. We studied the Vision, Aphasia, Neglect (VAN) stroke assessment scale in the prehospital setting for its simplicity to both teach and perform. This prospective prehospital cohort study was designed to validate the use and efficacy of VAN within our stroke systems of care, which includes multiple comprehensive stroke centers (CSCs) and EMS agencies.

METHODS

The performances of VAN and the National Institutes of Health Stroke Scale (NIHSS) ≥6 for the presence of both emergent large vessel occlusion (ELVO) alone and ELVO or any intracranial hemorrhage (ICH) combined were reported with positive predictive value, sensitivity, negative predictive value, specificity, and overall accuracy. For subjects with intraparenchymal hemorrhage, volume was calculated based on the ABC/2 formula and the presence of intraventricular hemorrhage was recorded.

RESULTS

Both VAN and NIHSS ≥6 were significantly associated with ELVO alone and with ELVO or any ICH combined using χ² analysis. Overall, hospital NIHSS ≥6 performed better than prehospital VAN based on statistical measures. Of the 34 cases of intraparenchymal hemorrhage, mean±SD hemorrhage volumes were 2.5±4.0 mL for the five VAN-negative cases and 17.5±14.2 mL for the 29 VAN-positive cases.

CONCLUSIONS

Our VAN study adds to the published evidence that prehospital EMS scales can be effectively taught and implemented in stroke systems with multiple EMS agencies and CSCs. In addition to ELVO, prehospital scales such as VAN may also serve as an effective ICH bypass tool.