Abstract TP240: The PLUMBER (Prevalence of Large Vessel Occlusion Stroke in Mecklenburg County Emergency Response) Study

Introduction: Regional Emergency Medical System (EMS) protocols for acute stroke endorse routing patients with possible large vessel occlusion (LVO) acute ischemic strokes (AIS) directly to endovascular centers. These routing algorithms include prehospital stroke severity screens (PSSS) to determine the likelihood of an LVO AIS. An essential, but unreported, determinant of the predictive value of PSSS tools is the prevalence of LVO AIS stroke in the EMS population screened for stroke. Hypothesis: Among EMS patients transported to Mecklenburg county hospitals screened for stroke, acute LVO AIS prevalence ranges from 5-10%. Methods: We are conducting a prospective, observational study of all patients transported by the Mecklenburg county EMS agency who are either (1) dispatched as a possible stroke and/or (2) with a primary impression of stroke recorded by prehospital providers. We are reviewing medical records and neurovascular imaging studies to determine an acute LVO AIS diagnosis and the site(s) of occlusion. Results: Thus far, over a six-month period we have enrolled 1441 patients, of whom 33% (n=480) had a diagnosis consistent with acute stroke (ischemic stroke, hemorrhagic stroke, or transient ischemic attack), with 20% (n=287) being an AIS. Eighty-eight percent (n=253) of AIS patients underwent an intracranial CTA or MRA. The prevalence of LVO stroke in the EMS population enrolled was 5.7% (n= 82, 95% CI 4.6-7.0%), with the most common vessel occluded being M1 (n=46, 56% of LVO AIS). The prevalence of LVO AIS in patients dispatched as a possible stroke was 4.8% (n =56; 95% CI 3.6-6.1%), while the prevalence in patients with a primary impression of stroke was 10% (n=74; 95% CI 8.2-13%). Conclusions: Among patients screened for stroke by our county’s EMS agency, the prevalence of LVO AIS is low. This low LVO AIS prevalence, combined with a PSSS tool with modest accuracy, will yield poor predictive value for LVO AIS in an EMS population, resulting in a substantial rate of over-triage of non-LVO patients to endovascular centers. Data collection is ongoing to determine the accuracy of a prehospital stroke screen in identifying LVO AIS patients.

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Retrospective Validation of Prehospital Acute Stroke Severity Scale to Predict Large Vessel Occlusion in Acute Stroke Patients - Single Center study in China

10.21203/rs.2.10860/v1 ◽

2019 ◽

Author(s):

Xiaoli Si ◽

Yuanjian Fang ◽

Wenqing Xia ◽

Tianwen Chen ◽

Huan Huang ◽

...

Keyword(s):

Acute Stroke ◽

Predictive Value ◽

Large Vessel ◽

Motor Deficits ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Anterior Circulation ◽

Vessel Occlusion ◽

Consciousness Disorder ◽

Gaze Palsy

Abstract Background and Purpose - To date, identifying emergent large vessel occlusion (ELVO) patients in the prehospital stage is important but still challenging. We aimed to retrospectively validate a simple prehospital stroke scale——Prehospital Acute Stroke Severity (PASS) scale to identify ELVO. Methods - We retrospectively evaluated our consecutive cohort of acute ischemic stroke (AIS) who underwent CT angiography (CTA), MR angiography (MRA) or digital subtraction angiography (DSA). PASS scale was calculated based on National Institutes of Health Stroke Scale (NIHSS) items retrospectively. The comparison of diagnostic parameters between PASS scale and NIHSS scale were performed. Results - Finally, a total of 605 patients were enrolled. ELVO patients with PASS≥2 had a median NIHSS score of 14. The best predictive value of PASS≥2 showed a similar predictive value compared with NIHSS≥9. Cortical symptoms such as consciousness disorder and gaze palsy were more specific indicators for ELVO than motor deficits. Consciousness disorder was more serious in posterior circulation infarct (PIC) while gaze palsy was more common in anterior circulation infarct (AIC). Conclusions - PASS scale had both good discrimination and calibration in our retrospective cohort. It could reflect acute stroke severity well and predict ELVO in an effective and simple way. Moreover, cortical symptoms had high specificities to predict ELVO on their own.

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Pomona Large Vessel Occlusion Screening Tool for Prehospital and Emergency Room Settings

Interventional Neurology ◽

10.1159/000486515 ◽

2018 ◽

Vol 7 (3-4) ◽

pp. 196-203 ◽

Cited By ~ 2

Author(s):

Kessarin Panichpisal ◽

Kenneth Nugent ◽

Maharaj Singh ◽

Richard Rovin ◽

Reji Babygirija ◽

...

Keyword(s):

Los Angeles ◽

Acute Stroke ◽

Predictive Value ◽

Area Under The Curve ◽

Predictive Performance ◽

Large Vessel ◽

Stroke Severity ◽

Vessel Occlusion ◽

Comparable Accuracy ◽

Score Model

Background: Early identification of patients with acute ischemic strokes due to large vessel occlusions (LVO) is critical. We propose a simple risk score model to predict LVO. Method: The proposed scale (Pomona Scale) ranges from 0 to 3 and includes 3 items: gaze deviation, expressive aphasia, and neglect. We reviewed a cohort of all acute stroke activation patients between February 2014 and January 2016. The predictive performance of the Pomona Scale was determined and compared with several National Institutes of Health Stroke Scale (NIHSS) cutoffs (≥4, ≥6, ≥8, and ≥10), the Los Angeles Motor Scale (LAMS), the Cincinnati Prehospital Stroke Severity (CPSS) scale, the Vision Aphasia and Neglect Scale (VAN), and the Prehospital Acute Stroke Severity Scale (PASS). Results: LVO was detected in 94 of 776 acute stroke activations (12%). A Pomona Scale ≥2 had comparable accuracy to predict LVO as the VAN and CPSS scales and higher accuracy than Pomona Scale ≥1, LAMS, PASS, and NIHSS. A Pomona Scale ≥2 had an accuracy (area under the curve) of 0.79, a sensitivity of 0.86, a specificity of 0.70, a positive predictive value of 0.71, and a negative predictive value of 0.97 for the detection of LVO. We also found that the presence of either neglect or gaze deviation alone had comparable accuracy of 0.79 as Pomona Scale ≥2 to detect LVO. Conclusion: The Pomona Scale is a simple and accurate scale to predict LVO. In addition, the presence of either gaze deviation or neglect also suggests the possibility of LVO.

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120 Prospective study determining the predictive value of inattention in the evaluation of suspected acute stroke; a territory wide study

Journal of Neurology Neurosurgery & Psychiatry ◽

10.1136/jnnp-2019-anzan.106 ◽

2019 ◽

Vol 90 (e7) ◽

pp. A39.1-A39

Author(s):

Jonathan JD Baird-Gunning ◽

Shaun Zhai ◽

Brett Jones ◽

Neha Nandal ◽

Chandi Das ◽

...

Keyword(s):

Acute Stroke ◽

Predictive Value ◽

Strong Predictor ◽

Large Vessel ◽

List Type ◽

Large Vessel Occlusion ◽

Stroke Patients ◽

Vessel Occlusion ◽

Predictive Values ◽

Stroke Mimics

Introduction25%-30% of patients admitted with acute stroke are stroke mimics. Clinical assessment plays a major role in diagnosis in the hyperacute clinical setting. Identifying physical signs that correctly identify stroke is therefore important. A retrospective study1 suggested that the presence of sensory inattention (or neglect) was seen exclusively in stroke patients, suggesting that inattention might be a reliable discriminator between stroke and mimics. This study aimed to test that hypothesis.MethodsProspective assessment of suspected stroke patients for the presence of neglect (NIHSS definition). Neglect could be visual and/or somatosensory. The presence of neglect was then correlated with eventual diagnosis at 48 hours. Sensitivity, specificity and predictive values were calculated. A post-hoc analysis evaluated the correlation of neglect with large vessel occlusion in patients who underwent angiography.Results115 patients were recruited, 70 ultimately with stroke and 45 with other diagnoses. Neglect was present in 27 patients (of whom 23 had stroke) and absent in 88. This yielded: sensitivity 32.9%, specificity 91.1%, positive predictive value 85.2%, and negative predictive value 41.9%. Two patients with neglect had a diagnosis of functional illness, one a seizure, and one a brain tumour. Neglect was present in 7 out of 8 patients with large vessel occlusion (sensitivity 87.5%) and was absent in all patients who did not have large vessel occlusion on angiogram.ConclusionWhen present, neglect is a strong predictor of organic pathology and large vessel occlusion. However, it is not 100% specific and can be seen in functional presentations.ReferenceGargalas S, Weeks R, Khan-Bourne N, Shotbolt P, Simblett S, Ashraf L, Doyle C, Bancroft V, David AS: Incidence and outcome of functional stroke mimics admitted to a hyperacute stroke unit. J Neurol Neurosurg Psychiatry 2017, 88:2–6.

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Abstract T MP59: Texas Stroke Intervention Pre-Hospital Stroke Severity Scale (aka LEGS score): A Triaging Tool for Interventional Stroke Therapy

Stroke ◽

10.1161/str.45.suppl_1.tmp59 ◽

2014 ◽

Vol 45 (suppl_1) ◽

Author(s):

Alexander Venizelos ◽

Sherman Chen ◽

Ryan Gianatasio ◽

Stewart Coffman ◽

Mark Gamber ◽

...

Keyword(s):

Positive Predictive Value ◽

Negative Predictive Value ◽

Predictive Value ◽

Good Predictor ◽

Mr Angiography ◽

Large Vessel ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Severity Scale ◽

Vessel Occlusion

Introduction: A pre-hospital stroke severity scale that correlates well with an NIHSS of 10 or greater as well as with large vessel occlusions, but is easier and faster to perform than full NIHSS, would be a very useful triaging tool to emergency medical services (EMS). The LEGS score (Lower extremity strength, Eyes/visual fields, Gaze deviation, Speech difficulty) is a 16-point pre-hospital stroke severity scale that is a shortened NIHSS-5. Hypothesis: We assessed the hypothesis that the LEGS score was a useful pre-hospital stroke severity scoring system to identify large vessel acute ischemic strokes. Methods: The LEGS score (0-16) and NIHSS (0-42) were performed in the emergency department over a 6-month period. We retrospectively reviewed those charts for correlation to an NIHSS of 10 or greater and evidence of large-vessel occlusion on either CT or MR Angiography within 48 hours of last known normal. Results: A total of 181 consecutive ischemic stroke patients were evaluated. LEGS score 4 or greater was a good predictor of an NIHSS of 10 or greater (59/181; positive predictive value 92%; and specificity 95%) and false positives noted was 5/181. LEGS score of less than 4 was a good predictor of an NIHSS of less than 10 (108/181; negative predictive value 91%; and sensitivity 95%) and false negatives noted was 10/181. Of those patients 155 underwent intracranial vascular imaging. LEGS score of less than 4 was a good test to rule-out large vessel occlusion (negative predictive value of 86%; 89/103), but had modest sensitivity (69%; 31/45) and positive predictive value (60%; 31/52). The LEGS score of 4 or greater, however, was fairly specific for determining large-vessel occlusions at 81% (89/110). Conclusions: LEGS score of 4 or greater has good correlation with an NIHSS of 10 or greater as well as modest correlation with large vessel occlusion on CT or MR Angiography. This shortened NIHSS-5 may be a useful pre-hospital indicator of patients who may benefit from endovascular intervention.

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

Journal of NeuroInterventional Surgery ◽

10.1136/neurintsurg-2020-016054 ◽

2020 ◽

pp. neurintsurg-2020-016054 ◽

Cited By ~ 1

Author(s):

Lee Birnbaum ◽

David Wampler ◽

Arash Shadman ◽

Mateja de Leonni Stanonik ◽

Michele Patterson ◽

...

Keyword(s):

Predictive Value ◽

Systems Of Care ◽

Prehospital Setting ◽

Large Vessel ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Intraparenchymal Hemorrhage ◽

Vessel Occlusion ◽

Statistical Measures ◽

Published Evidence

BackgroundNumerous 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.MethodsThe 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.ResultsBoth 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.ConclusionsOur 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.

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Abstract TP251: Pomona Large Vessel Occlusion Scale for Pre-hospital and Emergency Room Settings

Stroke ◽

10.1161/str.48.suppl_1.tp251 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Kessarin Panichpisal ◽

Nazli Janjua ◽

Karen Tse-Chang ◽

Kimberly.A.Jones A Jones ◽

Katrina Woolfolk ◽

...

Keyword(s):

Emergency Room ◽

Acute Stroke ◽

High Sensitivity ◽

Screening Tools ◽

Large Vessel ◽

Stroke Severity ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Historical Cohort ◽

Lower Accuracy

Background: Early detection of acute stroke with large vessel occlusion (LVO) in both pre-hospital and emergency room settings results in favorable clinical outcomes. There is still no universal guideline for LVO screening. Method: We proposed that the presence of any of the following signs (Pomona scale): gaze deviation, expressive aphasia or neglect has a high sensitivity and accuracy to predict LVO. We reviewed a historical cohort of all acute stroke activation patients at Pomona Valley Hospital during February 2014 to January 2016. We tested Pomona scale in both groups. The predictive performance of Pomona scale was compared with different NIHSS cutoffs ( ≥4, ≥6, ≥8, ≥10), Los Angeles Motor Scale (LAMS), Cincinnati Prehospital Stroke Severity (CPSS) scale, Vision Aphasia and Neglect scale (VAN) and Prehospital Acute Stroke Severity (PASS) scale. Results: LVO was detected in 129 of the 777 acute stroke activation (17%). Two hundred and forty-two patients had nonLVO stroke (31%). NIHSS ≥4 and Pomona scale had highest sensitivity (0.99 and 0.98 respectively) to predict LVO. LAM scale had lowest sensitivity (0.68). Pomona scale had moderate accuracy (0.61) which was comparable with VAN (0.66) and PASS (0.67). NIHSS ≥4 had the least accuracy (0.28). When Pomona scale was combined with arm weakness, it had highest accuracy (0.77) and high sensitivity (0.92) to predict LVO in acute ischemic stroke subgroup. Using various NIHSS cut off to screen for LVO had lower accuracy than using other LVO screening tools. Conclusion: Pomona scale is very sensitive to predict LVO. It may be used as a screening tool for LVO in emergency room setting. Combination of arm weakness and Pomona scale may be used as a Pre-hospital LVO screening with moderately high accuracy.

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Abstract TP82: Factors Associated With Good Collateral Flow in Acute Stroke Patients With Large Vessel Occlusion

Stroke ◽

10.1161/str.51.suppl_1.tp82 ◽

2020 ◽

Vol 51 (Suppl_1) ◽

Author(s):

Pierre Seners ◽

Pauline Roca ◽

Laurence Legrand ◽

Guillaume Turc ◽

Catherine Oppenheim ◽

...

Keyword(s):

Acute Stroke ◽

Large Vessel ◽

Stroke Severity ◽

Lesion Volume ◽

Dynamic Susceptibility ◽

Collateral Flow ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Factors Associated ◽

Tandem Occlusion

Introduction: Retrograde collateral flow is critical to maintain tissue perfusion despite large vessel occlusion. However, the premorbid factors associated with good collateral flow remain unclear, with substantial discrepancies in the literature. Methods: Patients from the registries of 6 French stroke centres with the following criteria were included: (1) acute stroke with isolated M1 occlusion ( i.e , without tandem occlusion) referred for thrombectomy between May 2015 and March 2017; and (2) baseline brain MRI, including diffusion weighted imaging, MR-angiography and dynamic susceptibility-contrast perfusion-weighted imaging (PWI). A collateral flow map derived from PWI source data was automatically generated, replicating Kim et al’s previously validated method (Ann. Neurol., 2014). Collateral flow was dichotomized into good and poor. The association between good collateral flow and baseline clinical, biological and radiological variables was studied. Results: One hundred and sixteen patients were included, of which 66 (57%) had good collaterals. As expected, the latter patients had lower admission NIHSS (median: 15 vs . 18, P=0.005) and lower baseline DWI lesion volume (median: 7ml vs . 32ml, P<0.001) than patient with poor collaterals. Onset-to-imaging delay and M1 occlusion site (proximal vs . distal) were similar in both groups (123min vs . 118min, P=0.75; 70% vs. 68%, P=0.85, respectively). There was no significant (P>0.05) difference in gender, age, history of hypertension or diabetes, current smoking, baseline blood glucose and use of statins or antiplatelets between the good and poor collaterals groups. Conclusions: Despite the expected association between PWI-derived collateral flow and baseline clinical and radiological stroke severity in our sample of acute M1 occlusions, there was no association with premorbid factors previously found associated in some -but not all- studies. Our findings suggest that collateral flow is predominantly explained by genetic factors.

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Abstract TMP62: Utility of the Los Angeles Motor Scale to Identify Emergency Large Vessel Occlusion in Acute Stroke

Stroke ◽

10.1161/str.48.suppl_1.tmp62 ◽

2017 ◽

Vol 48 (suppl_1) ◽

Author(s):

Prasannna Tadi ◽

Pranav Reddy ◽

Sravanthi Pemmasani ◽

Nasir Fakhri ◽

Matthew Siket ◽

...

Keyword(s):

Los Angeles ◽

Positive Predictive Value ◽

Acute Stroke ◽

Negative Predictive Value ◽

Predictive Value ◽

Large Vessel ◽

Large Vessel Occlusion ◽

Vessel Occlusion ◽

Vessel Imaging ◽

Los Angeles Motor Scale

Introduction: Stroke is a common medical emergency. The outcome depends upon access to stroke specialists, rapid scanning, assessment, and treatments. Identification of large vessel occlusion (LVO) is critical in the selection of patients for emergency embolectomy (clot removal) in patients with acute ischemic stroke. A pre-hospital stroke severity scale, such as the Los Angeles Motor Scale (LAMS) may have utility in selecting appropriate patients for CTA, while minimizing radiation exposure risk to the population as a whole. Methods: This was a retrospective analysis of 249 consecutive code stroke activations at a comprehensive stroke center during a 3.5 month period using a LAMS cutoff of ≥4 to trigger CTA acquisition. We determined the sensitivity, specificity, positive predictive value, and negative predictive value of using LAMS to detect large vessel occlusion (LVO). Gold standard was any vessel imaging within 24 hours. Inter-rater reliability of LAMS scoring was determined by blinded scoring of physical exam data from the chart by 3 neurovascular physicians. Results: There were 249 code stroke activations during the study period: 91 acute CTAs were recommended based on LAMS scoring. 20 large vessel occlusions were detected. 158 patients did not have a CTA acutely; none had a LVO during subsequent vessel imaging. The sensitivity is 100%, negative predictive value 100%, specificity 69%, positive predictive value 22% of the LAMS triage method. Inter-rater Reliability: Shrout-Fleiss pairwise weighted kappa coefficients between the three raters on LAMS scores were 0.67, 0.55, and 0.62. Kappa coefficients for pairs of raters when LAMS were dichotomized as <3 vs 4-5 were 0.64, 0.50, and 0.71. Clinically meaningful disagreements were evident. Conclusions: Accuracy and ease-of-use makes LAMS an ideal clinical tool to rapidly assess acute stroke patients for LVO and emergency mechanical thrombectomy. LAMS demonstrated excellent sensitivity in excluding patients who did not have a LVO. Appropriate training is required to ensure accuracy of LAMS scoring by providers.

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