Abstract TP242: The Los Angeles Motor Scale Outperforms the Vision, Aphasia, Neglect Test as a Prehospital Stroke Scale

Abstract

Introduction: In the prehospital setting, it is important to identify which patients need to be sent to a comprehensive stroke center. Methods: This IRB-approved prospective study included all patients transported for stroke by our EMS system from December 2018-May 2019. Patients were administered the Los Angeles Motor Scale (LAMS) and vision, aphasia, neglect (VAN) test by paramedics prior to hospital arrival. LAMS 4 or 5 was considered high for the purposes of our study. Patients were considered VAN positive if they were deficient in any of the three areas it tests. Results: Our cohort (n=480) was 50% male. Median age was 72, IQR 62-81 and range 13-108 years. The LAMS/VAN breakdown (n=378 patients who received both) was as follows: Low LAMS/Negative VAN: 32% High LAMS/Negative VAN: 10% Low LAMS/Positive VAN: 38% High LAMS/Positive VAN: 20% 68% of patients had either high LAMS or positive VAN. 26% received CTA perfusion imaging, 14% received tPA, and 7% received mechanical intervention. 9% were hemorrhagic strokes, 43% ischemic, and 11% TIAs. The median National Institutes of Stroke Score (NIHSS) at hospital arrival was 6, with IQR 2-13 and range 0-36. 50% of patients were discharged home and 5% expired. Table 1: relative risk (if applicable) and p-values associated with certain outcome-scale combinations, calculated using Fisher’s exact test or Wilcoxon’s rank-sum test (NS = not significant). In predicting mechanical intervention, LAMS had sensitivity 87% and specificity 72%, VAN had sensitivity 73% and specificity 41%, LAMS or VAN had sensitivity 96% and specificity 31%, LAMS and VAN had sensitivity 62% and specificity 82%. Conclusions: The LAMS is more effective than the VAN for general prehospital usage. Combining the two scales results in higher sensitivity at the cost of specificity in predicting mechanical intervention, which may be useful so that all potentially eligible patients for mechanical intervention can be sent to a comprehensive stroke center.