Introduction: For many patients with large vessel occlusions (LVO), endovascular therapy significantly improves patient outcomes. Data are needed to inform the decision when bypass a local primary stroke center for an endovascular center.
Hypothesis: The LAMS and other physical findings can predict LVO.
Methods: Interim analysis of a convenience sample of stroke code patients presenting to a suburban tertiary care center ED. Paramedics examined patients using the LAMS. Without any specific additional training, paramedics were also asked to assess for leg weakness, visual disturbances, altered level of consciousness, and language abnormalities (dysarthria, aphasia). Sensitivity and specificity of a LAMS score of ≥ 4 were calculated. A stepwise logistical regression on the other physical exam elements that might predict LVO was performed.
Results: 190 cases, mean age (SD) 67 (18), 51% female; 85 (45%) had an acute stroke, 44 (23%) had LVO. For stroke prediction, LAMS’ sensitivity = 70% and specificity = 80%. ROC = 80% (95% CI 74-86%). For prediction of LVO, only LAMS as a complete test was associated with LVO (OR 1.78 per LAMS point ( 95% CI 1.42-2.23). Sensitivity of this model was 27%, specificity 95%. By including the LAMS components individually as potential predictors of LVO, grip strength superseded LAMS as the only predictor of LVO. Odds ratio for LAMS prediction of LVO was 4.18 per point, 95% CI 2.48-7.04, sensitivity 49%, specificity 92%. ROC =75% (95% CI 66-84%).
Conclusion: When performed by paramedics and EMTs in an enriched stroke code population, LAMS can be used to identify LVO with high specificity. Specifically, the hand grip element predicts LVO. The overall poor sensitivity of all stroke scales for stroke in general is unlikely to change.