Current Methods for the Prehospital Detection of Large Vessel Occlusion (LVO) Ischemic Stroke

Abstract

This review describes the technologies and methods currently utilized to detect large vessel occlusion (LVO) ischemic stroke in the prehospital setting. A comparison of various LVO stroke scales, including their similarities and differences, is included. Emerging technology, novel stroke detection methods, and likely areas of future research are discussed. Many prehospital stroke detection scales have been described previously in the medical literature, characterized by varying degrees of efficacy. Despite their cost-effectiveness and ease of use, prehospital stroke scales do not reliably detect LVO. Current efforts in prehospital LVO stroke detection are aimed at improving upon the sensitivity and specificity of these scales, leveraging new screening technologies to streamline LVO triage and decrease time-to-intervention. The prehospital stroke scales that we reviewed differ greatly in many respects, including their definition of LVO and the type and number of items tested. Despite the tremendous global effort made to rapidly triage and deliver LVO stroke patients to definitive treatment centers, no single scale has emerged with both a high positive predictive value (PPV) and negative predictive value (NPV). This has led to a lack of consensus, preventing widespread adoption of a single scale for prehospital LVO detection. Despite the ever-increasing number of stroke scales available to the prehospital clinician, LVO detection remains a challenge. Future advances in prehospital LVO stroke detection are expected to involve new and improved in-field diagnostic testing.