Evaluating Diagnostic Accuracy and Study Findings for LVO Strokes

Date: October 2, 2024 Reference: Paxton et al. Headpulse measurement can reliably identify large-vessel occlusion stroke in prehospital suspected stroke patients: Results from the EPISODE-PS-COVID study. AEM Sept 2024 Guest Skeptic: Dr. Lauren Westafer an Assistant Professor in the Department of Emergency Medicine at the UMass Chan Medical School – Baystate. She is the co-founder of FOAMcast and a pulmonary embolism and implementation science researcher. Dr. Westafer serves as the Social Media Editor and a research methodology editor for the Annals of Emergency Medicine. Case: The family of a 69-year-old woman activated emergency medical services (EMS) for slurred speech that they noticed when she woke up a couple of hours before. The patient has a history of hypertension, diabetes, gastroesophageal reflux disease (GERD), and dyslipidemia and lives alone but speaks with her son daily. The son reported she seemed fine yesterday evening when they went to dinner, perhaps more tired than usual. The patient had some slurred speech but no obvious facial droop or asymmetric limb weakness. Background: Stroke remains a leading cause of morbidity and mortality worldwide, with large vessel occlusion (LVO) strokes representing approximately one-third of all acute ischemic strokes (AIS) in the United States. However, LVO strokes disproportionately contribute to stroke-related disability and death, accounting for nearly two-thirds of post-stroke dependence and over 90% of stroke mortality [1,2]. The SGEM has covered LVO strokes several times (SGEM#137, SGEM#292, SGEM#333 and SGEM#349). Rapid identification and transport to an endovascular thrombectomy (EVT)-capable center are important for improving outcomes in these patients, as EVT is the standard treatment for LVO stroke with moderate to severe symptoms​ [3-5]. Prehospital identification of LVO stroke remains a significant challenge for emergency medical services (EMS) [6].  Traditional stroke scales used in the field, such as the Los Angeles Motor Scale (LAMS) [7], the Cincinnati Stroke Triage Assessment Tool (C-STAT) [8,9], and the Rapid Arterial Occlusion Evaluation (RACE) scale [10], have shown varied effectiveness. These scales generally demonstrate high specificity but low sensitivity, often resulting in false negatives where LVO strokes are missed​ [11-13]. Clinical Question: Can a cranial accelerometry (CA) headset device be used by paramedics in the prehospital setting to accurately detect patients with a large vessel occlusion (LVO) stroke? Reference: Paxton et al. Headpulse measurement can reliably identify large-vessel occlusion stroke in prehospital suspected stroke patients: Results from the EPISODE-PS-COVID study. AEM Sept 2024 Population: Consecutive adult patients suspected of acute ischemic stroke (AIS) by prehospital emergency medical services (EMS) in the United States. Intervention: The Harmony 5000 CA headset device (MindRhythm Inc). Comparison: The Los Angeles Motor Scale (LAMS). Outcome: Primary Outcome: The feasibility of prehospital deployment of the device, defined by the proportion of subjects with acceptable ECG and headset data. Secondary Outcome: The device's diagnostic accuracy in detecting LVO stroke. Type of Study: This was a prospective, multicenter observational diagnostic accuracy study. Dr. James Paxton This is an SGEMHOP, and we are pleased to have the lead author, Dr. James Paxton on the show. Dr. Paxton is in the Department of Emergency Medicine, at Wayne State University School of Medicine.  Authors’ Conclusions: "Obtaining adequate recordings with a CA headset is highly feasible in the prehospital environment. Use of the device algorithm incorporating both CA and LAMS data for LVO detection resulted in significantly higher sensitivity without reduced specificity when compared to the use of LAMS alone." Quality Checklist for A Diagnostic Study: