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TECH CORNER Updates in Large Vessel Occlusion Stroke Triage Scores By Fawaz Al-Mufti, MD The role of neurointensivists has evolved Stroke VAN is one of the most recently developed scales utilizing rapidly over the past decade and has a relatively novel approach to detecting LVO strokes. Most expanded to incorporate the triage of studies use a numbering system and ROC analysis to determine patients being transferred to the Neuro ICU, cut-off values for scores in order to maximize sensitivity and Neurology, and Neurosurgery services. In specificity. Stroke VAN (vision, aphasia, and neglect) has no the era of new standards of care where large scoring or severity testing and does not test one branch of the vessel occlusion (LVO) strokes are the new MCA multiple times. A VAN positive patient must have any arm STEMIs, accurate yet concise clinical exams weakness (any severity) and one cortical symptom (vision loss, are crucial for appropriate triage. aphasia, or neglect). Several scales have been developed that attempt to screen potential Limitations include the possibility that a right MCA M2 occlusion LVO patients at a prehospital scenario by trained EMTs. These with visual field loss and aphasia would be technically VAN include the NIH Stroke Scale, Cincinnati Prehospital Stroke Scale, negative if patient has no arm weakness. Furthermore, neglect Los Angeles Motor Score, and Rapid Arterial Occlusion Evaluation. may be difficult to assess. The lack of scoring is both a positive and a negative as optimization cannot be done without having a The NIH Stroke Scale is relatively time consuming and severity threshold. cumbersome for prehospital use but is the gold standard that stroke scales developed for EMTs are compared to for sensitivity Another newly introduced score presented at the International and specificity. Stroke Conference in Los Angeles last month was the FAST- ED Score (The Field Assessment Stroke Triage for Emergency The Cincinnati Prehospital Stroke Scale (CPSS) takes less time to Destination) which is a simple prehospital scale based on items of perform and is widely used by EMS. The CPSS assesses for facial the NIHSS with higher predictive value for LVOs: facial palsy, arm droop, arm drift, and slurred speech. A major limitation is that weakness, speech changes, eye deviation, and neglect. This scale CPSS only assesses for the presence or absence of stroke not the requires calculation and a set score but it can be used by EMS to presence or absence of LVO strokes. accurately identify LVOs in the prehospital setting enabling rapid triage of patients to endovascular-capable stroke centers. The Los Angeles Motor Score is another scale that can be rapidly completed. It too tests for facial droop and arm drift, but it A checklist or smartphone app as a reference will likely be crucial assesses grip strength rather than speech. Points are assigned to the success of any one score and indeed many services and to determine stroke severity. Cortical signs that are usually hospitals are working on developing these apps and some have impaired in stroke with LVO are not evaluated. A score of one or assimilated apps into their prehospital stroke assessment that two is positive for a stroke, four or higher is a high probability of instantly transmit stroke scale findings to the hospital. LVO strokes. EMS determination of stroke severity is a relatively new concept The Rapid Arterial oCclusion Evaluation Scale (RACE) is another that is destined to become the norm. Several scores have been scale that has gained popularity, however, it takes slightly more validated and many more will likely surface due to the demand time to perform. RACE assesses for facial palsy, arm motor but, at this point, the optimal scale has yet to be developed. The function, leg motor function, head and gaze deviation, and, if perfect test should allow EMS providers to be able to quickly and right hemiparesis is found, the examiner is instructed to check for accurately perform a stroke screen under stressful circumstances. aphasia. If left hemiparesis is found, the examiner is instructed to check for neglect. A cutoff value of RACE ≥5 is correlated with the presence of LVOs. 21


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