Abstract TMP76: Ischemic Stroke Location and Vascular Risk in Dizziness Visits and The Follow-up Period: A Population-based Study

Abstract

Objective: Prior studies found a concerning frequency of missed ischemic stroke among Emergency Department (ED) dizziness visits. We aim to describe details about the location of infarction (identified at ED dizziness visits or in the follow-up time period) and vascular risk. These data could inform opportunities to identify index strokes or reduce the risk of subsequent events. Methods: From October 2016 to April 2018, ED visits for dizziness, vertigo, or imbalance were identified in Nueces County, Texas. Validated index or subsequent 90-day ischemic stroke events were identified by linkage to the Brain Attack Surveillance in Corpus Christi (BASIC) project. Infarct locations were classified using imaging reports. The proportion of the events associated with Atherosclerotic cardiovascular disease (ASCVD) score ≥0.10, a common trigger for preventive therapy, was summarized. Results: There were 55 ischemic strokes identified at the time of the ED dizziness visit and 33 ischemic strokes identified in the subsequent 90-days. The Figure displays infarct location, days since ED visit, and ASCVD score. Posterior fossa infarction comprised 47% (26/55) (17 cerebellar, 9 brainstem) of the strokes identified at the dizziness visit and 39% (13/33) (11 cerebellar, 5 brainstem) of the strokes in the follow-up period. Baseline ACSVD scores were ≥0.10 in 78% (43/55) of patients with stroke identified at the dizziness visit and 79% (26/33) of patients with stroke identified in the subsequent 90-days. Conclusions: Posterior fossa lesions account a minority of the ischemic strokes that present to the ED with dizziness or occur in the subsequent 90-days. A substantial majority of these strokes have ASCVD scores higher than a common threshold for preventative therapies. Vascular risk assessment during ED dizziness visits might help providers to both diagnose acute strokes and to prompt preventative strategies in presumed non-stroke cases at increased risk for short-term stroke.