Validation of TriAGE+ for Predicting Stroke Risk in ED Patients Presenting With Dizziness

Overview

Ischemic cerebrovascular diseases originating from the brain's posterior circulation account for 20-25% of cases. Among patients diagnosed with cerebellar infarction, 10% present with isolated dizziness as their sole symptom. Notably, posterior circulation strokes and cerebellar infarcts are misdiagnosed 2 to 4 times more frequently than anterior circulation strokes. In 2017, Kuroda et al. developed the TriAGE+ score to assess stroke risk in patients presenting with dizziness. This study aims to externally validate the TriAGE+ score, focusing on its safety, applicability, and reliability in predicting cerebrovascular disease in the emergency department.

Dizziness is a frequent complaint in emergency departments (ED), accounting for approximately 4% of visits. Epidemiological studies suggest that 3-20% of these patients experience dizziness due to cerebrovascular causes. In Turkey, data collected from 2013 to 2017 indicate that 2.4% of ED visits involved dizziness, with 36.8% of those patients being hospitalized due to central neurological events. Cerebrovascular events (CVEs) involving the brain's posterior circulation-supplied by the vertebrobasilar arterial system and including regions such as the cerebellum, medulla oblongata, pons, and midbrain-are a common but often missed cause of dizziness. Studies have shown that 8.4% of patients presenting with isolated dizziness were later diagnosed with a posterior circulation stroke, and isolated dizziness has been recognized as the most common symptom in transient ischemic attacks (TIAs) and posterior circulation strokes. In cerebellar stroke patients, 10% present with isolated dizziness. However, the National Institutes of Health Stroke Scale (NIHSS), which is commonly used to assess stroke severity, often underestimates posterior circulation strokes due to its focus on symptoms typically associated with anterior circulation infarcts. Posterior circulation strokes make up 20-25% of ischemic strokes, yet they are underdiagnosed 2 to 4 times more frequently than their anterior counterparts. This diagnostic challenge underscores the need for an effective risk stratification tool to aid clinicians. Although several risk scores for cerebrovascular events exist, including the widely used ABCD2 score developed by Navi et al., they are often inadequate in assessing stroke risk in patients presenting with dizziness, as they emphasize unilateral weakness and speech impairment, both of which are less relevant to posterior circulation strokes. In 2017, Kuroda et al. developed the TriAGE+ score to specifically predict stroke risk in patients presenting with dizziness. Their study, conducted in Japan across five emergency departments, included 498 patients. The score, which ranges from 0 to 17, was designed to categorize patients into four risk groups: low (\<5), moderate (5-7), high (8-9), and very high (\>9) risk for stroke. A threshold score of 10, determined through Receiver Operating Characteristic (ROC) analysis, provided a balance between sensitivity (77.5%; 95% CI 72.8-81.8) and specificity (72.1%; 95% CI 64.1-79.2). While this study demonstrated that the TriAGE+ score effectively predicted stroke risk, it was limited by its retrospective design and single-region focus, necessitating external validation. Subsequently, Ho-Kun Yu et al. conducted an external validation study in Hong Kong in 2023, which, though supportive of the score's efficacy, shared similar limitations, including its retrospective, single-center design. As the TriAGE+ score was developed and validated primarily in Asia, it is critical to assess its generalizability and applicability in other populations. Our study seeks to perform an external validation of the TriAGE+ score in Turkey, with the aim of evaluating its safety, applicability, and reliability in a different population.