Solutions for Vertigo presentations in the Emergency Department (SOLVE) Project

描述（由申请人提供）：一线医生需要可靠的解决方案来区分良性和恶性的头晕原因。目前的鉴别策略依赖于临床教条或脑部计算机断层扫描，但这些策略存在重大缺陷，并与误诊有关。在头晕的表现中，急性前庭综合征——一种常见的急性头晕类型——是医生决定最关键的表现。一方面，急性前庭综合征最常见的病因是完全良性的外周前庭病毒综合征（即所谓的前庭神经炎或迷路炎），但另一方面，病因也可能是危及生命的中风。以前没有研究准确地估计中风病因在急性前庭综合征表现中的比例等基本信息。此外，以前没有研究使用严格的方法来估计单个患者中风的风险。头晕表现不同于其他常见的诊断困境（如胸痛和头痛表现），因为没有实验室、电生理或神经影像学检查是有效和实用的鉴别方法。虽然磁共振成像（MRI）对中风是一种敏感的测试，但在现实世界的紧急情况下，它并不是一种实用的测试。中风风险评分——从常规收集的临床信息中计算出来——可能是一个实用的鉴别指标。另一种可能的鉴别方法可能是“头部推力测试”，这是一种简单的前庭系统床边测试。然而，卒中风险评分还没有在这种独特的表现中发展起来，头部推力测试也没有经过严格的研究来确定其在这种重要的临床环境中的操作特征。在这个R18应用程序中，我们的目标是采取初步步骤来优化急性头晕表现的医疗保健价值和安全性。将招募具有代表性的样本，所有受试者将进行标准化的临床评估，不知道MRI结果。

DESCRIPTION (provided by applicant): Frontline physicians need reliable solutions to discriminate benign from sinister causes of dizziness. Current strategies to discriminate rely on either clinical dogma or brain computerized tomography scans, but these strategies have major flaws and are linked to misdiagnosis. Among dizziness presentations, the acute vestibular syndrome - a common category of acute-onset dizziness - is the presentation where physician decisions are the most crucial. On the one hand, the most common cause of the acute vestibular syndrome is an entirely benign peripheral vestibular viral syndrome (i.e., so called vestibular neuritis or labyrinthitis), but on the other hand the cause may be a life threatening stroke. No previous study accurately estimates basic information such as the proportion of stroke etiology in acute vestibular syndrome presentations. In addition, no previous study uses rigorous methodology to estimate the risk of stroke in an individual patient. Dizziness presentations are different from other common diagnostic dilemmas (e.g., chest pain and headache presentations) because no laboratory, electrophysiological, or neuro-imaging test is a valid and practical discriminator. Though magnetic resonance imaging (MRI) is a sensitive test for stroke, it is not a practical test to use as a discriminator in the real world emergency settings. A stroke risk score - calculated from routinely collected clinical information - may be a practical discriminator. Another potential discriminator may be the 'head thrust test,' a simple bedside test of the vestibular system. However, a stroke risk score has not been developed in this unique presentation and the head thrust test has not undergone rigorous study to determine its operating characteristics in this important clinical setting. In this R18 application, we aim to take the initial steps to optimizing value and safety of health care in acute dizziness presentations. A representative sample will be recruited and all subjects will undergo a standardized clinical evaluation blinded to MRI results. Using MRI with diffusion weighted sequences as a gold standard test for stroke etiology, we plan to develop a statistical model assessing the risk of stroke in patients presenting with the acute vestibular syndrome. Model based predictions will be based on clinical measurements and the head thrust test. The model will be used to assess the prevalence of stroke in the target patient population and the significance of the head thrust test as a risk predictor with and without clinical covariates. Using specific sensitivity and specificity tradeoff parameters, we will formulate a decision rule based on the model. Internal model validation will be performed to obtain unbiased estimates of operating characteristics. The reliability of the head thrust test will also be measured. This will help estimate model performance in future samples. This demonstration project will lay the groundwork for future multi-center validation and implementation studies that could ultimately improve the value of care and patient safety, while also fostering the appropriate use of processes of care and reducing unnecessary expenditures.