Written by Shannon Markus
The Sudbury Vertigo Risk Score helps identify patients with vertigo who are at risk for stroke. It has remarkable sensitivity for serious neurologic pathology but has yet to be validated.
A new spin on vertigo risk
Vertigo is a common ED complaint, though only 2-5% of cases stem from serious conditions like stroke or brain tumor. Vertigo can feel like a minefield – current diagnostic approaches lack clinical guidelines, leading to inconsistent use of imaging. All the while, patients diagnosed with benign dizziness have a significantly higher risk of stroke after discharge.
A prospective cohort study was conducted across three Canadian EDs aiming to identify features in vertigo patients associated with stroke, TIA, vertebral artery dissection, or brain tumor. Of 2,078 patients, 5.3% had one of these serious conditions. Age >65, HTN, and motor deficits were factors strongly linked to serious outcomes, while episodic dizziness or positional triggers were negatively associated. They derived the Sudbury Vertigo Risk Score (below), which showed high accuracy in identifying patients at risk for serious diagnoses. Using the cutoff of 4, the sensitivity for predicting a serious diagnosis was 100% (95%CI 97-100%) and the specificity was 72.1% (95%CI 70.1% to 74%). The probability of a serious diagnosis ranged from 0% for a score of <5, 2.1% for a score of 5 to 8, and 41% for a score >8.
However, the data aren’t perfect. Stroke/TIA were diagnosed based on the WHO definitions – clinical diagnoses mainly based on history and examination, not imaging. Diagnoses were also obtained verbally via follow-up patient calls as opposed to medical records. Importantly, the score has not been externally validated.

How will this change my practice?
While I love a simplified formula to demystify my approach to this commonly dreaded complaint, I’m not sure that this changes much… yet. If categorized into strata that dictate a course of action (no further investigation vs. imaging vs. rapid consultation, etc.) and externally validated, I could see this improving resource use and timely diagnosis of serious pathology for dizzy patients in the future. Check back tomorrow when we cover a new validation study!
Source
Development of a Clinical Risk Score to Risk Stratify for a Serious Cause of Vertigo in Patients Presenting to the Emergency Department. Ann Emerg Med. 2025 Feb;85(2):122-131. doi: 10.1016/j.annemergmed.2024.06.003. Epub 2024 Aug 1. PMID: 39093245