The Power of Diagnostic Tests for Benign Paroxysmal Positional Vertigo: A Syndromic Approach

Objective: To determine diagnostic power of the symptoms and findings of patients with complaints of dizziness/balance disorder and to identify the syndromic diagnostic components for the benign paroxysmal positional vertigo (BPPV). Methods: A retrospective methodological study of 147 adult patients with dizziness/balance disorder visiting the Otorhinolaryngology Clinic between January and December 2014 was conducted. The symptoms, signs and laboratory test results of the patients in BPPV and non-BPPV groups were compared and analyzed through sensitivity, specificity, predictive values, likelihood ratios, post-test odds and probabilities, logistic regression analysis and ROC. The criterion indices having high post-test probability values were determined. Results: The most common three diagnoses were psychogenic vertigo (34.0%), peripheral vertigo of unknown origin (22.4%), and BPPV (16.3%). Five complaints and findings were found to have statistically significant diagnostic power: characteristic dizziness complaint, dizziness attacks lasting less than two minutes, dizziness being present for less than one week, supine roll and Dix-Hallpike test positivity. The post-test probability increased to 95.4% in patients with attacks lasting less than two minutes and dizziness lasting less than one week, when the Dix-Hallpike test was positive (triple-index positivity). According to the logistic regression model, positive result of the Dix-Hallpike test increased the probability of BPPV by 65.6 times. Accuracy of the model was 92.5%, with the area under the ROC curve of 0.891. Conclusion: Our study results have provided evidence basis for diagnostic power of the Dix Hallpike test and, to a lesser extent, of the supine roll test