Background: Many patients consult neurologists because of vertigo. Benign paroxysmal positional vertigo (BBPV) is one of the most common types of vertigo. Although the clinical presentation of this common condition is straightforward, the diagnosis and diagnostic maneuvers can be challenging. Objectives: How useful is the Dix-Hallpike test in establishing the diagnosis of BPPV? How useful is an alternative positional test, such as the side-lying maneuver, in the diagnosis of BPPV? Methods: We addressed the question through development of a structured critically appraised topic. Participants included consultant and resident neurologists, clinical epidemiologists, medical librarian, and clinical content expert in the field of otolaryngology. Participants started with a clinical scenario and structured questions, devised search strategies, located and compiled the best evidence, performed critical appraisals, synthesized the results, summarized the evidence, provided commentary, and declared bottom-line conclusions. Results: A single study comparing the Dix-Hallpike and side-lying tests was identified. For the Dix-Hallpike test, the estimated sensitivity was 79% [95% confidence interval (CI) 65-94], specificity was 75% (33-100), positive likelihood ratio (LR) was 3.17 (95% CI 0.58-17.50), negative LR was 0.28 (95% CI 0.11-0.69). For the side-lying test, the estimated sensitivity was 90% (95% CI 79-100), specificity was 75% (33-100), positive LR was 3.59 (95% CI 0.65-19.67), negative LR was 0.14 (95% CI 0.04-0.46). The study employed very weak methodology, and therefore the results had limited validity. Conclusions: The Dix-Hallpike test is the standard from which the diagnosis of posterior semicircular canal BPPV is made. Hence evaluations of its diagnostic test properties and utility are challenging. For patients unable to move into the Dix-Hallpike test positions, alternative tests such as the side-lying test can be attempted. These modifications, however, are rarely necessary.
