From the Guidelines
The incidence of BPPV is approximately 1% in the general population, and the otoconia involved are composed of calcium carbonate crystals, not calcium phosphate, with the posterior semicircular canal being most commonly affected, followed by the lateral and then the superior canal. The pathophysiology of BPPV is characterized by the displacement of otoconia from their normal location in the utricle and saccule of the vestibular system into the semicircular canals, causing brief episodes of vertigo with certain head movements 1. In terms of canal involvement, the posterior semicircular canal is most commonly affected, accounting for about 85-95% of cases, followed by the lateral (horizontal) canal, which accounts for 5-15% of cases, and the superior (anterior) canal is least commonly affected, accounting for about 1-2% of cases 1. Some key points to consider in the diagnosis and treatment of BPPV include:
- The use of bedside testing, such as the Dix-Hallpike test or supine roll test, to confirm the diagnosis of BPPV 1
- The effectiveness of canalith repositioning procedures (CRPs) in relieving symptoms of BPPV, with success rates of around 80% with only 1-3 treatments 1
- The importance of patient education and self-repositioning maneuvers in the management of BPPV 1
- The potential for BPPV to have a significant impact on individual health-related quality of life, and the importance of treatment in improving quality of life 1. Overall, the management of BPPV should prioritize a thorough diagnosis, effective treatment, and patient education to improve outcomes and quality of life 1.
From the Research
BPPV Questions
- Incidence: The incidence of BPPV is not explicitly stated as 1% in the provided studies, however, study 2 mentions that BPPV accounts for approximately 20-30% of referrals to specialist vestibular centres.
- Otoconia composition: According to study 3, otoconia are composed of calcium phosphate, and calcium homeostasis contributes to the pathogenesis of BPPV.
- Most likely affected canal: Studies 4, 5, and 6 suggest that the posterior canal is the most commonly affected, followed by the lateral canal, and then the superior canal is not typically mentioned as a common site, but study 5 does mention the posterior and/or lateral semicircular canals are usually affected.
- Location of otoconia in normal individuals: Study 3 does not explicitly state that otoconia are in the SCCs (semicircular canals) in normal individuals, but rather mentions that otoconia are of utricular origin and can become dislodged and float freely within the endolymph of a semicircular canal.