Many sub-types of BPPV have been defined depending on the position and characteristics of the displaced otoconia

BPPV occurs when calcium phosphate crystals (otoconia) become dislodged from the utricular otoconial membrane and enter the semicircular canals. These free particles are heavier than the inner ear fluid and cause abnormal cupular deflections with certain head movements, leading to false and intense movement perceptions.

In BPPV, jerky eye movements, known as nystagmus, occur during triggering head movements (or diagnostic examinations). By observing these, the affected canal, the position of the otoconia within the canal, and whether the otoconia are attached to the cupula, or free-floating can be discerned. 

In order to have a high success rate, a well-equipped vestibular laboratory is not enough…

A clinician should have thorough knowledge and years of experience with the many subtypes of BPPV and other vestibular diseases.

The Videonystagmography (VNG) test is essential for precisely diagnosing and effectively treating BPPV. The VNG headset removes visual clues and records eye movements during diagnostic procedures. These recordings can then be interpreted and compared with follow-up recordings.