Short CRP for Anterior Canalithiasis: A New Maneuver Based on Simulation With a Biomechanical Model

Anterior Canal BPPV- A Rare Form of Vertical Canaloliathiasis: Series of 11 Cases

The most common cause of peripheral vertigo is Benign Paroxysmal Positional Vertigo (BPPV) primarily due to involvement of posterior semicircular canal. BPPV due to anterior canal is rare entity. This is a retrospective study, in which data of 628 patients who underwent vertigo test were analyzed. Amongst which 354 were patients of BPPV. It was found that 305 patients had posterior canal BPPV, 18 patients had lateral canal BPPV and 11 patients had anterior canal BPPV. The VNG data of 11 patients with anterior canal BPPV along with their treatment outcomes was analyzed. Of the eleven patients of anterior canal BPPV, ten patients had torsional nystagmus with or without downbeat nystagmus in Deep Head Hanging test. Only one patient had isolated downbeat nystagmus in Supine Head Hanging Test. Patients were treated with modified Yacovino's maneuver. Eight patients had immediate relief with modified Yacovino's repositioning maneuver. One patient had immediate conversion to left posterior canal BPPV and was treated for the same. Two patients presented with delayed conversion to posterior canal BPPV and were treated for the same. Anterior canal BPPV is rare but existent entity. It has a typical torsional and downbeat Nystagmus which is induced by Dix-Hallpike and Deep head hanging test. There is no reversal of nystagmus on getting up. It can be easily corrected by Yacovino's maneuver in the majority of the cases.

Diagnostic and Therapeutic Maneuvers for Anterior Canal BPPV Canalithiasis: Three-Dimensional Simulations

Background and Objectives: Anterior canal BPPV is a rare BPPV variant. Various diagnostic and therapeutic maneuvers have been described for its management. The aim of this study was to use three-dimensional simulation models to visualize otoconial debris movement within the anterior canal during diagnostic tests and different liberatory maneuvers. This can help to optimize existing treatment maneuvers and help in the development of better management protocols. Methods: Based on reconstructed MRI images and fluid dynamics, a 3D dynamic simulation model (as a function of time) was developed and applied. Simulations of the supine head-hanging test for diagnosis of ac-BPPV were studied. Three repositioning maneuvers were simulated: 1) the Yacovino maneuver and its modifications, 2) the reverse Epley maneuver and 3) the short canal repositioning (CRP) maneuver. Results: The simulation showed that the supine head-hanging test is a good test for diagnosis of ac-BPPV affecting both labyrinths and demonstrated why there is no inversion of nystagmus on sitting up. The Yacovino maneuver was seen to be an effective treatment option for ac-BPPV without having to determine the side involved. However, simulations showed that the classical Yacovino maneuver carried a risk of canal switch to the posterior canal. To overcome this risk, a modified Yacovino maneuver is suggested. The reverse Epley maneuver was not an effective treatment. Short CRP is useful in ac-BPPV treatment; however, it requires determination of side of involvement. Conclusion: The 3D simulator of the movement of the otoconial debris presented here can be used to test the mechanism of action and the theoretical efficacy of existing diagnostic tests and maneuvers as well as to develop new treatment maneuvers to optimize BPPV treatment.