Three-dimensional biomechanical model of benign paroxysmal positional vertigo

Benign Paroxysmal Positional Vertigo (BPPV) is a common disorder of the vestibular labyrinth of the inner ear. The clinical results point toward the possibility of loose basophilic particles (otoconia) free within the labyrinth resulting in the pathology of the condition. When there is a change in head position relative to gravity, the gravito-inertial forces acting on the debris result in the displacement of the fluid (endolymph) within the labyrinth and hence, an excitatory or inhibitory neural response. This is perceived as a false sense of angular head rotation and leads to inappropriate eye movements, dizziness and severe vertigo. The present study describes biomechanical modeling of the condition of BPPV. The particle(s) were modeled as spheres free to move in the membranous labyrinth lumen (canalithiasis) and/or adhered to the cupula (cupulolithiasis). For this, differential equations describing the gravito-inertial forces acting on particle(s) under the two conditions, and the viscous interactions with the endolymph were coupled together and solved within 3D labyrinthine geometry. Results are relevant to the origin, diagnosis and treatment of Benign Paroxysmal Positional Vertigo (BPPV).