Numerical simulations to determine the stimulation of the crista ampullaris during the Head Impulse Test

• Published in: Computers in biology and medicine Vol. 163; p. 107225
• Main Authors: Arán-Tapia, Ismael, Soto-Varela, Andrés, Pérez-Muñuzuri, Vicente, Santos-Pérez, Sofía, Arán, Ismael, Muñuzuri, Alberto P.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.09.2023; Elsevier Limited
• Subjects: Alignment; Computational Fluid Dynamics; Computed tomography; Computer applications; Crista ampullaris; Cristae; Deviation; Fluid dynamics; Fluid-Solid Interaction; Fluid-solid interactions; Geometry; Hair; Head; Head Impulse Test; Hydrodynamics; Mathematical models; Maxima; Open source software; Personalized medicine; Precision medicine; Semicircular canals; Shear strain; Shear strain XY; Simulation; Stimulation; Velocity; Vestibular system; CFD; LTI; HIT; Fluid-Solid Interaction; Head Impulse Test; Computational Fluid Dynamics; VOR; Vestibular system; Crista ampullaris; Personalized medicine; Shear strain XY; FSI
• ISSN: 0010-4825; 1879-0534
• DOI: 10.1016/j.compbiomed.2023.107225

The Head Impulse Test, the most widely accept test to assess the vestibular function, comprises rotations of the head based on idealized orientations of the semicircular canals, instead of their individual arrangement specific for each patient. In this study, we show how computational modelling can help personalize the diagnosis of vestibular diseases. Based on a micro-computed tomography reconstruction of the human membranous labyrinth and their simulation using Computational Fluid Dynamics and Fluid-Solid Interaction techniques, we evaluated the stimulus experienced by the six cristae ampullaris under different rotational conditions mimicking the Head Impulse Test. The results show that the maximum stimulation of the crista ampullaris occurs for directions of rotation that are more aligned with the orientation of the cupulae (average deviation from alignment of 4.7°, 9.8°, and 19.4° for the horizontal, posterior, and superior maxima, respectively) than with the planes of the semicircular canals (average deviation from alignment of 32.4°, 70.5°, and 67.8° for the horizontal, posterior, and superior maxima, respectively). A plausible explanation is that when rotations are applied with respect to the center of the head, the inertial forces acting directly over the cupula become dominant over the endolymphatic fluid forces generated in the semicircular canals. Our results indicate that it is necessary to consider cupulae orientation to ensure optimal conditions for testing the vestibular function. •CFD and FSI are useful to describe the vestibular function using a micro-CT of a human membranous labyrinth.•Rotations with respect to the head center determine inertial forces acting on crista ampullaris during the Head Impulse Test.•Mapping shear strain XY stimulus determines that there are two maximum and two minimum directions of rotation for each cupula.•Cupula orientation is more important than the semicircular canals orientation when personalizing the vestibular diagnosis.