Volume 15, Number 4
2005
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Biomechanics of horizontal canal benign paroxysmal positional vertigo
Featured Article (2,002 KB)
pp. 203 - 214
Suhrud M. Rajguru, Marytheresa A. Ifediba, Richard D. Rabbitt
Horizontal canal (HC) benign paroxysmal positional vertigo
(HC-BPPV) is a vestibular disorder characterized by bouts of
horizontal ocular nystagmus induced during reorientation of the
head relative to gravity. The present report addresses the
application of a morphologically descriptive 3-canal
biomechanical model of the human membranous labyrinth to study
gravity-dependent semicircular canal responses during this
condition. The model estimates dynamic cupular and endolymph displacements
elicited during HC-BPPV provocative diagnostic maneuvers and canalith
repositioning procedures (CRPs). The activation latencies in response to an
HC-BPPV provocative diagnostic test were predicted to vary depending upon
the initial location of the canalith debris (e.g. within the HC lumen vs.
in the ampulla). Results may explain why the onset latency of ocular nystagmus
evoked by the Dix-Hallpike provocative maneuver for posterior canal BPPV are
typically longer than the latencies evoked by analogous tests for HC-BPPV. The
model was further applied to assess the efficacy of a 360°-rotation CRP for
the treatment of canalithiasis HC-BPPV.
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