A Pilot Study to Investigate the Relationship Between Interaural Differences in Temporal Bone Anatomy and Normal Variations in Caloric Asymmetry Purpose This study assesses interaural differences in temporal bone anatomy in subjects with normal caloric findings. Method Eligible patients included those referred to the Duke University Medical Center otology clinic complaining of dizziness, with a head computed tomography scan and caloric stimulation results within normal ranges (inter-ear difference ... Research Article
Research Article  |   March 08, 2018
A Pilot Study to Investigate the Relationship Between Interaural Differences in Temporal Bone Anatomy and Normal Variations in Caloric Asymmetry
 
Author Affiliations & Notes
  • David Carpenter
    Division of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC
  • David Kaylie
    Division of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC
  • Erin Piker
    Division of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC
  • Dennis Frank-Ito
    Division of Head and Neck Surgery & Communication Sciences, Duke University Medical Center, Durham, NC
    Computational Biology & Bioinformatics PhD Program, Duke University, Durham, NC
    Department of Mechanical Engineering & Materials Science, Duke University, Durham, NC
  • Disclosure: The authors have declared that no competing interests existed at the time of publication.
    Disclosure: The authors have declared that no competing interests existed at the time of publication. ×
  • Correspondence to Dennis Frank-Ito: dennis.frank@dm.duke.edu
  • Editor: Sumitrajit Dhar
    Editor: Sumitrajit Dhar×
  • Associate Editor: Owen Murnane
    Associate Editor: Owen Murnane×
Article Information
Balance & Balance Disorders / Research Articles
Research Article   |   March 08, 2018
A Pilot Study to Investigate the Relationship Between Interaural Differences in Temporal Bone Anatomy and Normal Variations in Caloric Asymmetry
American Journal of Audiology, March 2018, Vol. 27, 110-120. doi:10.1044/2017_AJA-16-0048
History: Received April 27, 2016 , Revised August 25, 2016 , Accepted September 29, 2017
 
American Journal of Audiology, March 2018, Vol. 27, 110-120. doi:10.1044/2017_AJA-16-0048
History: Received April 27, 2016; Revised August 25, 2016; Accepted September 29, 2017

Purpose This study assesses interaural differences in temporal bone anatomy in subjects with normal caloric findings.

Method Eligible patients included those referred to the Duke University Medical Center otology clinic complaining of dizziness, with a head computed tomography scan and caloric stimulation results within normal ranges (inter-ear difference ≤ 10% or < 25% unilateral weakness). Three-dimensional reconstructions of computed tomography scans in 11 patients were used to calculate the surface area and volume of lateral semicircular canals (LSCCs), mastoid airspaces, mastoid bones, and internal auditory canal diameter and circumference. Percent differences in interaural temporal bone anatomy (i.e., left-to-right asymmetry) were analyzed and correlated with warm caloric inter-ear difference (WCD) and clinically indicated caloric predictor asymmetry.

Results A multivariate model predicting WCD from 9 interaural anatomic variables demonstrated a Pearson's coefficient of 0.999. A similarly constructed model of the clinically indicated caloric predictor demonstrated a Pearson's coefficient of 0.999. The univariate correlation was strongest for WCD versus Proctor internal auditory canal diameter (r = 0.476; p = .139) and WCD versus lateral semicircular canal surface-area-to-volume ratio (r = −0.474; p = .141).

Conclusions This pilot study provides multivariate models that predict caloric asymmetry in subjects without vestibular pathologic findings per caloric testing, based on interaural differences across variables of the temporal bone anatomy.

Supplemental Material https://doi.org/10.23641/asha.5895988

Acknowledgments
Research reported in this article was supported by the National Institute on Deafness and Other Communication Disorders of the National Institutes of Health under Grant 5T32DC013018-03 and by the National Center for Advancing Translational Sciences of the National Institutes of Health under Grant TL1TR001117 (awarded to David Carpenter). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. The authors thank Aniruddha Patki and Ofri Ronen for their contributions to this work and give special thanks to ANSYS, Paolo Maccarini, and Murali Kadiramangalam (ANSYS Global Academic Program Director) for support. All authors gave final approval for publication.
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