TY - JOUR
T1 - Superior Canal Dehiscence Length and Location Influences Clinical Presentation and Audiometric and Cervical Vestibular-Evoked Myogenic Potential Testing
AU - Niesten, Marlien E.F.
AU - Hamberg, Leena M.
AU - Silverman, Joshua B.
AU - Lou, Kristina V.
AU - McCall, Andrew A.
AU - Windsor, Alanna
AU - Curtin, Hugh D.
AU - Herrmann, Barbara S.
AU - Grolman, Wilko
AU - Nakajima, Hideko H.
AU - Lee, Daniel J.
N1 - Publisher Copyright:
© 2014 S. Karger AG, Basel.
PY - 2014
Y1 - 2014
N2 - Superior canal dehiscence (SCD) is caused by an absence of bony covering of the arcuate eminence or posteromedial aspect of the superior semicircular canal. However, the clinical presentation of SCD syndrome varies considerably, as some SCD patients are asymptomatic and others have auditory and/or vestibular complaints. In order to determine the basis for these observations, we examined the association between SCD length and location with: (1) auditory and vestibular signs and symptoms; (2) air conduction (AC) loss and air-bone gap (ABG) measured by pure-tone audiometric testing, and (3) cervical vestibular-evoked myogenic potential (cVEMP) thresholds. 104 patients (147 ears) underwent SCD length and location measurements using a novel method of measuring bone density along 0.2-mm radial CT sections. We found that patients with auditory symptoms have a larger dehiscence (median length: 4.5 vs. 2.7 mm) with a beginning closer to the ampulla (median location: 4.8 vs. 6.4 mm from ampulla) than patients with no auditory symptoms (only vestibular symptoms). An increase in AC threshold was found as the SCD length increased at 250 Hz (95% CI: 1.7-4.7), 500 Hz (95% CI: 0.7-3.5) and 1,000 Hz (95% CI: 0.0-2.5), and an increase in ABG as the SCD length increased at 250 Hz (95% CI: 2.0-5.3), 500 Hz (95% CI: 1.6-4.6) and 1,000 Hz (95% CI: 1.3-3.3) was also seen. Finally, a larger dehiscence was associated with lowered cVEMP thresholds at 250 Hz (95% CI: -4.4 to -0.3), 500 Hz (95% CI: -4.1 to -1.0), 750 Hz (95% CI: -4.2 to -0.7) and 1,000 Hz (95% CI: -3.6 to -0.5) and a starting location closer to the ampulla at 250 Hz (95% CI: 1.3-5.1), 750 Hz (95% CI: 0.2-3.3) and 1,000 Hz (95% CI: 0.6-3.5). These findings may help to explain the variation of signs and symptoms seen in patients with SCD syndrome.
AB - Superior canal dehiscence (SCD) is caused by an absence of bony covering of the arcuate eminence or posteromedial aspect of the superior semicircular canal. However, the clinical presentation of SCD syndrome varies considerably, as some SCD patients are asymptomatic and others have auditory and/or vestibular complaints. In order to determine the basis for these observations, we examined the association between SCD length and location with: (1) auditory and vestibular signs and symptoms; (2) air conduction (AC) loss and air-bone gap (ABG) measured by pure-tone audiometric testing, and (3) cervical vestibular-evoked myogenic potential (cVEMP) thresholds. 104 patients (147 ears) underwent SCD length and location measurements using a novel method of measuring bone density along 0.2-mm radial CT sections. We found that patients with auditory symptoms have a larger dehiscence (median length: 4.5 vs. 2.7 mm) with a beginning closer to the ampulla (median location: 4.8 vs. 6.4 mm from ampulla) than patients with no auditory symptoms (only vestibular symptoms). An increase in AC threshold was found as the SCD length increased at 250 Hz (95% CI: 1.7-4.7), 500 Hz (95% CI: 0.7-3.5) and 1,000 Hz (95% CI: 0.0-2.5), and an increase in ABG as the SCD length increased at 250 Hz (95% CI: 2.0-5.3), 500 Hz (95% CI: 1.6-4.6) and 1,000 Hz (95% CI: 1.3-3.3) was also seen. Finally, a larger dehiscence was associated with lowered cVEMP thresholds at 250 Hz (95% CI: -4.4 to -0.3), 500 Hz (95% CI: -4.1 to -1.0), 750 Hz (95% CI: -4.2 to -0.7) and 1,000 Hz (95% CI: -3.6 to -0.5) and a starting location closer to the ampulla at 250 Hz (95% CI: 1.3-5.1), 750 Hz (95% CI: 0.2-3.3) and 1,000 Hz (95% CI: 0.6-3.5). These findings may help to explain the variation of signs and symptoms seen in patients with SCD syndrome.
KW - Audiometry
KW - Cervical vestibular-evoked myogenic potential
KW - Length, auditory
KW - Superior canal dehiscence, location
KW - Superior canal dehiscence, size
UR - http://www.scopus.com/inward/record.url?scp=84892402359&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84892402359&partnerID=8YFLogxK
U2 - 10.1159/000353920
DO - 10.1159/000353920
M3 - Article
C2 - 24434937
AN - SCOPUS:84892402359
SN - 1420-3030
VL - 19
SP - 97
EP - 105
JO - Audiology and Neurotology
JF - Audiology and Neurotology
IS - 2
ER -