Posterior semicircular canal dehiscence: value of VEMP and multidetector CT.
OBJECTIVE
To illustrate that posterior semicircular canal dehiscence can present similarly to superior semicircular canal dehiscence.


METHODS
The symptomatology initially presented as probable Menière's disease evolving into a mixed conductive hearing loss with a Carhart notch-type perceptive component suggestive of otosclerosis-type stapes fixation. A small hole stapedotomy resulted in a dead ear and a horizontal semicircular canal hypofunction. Recurrent incapacitating vertigo attacks developed. Vestibular evoked myogenic potential (VEMP) testing demonstrated intact vestibulocollic reflexes. Additional evaluation with high resolution multidetector computed tomography (MDCT) of the temporal bone showed a dehiscence of the left posterior semicircular canal.


CONCLUSIONS
Besides superior semicircular canal dehiscence, posterior semicircular canal dehiscence has to be included in the differential diagnosis of atypical Menière's disease and/or low tone conductive hearing loss. The value of performing MDCT before otosclerosis-type surgery is stressed. VEMP might contribute to establishing the differential diagnosis.
Vanspauwen
R
R
Antwerp University Research Center for Equilibrium and Aerospace (AUREA), University Department of Otorhinolaryngology, Head and Neck Surgery, Antwerp, University Hospital, University of Antwerp, Antwerp, Belgium.
Salembier
L
L
Van den Hauwe
L
L
Parizel
P
P
Wuyts
F L
FL
Van de Heyning
P H
PH
D000328:Adult; D003937:Diagnosis, Differential; D004594:Electrophysiology / Q000379:methods*; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D013506:Otologic Surgical Procedures; D010040:Otosclerosis / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D012665:Semicircular Canals / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D012720:Severity of Illness Index; D014057:Tomography, X-Ray Computed / Q000379:methods*