The Journal of International
Advanced Otology
Original Article

Superior Semicircular Canal Dehiscence by Superior Petrosal Sinus: Proposal for Classification


Department of Audiology and Otoneurological Evaluation – Lyon University Hospital, Lyon, France


Paris Hearing Institute, Institut Pasteur, Paris, France


Claude Bernard Lyon 1 University, Lyon, France


Department of Otolaryngology – Head & Neck Surgery, Edouard Herriot Hospital - Hospices Civils de Lyon, Lyon, France


Integrative Multisensory Perception Action & Cognition Team — ImpAct, Lyon Neuroscience Research Center, Lyon, France


Univ Lyon, INSA-Lyon, CNRS, UCBL, MATEIS, UMR 5510, Villeurbanne, France


Department of Radiology, Hospices Civils de Lyon, Lyon, France

J Int Adv Otol 2021; 17: 35-41
DOI: 10.5152/iao.2020.9384
Read: 989 Downloads: 403 Published: 01 January 2021

OBJECTIVES: This study aimed to present 3 different clinical stages in patients presenting with superior semicircular canal dehiscence (SSCD) by the superior petrosal sinus (SPS). A specific 3-class classification based on clinical, radiological, and audio-vestibular arguments is proposed.

MATERIALS AND METHODS: We retrospectively compared clinical and radiological findings in 3 patients with different degrees of audio-vestibular dysfunction in whom the imagery evocated the diagnosis of SSCD by SPS. Imaging sensitivity was improved by combining inner ear high-resolution computed tomography (HRCT) scan and magnetic resonance imaging in fusion, allowing us to compare and corroborate clinical and audio-vestibular findings in each case with the imagery.

RESULTS: HRCT and 3T inner ear fusion imaging highlighted a direct contact and/or compression between SPS and the membranous superior semicircular canal (SSC). We propose a new classification of SSCD by SPS. Class “A” corresponds to an HRCT image with a “cookie bite” and thin bone still covering the SSC. Class “B” corresponds to a “cookie bite” image with confirmed contact between the SPS wall and the membranous SSC in MRI labyrinthine sequences. Class “C” type corresponds to a “cookie bite” image, contact, and obvious compression of the membranous SSC by SPS on MRI sequences.

CONCLUSION: Anatomical systematization is needed for daily practice. This classification of SSCD by SPS would contribute to a better understanding of the wide variety and variability in the occurrence and onset of symptoms.

Cite this article as: Ionescu E, Reynard P, Coudert A, Roiban L, Ltaief Boudrigua A, Thai-Van H. Superior Semicircular Canal Dehiscence by Superior Petrosal Sinus: Proposal for Classification. J Int Adv Otol 2021; 17(1): 35-41.

EISSN 2148-3817