title: Sensorineural hearing loss and otosclerosis: a clinical and radiologic survey of 437 cases.
abstract: The aim of this study was to determine if a relationship exists between bone level thresholds and the extension of otosclerotic foci within the otic capsule. The study consisted of a retrospective case review in a university hospital. We included patients who underwent surgery for otosclerosis in our department and who had a CT scan prior to surgery. We analyzed the data charts and CT scans of 437 cases (386 patients). On CT scan, we distinguished patients with fenestral otosclerosis and/or with a pericochlear focus. A pericochlear focus could be extended (Group 2) or not (Group 1) to the cochlear endosteum. Data for Groups 1 and 2 were compared with those for the control group of all patients for whom CT scan showed no cochlear focus (Group 3). Of the 437 CT scans, 399 were positive (91.3%). An anterior focus was reported in 305 cases (69.8%), a footplate thickening in 21 cases (4.8%) and both anomalies were encountered in 60 cases (13.7%). A pericochlear focus was reported in 53 examinations. This focus was extended to the endosteum in 14 cases (26.4% of the pericochlear foci). In Group 1, preoperative air conduction (AC) thresholds were significantly lower than in the control group (p < 0.05). The air--bone gap was also significantly larger in Group 1 (p < 0.05). Bone conduction (BC) thresholds were lower in Group 1 than in the control group but the difference was not significant. In Group 2, preoperative AC thresholds were significantly lower than in the control group (p < 0.05). BC thresholds were also lower in Group 2 than in the control group and the difference was significant (p < 0.05). As a result of this study, we assume that there may be a relationship between bone level thresholds and the radiological extension of otosclerosis within the otic capsule.
authors.affiliation: Department of Otolaryngology, Purpan Hospital, Toulouse, France. shin.y@chu-toulouse.fr
authors.forename: Y J
authors.initials: YJ
authors.lastname: Shin
authors.forename: B
authors.initials: B
authors.lastname: Fraysse
authors.forename: O
authors.initials: O
authors.lastname: Deguine
authors.forename: C
authors.initials: C
authors.lastname: Cognard
authors.forename: J P
authors.initials: JP
authors.lastname: Charlet
authors.forename: A
authors.initials: A
authors.lastname: Sévely
mesh_terms: D000328:Adult; D001309:Auditory Threshold / Q000502:physiology*; D001844:Bone Conduction / Q000502:physiology*; D003051:Cochlea / Q000503:physiopathology / Q000601:surgery; D004429:Ear Ossicles / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008297:Male; D008875:Middle Aged; D010040:Otosclerosis / Q000175:diagnosis* / Q000503:physiopathology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome