Measurement of stapes footplate thickness using ultra-high-resolution computed tomography: stapes axial plane correlates better with otosclerosis than lateral semicircular canal plane.

BACKGROUND, AIMS: Stapes footplate thickness measurement using ultra-high-resolution CT has been described only in the lateral semicircular canal plane. The purpose of this study was to compare stapes footplate thickness between the lateral semicircular canal and stapes axial planes in patients with otosclerosis compared to controls. MATERIAL AND METHODS: We performed a retrospective single-center study of patients undergoing high-resolution temporal bone CT. Two radiologists measured stapes footplate thickness in both the lateral semicircular canal and stapes axial planes. RESULTS: Between February 2020 and October 2022, we collected 81 ears from 49 patients (75% of women; mean age 51.22 ± 16.6 years, 17 otosclerosis, and 64 controls). In the stapes axial plane, there was a significant anterior thickening in otosclerosis patients (Reader 1: 0.52 ± 0.12 [0.3-0.7] vs. 0.41 ± 0.08 [0.3-0.6], p = 0.001; Reader 2: 0.54 ± 0.06 [0.5-0.7] vs. 0.39 ± 0.08 [0.2-0.6], P < 0.001) compared to controls. These differences were not significant using the lateral semicircular canal plane. CONCLUSION: The stapes footplate was thickened at its AC in otosclerosis patients using only the stapes axial plane. SIGNIFICANCE: We propose to use the stapes axial plane instead of the lateral semicircular canal plane when analyzing the stapes.

Interest of computer tomography in the study of prognostic factors of otosclerosis.

BACKGROUND: Otosclerosis is a primary osteodystrophy of the otic capsule that causes stapedo-vestibular ankylosis. Its diagnosis is suspected on the basis of clinical and audiometric elements, basically in the presence of conductive hearing loss with a normal eardrum. The CT-scan is an essential examination for the preoperative evaluation of otosclerosis. The aim of our study was to evaluate the use of CT-scanning in predicting the functional outcome of otosclerosis surgery by correlating postoperative audiometric results and preoperative CT findings. METHODS: We conducted a retrospective study at the ENT Department in association with the Medical Imaging Department of our hospital, over a period of 8 years, from January 2014 to December 2022 and involving 90 patients (104 ears). RESULTS: The average age of our patients was 40 years with extremes ranging from 22 to 61 years. We noted a sex ratio of 0.38. The preoperative CT-scan showed signs of otosclerosis in 87% of the cases and infra-radiological forms in 13% of the cases. Veillon stage II was the most frequent radiological stage encountered with a percentage of 48%. A good audiometric evolution, defined by a closure of postoperative Air Bone Gap (ABG ≤ 20 dB) and by an improvement of Bone Conduction (BC gain ≥ 0), was recorded in 86 cases (82.7%) for ABG and in 84 cases (80.8%) for BC gain. Scanographic predictive factors of poor postoperative outcome for ABG and BC gain were: advanced stages (Veillon stage III and IV), endosteal effraction, and round window involvement. According to multivariate analysis, only the extent of otosclerotic foci was directly and independently associated with the postoperative audiometric outcome. CONCLUSION: The CT-scan is an essential examination in the preoperative evaluation of otosclerosis. It allows a positive diagnosis to be made and evaluate the extension of otosclerosis. Moreover, thanks to the analysis of the extent of the otosclerosis foci, mainly by the Veillon classification, the CT-scan allows to predict the postoperative audiometric prognosis.

Cochlear Otosclerosis and Secondary Hydrops (Ménière's Syndrome).

ABSTRACT: This article discusses a case of cochlear otosclerosis leading to secondary hydrops and near-complete hearing loss. Histopathological examination revealed advanced multifocal otosclerosis in both temporal bones, with specific focus on cochlear invasion and significant bone resorption. The severity of the case ruled out surgical intervention due to the risk of further hearing loss. The article emphasizes the challenges in managing otosclerosis-related hydrops and highlights the potential use of advanced imaging techniques for diagnosis. The study underscores the complexity of otosclerosis-induced hearing loss, contributing to the understanding of this pathology and its impact on auditory function.

[Clinical and radiological classification of otosclerosis]. / Kliniko-rentgenologicheskaya klassifikatsiya otoskleroza.

The article presents various classifications of forms of otosclerosis (OS), which change with the development of diagnostic methods. At the same time, according to the literature, a unified OS classification has not yet been adopted. All existing classifications are imperfect to some extent. The classification of clinical forms of OS according to TPA data makes it possible to determine the indications for surgical treatment and to suggest its possible effect, but not the localization of OS foci. X-ray classifications of localization of OS foci indicate their diversity, distribution, and do not always correlate with the type of hearing loss. At the same time, modern diagnostics of OS should be based on audiological data, localization of foci and their density according to the results of X-ray methods of examination. Based on the examination and treatment of 1532 patients with various forms of OS, a modern clinical and radiological classification of the disease is proposed, based precisely on these provisions. This classification, in our opinion, will improve the quality of diagnosis of various forms of OS, will allow to differentiate the tactics of treating patients with this disease to stabilize hearing loss, indications for surgical treatment, suggest its effectiveness with a reduction in the risk of surgical failures and possible further rehabilitation of the patient.

Diagnostic Efficacy of High-Resolution Computed Tomography Densitometry for Diagnosing Otosclerosis.

OBJECTIVES: The purpose of this study is to evaluate the reliability of temporal bone density measurements for diagnosing otosclerosis. MATERIALS AND METHODS: A retrospective case-control study is presented. Bone density was measured in Hounsfield units (HUs) by using high-resolution computed tomography in eight regions of interest (ROI) where otosclerotic foci are usually localized. The density of 113 otosclerotic ears was compared with that of 33 nonotosclerotic ears to determine sensitivity and specificity. Furthermore, the binormal receiver operating characteristic curve of each ROI's density was calculated to estimate the diagnostic value for osteosclerosis. In addition, the radiological density of seven cases-where radiological visual examination exhibited no findings but surgery confirmed stapes fixation-was compared with nonotosclerotic controls. RESULTS: ROI densities were significantly lower in otosclerotic patients compared with nonotosclerotic controls. The area under the curve of the fissula ante fenestram (FAF) presented the highest diagnostic performance: 1,871 HU cut-off value (area under the curve = 0.986), 96.64% sensitivity, and 100% specificity. Significantly lower densities in the FAF area were observed in the seven cases with negative radiology but intraoperatively confirmed otosclerosis. CONCLUSION: The high-resolution computed tomography density of the FAF is a reliable measurement for diagnosing otosclerosis. A value less than 1,871 HU exhibited the highest sensitivity and specificity in a European Caucasian population.

Assessment of the ability of the radiological incudo-stapedial angle to predict the stapedotomy technique type: a prospective case-series study.

PURPOSE: This study aimed to propose a radiological classification of the incudo-stapedial angle by preoperative high-resolution computed tomography (HRCT) images and to highlight its importance for predicting the use of reversal-steps stapedotomy (RSS) rather than the traditional non-reversal technique. METHODS: We included 83 candidates for stapedotomy operation. Two physicians measured the radiological incudo-stapedial joint angle in the preoperative HRCT. According to this measurement, the radiological incudo-stapedial joint was classified into three types: obtuse, right, and acute. In addition, this radiological classification was correlated with the intraoperative use of the stapedotomy technique, either reversal or non-reversal. RESULTS: The RSS technique was used in forty-two (97.7%) cases with an obtuse angle and twenty-six (89.7%) with a right angle. At the same time, the traditional non-reversal technique was used in all patients with an acute angle. The three groups differed significantly regarding the method used for stapedotomy (P value < 0.001). Moreover, Spearman's correlation coefficient revealed a significant correlation between the used technique and the radiological type of the incudo-stapedial angle (P value < 0.001). CONCLUSIONS: This prospective study proposed a preoperative radiological classification of the incudo-stapedial angle. This classification was significantly correlated with the type of stapedotomy technique. The RSS technique was feasible in most cases with an obtuse and right radiological incudo-stapedial angle. In contrast, the non-reversal method was used in all patients with an acute radiological incudo-stapedial angle. This radiological classification could predict the choice for the stapedotomy technique with an accuracy of 95.18%, a sensitivity of 73.33%, and a specificity of 100%.

Cochlear implantation in advanced otosclerosis: utility of pre-operative radiological assessment in predicting intra-operative difficulty and final electrode position.

OBJECTIVE: This study aimed to determine if pre-operative radiological scoring can reliably predict intra-operative difficulty and final cochlear electrode position in patients with advanced otosclerosis. METHOD: A retrospective cohort study of advanced otosclerosis patients who underwent cochlear implantation (n = 48, 52 ears) was compared with a larger cohort of post-lingually deaf adult patients (n = 1414) with bilateral hearing loss and normal cochlear anatomy. Pre-operative imaging for advanced otosclerosis patients and final electrode position were scored and correlated with intra-operative difficulty and speech outcomes. RESULTS: Advanced otosclerosis patients benefit significantly from cochlear implantation. Mean duration of deafness was longer in the advanced otosclerosis group (19.5 vs 14.3 years; p < 0.05). CONCLUSION: Anatomical changes in advanced otosclerosis can result in increased difficulty of surgery. Evidence of pre-operative cochlear luminal changes was associated with intra-operative difficult insertion and final non-scala tympani position. Nearly all electrodes implanted in the advanced otosclerosis cohort were peri-modiolar. No reports of facial nerve stimulation were observed.

Radiological parameters and audiometric findings in otosclerosis: is there any relationship?

OBJECTIVE: The role of high-resolution computed tomography scans in otosclerosis remains uncertain. There is a debate over the relationship between radiological and audiometric findings among patients. METHOD: Pre-operative audiometry and high-resolution computed tomography findings from 40 ears with surgically confirmed otosclerosis were compared. High-resolution computed tomography scan data regarding the characteristics of the disease foci, the endosteal extension and the occurrence of internal auditory canal diverticula were obtained. The influence of each radiological variable on the simple pure tone average, the high-frequency pure tone average and the bone-conduction pure tone average were investigated. RESULTS: Cases with endosteal extension (p = 0.047) and a higher number of affected sites within the otic capsule had a worse bone-conduction pure tone average, although it was only significant for the latter (p = 0.006). Those without concomitant retrofenestral disease (p = 0.019) had better simple pure tone average. CONCLUSION: The number of sites of involvement and concomitant retrofenestral disease seem to significantly impact audiometric findings in otosclerosis.

High-resolution computed tomography and pure-tone audiometry in patients with otosclerosis in the spongiotic phase.

OBJECTIVE: There is no consensus in the literature regarding the relationship between high-resolution computed tomography findings and hearing thresholds in pure-tone audiometry in otosclerosis. This study evaluated the association between high-resolution computed tomography findings and pure-tone audiometry in otosclerosis in the spongiotic phase. METHODS: A cross-sectional study was conducted of 57 ears with surgically confirmed stapes fixation and tomographic findings. Air conduction and bone conduction thresholds on audiometry, and air-bone gap, were analysed. RESULTS: There were no correlations between sites affected by otospongiosis and air conduction threshold, bone conduction threshold or air-bone gap in the analysed tomographic images, but the diameter of the otospongiotic focus was greater in the presence of extension of the otospongiotic foci to the cochlear endosteum. CONCLUSION: There were no relevant associations between high-resolution computed tomography findings and pure-tone audiometric measurements. However, the diameter of the otospongiotic focus was greater in the presence of extension of the otospongiotic foci to the cochlear endosteum.

[Role of computed tomography in the preoperative diagnosis of otosclerosis]. / Stellenwert der Computertomographie in der präoperativen Diagnostik der Otosklerose.

BACKGROUND: Otosclerosis is an osteodystrophy of the otic capsule and presents with progressive conductive hearing loss. Imaging studies, especially computed tomography (CT) and cone-beam CT, have gained increased relevance in the diagnosis of otosclerosis. OBJECTIVE: This study investigated whether there is a correlation between the extent of otosclerosis in high-resolution or cone-beam CT and hearing loss in pure-tone audiometry. MATERIALS AND METHODS: Based on an existing classification of otosclerotic foci, a classification was established. Preoperative CT scans of patients undergoing stapedotomy between 2015 and 2019 were evaluated and classified by two independent otorhinolaryngologists. The preoperative pure-tone audiograms were analysed and compared to the results of CT. RESULTS: A total of 168 CT studies (i.e., 168 ears) in 156 patients with intraoperatively confirmed otosclerosis were included in our study. A correlation between the extent of the otosclerotic focus or the calculated scores and hearing loss in pure-tone audiometry (air conduction, bone conduction and air-bone-gap) could not be proven. CONCLUSION: Preoperative CT is not obligatory. However, preoperative imaging using CT or cone-beam CT can be helpful to confirm the diagnosis and exclude other middle or inner ear pathologies as well as in planning of the surgical procedure in the overall context of otoscopy and audiometry. A correlation with the degree of hearing impairment could not be demonstrated and remains unclear.

Do CT values change over time and correlate with hearing in the non-surgical ears of otosclerosis patients?

BACKGROUND: High-resolution computed tomography (HRCT) is often used to diagnose otosclerosis. AIMS/OBJECTIVES: To investigate whether CT values change over time and correlate with hearing in the non-surgical ears of otosclerosis patients. MATERIALS AND METHODS: 32 patients with bilateral otosclerosis who had undergone unilateral stapedectomy were enrolled in the study. HRCT examination and pure tone audiometry were performed before and after the surgery. CT values of different regions of interest (ROIs) were measured manually and the data were collected for analysis. RESULTS: The CT value of anterior to the inner auditory meatus (AIAM) decreased by 88.5 HU (p < .05), and the changes in CT values in other ROIs showed no statistical difference. Regarding hearing, the value of air bone gap (ABG) increased by 3.6 dB (p = .020), and the average hearing deterioration rate of ABG was 3.1 dB/year. The CT value of the mid-point of the stapes footplate (MPSF) showed a certain correlation with the change of ABG (p < .05). CONCLUSIONS AND SIGNIFICANCE: The CT value of AIAM may change over time. The overall hearing of non-surgical ears in otosclerosis patients shows a deteriorating trend. Moreover, the changes in the CT value of MPSF may be related to the hearing, which needs further research.

Otopathologic and Computed Tomography Correlation of Internal Auditory Canal Diverticula in Otosclerosis.

INTRODUCTION: Internal auditory canal (IAC) diverticula, also known as IAC cavitary lesions or anterior cupping of the IAC, observed in otopathologic specimens and high-resolution computed tomography (CT) scans of the temporal bone are thought to be related to otosclerosis. Herein, we examined the usefulness of CT scans in identifying diverticula and determined whether IAC diverticula are associated with otosclerosis on otopathology. METHODS: One hundred five consecutive specimens were identified from the National Temporal Bone Hearing and Balance Pathology Resource Registry. Inclusion criteria included the availability of histologic slides and postmortem specimen CT scans. Exclusion criteria included cases with severe postmortem changes or lesions causing bony destruction of the IAC. RESULTS: Ninety-seven specimens met criteria for study. Of these, 42% of the specimens were from male patients, and the average age of death was 77 years (SD = 18 yr). IAC diverticula were found in 48 specimens, of which 46% were identified in the CT scans. The mean area of the IAC diverticula was 0.34 mm 2 . The sensitivity and specificity of detecting IAC diverticula based on CT were 77% and 63%, respectively. Overall, 27% of specimens had otosclerosis. Histologic IAC diverticula were more common in specimens with otosclerosis than those without (37.5% versus 16%; p = 0.019). Cases with otosclerosis had a greater mean histologic diverticula area compared with nonotosclerosis cases (0.69 mm 2 versus 0.14 mm 2 ; p = 0.001). CONCLUSION: IAC diverticula are commonly found in otopathologic specimens with varied etiologies, but larger diverticula are more likely to be associated with otosclerosis. The sensitivity and specificity of CT scans to detect IAC diverticula are limited.

OTOPLAN, Cochlear Implant, and Far-Advanced Otosclerosis: Could the Use of Software Improve the Surgical Final Indication?

Cochlear implant surgery in far-advanced otosclerosis can be challenging due to the degenerative process that affects the cochlea. We used OTOPLAN® to plan and define the details of surgery in a patient with such severe alteration of the cochlea that cochlear implant could be contraindicated. A 73-year-old man affected by bilateral far-advanced otosclerosis, previously treated by bilateral stapedotomy, presented 0% of speech discrimination using bilateral hearing aids. A unilateral cochlear implant was planned. The patient underwent radiologic investigation pre-surgery with temporal bone computer tomography, magnetic resonance imaging, and OTOPLAN. Radiology confirmed bilaterally advanced signs of fenestral and cochlear otosclerosis with large osteolytic cavities along the whole cochlea leading to the mixture of endolymph and perilymph. The OTOPLAN identified the alteration of the cochlea in detail. Based on the results of the software, we used a perimodiolar implant on the left ear. No intraoperative or post-operative surgical complications were observed. The patient was checked 6 months after surgery, he did not refer any problems and obtained 75% of speech discrimination at 65 dB. Our case suggests that OTOPLAN is a useful tool in far-advanced otosclerosis because careful planning of the surgery can positively affect the results. Despite the complexity of the anatomy, the software exactly described the real intrasurgical finding. We think that the use of OTOPLAN might improve the surgical indication.

Outcomes of Stapedotomy in Patients With Concomitant Otosclerosis and Superior Semicircular Canal Dehiscence: Should a Radiographic Third-Window Be a Contraindication to Stapes Surgery?

OBJECTIVE: Review surgical outcomes of stapedotomy in patients with concomitant otosclerosis and superior semicircular canal dehiscence. STUDY DESIGN: Retrospective case review. SETTING: Tertiary referral center. PATIENTS: Patients with otosclerosis and radiographic superior semicircular canal dehiscence undergoing stapedotomy between 2008 and 2020. INTERVENTION: Stapedotomy. MAIN OUTCOME MEASURES: Pre- and postoperative hearing and unmasking of third-window symptoms. Hearing was measured by air conduction (AC) and bone conduction (BC) pure-tone averages (PTA), air-bone gap (ABG), and word recognition scores (WRS). Third-window symptoms included hyperacusis, autophony, sound- or pressure-induced vertigo, imbalance, or oscillopsia. RESULTS: Twenty patients with otosclerosis and radiographic superior semicircular canal dehiscence underwent stapedotomy, 13 primary and 7 revision. Mean AC PTA was 49.3 dB preoperatively and 35.6 dB postoperatively (p = 0.0077), while the ABG improved on average from 23.9 to 9.68 dB (p < 0.0001). The ABG improved to ≤10 dB in 12/20 patients (60%), and ≤20 dB in 18/20 patients (90%). There was no significant difference in BC PTA or WRS postoperatively. Two patients (10%) experienced potential transient unmasking of third-window symptoms-hyperacusis and prolonged imbalance-which both resolved. There were no other complications. There was no significant difference in audiologic outcomes or unmasking of third window symptoms between primary or revision cases. CONCLUSIONS: Persistent conductive hearing loss is common following stapedotomy for otosclerosis in patients with concomitant superior semicircular canal dehiscence. However, a majority of patients can achieve excellent hearing outcomes, while unmasking of third window symptoms appears to be rare. Radiographic superior semicircular canal dehiscence may not be an absolute contraindication to stapes surgery for otosclerosis.

[Analysis of the imaging characteristics of otosclerosis based on 10 µm otology CT].

Objective: To evaluate the imaging features of otosclerosis based on10 µm otology CT. Methods: Data of 27 patients with otosclerosis (51 sides) in Beijing Friendship Hospital, Capital Medical University from October 2020 to July 2021 were retrospectively collected, including 9 males and 18 females age ffrom 22 to 70 (42±12) years. All patients underwent 10 µm otology CT examination and surgical treatment. The types, amounts and involved sites of otosclerosis were analyzed and the sensitivity of 10 µm otology CT in diagnosing otosclerosis were evaluated. Results: Fenestral type accounted for 49.0% (25/51 sides), and diffuse type accounted for 51.0% (26/51 sides),and he retrofenestral type without fenestral lesion was not seen. Single lesions accounted for 45.1% (23/51 sides) and multiple lesions accounted for 54.9% (28/51 sides). The incidence of involvement of the fissula ante fenestram and annular ligaments were both 100%. The incidence of involvement of stapes footplate, vestibule, cochlea, round window, inner auditory canal wall, facial nerve canal, stapes muscle and semicircular canal was 60.8% (31 sides), 33.3% (17/51 sides), 21.6% (11/51 sides), 17.6% (9/51 sides), 13.7% (7/51 sides), 9.8% (5/51 sides), 7.8% (4/51 sides) and 5.9% (3/51 sides), respectively. The sensitivity of 10 µm otology CT in diagnosis of otosclerosis was 100%. Conclusion: 10 µm otology CT can fully display the imaging features of otosclerosis, and has the potential to be an effective routine method for otosclerosis.

[A case of obliteration of a round window in otosclerosis]. / Sluchai obliteratsii kruglogo okna pri otoskleroze.

The article presents a brief review of the literature on the anatomy and physiology of the round window (RW) niche, the causes of occlusion, the diagnosis of this pathology, the features of auditory disorders and tactics when it is detected in patients with otosclerosis (OS). A clinical case of diagnosis and effective surgical treatment for obliteration of RW in a patient with advanced OS, which occurred in 2019 in 0.7% of cases, is described. Removal of RW niche obliteration was carried out with a curette and microcresis by smoothing the canopy over RW until partial visualization of the secondary membrane. It was this stage of the operation that made it possible to restore the normal hydrodynamics of the inner ear fluids and contributed to a functional result. Thus, the diagnosis of RW obliteration in patients with OS is difficult, but possible when using computed tomography of the temporal bones and assessing the mobility of the RW membrane or analyzing changes in hearing at the end of the operation, if it is performed under local anesthesia. The simultaneous performance of stapedoplasty and the removal of bone obliteration of RW makes it possible to safely achieve functional rehabilitation in patients with OS.

Postoperative Audiometric Results of Patients with Otosclerosis in relation with High-resolution Computed Tomography and Intraoperative Macroscopic Findings.

OBJECTIVE: To analyse postoperative audiological findings in fenestral otosclerosis patients treated with stapedotomy, focal location-extensiveness findings on temporal high-resolution computed tomography (HRCT), and intraoperative macroscopic stapes footplate findings. Moreover, preoperative audiological findings were compared with HRCT and intraoperative macroscopic findings. STUDY DESIGN: An observational study. PLACE AND DURATION OF STUDY: Department of Otorhinolaryngology, University of Health Sciences, Ankara Numune Training and Research Hospital, Turkey from January 2015 to January 2018. METHODOLOGY: Patients were classified according to the temporal bone HRCT findings into three groups based on otosclerotic focus location and extensiveness. Macroscopic classification was based on the intraoperative findings of blue and white footplate. Patients with obliterative otosclerosis were not included in the study. Preoperative and postoperative audiological findings as well as surgical success were investigated. Findings were compared with HRCT and macroscopic classification groups. RESULTS: Postoperative air bone gap (ABG) increased as HRCT class increased from 0 to 3, meaning a more extensive otosclerotic focus (p=0.002). The comparison of the audiological outcomes, in accordance with the intraoperative findings, revealed that the postoperative air conduction pure-tone averages (AC PTA), ABG and ABG difference were higher in the white footplate group, with statistically significant differences compared to blue footplate group (p = 0.039, p = 0.001 and p=0.029, respectively). CONCLUSION: Postoperative audiological findings were found to be correlated with intraoperative and HRCT findings. A white footplate seen at surgery or a more extensive otosclerotic focus on temporal HRCT indicates a suboptimal audiological outcome. HRCT findings should be taken into account when planning the surgery. Key Words: Otosclerosis, Temporal bone HRCT, Footplate color, Stapedotomy, Audiometry.