Actualización en el diagnóstico radiológico de la otosclerosis

[Clinical and radiological classification of otosclerosis]

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.

[A case of obliteration of a round window in otosclerosis]

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.

Diagnostic Protocol for Detecting Otosclerosis on High-Resolution Temporal Bone CT

OBJECTIVES

To present a systematic checklist to improve diagnosing otosclerosis (OS) on high-resolution computed tomography (HRCT) of the temporal bones and review this protocol's efficacy in diagnosing OS on HRCT.

METHODS

A retrospective case series was performed at a University Referral Hospital in urban Chicago, Illinois. High-resolution computed tomographies of the temporal bone were reviewed including 17 ears in the test group with surgically confirmed OS and 21 ears in the control group surgically confirmed to not have OS. Preoperative HRCTs were evaluated by a single neuroradiologist using a systematic protocol created to assist in diagnosing OS. This looked for radiolucency at the fissula ante fenestram and pericochlear region, and new bone formation around the oval and round windows.

RESULTS

The radiologist accurately diagnosed OS in all 17 test group ears and ruled out OS in all 21 control group ears using the protocol. All 17 test ears were read to have lucency at the fissula ante fenestram, 9 (53.0%) to have new bone formation, and 8 (47.1%) to have cochlear lucency. The radiologist was more confident in diagnosing OS when cochlear lucency was present with the fissula ante fenestram lucency.

CONCLUSIONS

This HRCT checklist is a highly accurate tool for evaluating the presence of OS when images are reviewed in the systematic fashion described. Imaging prior to surgery aids in counseling patients, preparing surgically, and excluding other pathologies.

Retrospective Review of Otic Capsule Contour and Thickness in Patients with Otosclerosis and Individuals with Normal Hearing on CT

BACKGROUND AND PURPOSE

Otosclerosis is commonly identified on CT as a focus of hypodensity in the otic capsule anterior to the oval window. However, otosclerosis can have a sclerotic phase approximating the density of normal bone, making diagnosis challenging. This study assesses differences in otic capsule contour and thickness anterolateral to the anterior margin of the oval window in patients with otosclerosis compared with individuals with normal hearing.

MATERIALS AND METHODS

Axial CT of 104 ears with clinically diagnosed otosclerosis and 108 consecutive ears of audiometrically normal individuals were retrospectively reviewed. Two radiologists independently evaluated the pattern of otosclerosis, otic capsule contour, and bone thickness on standardized axial images at the level of the oval window and cochleariform process. Measurements were made from the posterolateral margin of the cochlea to the apex of the otic capsule convex contour just anterolateral to the anterior margin of the oval window. In the absence of a convex contour, the sulcus between the oval window and the cochleariform process was identified, and measurement to the depth of the sulcus was used. Receiver operating characteristic analysis determined the best cutoff value of otic capsule thickness.

RESULTS

Mean otic capsule thickness (2 SDs) was 3.08 (0.93) mm and 1.82 (0.31) mm in patients with otosclerosis and individuals with normal hearing, respectively (P < .001), with excellent interobserver agreement. Otic capsule thickness of >2.3 mm had 96.2% sensitivity, 100% specificity, 100% positive predictive value, and 96.4% negative predictive value for otosclerosis. A bulging/convex contour of the otic capsule had 68.3% sensitivity, 98.1% specificity, 97.3% positive predictive value, and 76.3% negative predictive value.

CONCLUSIONS

Patients with otosclerosis have significantly thicker bone abutting the oval window than individuals with normal hearing.

[The diagnostics and surgical treatment of the patients presenting with otosclerosis in the Primorye Territory]

The objective of the present study was to characterize the effectiveness of the audiological and radiological diagnostic techniques as well as the results of the surgical treatment of the patients presenting with otosclerosis based at the hospital clinic of the Pacific State Medical University. The analysis included 49 surgical interventions for stapedoplasty carried out on 42 patients during the period from 2015 to 2017. The tympanic form of the disorder was diagnosed in 51.02% of the cases, the mixed form I in 16.28%, and the mixed form II in 32.7%. The excellent results within two months after surgery were obtained in 87.2% of the treated patients, the good and satisfactory results in 8.72% and 4.08% of them respectively.