Labyrinthine Ossification Research Articles

Radiologic Findings in Pediatric Sudden Sensorineural Hearing Loss.

Pediatric sudden sensorineural hearing loss (pSSNHL) is a rare phenomenon. There is currently no consensus on the role of imaging in the work-up for this patient population. We aim to evaluate the efficacy of magnetic resonance imaging (MRI) and high-resolution computed tomography (CT) studies in determining the etiology of pSSNHL. Retrospective case review. Tertiary Hospital and Ambulatory Otolaryngology Clinic. Patients ≤18 years of age with sudden sensorineural hearing loss (SSNHL) and who had either MRI or CT imaging between January 2010 and May 2019 were included. Diagnostic imaging. Clinical characteristics and radiology impressions. A total of 11 patients were identified, and 10 had unilateral SSNHL. MRI was performed on all patients, five patients had additional CT imaging. Abnormal imaging findings relevant to SSNHL were observed in five patients (45.5%), which included enlarged endolymphatic duct and sac, labyrinthine ossification, apical petrositis, hypoplastic cochlear nerve, and arachnoid cyst in the internal auditory canal; one patient had unrelated findings (enlarged pituitary gland), all remaining imaging studies were normal. In our cohort, we found a higher imaging yield on pSSNHL than what has been reported for adult populations, indicating that the use of imaging in the diagnostic work-up is especially important in children.

Experience in Cochlear Reimplantation. Descriptive Study of a 20-Year Period

Introduction and objectivesThe cochlear implant is a surgical procedure that has increased substantially, because the paediatric population is diagnosed and implanted early and because there are increased potential indications. This device has the inherent risk of failure in performance, as dies any active medical device, which is the most common cause of implant removal. Our goal was to understand what the causes that produced removal in our series were, and confirm if these conformed to reality as reviewed in the literature. MethodsThis was a retrospective, descriptive, observational study of 859 cochlear implant surgeries carried out between October 1991 and May 2011. The causes of implant removal were classified according to the European Consensus Statement on Cochlear Implant Failures and Explantations. ResultsThe reimplantation rate was 6.16% (n=51). The most common reason for removal was technical device failure (45.5%), followed by infection/rejection (23.6%) and upgrade (12.7%). Less common causes: there were 3 cases (5.6%) of electrode misplacement, 2 cases (3.6%) of labyrinthine ossification, 2 (3.6%) as a result of head trauma, 2 (3.6%) from need for nuclear magnetic resonance imaging and 1 case (1.8%) from psychiatric illness. ConclusionsCochlear reimplantation is a safe procedure, with a low complication rate. In our centre, it reaches an overall rate of 6.16%. Technical device failure remains the most common cause of this procedure, although there is a significant percentage of reimplantation for device update

Experiencia en reimplantación coclear. Estudio descriptivo durante un período de 20 años

Introduction and objectivesThe cochlear implant is a surgical procedure that has increased substantially, because the paediatric population is diagnosed and implanted early and because there are increased potential indications. This device has the inherent risk of failure in performance, as dies any active medical device, which is the most common cause of implant removal. Our goal was to understand what the causes that produced removal in our series were, and confirm if these conformed to reality as reviewed in the literature. MethodsThis was a retrospective, descriptive, observational study of 859 cochlear implant surgeries carried out between October 1991 and May 2011. The causes of implant removal were classified according to the European Consensus Statement on Cochlear Implant Failures and Explantations. ResultsThe reimplantation rate was 6.16% (n=51). The most common reason for removal was technical device failure (45.5%), followed by infection/rejection (23.6%) and upgrade (12.7%). Less common causes: there were 3 cases (5.6%) of electrode misplacement, 2 cases (3.6%) of labyrinthine ossification, 2 (3.6%) as a result of head trauma, 2 (3.6%) from need for nuclear magnetic resonance imaging and 1 case (1.8%) from psychiatric illness. ConclusionsCochlear reimplantation is a safe procedure, with a low complication rate. In our centre, it reaches an overall rate of 6.16%. Technical device failure remains the most common cause of this procedure, although there is a significant percentage of reimplantation for device update

Value of Routine Plain X-Ray Position Checks after Cochlear Implantation

To analyze the value of a routine x-ray position check after cochlear implantation and to assess if an increased resistance during electrode insertion is a sufficient predictor of electrode misplacement. Retrospective data collection. University hospital. Plain x-rays (Stenvers' projection) and the respective surgery reports of 218 patients having received cochlear implantation (243 ears) were analyzed for possible electrode misplacements and intraoperative conspicuities during electrode insertion. Electrode misplacement (tip-over, loop, kinking, scalar transition, and incomplete insertion) was observed in 8% of the entire study cohort, but only in 5% if cases with inner ear dysplasia or labyrinthine ossification (n = 28) were excluded from analysis. Intraoperatively, an increased resistance during electrode insertion was found in 16% but only in 8% when cases with inner ear dysplasia or labyrinthine ossification were excluded. The intraoperative finding of an increased resistance during electrode insertion had a sensitivity of 55% and a specificity of 88% for predicting radiographically confirmed electrode misplacements (positive predictive value, 29%; negative predicting value, 96%). Nearly half of the cases of electrode misplacement would have been overlooked if radiographic position checks would have been done only in patients with intraoperative conspicuities during electrode insertion. This finding advocates routine radiographic position checks, although electrode misplacements are relatively rare in patients with regular inner ear anatomy.

Prevalence of labyrinthine ossification in CT and MR imaging of patients with acute deafness to severe sensorineural hearing loss

Objective: To evaluate the prevalence of labyrinthine ossification, and especially cochlear ossification, in a cohort of patients with unilateral sudden deafness or severe sensorineural hearing loss. Design: Retrospective data collection. Study sample: Sixty-four consecutive patients with unilateral sudden deafness or severe sensorineural hearing loss and either high-resolution CT (HRCT) of the temporal bone (isotropic spatial resolution ≤ 0.8 mm; n = 18) or high resolution CISS MRI (isotropic spatial resolution ≤ 1 mm; n = 55) were included. Nine patients underwent both imaging modalities. A standardized reading regarding labyrinthine ossifications was performed by an experienced head and neck radiologist blinded to clinical symptoms. Results: Radiologic signs of cochlear ossification were present in 14 patients (12 CT and 2 MRI). Eight patients showed unilateral and six patients bilateral signs of cochlear ossification. In all except one of the unilateral cases, the deafened ear was affected. Conclusions: Signs of cochlear ossification were found in an unexpectedly high rate (14/64, 22%) of patients with acute deafness. The data suggest HRCT of the temporal bone to be more sensitive to detect labyrinthine ossification than MRI. HRCT of the temporal bone should therefore be considered in patients with impaired recovery of acute deafness to exclude cochlear ossification; if present, and, in cases of early signs, the patient should be evaluated further to facilitate early cochlear implantation before progression impedes electrode insertion, reflecting latest developments considering cochlea implants for single-sided deafness to be effective.

Temporal Bone High-Resolution Computed Tomography in Non-Syndromic Unilateral Hearing Loss in Children

Objective: The aim of this study was to disclose possible inner ear abnormalities/pathologies by means of high-resolution computed tomography (HRCT) of the temporal bone (TBHRCT) in children with unilateral hearing loss (UHL). Methods: Retrospective review of audiological evaluation and TBHRCT in 22 children with UHL. Results: Two thirds of the children showed profound hearing loss. Review of HRCT scans identified inner ear malformations/pathologies in 9 (41%) cases and a high jugular bulb (HJB), always dehiscent with the vestibular aqueduct, in another 5 (22%). Inner ear malformations included enlarged vestibular aqueduct, common cavity and cochleovestibular hypoplasia, while labyrinthine ossification was the detected pathology. In 1 child, the common cavity of the right ear was associated with congenital melanocytic naevus of the left eyelid and lipomeningocele. To the best of our knowledge, this condition has never been described. Conclusions: The aetiology of UHL may be revealed in more than half of patients by means of TBHRCT. Besides common inner ear abnormalities, TBHRCT should be evaluated carefully to rule out HJB, dehiscences, diverticulum or erosion of inner ear structures.

Cochlear stenting: how I do it

Post-meningitis cases with profound sensorineural hearing loss are known to have progressive labyrinthine ossification; such cases need to be implanted early. In our region, often a substantial amount of time is spent procuring the necessary finances for a cochlear implant; therefore, here we describe our technique of maintaining cochlear lumen patency in post-meningitis cases with early ossification, for a complete functional electrode insertion at a later date. This is a descriptive case study of a patient having post-meningitis profound deafness, with imaging studies showing early cochlear ossification, who was rehabilitated with a cochlear implant. At a tertiary referral centre, a 1-year-old child with post-meningitis bilateral profound sensorineural hearing loss was rehabilitated with cochlear implantation. The left cochlea with early ossification was stented with a customised sterile electrode to prevent scalar occlusion; 3 months later the stent was replaced with a commercial Nucleus Contour Advance implant. A complete insertion of the functional electrode array replaced the stent. Categories of auditory performance (CAP) were used to assess the outcome in our case. The pre-operative CAP score was 1 (detects environmental sounds) and the score at 15 months post implant was 6 (understands some spoken words). In post-meningitis cases with progressive cochlear ossification, stenting the cochlear lumen prevents scalar occlusion and ensures a complete insertion of a functional electrode at a later date.

Vestibular End-Organ and Balance Deficits After Meningitis and Cochlear Implantation in Children Correlate Poorly With Functional Outcome

Assess vestibular and balance function in meningitis-induced profound sensorineural hearing loss (SNHL). Prospective cohort study. Tertiary pediatric referral center. Nine pediatric participant with profound SNHL after bacterial meningitis with (8) and without (1) unilateral Cochlear implant. Horizontal canal function in response to caloric and high-frequency rotation (0.25-5 Hz). Saccular function assessed by the vestibular evoked myogenic potential. Static and dynamic balance performance on the balance subset of the Bruininsk-Oseretsky Test of Motor Proficiency 2. Labyrinthine ossification on computed tomography preimplant, with follow-up imaging in a subset (n = 7). Horizontal canal function in response to caloric stimulation was abnormal in all children, with 5 of 8 demonstrating bilateral areflexia and 3 of 8 having asymmetric hypofunction with better function on the implanted side. In response to rotation, horizontal canal function was abnormal in all but 1 child (8 of 9). Saccular function, assessed by VEMP, was intact in most of the children (5 of 7). Static and dynamic balance (Bruininsk-Oseretsky Test of Motor Proficiency 2 scores) were significantly poorer in the meningitis group compared with both normal-hearing controls (p < 0.01) and children with SNHL of variable etiology and Cochlear implant (p < 0.01). Labyrinthine ossification was present in all cases, with variable extent, location, and progression. Vestibular function and balance are compromised in children with SNHL after meningitis. Whereas vestibular loss seems well compensated at low frequency through an overreliance on visual inputs, deficits surface during high-frequency rotation, particularly in dark. Saccular function seems less susceptible to damage from meningitis. Extent, location, and progression of ossification were variable. Despite profound dysfunction on objective testing, subjective limitations in functional balance were not reported, demonstrating the significant ability of children to compensate for even the most severe vestibular losses.

Clinical outcomes of scala vestibuli cochlear implantation in children with partial labyrinthine ossification

Conclusion. Cochlear implantation via the scala vestibuli is a viable approach in those with ossification in the scala tympani. With extended cochlear implant experience, there is no significant difference in the mapping parameters and auditory performance between those implanted via scala vestibuli and via scala tympani. Objectives. To assess the clinical outcomes of cochlear implantation via scala vestibuli. Patients and methods. In a cohort follow-up study, 11 prelingually deafened children who received cochlear implantation between age 3 and 10 years through the scala vestibuli served as participants. The mapping parameters (i.e. comfortable level (C), threshold level (T), dynamic range) and auditory performance of each participant were evaluated following initial cochlear implant stimulation, then at 3 month intervals for 2 years, then semi-annually. The follow-up period lasted for 9 years 9 months on average, with a minimum of 8 years 3 months. Results. The clinical results of the mapping parameters and auditory performance of children implanted via the scala vestibuli were comparative to those who were implanted via the scala tympani. No balance problem was reported by any of these patients. One child exhibited residual low frequency hearing after implantation.

Changes in programming over time in postmeningitis cochlear implant users

Although successful cochlear implantation of patients with deafness following meningitis is expected, long-term stability of electrical current requirements has not been systematically evaluated. This study evaluated changes in programming for patients deafened by bacterial meningitis and stability of auditory performance over time. In this retrospective descriptive study, cochlear implant (CI) stimulation mode and performance of 14 patients deafened by meningitis were compared with those of an age-matched control group of patients deafened by other causes. There were no significant differences in mean performance between the meningitis group and control group (P > 0.05). However, the postmeningitis group required progressively higher stimulation levels and higher programming modes over time as compared to the control group. Even with deafness accompanied by labyrinthine ossification attributed to meningitis, neural elements were present and could be stimulated. Because increasing levels of stimulation were required over time, postmeningitic children with CIs, and those with cochlear ossification in particular, may need frequent programming adjustments to maintain performance. These patients need close follow-up of stimulation levels and programming modes postoperatively in order to perform optimally with CIs. B-3.

Rare temporal bone pathology of the Singa calvaria from Sudan.

Evidence has recently accumulated that the Singa calvaria from Sudan probably dates from Oxygen Isotope Stage 6 (>130 ka). Morphological studies have indicated a mixture of archaic and more modern human traits, but such analyses are complicated by the possibility that the vault is pathologically deformed, although the exact etiology has not been established. Now computed tomography (CT) has revealed that the right temporal bone lacks the structures of the bony labyrinth. The most likely cause of this rare pathological condition appears to be labyrinthine ossification, in which newly deposited bone obliterates the inner ear spaces following an infectious disease or occlusion of the labyrinthine blood supply. A possible cause of vascular compromise could have been the presence of an expanding acoustic neuroma in the internal acoustic meatus, which is suggested by a significantly wider right meatus compared with the left side. Interestingly, labyrinthine ossification is also consistent with the controversial diagnosis that an anemia caused the characteristic diploic widening at the parietal bosses, because prime etiological factors of ossification are among the common complications of some of these blood diseases. CT examination of the vault and a review of the literature suggest that a blood disorder may well have caused the unusual parietal morphology. Given the nature of these pathological conditions, the Singa individual must have experienced a period of considerable disability. The morphological evidence from the normal bony labyrinth on the left side and from the CT evaluation of the vault is consistent with the interpretation of Singa as a late archaic hominid or an early representative of Homo sapiens drawn from a population which might be directly ancestral to modern humans.

Postmeningitic labyrinthine ossification primarily affecting the semicircular canals.

In a series of six cochlear-implant candidates, including three small children, labyrinthine ossification in various stages of development was observed at CT. In four of the candidates the ossifying process was more advanced in the semicircular canals than in the cochleae, and in two equally distributed. The ossifying process developed during a period of 4-5 months in two of the children. Asymmetry of its extension was found in four patients. The causative organisms were Hemophilus influenzae and Streptococcus pneumoniae. The radiologic assessment of cochlear-implant candidates should include the semicircular canals where the ossification may start, and herald the development of cochlear ossification.

Pathology of labyrinthine ossification

Ossification of the inner ear is the result of multifactorial pathogeneses, such as infection or malignant infiltration, and otosclerosis. Ossification of the inner ear spaces is a well documented sequela of suppurative labyrinthitis. In this study of human temporal bones, sections from 14 patients (28 temporal bones) were studied. In addition to the osseous tissue within the inner ear, findings included neoplasms, otosclerosis, otitis media, trauma, and Fabry's disease. We have attempted to correlate these conditions and their influence on the formation of osseous tissue within the spaces of the inner ear. Tympanogenic infection and vascular compromise were found to play an important role in ossification. The scala tympani of the basal turn of the cochlea was frequently the site involved.

Labyrinthine Ossification after Meningitis: Its Implications for Cochlear Implantation

Labyrinthine ossification can be found in a high percentage of patients with profound deafness resulting from bacterial meningitis. Radiographic evidence of ossification can be found as early as 2 months after the acute infection, indicating that the intracochlear process probably begins much earlier. If long, intracochlear cochlear implants are to be most successfully used in these patients, an aggressive approach to clinical management following the meningitis should be taken. Illustrative case reports and suggested guidelines for evaluation and treatment are given.

Labyrinthine Ossification Following Meningitis and Its Implications for Cochlear Implantation

At the 1989 spring meeting of the American Neurootology Society in San Francisco, Calif, Michael A. Novak, MD, Robert C. Fifer, PhD, and Joseph C. Barkmeier, MD, Carle Clinic, Urbana, Ill, discussed the problem of labyrinthitis ossificans and its implications for cochlear implantation. The temporal course of labyrinthine ossification after meningitis is unclear, but, in two pediatric cases, using computed tomographic scanning techniques, the authors were able to identify haziness of the basal turn of the cochlea (suggesting fibrosis and/or ossification) as early as 4 and 5 months, respectively, after the illness. Surgery was performed in the former case within 1 month of the scan, but ossification of the cochlea permitted insertion of only eight electrodes of the nucleus device. If long intercochlear electrode arrays are to be used, it is critical that impending ossification be identified as early as possible. The authors, therefore, recommend obtaining a computed tomographic scan

Cochlear implant candidates: assessment with CT and MR imaging.

Eighty-seven patients with severe to profound hearing loss were evaluated for possible placement of a multichannel cochlear implant hearing device. After initial clinical screening, 42 patients underwent computed tomographic (CT) examination. Five of these patients were also examined with magnetic resonance (MR) imaging. Twenty-two patients received implants. CT of the middle and inner ear was normal in 24 patients (57.1%) and showed labyrinthine ossification in 12 (28.6%), cochlear or fenestral otosclerosis (or both) in four (9.5%), and congenital cochlear malformation in two (4.8%). The information provided by CT was used to (a) exclude patients in whom multichannel cochlear implantation would most likely be unsuccessful (owing to obliterative labyrinthine ossification, or congenital cochlear malformation, severe cochlear, or fenestral otosclerosis), (b) help select the best ear for implantation, and (c) provide a preoperative picture of normal variants and avoidable surgical pitfalls. MR experience is limited but assessment of the size of the cochlear nerve and the membranous labyrinth is possible with this modality and may provide additional information in the evaluation of these patients.

Labyrinthitis Ossificans

Three cases with postinflammatory inner ear sequelae are presented to illustrate unusual histopathologic changes. Endolymphatic hydrops without changes in the perilymphatic system was present in one ear following "influenza" meningitis and labyrinthitis ossificans in the contralateral ear. The characteristic histopathological changes of the temporal bones with hematogenic bacterial infection were an extensive labyrinthine ossification associated with a generalized sclerotic change of the whole periotic bone. Bony fixation of the stapedial footplate occurred with the generalized inflammatory process of the otic capsule. Severe and diffuse labyrinthitis ossificans occurred in one case due to tympanogenic inflammation spreading through the round window membrane in the course of suppurative otitis media. A general immunosuppression leading to fatal termination was the apparent factor predisposing to the inner ear complication.

The pathology of labyrinthine ossification.

The pathology of labyrinthine ossification.