Temporal bone density measurements using CT in otosclerosis

OBJECTIVE: To assess the bone density around the bony labyrinth in otosclerosis patients and to compare it to that of a control population. MATERIAL AND METHODS: This was a prospective case-control study. Ten patients with otosclerosis (mean age 42 years; range 24-55 years) and 33 control patients with vestibular schwannoma (mean age 46 years; range 20-71 years) were included. All patients underwent a clinical examination, audiometry and a CT scan comprising axial and coronal views of both temporal bones. In the otosclerosis group, audiometry showed unilateral involvement in six patients and bilateral hearing loss in four. The bone density was measured at the fissula ante fenestram (FAF) and at five other anatomical points on the bony labyrinth. RESULTS: In the control group, the bone density was similar at the six anatomical points. In the otosclerosis patients, the mean bone density at the FAF was lower than that in control patients (1649+/-99.1 vs 2049+/-13.4 HU; p < 0.01). For patients with FAF bone densities < 2000 HU, a correlation was observed between hearing threshold and FAF bone density. CONCLUSION: FAF bone density appears to be a good indicator of disease progression, and could serve as a follow-up and prognostic parameter.     

Stability of computed tomography densitometry in patients with otosclerosis:a two-year follow-up

Objectives:To quantify the progression of otosclerosis in the unoperated ear between two stapedotomy procedures for patients with bilateral otosclerosis which can help to determine whether a HRCT scan should be re-performed before the second surgery for patients who already received HRCT imaging before the initial surgery.Methods:35 patients who underwent bilateral stapedotomy were included.Two rounds of HRCT examination and audiometry were performed at the time of the first surgery and second surgery on the ear that was not operated on during the initial surgery.The relationship between the changes in HRCT densitometry and audiometry over time was analyzed.Results:The second round of HRCT did not add significant information about the changes to the otosclerosis lesions in either the imaging diagnosis or the HRCT density values except for small changes in the HRCT densitometry readings at the area anterior to the inner auditory(P=0.01).While the changes in HRCT manifestation are small,changes near the fissula ante fenestram(FAF)were still positively correlated with the air bone gap(ABG)of patients(p=0.031,r=0.388).Conclusions:The progression of lesions in otosclerosis is slow resulting in small and insignificant changes to the HRCT features.Therefore,a repeat HRCT evaluations prior to surgery is not necessary for patients who have had a previous HRCT evaluation within 2 years of the operation.The small changes in HRCT manifestation near the FAF were still correlated with negative effects on the ABG which could cause worsened hearing thresholds over this timeframe。     

Measuring the density of the fissula antefenestram and the section of the basal turn of the cochlea: Are they useful in the radiological diagnosis of otosclerosis?

IntroductionThe role of objective parameters in terms of improvement of the accuracy of high-resolution computed tomography (HRCT) of the temporal bone in the diagnosis of otosclerosis remains unclear.ObjectivesTo investigate the relationship between the density of the fissula antefenestram (FAF) and of the width of the transversal section of the basal turn of the cochlea (BTC), and the diagnosis of otosclerosis.MethodsThis is a retrospective study in which preoperative HRCT data from ears of patients submitted to stapedotomy due to otosclerosis (case group) were evaluated. For the control group, normal hearing ears having undergone HRCT for other purposes were included. Case and control HRCT images were objectively assessed by an experienced blinded radiologist. During this evaluation, measurements of the relative radiological density of the FAF and of the transversal section of the BTC were obtained. The results were compared between the groups. Also, a receiver operating characteristic curve was created and the area under the curve (AUC) was calculated for each variable. Significance level was set at .05.Results40 ears were included in each group. Case ears presented reduced values for the relative radiological density on the FAF (p-value<0.0001). Moreover, ears with otosclerosis (p-value: 0.022) presented lower transversal section of the BTC. The AUC for these variables reached 0.929 and 0.646, respectively.ConclusionsOtosclerotic ears present reduced radiological density on the FAF and narrower BTC. The relative density of the FAF also shows a great diagnostic power in the context of this disease.     

Are computed tomography and densitometric measurements useful in otosclerosis with mixed hearing loss? A retrospective clinical study

The objective of the study was to investigate the relationship between extent of otosclerotic foci and audiological findings in otosclerotic patients with mixed hearing loss using high-resolution computed tomography (HRCT) and also to measure the density of bony labyrinth in otosclerotic patients and compared with control group. This was a retrospective study. Twenty-five patients with clinical otosclerosis and mixed hearing loss were included in the study. The average threshold of air-bone conductions (AC, BC) within the 0.5–4 kHz frequency range, and average air bone gap (ABG) were calculated. Eleven patients with normal HRCT who received cochlear implant were included in the study as the control group. The lesions in HRCT were staged according to their extension. Eight different points of the otic capsule in each patient were measured using HRCT. Fifty ears total, from 25 patients, had bilateral otosclerosis. The mean AC of all the ears was 63 dB, mean BC was 35.2 dB, and mean ABG was 27.8 dB. HRCT staging indicated 22 ears had Grade 1, 21 ears had Grade 2, and 7 ears had Grade 3 lesions. There was a statistically significant difference between the mean AC, BC of ears with Grade 1 and Grade 2 when compared with the mean AC, BC of ears with Grade 3. When comparing the densitometric measurements of fissula ante fenestram localizations, a statistically significant difference was observed. HRCT examination and densitometric measurements in otosclerotic patients with mixed hearing loss presented significant results. We were unable to show a significant relationship between early stage and hearing thresholds, but there was a significant relationship in advanced stage. Densitometric measurements may provide significant results for otosclerosis, particularly for the FAF region when comparing with control group.     

Value of temporal bone density measurements in otosclerosis patients with normal-appearing computed tomographic scan

OBJECTIVES: Previous studies demonstrated that otosclerosis diagnosis benefits from temporal bone density measurements. We sought to assess bone density measurements of the fissula ante fenestram (FAF) in normal patients, in patients with otosclerosis, and in patients with cholesteatoma. We discuss the value of temporal bone density measurements in patients with otosclerosis who have a normal-appearing computed tomographic (CT) scan. METHODS: This was a prospective case-control study in which 219 temporal bones (123 adults, 18 to 84 years of age) were included between November 1, 2002, and April 30, 2004. All patients underwent a CT scan of the temporal bones. Axial views were obtained with density measurement of the FAF. RESULTS: The FAF density was significantly different (p < .0001) in the otosclerosis group (n = 119) compared to the control group (n = 100). There was no significant difference between the otosclerosis group with a normal-appearing CT scan and the control group (p = .64). CONCLUSIONS: From our results, it may be suggested that 1) temporal bone density measurements seem not to be strictly comparable between CT scan devices; and 2) temporal bone density measurements of the FAF did not allow the diagnosis of otosclerosis when the CT scan appeared normal.     

Results of stapedotomy in otosurgical treatment of adult patients with osteogenesis imperfecta

ObjectiveThis is a retrospective study of hearing results and characteristics of osteogenesis imperfecta (OI) patients treated for hearing loss by stapedotomy at tertiary reference center.MethodsThis study enrolled 20 patients with a clinical diagnosis of OI- (11M:9F). 18 patients (90%) underwent surgery due to hearing loss in the period 2003–16. The audiometric analysis provides the pure tone audiometry results of stapedotomy in adult patients in 2 periods (≤12 months and >12 months).Air-bone gap (ABG), hearing gain (HG), and changes in air and bone conduction thresholds after surgical treatment were analyzed.ResultsIn short-time follow-up we noted statistically significant improvement in mean AC thresholds and ABG (p < 0.001 for both), change in mean BC thresholds was statistically negligible. Comparing the observation periods short-term and long-term, it was found that AC thresholds, ABG, HG, ABG closure did not significantly change, although BC thresholds and BC closure deteriorated significantly (p < 0.05).ConclusionStapes surgery for OI can be considered as a method of treating the conductive and/or mixed hearing loss suffered by these patients; however, the surgery is more difficult than that for otosclerosis because OI cases often have extremely difficult anatomical conditions. The hearing results of OI stapes surgery differ from typical otosclerosis cases, with the ABG closure not being as good. In addition, sensorineural hearing loss inevitably progresses.     

Utilidad diagnóstica de la densidad ósea de la cápsula laberíntica en el diagnóstico de la otosclerosis por tomografía de alta resolución

ObjectiveThe aim of this study is to compare the bone density around the otic capsule in otosclerotic patients with a control group, and find the cut-off values of bone density from which we can diagnose the disease.Material and methodsA retrospective case-control study was performed. Bone densities in Hounsfield units (HU) from 28 otosclerotic ears were compared to the densities of 33 non otosclerotic capsules. These densities were measured in eight regions of interest (ROI) where the otosclerotic foci are usually found. The mean density of these regions (PROMED) was taken. Furthermore, the ROC curves of each ROI and the mean density (PROMED) were calculated.ResultsAll radiological densities in HU of each ROI and the mean density in otosclerotic patients were lower compared to non otosclerotic ears. The area under the ROC curve of each ROI and the mean density showed that the areas with greater accuracy for the diagnosis of otosclerosis were mean density, the fissula ante fenestram, and precochlear region, with cut-off values of 1980 HU, 1750 HU and 2114 HU, respectively.ConclusionThe mean density of the otic capsule (PROMED), the density in the fissula ante fenestram (ROI 1) and in the precochlear region (ROI 3) seem to be the most useful parameters to make a diagnosis of otosclerosis.     

Frequency-specific hearing results after stapes surgery for Chinese population otosclerosis with different degrees of hearing loss

Abstract

Background: Frequency-specific hearing studies are important for predicting hearing results and the prognosis after stapes surgery, to prepare for the rehabilitation of frequency-specific hearing in patients with otosclerosis.

Objectives: To evaluate outcomes of stapes surgery of Chinese otosclerosis patients with different degrees of hearing loss.

Methods: We conducted a retrospective analysis of 213 otosclerosis patients who underwent stapes surgery in our hospital. Pre- and post-operative audiometric evaluation using conventional audiometry.

Results: The post-op ABG was less than 20?dB in 94.52% of all cases after surgery. There was no statistical significance of the post-op ABG among different groups at all frequencies except extremely severe group (p?<?.05). There was a significant improvement of both AC and BC thresholds in post-op period and the most significant improvement was found in severe group. There were no serious post-op complications and no re-operations during the follow-up period.

Conclusion: Stapes surgery is a suitable treatment option for otosclerosis with mild to extremely severe HL. The mild to moderate hearing loss groups had the most significant improvement of AC thresholds in the low frequency region, and the severe to extremely severe groups appeared in the high frequency region.     

Unfavourable prognostic factors in patients treated surgically for otosclerosis

Abstract

Backgrounds: Otosclerosis is the cause of between 5% and 9% of all deafness cases and between 18% and 22% of conductive hearing loss cases. Neurosensory deafness develops in 30% of patients with otosclerosis.

Aims/Objectives: The aim was to seek a correlation that would reflect the dependence of the results of middle ear surgery on the type of abnormalities atypical of otosclerosis but found during the stapedotomy surgery.

Materials and Methods: The analysis included 140 patients who underwent surgery for otosclerosis. The hearing of all patients was assessed using an audiometric test.

Results: In the assessment of changes in the mean bone conduction values, statistically significant differences between the reference group and the subgroup of patients on whom a myringoplasty was performed, as well as in patients with adhesions present in the middle ear spaces, were found only for the 500?Hz frequency.

Conclusion and Significance: The removal of abnormalities, such as the loss of the eardrum (iatrogenic), changes to the lining and adhesions other than those typical of otosclerosis, restores middle ear mechanics after a stapedotomy on the inner ear and leads to a measurable improvement in mean bone conduction values.     

Significance of internal auditory canal diverticula in ears with otosclerosis

Abstract

Background: Diverticula in the internal auditory canal (IAC) have been reported in ears with otosclerosis.

Objective: We evaluated hearing levels and vascular activity in ears with otosclerosis with and without IAC diverticula and clarify the significance of IAC diverticula.

Materials and methods: Sixty-one ears from 54 patients who underwent stapes surgery for otosclerosis [fenestral (48 ears) and retrofenestral (13 ears) groups] were included in the present study. Preoperative hearing levels on pure tone audiometry (PTA) and intraoperative measurements of blood flow were compared between the groups.

Results: A total of 24 of 61 ears (39.3%) showed IAC diverticula, significantly higher than the frequency in ears without otosclerosis (3.7%). No significant differences in air- and bone-conduction thresholds on PTA were evident between ears with and without IAC diverticula in each group. Ears without IAC diverticula tended to show higher blood flow in the area anterior to the oval window than ears with IAC diverticula, but the difference was not significant.

Conclusions: The incidence of the IAC diverticula in otosclerosis was significantly higher than in cases without otosclerosis. The existence of IAC diverticula was not evidently related to the severity of the disease from the perspective of hearing level and vascular activity.     

Fully endoscopic laser stapedotomy: is it comparable with microscopic surgery?

Abstract

Background: Microscopic stapedotomy is very successful and has long history, but it still has some constraints. Thus, otoendoscopy is increasingly popular nowadays.

Aims/Objectives: The retrospective review study was to investigate the role of endoscopic laser stapedotomy in treating patients with otosclerosis.

Materials and methods: Seventeen patients who received endoscopic laser stapedotomy from April 2014 to July 2017 were enrolled and compared to 13 patients who had microscopic stapedotomy from February 2009 to March 2012. The anatomical structures, operative time, and postoperative hearing outcomes were assessed in two groups. Relation between external acoustic canal and operative time was also analyzed.

Results: Using an endoscope, the operative field was clear, with easily identified anatomy, without need to sacrifice bony structures. The operative time was significantly longer in the endoscopic group in 2014 and decreased in the following years. There was no significant difference of hearing improvements between the two groups. There was a weak correlation between the width of the external auditory canal and the operative time.

Conclusions and significance: Fully endoscopic stapes surgery is a feasible and safe surgical technique and results in satisfactory hearing outcomes. However, surgeons take longer to master the technique and to achieve shorter endoscopic operative times.     

Imaging of capsule otosclerosis using computerized tomography

To investigate whether otosclerotic foci in the bony capsule of the cochlea and labyrinth can be demonstrated by high-resolution computed tomography, CT images from 31 patients suspected of having cochlear otosclerosis were submitted to a retrospective analysis. Fourteen of the patients had a clinically confirmed otosclerosis associated with an advanced mixed hearing loss. In four of these cases, fresh otospongiotic foci were detected in the bone of the cochlear capsule, while older otosclerotic foci were not demonstrated. In fifteen patients with progressive, purely sensorineural hearing loss, no otospongiotic foci were detected in the cochlear capsule. In contrast, such foci were observed in two deaf patients in whom otosclerosis had been suspected.     

The radiological diagnosis of fenestral otosclerosis: the utility of histogram analysis using multidetector row CT

Bone density measurements using high-resolution CT have been reported to be useful to diagnose fenestral otosclerosis. However, small region of interest (ROI) chosen by less-experienced radiologists may result in false-negative findings. Semi-automatic analysis such as CT histogram analysis may offer improved assessment. The aim of this study was to evaluate the utility of CT histogram analysis in diagnosing fenestral otosclerosis. Temporal bone CT of consecutive patients with otosclerosis and normal controls was retrospectively analyzed. The control group consisted of the normal-hearing contralateral ears of patients with otitis media, cholesteatoma, trauma, facial nerve palsy, or tinnitus. All CT images were obtained using a 64-detector-row CT scanner with 0.5-mm collimation. AROI encompassing 10 × 10 pixels was placed in the bony labyrinth located anterior to the oval window. The mean CT value, variance and entropy were compared between otosclerosis patients and normal controls using Student’s t test. The number of pixels below mean minus SD in the control (%Low_cont) and total subjects (%Low_total) were also compared. In addition, the area under the receiver operating characteristic curves (AUC) value for the discrimination between otosclerosis patients and normal controls was calculated. 51 temporal bones of 38 patients with otosclerosis and 30 temporal bones of 30 control subjects were included. The mean CT value was significantly lower in otosclerosis cases than in normal controls (p < 0.01). In addition, variance, entropy, %Low_cont and %Low_total were significantly higher in otosclerosis cases than in normal controls (p < 0.01, respectively). The AUC values for the mean CT value, %Low_cont and %Low_total were 0.751, 0.760 and 0.765, respectively. In conclusion, our results demonstrated that histogram analysis of CT image may be of clinical value in diagnosing otosclerosis.     

Otosclerosis: etiopathogenesis and histopathology

Otosclerosis is a disease of the bony labyrinth manifesting clinically as a progressive conductive hearing loss, a mixed-type hearing loss, or a sensorineural hearing loss. The age of onset of the hearing loss caused by otosclerosis is principally between 15 and 40 years. Although histopathological inner ear changes due to otosclerosis have been very well documented, the true etiopathogenesis of the disease has yet to be described despite intensive research. Both genetic and environmental factors have been implicated, however.     

Temporal bone findings in a case of otopalatodigital syndrome

The principal features of the otopalatodigital syndrome are hearing loss, cleft palate, and skeletal dysplasia of the hands and feet. The right temporal bone was acquired from a boy with this syndrome who died at the age of 2 1/2 years. Behavioral audiometry had indicated a conductive hearing loss, with probable near-normal sensorineural function; brainstem evoked response audiometry indicated a mild sensorineural hearing loss. Histologic studies of the temporal bone revealed dysmorphic features in both the middle ear and the bony labyrinth. The ossicles were deformed, the stapes was fixed, and no round window was present. A defect of the modiolus resulted in a wide communication between the subarachnoid space of the internal auditory canal and the scala vestibuli. These anomalies would clearly have frustrated any attempt to improve the patient's hearing through reconstructive middle ear surgery.     

Early functional results using the nitibond prosthesis in stapes surgery

Conclusion: The NiTiBOND^® prosthesis allows early results to be obtained similar to those with a manually crimped prosthesis fitted by experienced surgeons, thus reducing the learning curve in this critical step of the procedure.

Objective: To analyze the 1-month results using the nitinol NiTiBOND^® prosthesis in primary otosclerosis surgery and to compare the results with those obtained with fully fluoroplastic or fully titanium pistons.

Materials and methods: Fifty consecutive cases operated on with the NiTiBOND^® prosthesis (nitinol group) were compared with 50 cases operated on with a fully fluoroplastic piston (fluoroplastic group), and with 131 cases operated on with a fully titanium piston (first titanium group), and also with 50 cases operated on with the same titanium piston just before using the NiTiBOND^® piston (last titanium group). Pure-tone and speech audiometry was performed 1 month after surgery for the nitinol group. Comparison was made between the early hearing results of the four groups.

Results: The mean air–bone gap closure for the nitinol group was 16?±?1.0?dB (mean?±?SEM, n?=?50); an air–bone gap of?<15?dB and?<10?dB was obtained in 100% and 84% of cases, respectively. These hearing results were similar to the last titanium group and significantly better than those observed in the fluoroplastic and first titanium groups.     

Review of a single surgeon’s stapedotomy cases performed with a nickel titanium prosthesis over a 14-year period

Abstract

Conclusion: Stapes surgery with a nickel titanium prosthesis is a safe and well-tolerated procedure that leads to a significant improvement in hearing outcomes.

Objective: To identify the efficacy and safety of stapedotomy procedures performed with a nickel titanium prosthesis for patients with otosclerosis.

Methods: A review of 431 unique stapedotomies performed over 14 years by a single surgeon at an academic tertiary care center yielded 312 cases with nickel titanium prosthesis that met inclusion criteria of otosclerosis diagnosis, initial surgery in operative ear, and presence of pre-operative and post-operative audiograms. Pure-tone averages (PTA) at baseline and 8 weeks after surgery were calculated over four frequencies; 0.5, 1, 2, and 4?kHz. Average air–bone gaps (ABG) were calculated from pre-operative and post-operative audiograms.

Results: Average pre-operative baseline PTA was 56.7?dB in the affected ear. Post-operative PTA was 30.1?dB, a 26.6?dB improvement. Initial average ABG was 29.7?dB, while post-operative ABG averaged 5.4?dB, a 24.2?dB improvement. Surgical success (closure of ABG within 10?dB) was achieved in 263 (84%) patients. Rate of surgical success was not correlated with age, gender, race, or affected ear. Complications included recurrent conductive hearing loss (14), progressive SNHL (4), and post-operative BPPV (3).     

GPER-1 and sex-hormone levels in patients with otosclerosis

ObjectiveOtosclerosis is a widespread disease but the etiopathogenesis is still not fully understood. Hormonal factors especially estrogens are accused in recent years. The study aimed to evaluate the levels of G-protein associated membrane estrogen receptor-1 (GPER-1) and sex-hormones in patients with otosclerosis.Subject and methodsThe study included 60 people (30 otosclerosis patients, 30 control group). Serum sex-hormone (estradiol, progesterone, prolactin and total testosterone) and GPER-1 levels were measured in otosclerosis patients and compared with the normal population. For the otosclerosis group, air conduction and bone conduction thresholds and air-bone gaps were viewed from audiograms and the relationships between hearing and GPER-1 or sex-hormone levels were also investigated.ResultsSex-hormone levels were not different between the groups. GPER-1 level was significantly lower in the otosclerosis group [3.1353 (0.76–8.21) ng/mL] than the control group [5.4773 (0.96–20.31) ng/mL] (p =0.017). Differential diagnosis with ROC analysis for the GPER-1 level was also significant (p=0.017). GPER-1 level was significantly lower for the females than the males in the otosclerosis group (p=0.043). Serum estradiol, progesterone, and prolactin levels were significantly higher (p=0.02, p =0.029 and p=0.019 respectively) and the GPER-1 level was significantly lower (p= 0.04) in the female patients compared to the female controls. There was no statistically significant relationship between GPER-1 or sex-hormone levels and hearing parameters.ConclusionGPER-1 level was lower in the otosclerosis patients compared to healthy volunteers and also lower in females than males in the patient group. Female sex-hormone levels were higher and GPER-1 level was lower in the female patient group than the female control group. Neither GPER-1 nor sex-hormone levels were not predictive of hearing levels. These findings indicate that sex-hormones especially estrogen and GPER-1 might have a potential role in the etiopathogenesis of otosclerosis. This is the first study in the literature that investigates the GPER-1 values in otosclerosis.