[The incidence of vestibular disorders among the patients suffering from otosclerosis]

The objective of the present study was to estimate the incidence of vestibular symptoms among the patients presenting with otosclerosis and their relationship with the form of this pathology. A total of 90 patients had the confirmed diagnosis of otosclerosis in the absence of concomitant diseases known to cause vestibular disorders. The patients were interviewed and underwent thorough examination. It turned out that 16.7% of them exhibited vestibular asymmetry; in other words, the frequency of this condition was higher than the incidence of vestibular disbalance in the general population. Most patients with vestibular symptoms and complaints were referred to the group with unilateral sensorineural hearing impairment that, however, can not be a marker of unilateral vestibular deficiency.

Is it possible to predict diffuse obliterative otosclerosis preoperatively by audiologic examination

Patients with diffuse obliterative otosclerosis have more extensive footplate pathology than annular cases. As a result of this more skill is required for diffuse otosclerosis cases, and postoperative hearing results are usually worse than annular cases. In this retrospective study we compared the preoperative audiological features of annular and diffuse otosclerosis patients. The subjects were 60 patients with conductive hearing loss who had undergone stapedectomy. Annular and diffuse groups were comprised of 30 patients each. Annular otosclerosis was defined as the footplate pathology involving the annular ligament only, where the footplate of the stapes is very thin and retains its bluish color. On the other hand diffuse, obliterative otosclerosis was defined as the pathology involving the whole footplate and also in some cases extending beyond the confines of the annular ligament. In each group preoperative air- and bone-conduction levels at 125-6000 Hz and 500-4000 Hz were noted respectively. Average air-bone gap for the obliterative otosclerosis group was 37.5 dB; the same value for the annular group was 23.8 dB (p<0.05). The gap characteristics of the audiogram were different for the two groups. The annular group had an air-bone gap which was nearly constant for all the frequencies. In the diffuse otosclerosis group, the air-bone gap was more prominent in the low frequencies and it decreased at higher frequencies. No difference was noted in bone-conduction thresholds, and Carhart notch between the two groups. This study demonstrated that a large air-bone gap in patients with conductive hearing loss may be a sign of diffuse obliterative otosclerosis. This may warn the surgeon that a more challenging surgery is possible, and the patient may have a less favorable hearing result. Therefore, in the presence of a large air-bone gap, it may be appropriate to inform the patient of the strong possibility of diffuse otosclerosis.

[CT findings in otosclerosis. A series of 11 cases]

INTRODUCTION

Our study's aim is to evaluate the reliability of computed tomography in diagnosis, extension and post-surgical follow-up of otosclerosis.

PATIENTS AND METHODS

A group of 11 patients was examined during a period of 25 months from 2002 to 2004. All of them had clinically and audiometrically suspected otosclerosis with bilateral conductive hear loss in 7 cases (3 had surgical management), unilateral in 2, and mixed earing loss in 2. High resolution CT was performed once in 8 patients and twice in the 3 operated.

RESULTS

CT showed otosclerosis foci in all our study's patients, which was bilateral in 9 and unilateral in 2. The extension of the lesions varied from type IA to type 4B according to the otosclerosis staging.

CONCLUSION

Computed tomography is, so far, the most efficient imaging modality in otosclerosis, showing otosclerosis foci when the clinical features are doubtful, allowing an accurate extension of the lesions and detecting complications during post-surgical follow-up.

Otosclerosis is a conformational disease

The otosclerotic focus is a result of the normal process of bone remodelling in the otic capsule - a place where there is little if any bone remodelling. There is still no single accepted theory for the pathogenesis of otosclerosis. Sources we used were relevant clinical and basic science publications from 1973 to 2001. The data from each publication were critically reviewed. In this paper we suggest a kind of molecular predisposition in otosclerosis, like molecular instability in some key protein with regulatory effect, cell receptor for example. Also it can be a destabilasing mutation of some repressor of the normal bone remodelling. Any triggering event like mechanic distress, vascular compromise, radiation, viral infection, etc. can start a process of conformational changes with subsequent induction of long-standing bone remodelling focuses. We conclude that many unusual features of otosclerosis can be explained if we consider this entity as a conformational disease.

Far Advanced Otosclerosis: Stapes Surgery or Cochlear Implantation?

OBJECTIVE

Nowadays, two surgical alternatives are to be considered in patients with far advanced otosclerosis: stapedectomy and cochlear implantation. The aim of this study was to analyze and compare the hearing and communicative results obtained in two groups of patients affected with far advanced otosclerosis, who were treated with the two different surgical procedures, to assess the proper surgical approach for these patients.

DESIGN

Retrospective study.

SETTINGS

University hospital and referral audiologic centre.

METHODS

We submitted 11 adult patients, affected by far advanced otosclerosis and exhibiting unsatisfactory communicative abilities with hearing aids, to two different procedures: 5 to cochlear implantation, and 6 to stapedotomy followed by hearing aid fitting. The benefits afforded by the two procedures were assessed by means of pure-tone audiometry and speech audiometry in an open field and by means of a speech perception test.

MAIN OUTCOME MEASURES

Hearing and communicative outcomes, measured 1 year after intervention.

RESULTS

The results achieved in the patients subjected to stapedotomy were unpredictable and variable: very good in some cases but unsatisfactory in others, whereas those who had cochlear implantation all achieved satisfactory results with regard to speech recognition.

CONCLUSIONS

Patients who underwent cochlear implantation achieved better hearing and communicative results than those who underwent stapedotomy. Even if the number of patients reported in this study is too small to provide definitive results, and despite the reportedly better results afforded by cochlear implantation, in our opinion, correction of far advanced otosclerosis should first be attempted via stapedotomy, and cochlear implantation should instead be reserved for cases in which stapedotomy is unsuccessful or for which imaging techniques unequivocally reveal a fenestral or cochlear obstruction.

Imaging of the windows of the temporal bone

Imaging of the window of the temporal bone has became an important tool in the analysis of hearing loss, vertigo, tinnitus in a context of trauma, malformation, otosclerosis, and chronic otitis media. A good knowledge of the anatomy and a good technical procedure are necessary for making an efficient diagnosis. The increased thickness of the footplate may be delineated in otosclerosis, chronic otitis media, malformation, when it is measured at 0.7 mm or more in horizontal computed tomography (CT) sections. The traumatic displacement of the stapes, particularly within the labyrinths, is easily diagnosed in horizontal CT section. Imaging of the round window is now very important for the detection of otosclerotic foci, congenital stenosis, and perilymphatic fistula with or without fracture. Magnetic resonance imaging (MRI) with the high-resolution T2 plays an important role in the detection of a small amount of fluid in the round window recess, confirming the traumatic perilymphatic fistula without fracture.

Cochlear ossification after meningitis

OBJECTIVE

This study aimed to assess the pathologic processes that result in ossification of the cochlear lumen after bacterial meningitis.

STUDY DESIGN

The study design was a retrospective case review.

SETTING

The study was conducted at a tertiary referral center.

PATIENTS

Profoundly deaf postmeningitic patients who underwent cochlear implantation were studied.

INTERVENTIONS

Diagnostic and therapeutic observations were performed.

MAIN OUTCOME MEASURES

The extent of cochlear ossification is classified and related to age at which infection occurred, cerebrospinal fluid leukocyte count, Gram's stain, organism, and delay between meningitis and implantation. The extent of ossification noted on high-definition computed tomographic (CT) scan is compared with surgical findings and related to the time delays between meningitis, imaging, and surgery.

RESULTS

Ossification fell into three groups: gross ossification of the scala tympani and variable amounts of the scala vestibuli; partial ossification localized to the basal turn of the scala tympani; and no ossification. There was no correlation between the extent of ossification and the age when infected, type of pathogen, cerebrospinal fluid leukocyte count, and time delay between meningitis and implantation. Visualization of bacteria on Gram's stain was a highly sensitive measure of ossification (0.93) but was not specific (0.6) with positive and negative predictive values of 0.76 and 0.86, respectively. High-definition CT underestimated the extent of ossification in 50% of cases when performed within 6 months of meningitis.

CONCLUSIONS

Ossification is either gross or localized to the basal turn of the scala tympani. If ossification does occur, it is rapid and complete within a few months of infection. The visualization of bacteria on Gram's stain is a sensitive indicator for the presence of ossification but has low specificity. High-definition CT, if performed within the first 6 months of meningitis, can be an inaccurate diagnostic tool and therefore should be performed as close to the date of surgery as possible.

CT of cochlear otosclerosis (otospongiosis)

High-resolution CT is the method of choice in determining the extent of demineralization in otospongiosis. By comparing the maximum and minimum densities, this examination has become of clinical importance in the diagnostic approach to otosclerosis and in the follow-up of fluorine therapy.