Word recognition score changes after stapedectomy for far advanced otosclerosis

OBJECTIVE

This study aimed to examine word recognition score (WRS) changes after stapedectomy for far-advanced otosclerosis (FAO). The WRS changes were examined to determine whether they were consistent with acclimatization or recovery from auditory deprivation changes that have been seen after the restoration of sound by amplification.

STUDY DESIGN

Retrospective.

SETTING

Private otology practice.

PATIENTS

A total of 24 patients were selected by including all the case in which a stapedectomy was performed within the past 10 years to improve the hearing of a severe or profoundly hearing-impaired patient with otosclerosis.

INTERVENTION

Diagnostic.

MAIN OUTCOME MEASURE

Changes in WRSs.

RESULTS

One month after surgery, the mean WRS had improved 16.5%. The WRSs continued to improve an additional 12% or more for 17 (71%) of 24 patients within 2 years after their initial postoperative hearing test. The mean WRS improvement within 2 years of the initial postoperative test was 16.2%.

CONCLUSIONS

Initial WRS changes were attributed to hearing thresholds no longer being at or beyond audiometric limits. Additional WRS changes were consistent with reports of acclimatization or recovery from auditory deprivation that have been seen after hearing aid use. The authors believe these additional WRS changes illustrate that at least some improvement in WRSs from acclimatization or auditory recovery may be fairly common after the restoration of sound. Finally, the authors believe the overall WRS improvement (32.7%) should be taken into account when considering stapedectomy for patients with FAO.

Forty years of stapes surgery

OBJECTIVE

This study reports the results of 14,449 stapedectomy operations performed during the past 40 years.

STUDY DESIGN

The study design was a retrospective case review. Approximately 100 operations were selected from each of the past 40 years, for a total of 5,444 operations, from which the results with the whole group were extrapolated.

SETTING

All operations were performed in a hospital during the first 30 years and in an ambulatory surgery center in the past 10 years.

PATIENTS

All patients in the study were the private patients of the author and were operated on by him personally. These patients had otosclerosis only.

INTERVENTIONS

Stapedectomy was performed on all patients.

MAIN OUTCOME MEASURES

The change in hearing after the operation was reported. Using the hearing of the average for 500, 1,000, and 2,000 Hz, the criteria for success were defined as closure of the air-bone gap to 10 dB or less and no decline in speech discrimination of >10%.

RESULTS

In the primary stapedectomy group, success was achieved in 95.1% of ears after 1 year, 94.7% of ears after 2-5 years, and 62.5% after >30 years. In the revision stapedectomy group, success was achieved in 71.1% after 1 year, 62.4% after 2-5 years, and 59.4% after 6-36 years.

CONCLUSIONS

The immediate success rate after primary and revision stapedectomy declines slowly over time, because of delayed conductive hearing loss and further sensorineural hearing loss, more than one would expect in matched control subjects without otosclerosis. Stapedectomy has stood the test of time as the first successful microsurgical operation.

Surface temperature distributions in carbon dioxide, argon, and KTP (Nd:YAG) laser ablated otic capsule and calvarial bone

HYPOTHESIS

The spatial and temporal surface temperature distribution was measured after laser irradiation in fresh porcine otic capsule and calvarial bone tissue using an HgCdTe (mercury-cadmium-tellurium) infrared camera.

BACKGROUND

Carbon dioxide (CO2) (lambda = 10.6 mm), argon (lambda = 514 nm), and Potassium-Titanyl-Phosphate Neodynium: Yttrium-Aluminum-Garnet (KTP[Nd:YAG]) (lambda = 532 nm) lasers are used for stapes surgery and in the treatment of chronic ear disease. Despite extensive clinical use, little is known about the thermal perturbations in otic capsule calcified tissues and what are safe energy parameters for laser use.

METHODS

A microspot manipulator, lens, and microfiber were used for continuous wave (CW) and super-pulse (SP) CO2, argon, and KTP(Nd:YAG) lasers, respectively. Peak temperatures after ablation were measured simultaneously along with the full-width--half-maximum of the thermal disturbance and fitted to a Gaussian distribution. The cooling time for the hot spot to return to ambient temperature also was recorded.

RESULTS

Temperature changes with CW CO2 irradiation were markedly elevated relative to SP mode and also required longer to cool. The KTP and argon-treated bone were irradiated in the presence and absence of an initiator (black ink): minimal surface temperature elevation was recorded in the absence of an initiator. Further, no surface modification was observed. In contrast, the addition of an initiator resulted in marked temperature elevations and significant surface carbonization with these two visible wavelength lasers. Cooling times varied from 10-40 seconds. No consistent relation to the measured thermal values and tissue microarchitecture was observed.

CONCLUSIONS

The measured cooling times and Gaussian distribution of surface temperatures serve as empiric guidelines for minimizing thermal injury to critical structures during laser surgery in the middle ear.

Etidronate for the the neurotologic symptoms of otosclerosis: preliminary study

The efficacy of etidronate, a bisphosphonate, was assessed as a treatment for the inner ear symptoms of otosclerosis in a retrospective case review of 896 patients diagnosed with otosclerosis, with primary complaints of dizziness, hearing loss, tinnitus or Meniere's syndrome. The diagnosis of otosclerosis was based on small-pixel computed tomography of the temporal bones. Of the 896 patients placed on an etidronate protocol, 545 were followed for more than six months and were analyzed. The symptomatic response to etidronate, as well as audiologic and computerized rotary chair results were used in the assessment. Patients who were previously on sodium fluoride were separately analyzed. In this preliminary study etidronate appeared to be an effective treatment for the neurotologic symptoms of otosclerosis. Prospective blinded efficacy studies of the bisphosphonates in the treatment of otosclerosis should be undertaken.

Application of oxygen free radical scavengers to diminish the occurrence of myringosclerosis

The present study was designed to establish whether or not an increased production of oxygen-derived free radicals is involved in the causation of myringosclerosis. Sclerotic lesions in the tympanic membrane were experimentally elicited by keeping rats with perforated tympanic membranes in an atmosphere containing roughly 40% oxygen. The animals were treated daily with a solution containing either copper zinc-superoxide dismutase plus catalase, deferoxamine, or copper sulfate plus iron chloride, applied to the traumatized area. After 1 week the extension of myringosclerotic plaques was determined otomicroscopically. The pars tensa and pars flaccida were then dissected free and prepared for light microscopic studies. The results showed that treatment with copper zinc-superoxide dismutase plus catalase and deferoxamine inhibited or reduced the development of myringosclerosis, whereas the ears treated with copper sulfate plus iron chloride appeared unaffected. Consequently, the findings support the hypothesis that the formation of oxygen free radicals contributes significantly to the development of myringosclerosis.

Analysis of middle ear mechanics and application to diseased and reconstructed ears

OBJECTIVE

To review current concepts of the mechanical processes of the human middle ear, and to apply them to practical issues in clinical otology and tympanoplasty surgery.

BACKGROUND

The wide range of conductive hearing losses associated with middle ear pathology and reconstruction cannot be adequately explained by simple models of middle ear function.

METHODS

Variables used to describe the system are sound pressure, volume velocity, and acoustic impedance. The relationship between specific middle ear structures and these variables is described such that inferences can be drawn regarding sound conduction in the normal, diseased, and reconstructed middle ear.

RESULTS AND CONCLUSIONS

Sound can be transmitted from the car canal to the cochlea via two mechanisms: the tympano-ossicular system (ossicular coupling) and direct acoustic stimulation of the oval and round windows (acoustic coupling). Acoustic coupling is negligibly small in normal ears, but can play a significant role in some diseased and reconstructed ears. In the normal ear, middle ear pressure gain (which is the result of ossicular coupling) is frequency-dependent and less than generally believed. The severity of conductive hearing loss due to middle-ear disease or after tympanoplasty surgery can be predicted by the degree to which ossicular coupling, acoustic coupling, and stapescochlear input impedance are altered. Hearing after type IV and V tympanoplasty is determined solely by acoustic coupling. The difference in magnitude between the oval- and round-window pressures is more important than the difference in phase in determining cochlear input. In tympanoplasty types I, II, and III, adequate middle-ear and round-window aeration is necessary and the tympanic membrane-ossicular configuration may be less crucial.

Cochlear implantation in otosclerosis: a unique positioning and programming problem

A case is reported in which a Nucleus 22 channel cochlear implant was inserted into the basal turn of the cochlea of a patient with advanced otosclerosis. It then passed out of the anterior end of the basal turn into an otospongiotic cavity related to the cochlea. Seven electrodes were located in the basal turn and it was possible to map them sufficiently well for the patient to derive considerable benefit from the implant. The problem of implant induced facial nerve stimulation in otospongiosis is also discussed.

Myringotomized mice develop myringosclerosis in the pars flaccida and not in the pars tensa

The development of myringosclerosis has been correlated with increased production of oxygen-derived free radicals. For the present study, we used a null mutant mouse lacking extracellular superoxide dismutase to test the hypothesis that increased production of free radicals can cause the development of myringosclerosis. Null mutant mice and wild-type, control mice were myringotomized and kept in ambient air for 3 weeks. Both groups developed myringosclerosis in the pars flaccida, but not in the pars tensa. The sclerotic lesions were visible in both the light and the electron microscope but not in the otomicroscope. In particular, the localization of the sclerotic deposits was found beneath both the inner and outer epidermal epithelium. No difference concerning the extent or number of sclerotic lesions between the null mutant and the wild-type mice could be distinguished.

[New advances in inner ear diagnostic imaging]

Recent applications of magnetic resonance in the ear pathology are described. Attention is drawn to the new magnetic resonance sequences in two and three dimensions and their contribution to the understanding of anatomy and pathology of the inner ear, especially the membranous labyrinth.

Revision surgery in otosclerosis--an investigation of the factors which influence the hearing result

The hearing improvement obtained by revision surgery for otosclerosis has been assessed in 163 patients with a conductive hearing loss. Several different surgical techniques had been used at the primary operation. On average at revision a hearing improvement of 11 dB was obtained. The hearing improvement was related to the surgical technique of the primary operation, the middle ear abnormalities and the surgical technique used at revision. Patients in whom a small-fenestra-technique had been used for the primary as well as the revision procedure, had a better result than patients who had total removal of the footplate. Patients with adhesions and an eccentric prosthesis only showed a small hearing improvement. Patients with necrosis of the long process of the incus were also difficult to manage. Since the complication rate was low it does not seem to be more dangerous to perform a revision than to perform a primary operation. The results obtained by revision are poorer than can be obtained by the primary procedure. This indicates that in stapes surgery the greatest chance for hearing improvement is the first operation, therefore centralization of this type of operation should be considered.

Interexaminer reliability of otoscopic signs and tympanometric measures for older adults

To accurately classify hearing loss and otic disorders among older adults, examiners must be able to consistently assess otoscopic signs and perform middle-ear screening tympanograms. As part of a population-based study of hearing loss in Beaver Dam, Wisconsin, the interexaminer reliability of otoscopic examinations and screening tympanograms was evaluated using 45 replicate examinations. Data from 1941 participants 48 to 91 years of age were used to compare otoscopic and tympanometric results. Overall agreement for nine otoscopic signs ranged from 73 percent (vascularity) to 100 percent (drainage). There were small examiner differences in tympanometric measures of equivalent ear-canal volume (Vea) and tympanogram width. No significant differences were observed for peak compensated static acoustic admittance and tympanogram peak pressure. Our findings suggest that examiners can be trained to consistently and accurately assess otoscopic signs and obtain reliable tympanometric results.

[Pathogenesis of otosclerosis. "State of the art"]

Women suffer from otosclerosis 1.6 times more often than males. Histologically, otosclerotic foci can be found in temporal bones of females 1.9 times more often than in those of males. Characteristic topographic regions are the oval window, round window niche and promontory. Otosclerosis can also occur principally in any area of the enchondral/periosteal layer of the otic capsule. Evidence is presented that otosclerosis is an inflammatory tissue reaction associated with macrophages, T- and B-lymphocytes, HLA-DR positive cells and plasma cells. Dependent on the stage of the osteolytic bone disease present deposits of complement and immunoglobulins (IgG, IgA) can be found. These immunoglobulins have been identified as antibodies to measles virus proteins. Using the polymerase chain reaction we were successful in demonstrating RNA sequences of measles viruses in otosclerotic bone from footplates removed during stapes surgery. Since most of the otosclerotic lesions were in direct contact to the perilymphatic space, it may be expected that the endolymphatic sac--as the immune competent organ of the inner ear--specifically reacts to antigens delivered from the otosclerosis focus into the perilymph. Perilymph samples from patients were collected during stapes surgery and their antibody titers against measles were compared with that in corresponding blood serum. All samples revealed a significantly elevated-specific anti-measles IgG amount which was significantly higher than in the corresponding serum. In contrast, antibody titer in the perilymph against herpes simplex or cytomegalo viruses did not differ from that of the serum. These findings indicate that otosclerosis is a measles virus associated inflammatory osteolytic disease of the temporal bone. Since women suffer from severe measles virus infections more often than males, it can be hypothesized that females have a higher susceptibility of their cochleo-vestibular tissues to these infections (organotropism). In addition, estrogens are well-known stimulators of osteocytic activity and may play a dominant role during ossification of an otospongeotic bone lesion. This may explain the onset of a conductive hearing loss due to otosclerosis during pregnancy.

Phenotype of in vitro human otosclerotic cells and its modulation by TGF beta

A study was carried out to obtain a more detailed picture of the phenotypes of human otosclerotic and normal bone cells and to analyse the response of both populations to treatment with TGF beta 1. Total collagen synthesis was found to be decreased, but fibronectin secretion increased in otosclerotic with respect to normal cells. Although overall glycosaminoglycan (GAG) synthesis was lower in otosclerotic cells, the sulphated GAG to hyaluronic acid (HA) ratio was higher, in particular there was greater expression of chondroitin (CS) and dermatan sulphates (DS). TGF beta 1 induced a more marked increase in collagen and fibronectin release and greater production of sulphated GAGs as DS and heparan sulphate (HS) in the otosclerotic cells. The fact that the phenotype of the otosclerotic cells differed from that of the normal cells and could be modified by TGF beta 1 treatment, suggests that TGF beta 1 is implicated in the pathogenesis of otosclerosis.

The role and significance of chondroitin sulfate in the development of otosclerosis

Chondroitin sulfate is a sulfated glycosaminoglycan that predominates in the ground substance of cartilage. Using monoclonal antichondroitin sulfate in 61 specimens of human otosclerotic lesions, we studied the distribution of this glucosaminoglycan in various stages of otosclerosis. Our findings show that chondroitin sulfate plays an important role in the development of otosclerosis. In addition, the distribution of chondroitin sulfate clearly delineates the stage of otosclerosis referred to as active into two distinct histologic stages. Dividing the active stage into "osteolytic" and "sponge-chondroid" would be reasonable based on our findings.

Middle ear and inner ear effects on clinical bone-conduction threshold

The measurement of bone-conduction thresholds is an integral part of audiologic evaluation. The relationship between bone-conduction and air-conduction thresholds is the differentiating diagnostic indicator between conductive and sensorineural hearing loss. At the same time, the influence of middle ear and inner ear structures upon the bone-conduction response has been well documented. We present two cases illustrating this influence and attempt to explain the clinical bone-conduction thresholds with operative findings.

Otosclerosis: a measles virus associated inflammatory disease

The etiology of otosclerosis is still unknown. Immunohistochemical studies have revealed the characteristics of chronic inflammation in the otospongiotic area. Paramyxoviral structures have been identified by electron microscopy and the expression of measles virus antigen has been observed by immunohistochemistry in active otosclerotic tissue. By use of the polymerase chain reaction, measles virus related sequences have been detected in otosclerotic bone tissue but not in control specimens. The aim of our study was i) to detect measles virus genome in affected patients using a more sensitive PCR system and ii) to search for anti-measles virus IgG in the perilymph. In 13 out of 14 specimens of bone fragments from surgically removed stapedes of patients suffering from otosclerosis, measles virus RNA sequences could be detected while other tissues from the same patients and from a negative control group lacked such sequences. Furthermore, IgG anti-measles virus antibodies were detected in the perilymph of 6 patients. Our results support our previously stated hypothesis that otosclerosis is a measles virus associated disease which provokes a local immune response within the inner ear.

Cochlear vascular pathology and hydrops in otosclerosis

Three ears with otosclerosis were found incidentally in a series of human temporal bones examined to evaluate cochlear sensorineural degeneration. Otosclerosis was identified with microdissection, surface preparation technique and transmission electron microscopy. Vascular abnormalities were present in all ears, and otosclerosis involved the cochlear endosteum extensively, mainly in the scala tympani of the basal turn. In the scala tympani of the lower half of the basal turn, shunts had formed so that venules deviated abruptly from their normal radiating course towards the spiral vein, left the scala and entered into otosclerotic foci. There was a marked loss of radiating venules in areas where otosclerosis affected the endosteum of the scala. In the pair of bones capillaries in the stria vascularis were extremely dilated, the widest being 80 microns in diameter. The third single bone from a patient with Meniere's disease had severe cochleo-saccular hydrops. Ten serially sectioned temporal bones with known otosclerosis were reviewed. Two of the bones, one of which had cochleo-saccular hydrops, displayed vascular shunts in the scala tympani and enormously dilated strial capillaries with a maximum diameter of 139 microns.

Flavonoids alter bone-remodelling in auditory ossicle organ cultures

The beneficial role of bioflavonoids in an otosclerosis-like bone-remodelling process can be implicated from its interference with bone resorption induced by prostaglandin E2 (PGE2) in cultured guinea pig ossicles. Ipriflavone (7-isopropoxy-isoflavon) and quercetin reduced PGE2-elevated collagenase-like peptidase (Cl-peptidase) activity and potentiated a PGE2-induced decrease in collagen synthesis. The fact that PGE2 effects are mediated through cyclic AMP in bone turnover and flavonoids act synergistically with PGE2 in collagen synthesis confirm a cyclic AMP phosphodiesterase inhibitory role of flavonoids. It has already been attempted to use Ipriflavone medical treatment of otosclerosis. Quercetin, which has a better than Ipriflavone water-solubility seems as promising as Ipriflavone in the control of the otosclerotic bone-remodelling disturbance.

Significance of chondrification in the development of otosclerotic stapedial footplate

Thirty-four otosclerotic stapes of active type were investigated histologically with hematoxylin-eosin (H-E), periodic acid-Schiff-alcine blue (PAS-AB), and/or toluidine blue stain. The results show that chondrification plays an important role in the development of otosclerosis. To date, this specific histopathologic change has not been well recognized. Based on the findings of this study, it is suggested that the active type of otosclerosis be subdivided into two phases, the osteolytic phase and spongy chondroid phase.

Revision surgery in otosclerosis--operative findings in 186 patients

Over a 14-year-period 186 revision operations for otosclerosis were performed. In 90% of the patients the indication for revision was too large an air-bone-gap. A number of different surgical techniques had been used at the primary operation. The purpose of the investigation was to describe the middle ear abnormality at the revision operation. Most often adhesions, acentric prosthesis, reobliteration and necrosis of the long process of the incus were found. The middle ear abnormality found at revision operation was correlated to the primary surgical technique used and the information obtained can be of value, when a revision operation is considered. The surgical technique used at revision operation was determined by the operative findings. The best hearing improvement was obtained when a small-fenestration-technique was used primarily or as the method for revision. In revision stapes surgery, the experience of the surgeon is important and centralization of this type of operation is recommended.

[Is reuse of autologous ear ossicles in cholesteatoma or chronic suppurative otitis media justified?]

From the 1950s onwards ossicular bone autografts have been used to restore the middle ear sound conduction mechanism. Controversy still exists regarding the appropriateness of autologous ossicular bone grafts in chronic middle ear diseases. This communication is based on a study of 149 ossicles surgically removed from 120 patients with different ear diseases, at the Department of Otolaryngology, Head and Neck Surgery of the University of Wuerzburg. It is the object of this study to systematically investigate the histological findings in the ossicles in cholesteatoma and chronic suppurative otitis media, and also to try to assess their significance. For comparison the ossicles of traumatic subluxation and otosclerosis are also included in our material. In about one-fourth of the incidences of cholesteatoma, squamous epithelium is found adherent to the ossicles with subepithelial connective tissue of varying thickness separating the matrix from the involved ossicle so that the matrix is never in direct contact with the underlying bone. Osteomyelitis is shown in both groups. Bone resorption predominates in the complicated metaplastic process due to the action of osteoclasts irrespective of the cholesteatoma group or the chronic otitis media group. Bone erosion is evident not only on the surface of the ossicles but also in the bone. On the other hand, ossicles in the groups of traumatic subluxation and otosclerosis remain histologically normal without evidence of pathologic changes. On the basis of these histological observations and on account of the high probability of adherent squamous epithelium in our opinion autologous ossicles from cholesteatoma and chronic suppurative otitis media should not be used in reconstructive middle ear surgery.

Effect of drinking water fluoridation on hearing of patients with otosclerosis in a low fluoride area: a follow-up study

Fluorine content in bone samples taken from the middle ears of otosclerotic patients was determined. Otosclerotic stapes footplate was found to have a significantly higher content of fluorine than skeletal bone from the meatus. Fluorine contents in footplate and meatal wall samples of otosclerotic patients drinking fluoridated water were slightly higher than those of patients drinking low-fluoride water. In the clinical part of the study, hearing levels of 280 patients with otosclerosis living in an area with low-fluoride water were assessed. In 344 operated ears, the preoperative and long-term postoperative air conduction and bone conduction thresholds of patients drinking fluoridated water did not differ significantly from those of patients drinking low-fluoride water. After a mean follow-up period of 9.6 years, air conduction thresholds of non-operated ears in patients drinking fluoride-poor water were found to be significantly worse than those of patients drinking fluoridated tap water, likewise there were significant differences in bone conduction thresholds at 2 and 4 kHz. Thus, fluoridation of drinking water has a beneficial effect on non-operated otosclerotic ears but has no significant effect on hearing levels of operated ears.