Effect of ototopic application of a corticosteroid preparation on cochlear function

Intratympanic Steroid Treatment in Idiopathic Sudden Sensorineural Hearing Loss: A Control Study

BACKGROUND AND OBJECTIVE: Although systemic steroids in sudden sensorineural hearing loss (SSHL) appears to be the most effective and the most widely accepted treatment today, a significant number of patients do not respond to steroid treatment or they cannot receive steroids for medical reasons. Intratympanic (IT) administration of steroids appears to be an alternative or additional method of management without the side effects of intravenous steroids. The aim of this study is to investigate the effectiveness and safeness of IT administration of steroids in patients who had not responded to IV treatment and to compare treatment efficacy with controls.

STUDY DESIGN AND SETTING: Our study consisted of 37 patients with SSHL who, at the end of 10 days of therapy with intravenous steroids as a 1st line treatment, had pure-tone 4-frequency (0.5, 1, 2, and 4 kHz) average (PTA) of worse than 30 dB or worse than 10 dB from the contralateral ear (defined as failed intravenous treatment). They were randomized into 2 groups, treatment and control. The 19 patients of the treatment group received approximately 0.5 mL sterile aqueous suspension of methylprednisolone acetate in a concentration of 80 mg/2 mL by direct injection. The procedure was carried out 4 times within a 15-day period. An audiogram was performed before each injection and approximately 1.5 months after the last session.

RESULTS: All patients tolerated the procedure well. No perforation or infection was noticed in any of the patients at their last visit. With regard to the 19 patients who received intratympanic treatment, in 9 patients, the PTA threshold improved more than 10 db, in 10 patients there was no change greater than 10 db, and no patients deteriorated more than 10 db. In the control group, none of the patients showed any change greater than 10 db. The difference was statistically significant ( P = 0.002). The treatment group showed an improvement in mean PTA of 14.9 dB, whereas the control group showed a deterioration of 0.8 dB, and this difference also was statistically significant ( P = 0.0005). IT treatment ( P = 0.0001), better post-IV PTA ( P = 0.0008), and absence of vertigo ( P = 0.02) were good predictors of the outcome. In contrast, sex, age, affected ear, days to admission, and pattern of the initial audiogram showed no significant influence on the outcome.

CONCLUSION AND SIGNIFICANCE: IT steroid administration after failed intravenous steroids is a safe and effective treatment in sudden sensorineural hearing loss.

Novel slow- and fast-type drug release round-window microimplants for local drug application to the cochlea: an experimental study in guinea pigs

Novel drug release microimplants (0.8 x 1.14 mm; custom-made by Leiras, now Schering OY, Finland) of slow- and fast-release types containing either 0.9 mg beclomethasone or no drug at all were placed unilaterally onto the round-window membrane (RWM) of 45 guinea pigs for a maximum duration of 28 days. The following parameters were tested on days 1, 14 and 28 after implantation: threshold levels of beclomethasone in the perilymph of the scala tympani, auditory brain stem responses (ABR thresholds and ABR threshold shifts), RWM morphology and hair cell loss (cytocochleograms). None of the animals in the non-implanted control group (n = 5) or placebo implant group (n = 15), but all animals in the slow-release-type implant group (n = 15) and fast-release-type implant group (n = 15) revealed the presence of beclomethasone on day 1 (34.9 and 64.3 pg/microl, respectively), day 14 (43.8 and 46.9 pg/microl, respectively) and day 28 after implantation (4.7 and 60.5 pg/microl, respectively). Histology of the RWMs appeared normal, and cytocochleograms revealed no inner hair cell loss and outer hair cell loss within normal ranges (from 0.5 +/- 0.4 to 0.8 +/- 0.2% per cochlea) in both ears in all experimental groups at any time during examination (days 1, 14 and 28). Initial values of ABR thresholds at 3, 6, 9 and 12 kHz did not differ significantly in any of the experimental groups. In non-implanted controls, no significant differences of ABR thresholds were observed in all frequencies tested in either ear on days 1, 14 and 28 compared to initial values, and ABR threshold shifts ranged from -3 +/- 5 dB (min.) to +5 +/- 7 dB (max.). On day 28 after implantation, there were no significant differences of ABR threshold shifts between this and the implant groups, except for 6 kHz of the slow-release device. Therefore, the placebo implants, the slow-release and the fast-release beclomethasone implants appear suitable for further experiments.

Intratympanic corticosteroids for Meniere's disease and vertigo

Hearing loss can be caused by acoustic trauma, aging, ototoxic medications, and various other causes. At the cellular level hearing loss seems to be mediated by reactive oxygen species and ultimately through the activation of apoptotic mechanisms. This article explains the cellular and molecular mechanisms of hearing loss and presents medications that could be used in the intratympanic treatment of hearing loss.

Intentional ablation of vestibular function using commercially available topical gentamicin-betamethasone eardrops in patients with Meniere's disease: further evidence for topical eardrop ototoxicity

OBJECTIVE

To determine whether the controversial findings of suspected ototoxicity from commercially available gentamicin sulfate and betamethasone sodium phosphate eardrops can be used in a therapeutic fashion to ablate (or attenuate) vestibular function in patients with unilateral Meniere's disease.

STUDY DESIGN

Prospective case review.

METHODS

At a tertiary care dizziness unit at the University Health Network, Toronto General Hospital, University of Toronto (Toronto, Ontario, Canada), adults with unilateral Meniere's disease undergoing intratympanic ablation therapy were studied. After insertion of a tympanostomy tube with the patient under local anesthesia, patients instilled gentamicin containing eardrops three times daily until they became vertiginous for longer than 24 hours and then for an additional 2 days longer or for 1 month, whichever came first. Electronystagmographic caloric test responses were measured before treatment using bithermal water caloric and after treatment using air caloric tests. Main outcome measures included clinical titration of drops to the onset of prolonged vertigo. As well, post-treatment findings on electronystagmography and audiometry were compared with pretreatment testing.

RESULTS

Twenty patients were available for review. Fifteen patients had a significant reduction in caloric test responses compared with pretreatment values; among them, 10 patients had absent air caloric test responses on the treated side. In 10 patients hearing worsened according to the 1995 American Academy of Otolaryngology-Head and Neck Surgery Committee on Hearing and Equilibrium Guidelines for reporting in Meniere's disease.

CONCLUSIONS

Topical gentamicin-betamethasone eardrops can pass through a tube into the middle ear, where they may prove primarily vestibulo-ototoxic patients with Meniere's disease. The study further confirms clinical observations that gentamicin-containing eardrops might prove ototoxic, especially in noninflamed ears with a tympanic membrane defect.

Efficacy of ofloxacin and other ototopical preparations for chronic suppurative otitis media in children

The safety and efficacy of ototopical preparations, such as ofloxacin, in the treatment of CSOM in infants and children do not currently have approval by the FDA even though ofloxacin is FDA-approved for treatment of CSOM that occurs in adults. However, treatment with ofloxacin is FDA-approved when AOM occurs in children who have a tympanostomy tube in place, and effective treatment of this acute infection should prevent the subsequent development of CSOM.

Protection against aminoglycoside otic drop-induced ototoxicity by a spin trap: I. Acute effects

Topical administration of aminoglycoside antibiotic drops containing neomycin and polymyxin B disrupts cochlear structure and function in rodents, possibly as a result of reactive oxygen species generation. This study investigated the ability of a spin trap, alpha-phenyl-tert-butyl-nitrone (PBN), to prevent acute aminoglycoside antibiotic drop-induced cochlear dysfunction. Guinea pigs were monitored for compound action potential thresholds and 1.0 microV root-mean-square cochlear microphonic isopotential curve values, then injected intraperitoneally with PBN (60 mg/kg) or saline solution. After 10 minutes, 50 microl of PBN (100 mmol/L) or artificial perilymph was applied to the round window membrane, followed after 10 minutes with artificial perilymph or aminoglycoside antibiotic drops (50 microl). From 10 to 60 minutes after exposure, mean compound action potential thresholds progressively increased in the artificial perilymph-aminoglycoside antibiotic drop group, beginning with high frequencies and later including ever-lower frequencies. These threshold shifts in compound action potentials were significantly greater (p<0.05) than those seen in the artificial perilymph-artificial perilymph or PBN-aminoglycoside antibiotic drop groups. This finding indicates that PBN provided protection against acute aminoglycoside antibiotic drop-induced compound action potential threshold sensitivity loss. Mean cochlear microphonic shift values at 60 minutes in the artificial perilymph-aminoglycoside antibiotic drop group significantly exceeded those of the other groups only at the highest frequencies. These data suggest that acute aminoglycoside antibiotic drop-induced cochlear disruption primarily affects high frequency compound action potential function and may be partially reactive oxygen species-mediated and preventable.

Hearing results of intratympanic steroid treatment of endolymphatic hydrops

OBJECTIVES/HYPOTHESIS

This study evaluated the effectiveness of a single application of steroids to the open middle ear in improving short-term hearing in patients with Meniere's disease and cochlear hydrops.

STUDY DESIGN

Retrospective study in which each patient's pretreatment hearing served as the control compared with posttreatment hearing.

METHODS

Patients were treated with a single application of dexamethasone, 8 mg, in hyaluronan. Following tympanotomy and lysis of round window adhesions, steroids were placed in the round window niche with absorbable gelatin sponge and the remainder of the middle ear was then filled with the steroid solution. Systemic steroids were not administered. Audiograms were performed within 1 month before surgery and at least 1 month after surgery.

RESULTS

Between September 1996 and July 1997, 21 ears in 19 patients underwent intratympanic steroid treatment. The criterion for hearing change was a 10-dB or greater change in pure-tone average (PTA), or a 15% change in speech discrimination score (SDS). Of the 15 ears meeting inclusion criteria for this study, five (33%) demonstrated hearing improvement and three (20%) demonstrated hearing deterioration. Maximum improvement was a 38-dB improvement in PTA and a 32% improvement in SDS.

CONCLUSION

A single application of intratympanic dexamethasone/hyaluronan solution directly to the round window did not produce dramatic short-term hearing improvement in patients with endolymphatic hydrops. Although the theoretical basis for intratympanic steroid treatment of endolymphatic hydrops is appealing, we urge close evaluation of the results of specific protocols of intratympanic steroid administration before widespread utilization of this treatment. The choice of steroid, route of administration, frequency of application, and need for simultaneous systemic administration require standardization to adequately assess the efficacy of this treatment.

A comparison of vowel production by children with multichannel cochlear implants or tactile aids: perceptual evidence

OBJECTIVE

To examine changes in perceived vowel production accuracy over time in prelingually deafened children who use a multichannel cochlear implant (Nucleus 22 channel) or a multichannel tactile aid (Tactaid 7) and to compare the levels of perceived vowel production accuracy attained by the two device groups.

DESIGN

The subjects were participants in longitudinal studies of the effects of sensory aids on the development of perceptual, speech, and language skills. As part of these studies, imitative vowel productions were elicited and transcribed before each child received their sensory aid and at 6 mo intervals thereafter. Data for the current study was obtained from the predevice interval and a later interval (postdevice) that was an average of 1.8 yr after the subjects received their respective devices. The subjects' vowel productions were judged for accuracy in matching an imitative model and for correctness of vowel features (height and place). Within-group analyses were completed to determine if vowel production scores improved over the course of the study for each device group. Between group comparisons were performed to examine differences in mean scores at each interval.

RESULTS

Before receiving their multichannel devices, the two groups of subjects demonstrated similar imitative vowel production skills. After an average of 1.8 yr of device use, the cochlear implant subjects demonstrated significantly improved production of diphthongs and all vowel categories except low vowels. The Tactaid 7 subjects demonstrated significant improvement only in the production of diphthongs. Thus, cochlear implant recipients' vowel production skills were found to be significantly better than those of the Tactaid 7 users after a comparable amount of device experience.

CONCLUSIONS

The vowel production gains of the cochlear implant subjects were similar in amount to those noted in other studies of children who use the Nucleus multichannel cochlear implant and further confirm the potential of this device for improved speech production in prelingually deafened children. The differences between the performance of the two groups demonstrate that vowel production skills improved to a greater degree through use of a multichannel cochlear implant than through use of the Tactaid 7.