Search

Objective: The purpose of this study was to investigate the effectiveness of intratympanic dexamethasone injection as a protection agent against cisplatin-induced ototoxicity. Study Design and Setting: The four groups of guinea pigs were injected as follows: 1) cisplatin, 2) intratympanic dexamethasone, 3) cisplatin following intratympanic dexamethasone, and 4) cisplatin after intratympanic saline. Before and 3 days following injections, the ototoxic effect was measured with distortion product otoacoustic emissions (DPOAEs). Results: The DPOAEs amplitudes and signal-to-noise ratio (SNR) values at 1 to 6 kHz frequencies for group 1 animals after injections significantly decreased over those before injections (P < 0.05). In group 2, there were no significant differences in DPOAE amplitude and SNR values between before and after intratympanic dexamethasone injections (P > 0.05). Considering group 3, there were also no significant differences in DPOAEs amplitudes and SNR values before and after of dexamethasone and cisplatin injections (P > 0.05). Conclusions: Intratympanic dexamethasone injection did not cause any ototoxic effect; in contrast, it might have a significant protective effect after cisplatin injection. [Copyright &y& Elsevier]

Objective: 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. Study design and setting: 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. Results: 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. Conclusions: 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. Significance: These patients need close follow-up of stimulation levels and programming modes postoperatively in order to perform optimally with CIs. EBM rating: B-3. [Copyright &y& Elsevier]

: ObjectiveWe sought to determine a dose-response curve for topical mitomycin C when used to prolong the patency of laser-assisted myringotomies.: Study design and settingBilateral myringotomies were performed using the argon laser in 40 guinea pigs with normal ears. Pledgets with (0.05, 0.2, 0.4, or 2.0 mg/mL) mitomycin C were applied topically. Monitoring consisted of weekly or biweekly otomicroscopy.: ResultsAs in previous studies, all saline-treated myringotomies closed by day 7. By day 14, all myringotomies (100%) in the 0.05 mg/mL group were closed. By contrast, all myringotomies (100%) remained patent in the 0.2 and 0.4 mg/mL treatment groups, and 56% of the myringotomies remained patent in the 2.0 mg/mL group at day 14. By day 56, all myringotomies were closed in the 2.0 mg/mL group, 5 (50%) myringotomies were patent in the 0.4 mg/mL group, and 1 (11%) myringotomy was patent in the 0.2 mg/mL group. The study was terminated on day 84 (12 weeks). At that time, only the 0.4 mg/mL group had patent myringotomies (n = 3; 30%). The highest dose (2.0 mg/mL) of mitomycin was significantly associated with otorrhea. Otorrhea also appeared to be associated with earlier myringotomy closure.: ConclusionThere is a dose-response curve for topical mitomycin C when used for prolonging myringotomy patency in doses up to 0.4 mg/mL. Higher doses do not appear to prolong patency and are associated with greater otorrhea, suggesting middle ear toxicity. [Copyright &y& Elsevier]

Objectives: The goal of the present study was to compare the frequencies of cochlear and non-cochlear patterns of distortion-product otoacoustic emissions (DPOAEs) in patients with nonacoustic (non-AN) tumors of the cerebellopontine angle (CPA)/internal auditory canal with those in patients with acoustic neuroma (AN). Study Design and Setting: We conducted a prospective study of patients with non-AN internal auditory canal/CPA tumors treated between 1992 and 1999 in a tertiary care setting. We collected data on behavioral pure tone average, speech discrimination score, acoustic immittance tests, DPOAEs, and tumor size. DPOAEs were divided into those with a cochlear or a noncochlear pattern. Comparisons were made with a control group of patients with AN of the CPA. Results: Twenty-four patients were included in the study: 12 patients in the non-AN group and 12 patients in the AN group. In the non-AN group, 5 (42%) patients had a cochlear pattern and 7 (58%) had a noncochlear pattern. In the AN group, 7 (58%) patients had a cochlear pattern and 5 (42%) had a noncochlear pattern. The differences between the non-AN and AN groups were statistically significant. In the non-AN group, patients with a cochlear-pattern DPOAE had significantly smaller tumors (P = 0.03) and a trend (P = 0.07) toward higher speech discrimination score. Age and pure tone average were not significantly different in the non-AN tumor patients. In the AN group, none of the study parameters were significantly related to the pattern of DPOAE. Conclusions: ANs appear to differ from other tumors of the CPA in their propensity to cause sensory versus neural hearing loss. A larger series of patients would be useful to confirm these preliminary findings. (Otolaryngol Head Neck Surg 2002;126:115-120.) [Copyright &y& Elsevier]