High-frequency otoacoustic emissions in universal newborn hearing screening.

OBJECTIVE: Distortion-product otoacoustic emissions (DPOAEs) are currently used in many newborn hearing screening programs as the initial hearing test, typically testing frequencies between 1 and 4 or 6 kHz, but they have been associated with high false-positive rates. The objective was to investigate the possible benefit of high-frequency DPOAEs for reducing false-positive rates. METHODS: 255 healthy newborns (138 males and 117 females) undergoing conventional hearing screening based on DPOAE and automated auditory brainstem response (AABR) testing were recruited. High-frequency DPOAE amplitudes, noise floors and signal-to-noise ratios (SNRs) were measured for f2 frequencies up to 12 kHz. RESULTS: Of the 255 newborns who participated in this study, 23 (9%) failed the conventional DPOAE test but passed the AABR test, and 8 (3%) failed both tests. For an SNR threshold of 6 dB, high-frequency DPOAE tests at f2 = 4, 6, 8 and 10 kHz resulted in a reduction in the false-positive rate from 9% to 0.4%, or to zero if only three of the four frequencies were required to exceed the threshold. SNRs were lower in newborns with birth weights greater than 4000 g; lower at 2 kHz in newborns with a gestational age of 41 weeks; slightly higher in vaginally-delivered newborns; and higher at 2 kHz with increasing age in the group that failed the conventional DPOAE test but passed AABR. CONCLUSION: High-frequency DPOAEs resulted in a reduction in the DPOAE failure rate and the false-positive rate. These findings may be helpful in universal newborn hearing screening programs.

The impact of erdosteine on cisplatin-induced ototoxicity: a proteomics approach.

Cisplatin is a commonly used chemotherapeutic agent and causes serious side effects, including progressive and irreversible hearing loss. No treatment is currently available for cisplatin-induced ototoxicity. We have previously demonstrated that erdosteine, a potent antioxidant, partially protected the cochlea against cisplatin toxicity in vivo. The aims of this study were to (1) evaluate the protein profiles of the cochlea following cisplatin administration and (2) evaluate the impact of erdosteine on the protein profile using a proteomics-based approach. Thirty Sprague-Dawley rats were injected intraperitoneally with saline (n = 10), cisplatin (n = 10) or with cisplatin and erdosteine (n = 10). The cisplatin dosage was 14 mg/kg and for erdosteine, 500 mg/kg. Following euthanasia, protein lysates were obtained from fresh-frozen cochleae and were processed for mass spectrometry and western blotting. We detected 445 proteins that exhibited a twofold change or greater in the cisplatin group as compared to the control group. Of these, 18 proteins showed a fourfold or greater change in expression associated with cisplatin administration, including ras-related protein Rab-2A, Rab-6A, cd81, ribosomal protein S5, and myelin basic protein, which were downregulated, while Ba1-647 and fibrinogen (alpha chain), amongst others, were upregulated. Co-administration of erdosteine revealed a reversal of these changes in the expression of ras-related protein Rab-2A, ribosomal protein S5, myelin basic protein, and fibrinogen (alpha chain); erdosteine also upregulated glutathione reductase. In this study, we identified various proteins that may play a role in cisplatin-induced ototoxicity. We also observed the changes resulting from co-treatment with an antioxidant.

Detection of otoacoustic emissions in chinchilla when the middle ear contains amniotic fluid.

OBJECTIVES/HYPOTHESIS: Otoacoustic emissions have frequently been used for newborn hearing screening. However, they have low specificities and high referral rates. The presence of amniotic fluid in the middle ear is one reason for these problems. The aim of this study was to determine the effects of human amniotic fluid on otoacoustic emissions and on middle-ear function. METHODS: Forty-six chinchillas were randomly divided into eight groups based on the type (amniotic fluid or normal saline) and volume (0.5, 1, 1.5, 2 ml) of liquid introduced into the middle ear. Distortion product otoacoustic emission (DPOAE) and wideband reflectance (WBR) measurements were taken under inhalational anaesthesia before and after introduction of middle-ear liquid. The differences in these measurements were subjected to statistical analyses. STUDY DESIGN: Prospective controlled animal study. RESULTS: Significant reductions of DPOAE levels and increases in WBR occurred across all frequencies when there was liquid in the middle ear, and the changes became greater for increased volumes of liquid. Changes in the noise level had important effects on the otoacoustic-emission signal-to-noise ratio at the three lowest frequencies. CONCLUSION: Both human amniotic fluid and saline in the chinchilla middle ear resulted in changes in otoacoustic-emission detection patterns and WBR that may be relevant to newborn hearing screening.

Acute mastoiditis in children with cochlear implants: is explantation required?

OBJECTIVE: Acute mastoiditis is an uncommon but challenging condition when it occurs in children with cochlear implant. The literature is scarce as to the management of this condition with regards to explantation. The objective of the study is to determine the need for explantation in patients with cochlear implants who suffer from acute mastoiditis. DATA SOURCES: Online medical databases-PubMed, Ovid Medline, Ovid Medline in process, Embase, Cochrane Library, CINAHL, Biosis, Google Scholar, and Scopus. REVIEW METHODS: A systematic review of all publications addressing the treatment of mastoiditis in cochlear implant children prior to November 2013 was conducted. Data were collected from online medical databases-PubMed, Ovid Medline, Ovid Medline in process, Embase, Cochrane Library, CINAHL, Biosis, Google Scholar, and Scopus. The review was performed in 3 phases; an initial screening review of abstracts was performed, followed by a detailed review of full articles based on inclusion and exclusion criteria, and lastly a final review to extract data from selected articles. RESULTS: Twelve articles were found eligible for this systematic review including a total of 43 patients. Subperiosteal abscess was present in 14.3%. All patients received intravenous antibiotics as an initial treatment, and if needed, surgical intervention was performed. Only 1 patient required explantation (2.3%). CONCLUSION: Prompt, aggressive medical and if needed surgical therapy can help in saving the implant and result in a favorable outcome.

Otoacoustic emissions in newborn hearing screening: a systematic review of the effects of different protocols on test outcomes.

BACKGROUND AND OBJECTIVES: Otoacoustic emission (OAE) tests are currently used to screen newborns for congenital hearing loss in many Universal Newborn Hearing Screening programs. However, there are concerns about high referral and false-positive rates. Various protocols have been used to address this problem. The main objective of this review is to determine the effects of different screening protocols on the referral rates and positive predictive values (PPV) of the OAE newborn screening test. METHODS: Eligible studies published in English from January 1990 until August 2012 were identified through searches of MEDLINE, Medline In-Process, Embase, PubMed (NCBI), ISI Web of Science, and the Cochrane Central Register of clinical controlled trials. Two reviewers independently screened the data sources, using pre-defined inclusion criteria to generate a list of eligible articles. Data extracted included the number of newborns screened, age at screening, OAE pass criteria, frequencies screened, number of retests, referral rates, and the number of newborns identified with permanent congenital hearing loss. RESULTS: Ten articles met the inclusion criteria, with a total of 119,714 newborn participants. The pooled referral rate was 5.5%. Individual referral rates ranged from 1.3% to 39%; the PPV from 2 to 40%. Increasing the age at initial screening and performing retests reduced the referral rate. Likewise, screenings involving higher frequencies had lower referral rates. CONCLUSION: Delaying newborn hearing screening improves test results but may not be practical in all contexts. The use of higher frequencies and more sophisticated OAE devices may be useful approaches to ensure better performance of the OAE test in newborn hearing screening.

Is type 2 diabetes mellitus associated with alterations in hearing? A systematic review and meta-analysis.

OBJECTIVES/HYPOTHESIS: The aim of this study was to systematically and quantitatively review the available evidence on the effects of type 2 diabetes mellitus on hearing function. DATA SOURCES AND REVIEW METHODS: Eligible studies were identified through searches of eight different electronic databases and manual searching of references. Articles obtained were independently reviewed by two authors using predefined inclusion criteria to identify eligible studies. Meta-analysis was performed on pooled data using Cochrane's Review Manager. RESULTS: Eighteen articles fulfilled the inclusion criteria. Hearing loss (HL) was defined by all studies as pure tone average greater than 25 dB in the worse ear. The incidence of HL ranged between 44% and 69.7% for type 2 diabetics, significantly higher than in controls (OR 1.91; 95% confidence interval 1.47-2.49). The mean PTA (pure tone audiometry) thresholds were greater in diabetics than in controls for all frequencies [test or overall effect Z = 3.68, P = 0.0002]. Auditory brainstem response (ABR) wave V latencies were also statistically significantly longer in diabetics when compared to control groups [OR 3.09, 95% CI 1.82- 4.37, P < 0.00001]. CONCLUSIONS: Type 2 diabetic patients had significantly higher incidence for at least the mild degree of HL when compared with controls. Mean PTA thresholds were greater in diabetics for all frequencies but were more clinically relevant at 6000 and 8000 Hz. Prolonged ABR wave V latencies in the diabetic group suggest retro-cochlear involvement. Age and duration of DM play important roles in the occurrence of DM-related HL.

Earigate™ for softening ear wax: is it safe when the eardrum is perforated?

OBJECTIVE: To determine the safety of Earigate™ as an ear wax softening product. STUDY DESIGN: Prospective, controlled animal study. METHODS: Bilateral wide myringotomies were performed in eleven chinchillas. In each animal, Earigate™ was delivered to a randomly selected experimental ear canal as 2 puffs twice a day. Auditory brainstem response (ABR) was used to assess the hearing of the animals before, 3 days and 10 days following the local application of Earigate™. The ABR threshold shifts were compared for both experimental and control ears. RESULTS: The mean hearing threshold shifts in the experimental animals were comparable at all frequencies and at days 3 and 10. No statistically significant differences were observed in the mean threshold shifts for all of the frequencies evaluated, between the control and experimental ears. CONCLUSIONS: The administration of Earigate™ to the middle ear of chinchillas did not cause any ototoxicity as assessed by ABR.

Oxymetazoline ototoxicity in a chinchilla animal model.

OBJECTIVE: To investigate possible ototoxic effects of a one-time application of oxymetazoline drops in a chinchilla animal model with tympanostomy tubes. Study Design. A prospective, controlled animal study. SETTING: The Research Institute of the Montreal's Children Hospital, McGill University Health Centre. SUBJECTS AND METHODS: Ventilation tubes were inserted in both ears of 12 animals. One ear was randomly assigned to receive oxymetazoline drops (0.5 mL). The contralateral ear did not receive any drops, serving as a control ear. OUTCOME MEASURES: Distortion product otoacoustic emissions were measured bilaterally for a wide range of frequencies (between 1 and 16 kHz) before and 1 day after the application of oxymetazoline in the experimental ears. Two months later, the animals were sacrificed and all cochleae were dissected out and processed for scanning electron microscopy. RESULTS: In this established chinchilla animal model, the measured distortion product otoacoustic emission amplitudes and the morphological appearance on scanning electron microscopy were similar for both control and experimental ears. CONCLUSION: Oxymetazoline did not cause ototoxicity in a chinchilla animal model 2 months after a single application via a tympanostomy tube.

Is ototopical nystatin ototoxic? A chinchilla model.

In this prospective controlled animal study, the authors investigated the potential ototoxic effects of ototopical application of nystatin through a tympanostomy tube, using their established chinchilla animal model. Each of the 10 animals used had ventilation tubes inserted in both ears; 1 ear was randomly assigned to receive nystatin suspension, whereas the other ear did not receive any medication, serving as control. Distortion product otoacoustic emissions (DPOAEs) were measured in each animal before application of nystatin and at 45 and 60 days after application. Each cochlea was also processed for scanning electron microscopy (SEM) at the end of the experiment. There was no significant difference in the DPOAEs and SEM appearances of the experimental and control ears over the 60-day period of the experiment. The authors conclude that transtympanic nystatin did not produce any long-term ototoxic effects detectable by DPOAEs or SEM.

Cost-related antibiotic dosage omissions-challenge for orbital cellulitis management in resource poor communities.

BACKGROUND: Orbital cellulitis is a medical emergency with potential vision and life threatening complications. AIM: To highlight clinical presentation and challenges in the management of orbital cellulitis in resource poor communities of southwestern Nigeria. METHOD: Retrospective review of patients managed for orbital cellulitis at the Wesley Guild Hospital, Ilesa, Nigeria for biodata, socioeconomic status, clinical presentation, compliance to prescribed medications and treatment outcome. Data was analyzed using SPSS version 11. RESULT: Seventeen patients with mean age and standard deviation of 10 +/- 9.9 years were managed for orbital cellulitis. Thirteen (76.5%) females and 4(23.5%) males giving a male to female ratio of 1:3.3 (p = 0.03). Most patients (94.1%) belonged to low socioeconomic status and sinusitis was the most common predisposing factor. 10 (58.8%) had intravenous antibiotics only while 7(41.2%) had surgical drainage of abscess in addition. Delayed and irregular administration of antibiotics was observed in 9 (52.9%) patients due to lack of funds thus necessitating change of choice in antibiotics. Complication include ptosis 3(17.6%), corneal opacity 2 (11.8%), optic atrophy 1(5.9%) and 1(5.9%) meningitis and death 1(5.9%). CONCLUSION: Cost and affordability should be major determinants of choice of empirical antibiotics in resource poor communities to ensure timely and regular treatment and improve prognosis in management of orbital cellulitis.