Contribution of Vestibular-Evoked Myogenic Potential (VEMP) testing in the assessment and the differential diagnosis of otosclerosis.

BACKGROUND: The aim of this prospective clinical study was to evaluate the clinical importance of Vestibular-Evoked Myogenic Potentials (VEMPs) in the assessment and differential diagnosis of otosclerosis and otologic diseases characterized by "pseudo-conductive" components. We also investigated the clinical appearance of balance disorders in patients with otosclerosis by correlating VEMP results with the findings of caloric testing and pure tone audiometry(PTA). MATERIAL AND METHODS: Air-conducted(AC) 4-PTA, bone-conducted(BC) 4-PTA, air-bone Gap(ABG), AC, BC tone burst evoked VEMP, and calorics were measured preoperatively in 126 otosclerotic ears. RESULTS: The response rate of the AC-VEMPs and BC-VEMPs was 29.36% and 44.03%, respectively. Statistical differences were found between the means of ABG, AC 4-PTA, and BC 4-PTA in the otosclerotic ears in relation to AC-VEMP elicitability. About one-third of patients presented with disequilibrium. A statistically significant interaction was found between calorics and dizziness in relation to PTA thresholds. No relationship was found between calorics and dizziness with VEMPs responses. CONCLUSIONS: AC and BC VEMPs can be elicited in ears with otosclerosis. AC-VEMP is more vulnerable to conductive hearing loss. Evaluation of AC-VEMP thresholds can be added in the diagnostic work-up of otosclerosis in case of doubt, enhancing differential diagnosis in patients with air-bone gaps. Otosclerosis is not a cause of canal paresis or vertigo.

The profile of otoacoustic emissions and multifrequency tympanometry in otosclerotic patients undergoing two types of stapes surgery: small fenestra and microtraumatic stapedotomy.

BACKGROUND: Otoacoustic emissions (OAEs) are influenced in otosclerosis. The aim of the current study was to investigate the profile of transient evoked (TEOAEs) and distortion product otoacoustic emissions (DPOAEs) in association with multifrequency tympanometry measures in otosclerotic patients undergoing 2 types of stapes surgery: small fenestra and microtraumatic stapedotomy. MATERIAL AND METHODS: A retrospective analysis of prospectively collected data was conducted evaluating 51 otosclerotic patients and 50 normal hearing subjects. Small fenestra and microtraumatic stapedotomy were performed in 27 and 24 patients, respectively. Pure tone audiometry (PTA) was always measured. Detection of TEOAEs and DPOAEs at 5 frequency steps (1, 1.4, 2, 2.8, and 4 kHz) preoperatively and at 2 and 5 months postoperatively, stratified by the type of surgery, represented the main goal of the study. Resonant frequency derived by multifrequency tympanometry was also evaluated. RESULTS: All patients demonstrated improvement in hearing level postoperatively, with significant closure of air-bone gap on PTA. Resonant frequency values returned to normal after microtraumatic stapedotomy but were exceedingly decreased following the small fenestra technique. The detection of both TEOAEs and DPOAEs was improved, but when the detection was stratified by the tested frequencies, significant increase in the number of patients with detectable OAEs was observed, mainly during testing at 1 and 1.4 kHz. CONCLUSIONS: Otosclerotic patients exhibited improvement in the detection of OAEs, particularly at low frequencies, after both procedures. Resonant frequency was normalized following the microtraumatic stapedotomy, whereas it is over-decreased after the small fenestra technique.

A longitudinal study of changes in distortion-product otoacoustic emissions and pure-tone thresholds in an industrial setting.

In a longitudinal study of 76 noise-exposed industrial workers, 34 (68 ears) of them were available for final evaluation after 9 years of observation. Distortion-product otoacoustic emissions (DP) at 65/55 dB SPL and pure-tone audiometry were used to detect noise-induced inner ear changes. Repeated measures analyses of variance were made on the subjects and in a control group, whereas significant threshold shifts (STS) and significant emission shifts (SES) were calculated. Both hearing thresholds and DP showed a high-frequency deterioration, but there was absence of statistical correlation between elevation of hearing thresholds and decrease of DP. There was no clear pattern between individual changes in audiometric thresholds and DP, and all combinations were present: ears with only STS, ears with only SES, ears with both STS and SES and ears with absence of STS and SES. Audiometric changes were maximal at 4 and 6 kHz and DP changes at 2 and 3 kHz. Since significant individual emission changes do not necessarily follow the same pattern as the group-averaged results, the use of DP for monitoring of individual subjects is not advised. However, its use in conjunction with audiometry in hearing conservation programs is highly recommended.

Cochlear dysfunction in patients with acute hypothyroidism.

The effect of acute hypothyroidism on the cochlear function was studied prospectively, in a group of 52 patients with thyroid carcinoma who underwent total thyroidectomy. All patients were examined before surgery and 6-8 weeks postoperatively. During this period there was no replacement with levothyroxine and the magnitude of thyroxin depletion was monitored by serum thyroid-stimulating hormone levels. Pure-tone audiometry, tympanometry and transiently evoked otoacoustic emissions were performed. A group of healthy volunteers of similar age and sex were used as controls. Tympanograms were normal, either on initial or on repeat testing. Audiometry showed elevation of all postoperative hearing thresholds, whereas the thresholds varied significantly across frequency. Transiently evoked otoacoustic emission testing showed response signal-to-noise ratios lower in the postoperative session (hypothyroid state) than in the preoperative session on all measured frequencies. Emission levels varied significantly across frequency, with maximum response observed at 2 kHz. Comparison of significant pure-tone and otoacoustic emission shifts for individual ears showed more ears affected in otoacoustic emission testing, indicating subclinical involvement. Comparing hearing thresholds and otoacoustic emission levels between patients and controls showed significant differences on postoperative testing. It may be thus concluded that acute hypothyroidism causes elevation of hearing thresholds in humans and to a greater degree subclinical damage of the cochlear function.

Vestibular evoked myogenic potentials in patients with BPPV.

BACKGROUND: The probable cause of Benign Paroxysmal Positional Vertigo (BPPV) is a degeneration of the oto lithic organs (utricle and saccule). The aim of the study is to find possible alterations in Vestibular Evoked Myogenic Potentials (VEMP) recordings in BPPV patients, because the saccule is part of the VEMP pathway. MATERIAL/METHODS: 27 BPPV patients (24 unilateral and 3 bilateral) aged 20 to 70 years and 30 healthy age matched controls. BPPV was diagnosed by the upbeating geotropic nystagmus found in the supine position with the head overextended towards one side. The subjects were investigated with pure tone audiometry, bi-thermal caloric test with electronystagmographic (ENG) recording, and VEMP recording. RESULTS: P1 latency and N1 latency did not present any statistical difference between control ears and affected ears of the BPPV population. The percentage of abnormal VEMP in the BPPV population was statistically higher than in the control ears (p < 0.005). No significant relationship could be shown between the occurrence of Canal Paresis and abnormal VEMP. No relationship was found between the side (right or left ear) where BPPV appeared clinically and the side where abnormal VEMP was registered. CONCLUSIONS: BPPV is a clinical entity associated with increased occurrence of abnormal VEMP recordings, possibly due to degeneration of the saccular macula, which is part of the neural VEMP pathway.

Universal newborn hearing screening, a revolutionary diagnosis of deafness: real benefits and limitations.

The finding that early detection of permanent congenital childhood hearing loss produces worthwhile benefit in terms of improved speech and language provides the rationale for the universal screening of newborns. The aim of the present study is to collect the current evidence with regard to the efficacy, the results and outcomes of universal hearing screening programs. An extensive search of the literature was performed in Medline and other available database sources. Study selection was based on the evaluation of the protocols used and the assessment of their efficacy in the early diagnosis of congenital hearing impairment. The initial referral rate and the rate of false positives were also evaluated. A total of 676,043 screened children have been identified in 20 studies. The average initial referral rate in these studies was 3.89%. The initial referral rate varied from 0.6 to 16.7%. The lost-to-follow-up rates varied from 3.7 to 65%. Although universal hearing screening is now widely adopted, there are still some serious drawbacks and limitations. False positives rates remain considerably high when newborns are screened with TEOAE's. The combination of TEOAE's and a-ABR provides a significantly reduced referral rate. Close cooperation between audiological centres and maternity units and a dedicated secretariat team are of paramount importance with regard to the reliability and efficacy of universal hearing screening.

Are GJB2 mutations an aggravating factor in the phenotypic expression of mitochondrial non-syndromic deafness?

Hearing impairment is a frequent condition, and genes have an important role in its etiology. The majority of hearing loss occurs in non-syndromic form, with deafness being the only clinically recognizable feature. More than 60 nuclear genes or loci have been shown to be involved in non-syndromic hearing loss, but mutations in mitochondrial DNA also cause hearing impairment. Mitochondrial DNA mutations usually lead to progressive hearing loss with an age of onset varying from childhood to early adulthood. It is interesting to note that there is a great variability among phenotypes between individuals harboring the same mitochondrial mutation, even within the same family, and the phenotype may range from profound deafness to completely normal hearing. In the past years, the debate on mitochondrial mutations has been about the penetrance, the tissue specificity and the mechanisms of modifier genes that can modulate the severity of the phenotypic expression of the deafness-associated mitochondrial DNA mutations. Here we summarize evidence regarding modifying genes, and we discuss the effect of the coexistence of mitochondrial and GJB2 mutations in families reported to date.

Screening protocols for the prevention of occupational noise-induced hearing loss: the role of conventional and extended high frequency audiometry may vary according to the years of employment.

BACKGROUND: Although occupational noise-induced hearing loss (NIHL) has become a major problem in industrialized societies, there is a notable lack of effective screening protocols to ensure its early diagnosis. The aim of this study was to detect a potential role of extended high frequency (EHF) audiometry in industrial hearing screening protocols. MATERIAL/METHODS: The population consisted of 151 persons, working for 8 hours daily in a noisy environment (90-110 dBA). The changes of hearing thresholds in industrial workers were analyzed, not only with respect to their age, as has been presented by previous studies, but also with respect to the duration of their previous employment. RESULTS: During the first 10 years of employment, the frequencies 12500, 14000 and 16000Hz were the only ones significantly affected. For the second decade of employment, thresholds were significantly elevated only at 2000 and 4000Hz. After exceeding 20 years of employment, the affected frequencies were 250, 500 and 1000Hz. The effects of age on hearing acuity were significant at all frequencies for the first 2 groups. CONCLUSIONS: EHF audiometry seems able to identify the first signs of NIHL, much earlier than conventional audiometry, and therefore may need to be implemented in the screening examinations especially of workers with less than 1 decade of employment. Hearing screening protocols could become more efficient by adjusting their frequency ranges according to the frequencies "at risk", which correspond to the duration of the workers' previous employment.

Canalithiasis of the anterior semicircular canal (ASC): treatment options based on the possible underlying pathogenetic mechanisms.

Benign paroxysmal positional vertigo (BPPV) of the anterior semicircular canal (ASC) is an uncommon disorder currently diagnosed with the Dix-Hallpike (D-H) examination. According to the literature, nystagmus and vertigo may be more pronounced when the affected ear is either up or down. In some patients, both right and left D-H tests can trigger nystagmus with the same direction. The proposed treatment options with the addition of a different manoeuvre applied by the authors of the present study in cases of ASC lithiasis, seem to present a respective variety regarding the position of the affected ASC during the procedure of canalith repositioning. The aim of this study is to analyse the mechanisms underlying both the proposed treatment options and the clinical findings in the D-H examination. The results of this analysis stimulate further investigation, since they probably imply that repositioning manoeuvres might vary in their effectiveness when applied to different clinical subgroups of ASC BPPV.

Tinnitus Retraining Therapy (TRT): outcomes after one-year treatment.

The aim of the study is to present our results regarding the efficacy of TRT for tinnitus relief in patients with clinically significant tinnitus compared to a group treated with vasoactive agents. In a nonrandomized prospective study, 63 patients with disabling tinnitus were recruited. Greek translation of the Tinnitus Handicap Inventory (THI) and visual analogue scale (VAS) for annoyance caused by tinnitus when conducting four major activities of everyday life (work, sleep, relaxation and concentration) were examined in a 12-month period. The THI score was significantly improved in the TRT group, as well as mean VAS scores, in all measures. Comparison of the mean improvement of THI and VAS scores after treatment showed significant differences between the two groups, favoring TRT treatment. Our data suggest that TRT is an effective treatment. It reduces the level of annoyance induced by tinnitus and improves the ability of patients to work, sleep, relax or be concentrated.

The A1555G mitochondrial DNA mutation in Greek patients with non-syndromic, sensorineural hearing loss.

Mitochondrial DNA mutations are undoubtedly a factor that contributes to sensorineural, non-syndromic deafness. One specific mutation, the A1555G, is associated with both aminoglycoside-induced and non-syndromic hearing impairment. The mutation is considered to be the most common of all mitochondrial DNA deafness-causing mutations but its frequency varies between different populations. Here we report on the first large screening of the A1555G mitochondrial DNA mutation in the Greek population. The aim of this study was to determine the frequency of the A1555G mutation in Greek sensorineural, non-syndromic deafness patients, with childhood onset. We screened 478 unrelated Greek patients with hearing loss of any degree and found two individuals harboring the A1555G mutation (0.42%). Both cases had been subjected to aminoglycosides. They were prelingual, familial and homoplasmic for the A1555G mutation. One of the cases was also found heterozygous for the frequent GJB2 35delG mutation, while the other case was negative. The A1555G mutation seems to be less common than in other European populations.

Rhinology resources on the internet: an update.

AIM: There has been a significant increase in the number of clinically useful biomedical resources available through the Internet over the last few years. The aim of this article is to present an updated list of all the worldwide web sites of rhinology. METHODS: All rhinologic links, which appear on the web site of the journal "Rhinology" were accessed and updated. Non-responding links were discarded and a new extensive survey of all rhinologic sites on the Internet was performed using on-line available search engines. All sites were accessed more than once at different times and their uniform resource locator (URL) address was recorded. RESULTS: The URL addresses of all rhinologic sites on the Internet appear in categories. Main categories include endoscopy and operative techniques, allergy, olfaction, rhinology clinics and research centers, organizations and societies, scientific journals, discussion groups, news and medical conferences, collective otolaryngology resources, and miscellaneous other sites of interest to rhinologists. CONCLUSIONS: This paper summarizes several types of resources available to rhinologists on the Internet. A complete universal list was composed, in which links to almost all interesting rhinologic links were included.

Distortion product otoacoustic emissions in an industrial setting.

Distortion product otoacoustic emissions (DPOAEs) is an objective sensitive test of cochlear function. The aim of this study was the evaluation of noise-induced hearing loss in a group of industrial workers, using this method in conjunction with standard puretone audiometry (PTA). One hundred and five subjects (210 ears) were included in the study. PTA, tympanometry, and DPOAEs were performed. Results were analyzed using a mixed analysis of variance model, and compared with the data of 34 normal persons of similar age and sex. We found statistically significant lower DPOAE levels in the noise-exposed group than in the control group. Additionally, the effect of frequency was significant, indicating that amplitude varied across frequency, with lower responses observed at 4 and 6 kHz, and maximum response found at 2 kHz. PTA showed a statistically significant effect of Group, owed to elevated puretone thresholds in the noise-exposed subjects, but a Frequency main effect was not found, although the interaction between Frequency and Group was statistically significant, as well as the interaction between Frequency and Ear. A main effect for Ear was found only in puretone thresholds, due to better thresholds in the left ears of the subjects, and not in DPOAE measurements. DPOAE levels were selectively affected at the higher frequencies, whereas puretone thresholds were affected at all frequencies. Direct comparison of the number of significantly affected ears between the two methods at 1, 2, and 4 kHz showed statistically significant differences at all comparisons, with more ears affected in PTA in comparison with DPOAEs at 4 kHz, whereas more ears were affected in DPOAEs at the lower frequencies (1 and 2 kHz). Therefore, it may be concluded that DPOAEs and PTA are both sensitive methods in detecting noise-induced hearing loss, with DPOAEs tending to be more sensitive at lower frequencies.

Strong linkage disequilibrium for the frequent GJB2 35delG mutation in the Greek population.

Approximately one in 1,000 children is affected by severe or profound hearing loss at birth or during early childhood (prelingual deafness). Up to 40% of congenital, autosomal recessive, severe to profound hearing impairment cases result from mutations in a single gene, GJB2, that encodes the connexin 26 protein. One specific mutation in this gene, 35delG, accounts for the majority of GJB2 mutations detected in Caucasian populations. Some previous studies have assumed that the high frequency of the 35delG mutation reflects the presence of a mutational hot spot, while other studies support the theory of a common founder. Greece is among the countries with the highest carrier frequency of the 35delG mutation (3.5%), and a recent study raised the hypothesis of the origin of this mutation in ancient Greece. We genotyped 60 Greek deafness patients homozygous for the 35delG mutation for six single nucleotide polymorphisms (SNPs) and two microsatellite markers inside or flanking the GJB2 gene. The allele distribution in the patients was compared to 60 Greek normal hearing controls. A strong linkage disequilibrium was found between the 35delG mutation and markers inside or flanking the GJB2 gene. Furthermore, we found a common haplotype with a previous study, suggesting a common founder for the 35delG mutation.

Auditory neuropathy: endocochlear lesion or temporal processing impairment? Implications for diagnosis and management.

BACKGROUND/OBJECTIVE: Auditory neuropathy/dys-synchrony, characterized by absent auditory brainstem responses, normal otoacoustic emissions or cochlear microphonics, and word discrimination disproportional to the pure-tone audiogram, may be accompanied by perceptual consequences that could jeopardize language acquisition in affected children. However, the related evidence is constantly changing leading to a serious debate. The aim of the present paper is to review the current knowledge on auditory neuropathy/dys-synchrony, and to present the therapeutic strategies that can be employed in its management, taking into account the potentially underlying pathophysiology. MATERIALS/METHODS: Literature review from Medline and database sources. Related books were also included. STUDY SELECTION: Controlled clinical trials, prospective and retrospective cohort studies, nested-based case-control and analytical family studies, laboratory and electrophysiological studies, animal models, case-reports, joint statements and review articles. DATA SYNTHESIS: Auditory neuropathy/dys-synchrony, in contrast to what is widely believed, is a very frequent disease, responsible for approximately 8% of newly diagnosed cases of hearing loss in children per year. Hyperbilirubinemia and hypoxia represent major risk factors, whereas generalized neuropathic disorders, or a genetic substrate involving the otoferlin gene, are responsible for the phenotype of auditory neuropathy/dys-synchrony in certain cases. Auditory nerve myelinopathy and/or desynchrony of neural discharges are the most probable underlying pathophysiologic mechanisms. Genetic testing may be helpful in cases of non-syndromic prelingual children. Auditory neuropathy/dys-synchrony management aims at restoring the compromised processing of auditory information, either through conventional amplification and/or alternative forms of communication, or by cochlear implantation (combined with intensive speech and language therapy). CONCLUSION: Auditory neuropathy/dys-synchrony is more frequent than considered in the past, especially amongst hearing-impaired children. Accurate diagnosis, based on subjective and objective hearing assessment techniques (including the various electrophysiological assessment measures), and timely treatment of the affected children is of paramount importance, with hearing aids, intensive speech and language therapy (and sign language when indicated) providing the mainstay of habilitation, and cochlear implantation representing a valid therapeutic alternative.

Juvenile nasopharyngeal angiofibroma stages I and II: a comparative study of surgical approaches.

OBJECTIVE: The aim of this study was to compare different surgical options used for removal of stages I and II juvenile nasopharyngeal angiofibromas (JNAs). Treatment morbidity was evaluated through blood loss, surgery duration, postoperative hospitalization and outcome. Moreover, an effort was made to explore the role and limits of endoscopic surgery. MATERIALS AND METHODS: 20 male patients (mean age 14.9 years) were treated for JNA using three different surgical approaches in the Department of Otolaryngology of the University of Athens between May 1998 and January 2007. 9 patients were managed using endoscopic approach, while 5 were treated through midfacial degloving. A transpalatal approach was performed in remaining 6 patients. Preoperative angiography with embolization was performed in all 9 patients who underwent endoscopic removal and in 3 patients treated by midfacial degloving technique. RESULTS: Findings demonstrated that endoscopic approach, assisted by preoperative embolization, lead to less intraoperative blood loss, shorter duration of surgical procedure, shorter length of hospital stay and no complications, compared with the conventional techniques. CONCLUSIONS: Our data suggest that with proper patient selection, endoscopic resection of stages I and II JNA, when it is performed after embolization of the feeding vessels, is remarkably bloodless and precise and may be preferable to traditional open approaches.

Sudden hearing loss in a family with GJB2 related progressive deafness.

Mutations of GJB2, the gene encoding connexin 26, have been associated with prelingual, sensorineural hearing loss of mild to profound severity. One specific mutation, the 35delG, has accounted for the majority of mutations detected in the GJB2 gene in Caucasian populations. Recent studies have described progression of hearing loss in a proportion of cases with GJB2 deafness. We report an unusual family with four 35delG homozygous members, in which the parents were deaf-mute whilst both children had a postlingual progressive hearing loss. Furthermore, the son suffered from sudden hearing loss.

Acoustic stapedial reflex in normal adults: biological behavior and determination of threshold levels.

OBJECTIVE: To record acoustic reflex thresholds for admittance (Y) and its components, susceptance (B) and conductance (G) in healthy subjects and to establish normative data. STUDY DESIGN: Acoustic reflex threshold was determined in 100 healthy persons, divided into 5 age groups of 20 persons each (20-29, 30-39, 40-49, 50-59 and 60-69 years old). Detection was performed for Y, B, and G at 226-, 678- and 1,000-Hz probe tones, using 500-, 1,000-, 2,000- and 4,000-Hz stimuli. RESULTS: Statistically significant differences in acoustic reflex thresholds were revealed between different components, stimuli and tones. The lowest threshold level was recorded for Y at 226 Hz using stimulus 1,000 Hz. Four percent missing values were observed at 226 Hz. Subjects belonging to different age groups had different reflex thresholds. CONCLUSION: Inclusion of acoustic reflex detection for B and G offers more detailed information about the middle ear status compared with Y alone, and appears to be sensitive in detecting subtle diseases.

Cochlear function in facioscapulohumeral muscular dystrophy.

OBJECTIVE: Facioscapulohumeral muscular dystrophy (FSHD) is commonly associated with high-frequency hearing impairment. Our objective was to evaluate a group of normally hearing patients with FSHD using otoacoustic emissions. STUDY DESIGN: Prospective, randomized clinical trial. SETTING: A tertiary University-based referral center in Athens, Greece. PATIENTS: The study group consisted of a consecutive sample of 24 patients diagnosed on clinical, histopathologic, and genetic grounds as having FSHD. All subjects were selected on the basis of normal to near normal audiometric pure tone thresholds. Controls consisted of 40 age-matched healthy volunteers. INTERVENTIONS: Transiently evoked otoacoustic emissions were performed. Whole reproducibility and total response were measured, as well as partial scores at the octave bands centered at 1, 2, 3, 4, and 5 kHz. MAIN OUTCOME MEASURES: Transiently evoked otoacoustic emission measurements were compared between the two groups. RESULTS: The audiometric findings were normal to near normal for both groups. Compared with controls, most patients had diminished scores in both whole and partial reproducibility scores and overall and partial response scores. CONCLUSION: Despite normal hearing, subclinical involvement of the cochlea is quite common in patients with FSHD. Our findings support the genetic homogeneity of this disorder and its association with cochlear damage. Otoacoustic emissions might provide a useful tool in the clinical workup and follow-up of these patients.

Neurotoxicity of BFM-95 on the medial olivocochlear bundle assessed by means of contralateral suppression of 2f1-f2 distortion product otoacoustic emissions.

OBJECTIVE: Berlin-Frankfurt-Munster 95 (BFM-95) is a common chemotherapeutic protocol against acute lymphoblastic leukemia (ALL). This prospective study investigates whether this protocol has an adverse effect on the medial olivocochlear bundle (MOCB) and/or outer hair cells' (OHCs) function. The distortion product otoacoustic emissions (DPOAEs) and their suppression by means of contralateral application of white noise were used for assessing the function of OHCs and the MOCB, respectively. STUDY DESIGN: Prospective study. SETTING: Oncology and otorhinolaryngology departments in a pediatric hospital. PATIENTS: Thirty-six children treated with ALL-BFM-95. INTERVENTIONS: Before chemotherapy, a baseline audiologic evaluation with tympanogram, standard and extended high frequency, pure-tone audiometry, and DPOAEs in the absence and presence of white noise was performed in all children. This population was divided in three groups. In a first group (n = 12), the evaluation was repeated after four sessions of vincristine administration; in the second group (n = 12), after 8 sessions; and in the third group (n = 12), several months after completion of the protocol. MAIN OUTCOME MEASURE: DPOAEs suppression by contralateral application of white noise. RESULTS: In the first and the third groups, we observed no changes in DPOAE amplitudes. Nevertheless, in the second group, the DPOAEs demonstrated significant decrease at 1416, 1685, 2002, and 2380 Hz. At baseline examination, all groups presented significant suppression at all frequencies. After eight vincristine sessions, instead of suppression, an increase of amplitudes was noted at 5 of 12 frequencies. Efferent-mediated DPOAE suppression reappeared in the third group at all frequencies (significant at 5 of 12 frequencies). CONCLUSION: ALL-BFM-95 seems to exert an early and reversible toxic effect on the MOCB, whereas its effects on OHCs are minimal and reversible. These minimal cochleotoxic and neurotoxic properties of ALL-BFM-95 might prove useful for research studies on the role of efferent innervation in hearing.