Inner-ear malformations as a cause of single-sided deafness.

OBJECTIVE: To determine the prevalence and distribution of inner-ear malformations in congenital single-sided deafness cases, as details of malformation type are crucial for disease prognosis and management. METHODS: A retrospective study was conducted of 90 patients aged under 16 years with congenital single-sided deafness. Radiological findings were evaluated using computed tomography and magnetic resonance imaging. Inner-ear malformations were identified and cochlear nerve status was determined in affected ears. RESULTS: Out of 90 ears, 42 (46.7 per cent) were found to have inner-ear malformation. Isolated cochlear aperture stenosis was the most common anomaly (n = 18, 20 per cent), followed by isolated cochlear aperture atresia (n = 11, 12.2 per cent) and cochlear hypoplasia (n = 7, 7.8 per cent). Cochlear nerve deficiency was encountered in 41 ears (45.6 per cent). The internal auditory canal was also stenotic in 49 ears (54.4 per cent). CONCLUSION: Inner-ear malformations, especially cochlear aperture anomalies, are involved in the aetiology of single-sided deafness more than expected. The cause of single-sided deafness differs greatly between congenital and adult-onset cases. All children with single-sided deafness should undergo radiological evaluation, as the prognosis and management, as well as the aetiology, may be significantly influenced by inner-ear malformation type.

Twenty years of experience in revision cochlear implant surgery: signs that indicate the need for revision surgery to audiologists.

OBJECTIVE: To report device failures, audiological signs and other reasons for revision cochlear implant surgery, and discuss indications for revision surgery. METHODS: Revision procedures between November 1997 and August 2017 were retrospectively analysed. Over 20 years, 2181 cochlear implant operations were performed, and 114 patients underwent 127 revision operations. RESULTS: The revision rate was 4.67 per cent. The full insertion rate for revision cochlear implant surgery was 88.2 per cent. The most frequent reasons for revision surgery were: device failure (59 per cent), wound breakdown (9.4 per cent) and electrode malposition (8.7 per cent). The device failure rate was: 2.78 per cent for Advanced Bionics, 1.82 per cent for Cochlear and 5.25 per cent for Med-El systems. The number of active electrodes was significantly increased only for Med-El devices after revision surgery. The most common complaints among 61 patients were: gradually decreased auditory performance, sudden internal device shutdown and headaches. CONCLUSION: The most common reason for revision surgery was device failure. Patients should be evaluated for device failure in cases of: no hearing despite appropriate follow up, side effects such as facial nerve stimulation, and rejection of speech processor use in paediatrics. After revision surgery, most patients have successful outcomes.

Relationship between aided cortical auditory evoked responses and aided behavioral thresholds.

OBJECTIVES: The present study aimed to determine the relationship between aided cortical auditory evoked potentials and aided behavioral thresholds. Secondary aims of the study were to investigate the relationship between age and Cortical Auditory Evoked Potentials latencies, and to analyze the relationship between the /m/, /g/ and /t/ stimuli. METHOD: Therefore, 20 subjects (4-8 years old) who diagnosed with moderate to severe hearing loss were included in the study. Behavioral pure-tone audiometry was performed using supra-aural earphones. After verification of the settings of hearing aid settings, aided behavioral thresholds were determined in the free field. Aided CAEPs were recorded using the HEARLab system in a sound-treated room. The /m/, /g/, and /t/ speech stimuli were applied with durations of 30, 20, and 30 ms respectively. RESULTS: A strong correlation was found between aided cortical auditory evoked responses at the level of 55 dB SPL and aided behavioral thresholds in the free field(r=0.86). We showed that the CAEP latencies were not correlated with the age (/m/ stimulus [r=-0.051; p=0.830], /g/ stimulus [r=-0.053; p=0.825], and /t/ stimulus [r=0.121; p=0,610]). The mean latency of the /m/ stimulus at 55 dB SPL intensity was longer than those of the /g/ and /t/ stimuli. CONCLUSION: The results of the present study demonstrated that the use of the cortical auditory evoked potentials is clinically useful for measuring the hearing aid benefit. The CAEP can predict the aided behavioral thresholds in children with moderate hearing loss.

Variations in Multiple Syndromic Deafness Genes Mimic Non-syndromic Hearing Loss.

The genetics of both syndromic (SHL) and non-syndromic hearing loss (NSHL) is characterized by a high degree of genetic heterogeneity. We analyzed whole exome sequencing data of 102 unrelated probands with apparently NSHL without a causative variant in known NSHL genes. We detected five causative variants in different SHL genes (SOX10, MITF, PTPN11, CHD7, and KMT2D) in five (4.9%) probands. Clinical re-evaluation of these probands shows that some of them have subtle syndromic findings, while none of them meets clinical criteria for the diagnosis of the associated syndrome (Waardenburg (SOX10 and MITF), Kallmann (CHD7 and SOX10), Noonan/LEOPARD (PTPN11), CHARGE (CHD7), or Kabuki (KMT2D). This study demonstrates that individuals who are evaluated for NSHL can have pathogenic variants in SHL genes that are not usually considered for etiologic studies.

Binaural squelch and head shadow effects in children with unilateral cochlear implants and contralateral hearing aids.

The aim of this study was to investigate the amount of binaural squelch effect (BSE) and head shadow effect (HSE) in children who use unilateral cochlear implants (CI) and contralateral hearing aids (HA). The study group consisted of 19 CI recipient children who consistently wore a contralateral HA. Speech sounds were used to evaluate speech perception performance in noise. Testing was performed in three listening conditions: (1) bimodal listening with noise source on HA side; (2) CI only with noise source contralaterally (HA off); (3) CI only with noise source on the CI side. Statistical analysis revealed a significant difference between the three listening conditions and post hoc tests indicated significant differences for all pairwise comparisons (p < 0.001). The average BSE and HSE were 11.8% and 17.1% respectively. The majority of bimodal CI users showed BSE and HSE with significant speech perception improvement in the presence of noise.

Effect of age on speech recognition in noise and on contralateral transient evoked otoacoustic emission suppression.

INTRODUCTION: We aimed to study the influence of age, in normal hearing individuals, on: the masking level difference test, the speech recognition in noise test, the transient evoked otoacoustic emissions test, and the contralateral transient evoked otoacoustic emission suppression test. We also aimed to research the effect of age when using these tests to evaluate the central auditory nervous system. METHODS: Transient evoked otoacoustic emissions and contralateral transient evoked otoacoustic emission suppression were measured in all subjects. Subjects also underwent masking level difference and speech recognition in noise tests. RESULTS: We found a decrease in transient evoked otoacoustic emission amplitudes, speech recognition in noise scores and hearing thresholds with age. We also found that higher masking level difference values were associated with lower speech recognition in noise scores and contralateral transient evoked otoacoustic emission suppression values. CONCLUSION: We conclude that decreasing speech recognition in noise scores are associated with decreasing contralateral transient evoked otoacoustic emission supression values. This effect may be related to medial efferent system dysfunction.

Intratympanic dexamethasone, intratympanic gentamicin, and endolymphatic sac surgery for intractable vertigo in Meniere's disease.

OBJECTIVE: To compare the efficacy of intratympanic dexamethasone (ID), intratympanic gentamicin (IG), and decompression of the endolymphatic sac (ESD) for intractable vertigo in Meniere's disease. STUDY DESIGN AND SETTING: This prospective study was conducted at Hacettepe University Medical Faculty, a tertiary care center. Dexamethasone was applied through a ventilation tube in 24 patients, intratympanic gentamicin (also through a ventilation tube) to 16 patients, and 25 patients underwent ESD. RESULTS: Satisfactory control of vertigo was 72%, 75%, and 52%, respectively for the ID, IG, and ESD. Two patients in the gentamicine group had total hearing loss. In the dexamethasone group, hearing level remained the same in 46% of the patients with 16% increase and 38% decrease (30% 10dB and 8% 20 dB). CONCLUSION: If the vertiginous symptoms still persist after 6 months of medical treatment, ID can be started. If there is no further improvement after 3 months with ID, patients with profound sensorineural hearing loss undergo treatment with IG, ESD is reserved for patients with good hearing. If ESD also fails, patients with good hearing may undergo vestibular nerve section; patients with nonservicable hearing become candidates for labyrinthectomy.

Relationship of vestibular aqueduct and inner ear pressure in Ménière's disease and the normal population.

OBJECTIVE: Etiopathogenesis of Ménière's disease has not been resolved. The principal histopathologic finding in this disease is endolymphatic hydrops. The majority of radiologic and histopathologic studies demonstrated a narrow vestibular aqueduct in Ménière's disease. There is no study in the literature investigating the relationship between inner ear pressure and vestibular aqueduct dimensions. Static acoustic compliance is a noninvasive procedure that is thought to measure perilymphatic pressure at the footplate. An increase in mechanical fluid pressure in the inner ear is transmitted to the footplate of the stapes. This causes a reduction in the compliance at the drum. The aim of this study is to investigate the relationship between vestibular aqueduct dimensions and static acoustic compliance in Ménière's disease and the normal population. STUDY DESIGN: Prospective study. METHODS: Forty patients with Ménière's disease and 40 healthy individuals with no otolaryngologic disorders were the subjects of this study. Each group was further divided into two according to static compliance value (normal and low static compliance). In these four groups dimensions of vestibular aqueduct were determined radiologically by high-resolution computerized tomography and correlated with normal and low static acoustic compliance values (normal and high perilymphatic pressure). RESULTS: The results demonstrated that vestibular aqueduct is narrower in patients with Ménière's disease than the normal population. However, there is no relationship between vestibular aqueduct dimensions and inner ear pressure obtained by static acoustic compliance measurements.

Cochlear implants: is there any relationship between stimulation rates and adaptation?

OBJECTIVE: To determine the relationship between stimulation rate and adaptation in cochlear implant users. STUDY DESIGN: A prospective clinical study. SETTING: This study was conducted at Hacettepe University Medical Faculty, which is a tertiary care and cochlear implant center in Ankara, Turkey. PATIENTS: Seven patients (three women, four men) who were using Nucleus CI 24 M cochlear implants (Cochlear Corp., Lane Cove, NSW, Australia). Two of them had become deaf after developing language skills, and five had congenitally deafness. RESULTS: Six patients demonstrated no tone decay. Only one patient, who had congenital hearing loss, demonstrated tone decay at stimulation rates of 250, 500, 720, 900 pulses per second. There is no statistically significant relationship between the stimulation rate and the selected electrode. CONCLUSION: The majority of the cochlear implant patients sustained the perception of a continuous electrical signal for 1 minute at 5 to 10 current levels above threshold.

Audiological findings in pregnancy.

This investigation was carried out in the Audiology and Speech Pathology Section of the Department of Otorhinolaryngology of Hacettepe University. The pregnant group comprised of 20 women followed by the Department of Gynaecology and Obstetrics of the same university; 18 non-pregnant women comprised the control group. The aim of this investigation was to study the relationship between hormonal changes in pregnancy and cochlear functions. All subjects underwent ENT examination, audiologic and acoustic immitance measurements and auditory brain stem response (ABR) tests. Results from each trimester and post-partum period of the pregnant group were compared. These results demonstrated that there was a decrease in hearing levels for 125 Hz, beginning in the first trimester and increasing in the second and third trimesters. Hearing returned to normal in the post-partum period. Similar findings were also obtained for 250 and 500 Hz; however, frequencies higher than 500 Hz demonstrated no significant correlation. Uncomfortable loudness was statistically significant between the third trimester and post-partum period. ABR tests did not reveal any differences. In conclusion, there is a low-frequency hearing loss and tolerance problem in pregnancy mimicking cochlear pathology. However, this hearing loss did not reach pathologic levels in any case and returned to normal in the post-partum period.

Relationship of the cochlear aqueduct and inner ear pressure in Ménière's disease and in a normal population.

OBJECTIVE: The aim of this study was to determine the dimensions of cochlear aqueduct radiologically in patients with Ménière's disease and in normal subjects, and to correlate these findings with normal and low static acoustic compliance (SAC) (high and normal perilymphatic pressure) to see whether the dimensions of the cochlear aqueduct play any role in the perilymphatic pressure in normal individuals and patients with Ménière's disease. STUDY DESIGN: Prospective double-blind study. SETTING: The study was conducted at Hacettepe University Medical Faculty, a tertiary care center. PATIENTS: Forty patients with Ménière's disease with bilateral involvement, diagnosed by vertigo attacks, fluctuating hearing loss, tinnitus, fullness in the ear, and cochlear sensitivity constituted the patient group. Forty healthy individuals with no otolaryngologic symptoms constituted the control group. INTERVENTIONS: All individuals underwent SAC measurement in terms of equivalent volume in milliliters, based on two volume measurements. To measure the dimensions of the cochlear aqueduct, high-resolution computed tomography of the temporal bone in the axial plane was performed. RESULTS: There was no statistically significant difference in the width of the cochlear aqueduct between patients with Ménière's disease and normal subjects. When SAC measurements were also taken into account, there was no difference in cochlear aqueduct dimensions between individuals with normal and low SAC values in the two groups. CONCLUSION: The dimensions of cochlear aqueduct are not significantly different in Méniére's disease patients and normal individuals. Also, the cochlear aqueduct does not appear to play a significant role in normal and low SAC values in the two groups of individuals.

Effect of teflon piston diameter on hearing result after stapedotomy.

This study compares hearing results after stapedotomy by 0.6 mm and 0.8 mm teflon pistons. Retrospective analysis studied 100 patients randomly selected who underwent stapedotomy for otosclerosis with insertion of 0.8 mm teflon piston prosthesis and 100 patients with 0.6 mm teflon piston prosthesis. Air-conduction hearing level in both groups were measured before and after the procedure and the gain of the air conduction between the 2 groups at different frequencies were compared statistically. The group with the 0.8 mm prosthesis had better results that were statistically significant and more pronounced at lower frequencies.

Transtympanic dexamethasone application in Ménière's disease: an alternative treatment for intractable vertigo.

The aetiology of Ménière's disease still remains unknown and its therapy is therefore empirical. As a result of immunological abnormalities demonstrated, steroids are commonly used in Ménière's disease. The place of topical steroids is still controversial. In this investigation topical dexamethasone is applied for three months through a ventilation tube in patients with intractable vertigo. The results showed that this treatment controls vertigo in 72 per cent of cases. No patient was worse than before treatment. Only in 17 per cent of the patients was there an increase in hearing level. When compared to the reports which used only tympanostomy tubes, this procedure seems to have a placebo effect with minimal harmful effects. It appears that transtympanic dexamethasone application is a good alternative to vestibular nerve section. Topical treatment may be sufficient in most patients. Systemic treatment may be used in patients where topical treatment fails.