Hong Ju Park

Proportion of bony cochlear nerve canal anomalies in unilateral sensorineural hearing loss in children

OBJECTIVE The aim of this study was to characterize the various bony anomalies of the inner ear in patients with unilateral sensorineural hearing loss using high-resolution temporal bone computed tomography and establish the relationship between hearing and the diameter of the bony cochlear nerve canal. METHODS We performed a retrospective review of 51 patients (mean age 11 years, range 0-20 years, 27 boys, 24 girls) who were diagnosed with unilateral sensorineural hearing loss with an audiogram. Coronal and axial diameter of the inner ear structures, including the internal auditory canal, bony cochlear nerve canal, and each turn of the cochlea and semicircular canals, were measured with high-resolution temporal bone computed tomography. The mean values (± 2 standard deviations) were calculated and compared between sensorineural hearing loss and normal ears, and between narrow bony cochlear nerve canal and normal bony cochlear nerve canal ears. Bony cochlear nerve canal atresia/stenosis was defined as a value less than 1.4mm in axial images. RESULTS The diameter of the bony cochlear nerve canal was significantly smaller in sensorineural hearing loss ears than in normal ears (p<.05). Associated inner ear anomalies, such as IAC stenosis (24%), cochlear hypoplasia (7-17%), and narrow semicircular canal bony island (8%) were only observed in the narrow bony cochlear nerve canal group. This group also showed statistically significant, severe to profound hearing loss compared to the normal bony cochlear nerve canal group (p<.05, R(2)=12.8%). CONCLUSIONS Most (57%) of the unilateral sensorineural hearing loss ears had bony cochlear nerve canal stenosis/atresia and this group showed associated inner ear anomalies. When the diameter of the bony cochlear nerve canal was less than 1.4mm, pure tone audio averages were more than 70 dB HL in most ears.

Management options for cochlear implantation in patients with chronic otitis media

OBJECTIVE Patients with chronic otitis media with/without cholesteatoma present a significant challenge to safe cochlear implantation (CI). The aim of our study is to describe our experience and propose management options for CI in patients with chronic otitis media. STUDY DESIGN Retrospective case study. SETTING Tertiary academic center. SUBJECT AND METHODS We enrolled the 9 ears of 8 subjects who received CI in the ear with chronic otitis media from 2006 to 2013 by a single surgeon. CI was performed as a single-stage or staged operation with mastoid surgery according to the activity of ear infection. RESULTS Six patients had bilateral chronic otitis media and 2 patients had long history of sensorineural hearing loss at contralateral ear. CI was performed with simultaneous radical mastoidectomy with closure of the EAC as a single-stage in 3 ears with a history of previous open cavity mastoidectomy and no active discharge. Staged CI was performed in 6 ears, after radical mastoidectomy with closure of the EAC in 3 ears and after intact canal wall mastoidectomy in 3 ears, due to active inflammation or complications related to otitis media. In one patient, wound infection had occurred, and implant was removed along with implantation at contralateral ear. Other subjects showed no evidence of recurrence. CONCLUSION Decision whether implantation as a single-stage or staged operation depends on the presence of active inflammation. Single-stage CI with proper mastoid surgery can be performed in patients without active inflammation. Staged procedure need to be done in ears with active inflammation. Proper application of mastoid surgery leads to safe CI for patients with chronic otitis media.

Interaural Differences of Distortion Product Otoacoustic Emission Amplitudes in Patients with Unilateral Tinnitus

Objective We aimed to determine whether abnormalities in outer hair cell (OHC) function were related to tinnitus through interaural comparison of distortion product otoacoustic emissions (DPOAEs). Study Design Cross-sectional study. Setting Tertiary care university teaching hospital. Participants Twenty-seven patients with unilateral tinnitus and pure-tone average of both ears ≤25 dB hearing loss (HL) at 500, 1000, 2000, and 4000 Hz were included. Subjects and Methods Pure-tone thresholds observed at 500 to 16,000 Hz and DPOAE amplitudes at f2 frequencies of 1001 to 6348 Hz were compared between the tinnitus ears and nontinnitus ears in patients with unilateral tinnitus. Results The pure-tone averages (13 ± 6 dB HL) in the nontinnitus ears were similar to those (15 ± 6 dB HL) in the tinnitus ears. There were no differences in pure-tone averages at all frequencies tested. While the DPOAE amplitudes measured at f2 frequencies of 1001 to 3174 Hz in tinnitus ears were not different from those in the nontinnitus ears, the tinnitus ears showed significantly reduced DPOAE amplitudes when compared with the nontinnitus ears at frequencies of 4004 to 6348 Hz. Conclusion OHC dysfunction was correlated with tinnitus at high frequencies, and DPOAE amplitudes can provide additional information about cochlear dysfunction, which is complementary to pure-tone audiometry.

Surgical treatment of posterior semicircular canal dehiscence syndrome caused by jugular diverticulum

OBJECTIVE We report a rare case of posterior semicircular canal dehiscence caused by a jugular diverticulum, and we describe its surgical treatment using a dehiscence resurfacing manoeuvre. METHOD The clinical findings, surgical procedure and outcomes are presented. RESULTS A 66-year-old man presented with disequilibrium, sound-induced vertigo, a reduced ocular vestibular evoked myogenic potential threshold, and pressure-induced vertical and torsional nystagmus. Computed tomography revealed a right posterior semicircular canal dehiscence caused by a diverticulum of the jugular bulb. The defect in the posterior semicircular canal was localised and resurfaced with bone paté, temporalis muscle fascia and conchal cartilage, under direct visualisation. Post-operatively, the patients symptoms disappeared and his ocular vestibular evoked myogenic potential threshold normalised. CONCLUSION This case illustrates that posterior semicircular canal dehiscence can be surgically managed by resurfacing the defect site via a transmastoid approach.

Abnormal CT findings are risk factors for otitis media-related sensorineural hearing loss.

Objectives: Inflammatory processes in chronic otitis media (COM) can damage the inner ear, resulting in sensorineural hearing loss (SNHL). The purpose of this study was to evaluate risk factors by computed tomography (CT) findings for COM-related SNHL in patients with unilateral COM. Design: Records from January 2009 to December 2012 of 231 patients with unilateral COM and a normal contralateral ear were retrospectively evaluated. Bone conduction thresholds were calculated for each ear at 0.5, 1, 2, and 4 kHz. If bone conduction threshold averaged across the four frequencies of the COM ear was 10 dB greater than that of the contralateral ear, the patient was classified under the SNHL group. Temporal bone CT images were analyzed to determine the presence or absence of soft tissue density in the attic (medial/lateral), antrum, oval window niche, and round window niche. Multivariate analysis of sex, age (< 50 years; ≥ 50 years), disease duration (< 20 years; ≥ 20 years), perforation size (small; moderate; large) and the presence of soft tissue density in the attic (medial/lateral), antrum, oval window niche, and round window niche was used to determine the factors related to COM-related SNHL. Results: Of the 231 patients, there were 51 patients (22.1%) in the SNHL group and 180 patients (77.9%) in the non-SNHL group. Multivariate analyses showed that the presence of soft tissue density in the antrum (odds ratio [OR] 3.80; 95% confidence interval [CI] 1.74–8.32; p = 0.001), age ≥ 50 years and more (OR 3.32; 95% CI 1.62–6.81; p = 0.001), disease duration ≥ 20 years (OR 2.80; 95% CI 1.31–6.02; p = 0.008), and the presence of soft tissue density in the round window niche (OR 2.42; 95% CI 1.12–5.21; p = 0.024) were independently related to COM-related SNHL. Conclusions: COM-related SNHL was present in 22% of ears with COM. The presence of soft tissue density in the antrum, determined from temporal bone CT, increased the OR of SNHL to 3.8. Age, disease duration, and the presence of soft tissue density in the round window niche were also independent predicting factors for SNHL. These findings may be used as informative references for patients with COM.

Hearing gain with a BAHA test-band in patients with single-sided deafness.

PURPOSE It is assumed that preoperative use of a bone-anchored hearing aid (BAHA) test-band will give a patient lower gain compared to real post-operative gain because of the reduction of energy through the scalp when using a test-band. Hearing gains using a BAHA test-band were analyzed in patients with unilateral hearing loss. MATERIALS AND METHODS Nineteen patients with unilateral sensorineural hearing loss were enrolled. A test-band, which was connected to BAHA Intenso with full-on gain, was put on the mastoid. Conventional air-conduction (AC) pure-tone averages (PTAs) and sound-field PTAs and speech reception thresholds (SRTs) were obtained in conditions A (the better ear naked), B (the better ear plugged), and C (the better ear plugged with a test-band on the poorer mastoid). RESULTS Air-conduction PTAs of the poorer and better ears were 91 ± 19 and 18 ± 8 dB HL. Sound-field PTAs in condition B were higher than those in condition A (54 vs. 26 dB HL), which means that earplugs can block the sound grossly up to 54 dB HL through the better ears. The aided PTAs (24 ± 6 dB HL) in condition C were similar to those of the better ears in condition A (26±9 dB HL), though condition C showed higher thresholds at 500 Hz and lower thresholds at 1 and 2kHz when compared to condition A. The hearing thresholds using a test-band were similar to the published results of BAHA users with the volume to most comfortable level (MCL). CONCLUSION Our findings showed that a BAHA test-band on the poorer ear could transmit sound to the cochlea as much as the better ears can hear. The increased functional gain at 1 and 2kHz reflects the technical characteristics of BAHA processor. The reduction of energy through the scalp when using a test-band seems to be offset by the difference of output by setting the volume to full-on gain and using a high-powered speech processor. Preoperative hearing gains using a test-band with full-on gain seems to be similar to the post-operative gains of BAHA users with the volume to MCL.

Trans-tensor tympani facial nerve decompression in traumatic facial nerve palsy.

OBJECTIVE The surgical approaches previously reported for facial nerve decompression have focussed on achieving good exposure of the lateral or superior aspects of the geniculate ganglion. This report aims to describe a unique case of facial nerve decompression beneath the geniculate ganglion. PATIENT A 30-year-old woman with right-sided facial palsy due to a temporal bone fracture. INTERVENTION Bony fragments at the base of the geniculate ganglion were removed via a trans-tensor tympani approach with extended posterior tympanotomy. RESULTS The patient’s facial movement recovered successfully, without complications such as sensorineural hearing loss and conductive hearing loss. CONCLUSION In rare cases requiring decompression of the facial nerve inferior to the perigeniculate area, the trans-tensor tympani approach should be considered as a valuable alternative option when surgical intervention is considered.

Middle ear surgery in only hearing ears and postoperative hearing rehabilitation.

Background and Objectives The aim of this study was to evaluate surgical interventions and hearing rehabilitation in patients with chronic middle ear disease of only hearing ears. Subjects and Methods Thirty-one patients with chronic middle ear disease of only hearing ears were enrolled in this retrospective study. Patients were classified into three groups according to the hearing level: groups A [pure tone audiometry (PTA)<40], B (40≤PTA<70), and C (PTA≥70). We evaluated hearing results and patterns of auditory rehabilitation. Results The main consideration for a surgical procedure was the presence of recurrent otorrhea and structural destruction. The reasons for surgical intervention in only hearing ears were otorrhea caused by chronic otitis media (68%), cholesteatoma (29%), and cholesterol granuloma (3%). The causes of contralateral deaf ears were chronic otitis media (81%) and sensorineural hearing loss (19%). Although there was hearing deterioration in some patients with severe hearing loss (PTA≥70), all patients achieved dry ears after surgery and functional hearing using auditory rehabilitation. Hearing aids were used in most patients with moderate to moderately severe hearing loss and cochlear implants were used for auditory rehabilitation in patients with severe to profound hearing loss. Conclusions Proper evaluation and indications for surgery in only hearing ears are important for successful eradication of inflammation and hearing preservation. Surgical interventions can achieve dry ear and enable further auditory rehabilitations using hearing aids and cochlear implantation.