Hearing loss patterns after cochlear implantation via the round window in an animal model.

PURPOSE: The mechanism and the type of hearing loss induced by cochlear implants are mostly unknown. Therefore, this study evaluated the impact and type of hearing loss induced by each stage of cochlear implantation surgery in an animal model. STUDY DESIGN: Original basic research animal study. SETTING: The study was conducted in a tertiary, university-affiliated medical center in accordance with the guidelines of the Institutional Animal Care and Use Committee. SUBJECTS AND METHODS: Cochlear implant electrode array was inserted via the round window membrane in 17 ears of 9 adult-size fat sand rats. In 7 ears of 5 additional animals round window incision only was performed, followed by patching with a small piece of periosteum (control). Hearing thresholds to air (AC) and bone conduction (BC), clicks, 1 kHz and 6 kHz tone bursts were measured by auditory brainstem evoked potential, before, during each stage of surgery and one week post-operatively. In addition, inner ear histology was performed. RESULTS: The degree of hearing loss increased significantly from baseline throughout the stages of cochlear implantation surgery and up to one week after (p<0.0001). In both operated groups, the greatest deterioration was noted after round window incision. Overall, threshold shift to air-conduction clicks, reached 61 dB SPL and the bone conduction threshold deteriorated by 19 dB SPL only. Similar losses were found for 1-kHz and 6-kHz frequencies. The hearing loss was not associated with significant changes in inner ear histology. CONCLUSIONS: Hearing loss following cochlear implantation in normal hearing animals is progressive and of mixed type, but mainly conductive. Changes in the inner-ear mechanism are most likely responsible for the conductive hearing loss.

Inlay "butterfly" cartilage tympanoplasty.

OBJECTIVES: The aim of this study was to analyze the outcome of inlay "butterfly" cartilage tympanoplasty. METHODS: The files of 42 patients (24 were male, 18 were female) who underwent primary or revision inlay butterfly cartilage tympanoplasty in 2005 to 2011 at a tertiary medical center were reviewed. Patients were regularly observed by otoscopy and audiometry. RESULTS: The mean patient age was 27 years (range, 14-75 years), and the mean duration of follow-up was 24 months (range, 3-36 months). The postoperative period was uneventful. The technical (anatomical) success rate was 92% at 1 year. There was a significant decrease in the mean air-bone gap in 32 patients (preoperatively, 49.6 dB; postoperatively, 26.2 dB; P = .006). Results were suboptimal in 3 patients with persistent small perforations of the operated ear. CONCLUSION: Inlay butterfly cartilage tympanoplasty appears to be effective in terms of defect closure and improved hearing, comparable with temporalis fascia graft tympanoplasty. Follow-up is necessary for at least 1 year when some perforation may reappear.

Cochlear hearing loss in patients with Laron syndrome.

The aim of this prospective clinical study was to test auditory function in patients with Laron syndrome, either untreated or treated with insulin-like growth factor I (IGF-I). The study group consisted of 11 patients with Laron syndrome: 5 untreated adults, 5 children and young adults treated with replacement IGF-I starting at bone age <2 years, and 1 adolescent who started replacement therapy at bone age 4.6 years. The auditory evaluation included pure tone and speech audiometry, tympanometry and acoustic reflexes, otoacoustic emissions, loudness dynamics, auditory brain stem responses and a hyperacusis questionnaire. All untreated patients and the patient who started treatment late had various degrees of sensorineural hearing loss and auditory hypersensitivity; acoustic middle ear reflexes were absent in most of them. All treated children had normal hearing and no auditory hypersensitivity; most had recordable middle ear acoustic reflexes. In conclusion, auditory defects seem to be associated with Laron syndrome and may be prevented by starting treatment with IGF-I at an early developmental age.

Prediction of aided and unaided audiograms using sound-field auditory steady-state evoked responses.

OBJECTIVE: To assess sound field auditory thresholds of hearing-impaired adults by using auditory steady-state evoked responses (ASSRs). DESIGN: ASSRs were recorded to carrier frequencies of 500, 1000, 2000, and 4000 Hz, each uniquely modulated at a single frequency of 80-100 Hz. ASSR thresholds were compared to behavioral auditory thresholds. STUDY SAMPLE: Twenty adults (11 male, age 35.6 years) with moderate-severe sensorineural hearing loss who had used hearing aids, and 10 normal-hearing subjects (mean age 22.4 years). RESULTS: For most frequencies, behavioral sound-field thresholds were slightly lower than ASSR thresholds in both aided and unaided conditions, with a significant correlation between them. Differences between ASSR and behavioral thresholds ranged between 516 dB in the unaided and between 5-16 dB in the aided condition. The ASSR amplitude growth function to 2000 Hz was steeper in both the aided and unaided conditions than in the normal-hearing group. CONCLUSIONS: Sound-field ASSRs can predict behavioral auditory thresholds in both the unaided and aided condition, as well as behavioral functional gains. The ASSR growth function for 2000 Hz is suggested to reflect an underlying mechanism of intensity encoding common to abnormal loudness perception frequently reported in cases of cochlear hearing loss.

Test-retest tinnitus characteristics in patients with noise-induced hearing loss.

PURPOSE: The purpose of the study was to examine the test-retest value of tinnitus pitch and loudness in patients with tinnitus and noise-induced hearing loss (NIHL). MATERIALS AND METHODS: The study sample consisted of 30 patients of mean age 35 +/- 6.7 years with long-standing tinnitus and hearing loss due to exposure to noise during military service. Ten patients had unilateral tinnitus, and 20 had bilateral tinnitus. All presented with a typical NIHL audiogram on the affected side(s). None of the patients was receiving drug therapy. RESULTS: There was no statistically significant difference in tinnitus pitch or loudness between the 2 tests for the whole group and separately in patients with unilateral or bilateral tinnitus. CONCLUSION: Subjective testing of pitch and loudness of tinnitus secondary to NIHL is accurate and reproducible, making it a valuable tool for diagnosis and follow-up. The lack of differences between patients with unilateral or bilateral tinnitus indicates that both types may be managed in a similar manner.

Predicting outcome of malignant external otitis.

OBJECTIVE: Malignant external otitis (MEO) continues to pose a diagnostic and therapeutic challenge. The lack of a diagnostic study since 1987 combined with recent findings of quinolone-resistant MEO prompted the present analysis of MEO outcome in a major tertiary medical center. METHODS: Seventy-five consecutive patients hospitalized for suspected MEO between 1990 and 2003 were divided into 2 diagnostic groups: MEO Type 1, presence of all obligatory clinical and radiologic criteria and most of the occasional criteria of Cohen and Friedman or absence of 1 obligatory criterion with failure of intensive treatment, and MEO Type 2, absence of one of the obligatory criteria with treatment response within 1 week. The groups were compared for demographic data, underlying diseases, ear parameters, culture findings, length of hospitalization, and treatment before hospitalization, obtained from the charts. RESULTS: Both types of MEO affected mostly diabetic patients and were characterized by granulations and discharge in the external ear, severe prolonged pain, soft tissue involvement and bone destruction on computed tomographic scan, and growth of Pseudomonas aeruginosa in culture. However, Type 1 MEO was associated with a significantly older patient age at presentation, higher rate of oral antidiabetic treatment, history of diabetic (vascular) complications, computed tomographic findings of nasopharyngeal involvement (soft tissue swelling, soft tissue asymmetry, or abscess formation), bone destruction, and temporomandibular joint involvement-all of which led to significantly longer treatment and shorter survival. CONCLUSION: The worse prognosis of Type 1 MEO compared with Type 2 should alert clinicians to establish earlier diagnosis and treatment.

Otologic and audiologic lesions due to blast injury.

AIM: To evaluate the effect of blast injury on the otologic and hearing state over time. SETTING: Otology unit of a tertiary referral center. METHODS: Seventy-three patients aged 16 to 73 years who sustained physical trauma from an explosion underwent otologic and audiologic examination 3-4 months and one year later. RESULTS: At the first examination, high-frequency sensorineural hearing loss was detected in 57 patients (78%), mixed hearing loss in 13 (19%), and low-tone conductive hearing loss in two (3%). Conductive hearing loss had improved by one year, while the cochlear hearing loss, in most cases, did not. Only 7% of the patients with tinnitus reported improvement after one year. CONCLUSIONS: The permanent otologic damage caused by blast injury cannot be determined before one year after the traumatic event.

Characteristics and prognosis of malignant external otitis with facial paralysis.

OBJECTIVE: To compare the characteristics and prognosis of patients with malignant (necrotizing) external otitis (MEO) with and without facial nerve palsy in today's era of third-generation antibiotics. DESIGN: Comparative retrospective case series. SETTING: Department of Otolaryngology-Head and Neck Surgery, Rabin Medical Center, a tertiary care medical center. PATIENTS: Forty-eight patients with MEO diagnosed and treated from 1990 to 2004. Eight had facial paralysis and 40 had normal facial nerve function. MAIN OUTCOME MEASURES: Clinical, laboratory, and imaging findings and survival. RESULTS: There was no statistically significant difference between patients with and without facial nerve involvement in terms of age, comorbidities, duration of complaints, physical findings, erythrocyte sedimentation rate, and bone scan findings. Computed tomography indicated a more progressive disease in patients with facial nerve involvement. However, no statistically significant between-group difference was found in overall survival. CONCLUSION: Although facial nerve involvement is a sign of progression of MEO, it does not, by itself, worsen prognosis.

Asymmetry in noise-induced hearing loss: relevance of acoustic reflex and left or right handedness.

OBJECTIVE: Noise-induced hearing loss (NIHL) is more severe in the left ear than the right ear. The aim of this study was to examine the possible association of handedness and acoustic reflex parameters on right or left NIHL predominance. STUDY DESIGN: Retrospective case review and prospective series. SETTING: Tertiary center. PATIENTS: Three samples were studied: 1) the files of 4,277 army personnel with NIHL were reviewed to analyze the relation between the side affected and age, sex, duration of noise exposure, and acoustic damage; 2) an additional 119 army personnel with NIHL were evaluated for the possible association of handedness and NIHL asymmetry; and 3) fifty-one normal-hearing subjects were tested for threshold and latency of acoustic reflex by handedness. INTERVENTION: None. MAIN OUTCOME MEASURE: Differences in NIHL asymmetry by background and noise-related variables and handedness. RESULTS: NIHL was more pronounced in the left ear, regardless of demographic characteristics, noise exposure parameters, acoustic reflex measures, or handedness. CONCLUSION: The asymmetry in hearing loss severity may be attributed to the cortical pathways, specifically to the more pronounced efferent auditory system on the right side, which reduces the susceptibility of the right ear to cochlear insult.

Bone conduction in otosclerosis--operated versus non-operated ears.

OBJECTIVE: To examine whether stapes surgery improves long-term bone conduction in patients with otosclerosis. SETTING: Tertiary university hospital. METHODS: Thirty patients (52 ears) who underwent stapedectomy between 1988 and 1994. Hearing tests were performed pre-operatively and 5 years postoperatively. RESULTS: The operated ears showed significant improvement in speech reception threshold and air conduction (250-4,000 Hz). Over the follow-up period, there were no significant differences in bone conduction thresholds between the operated and non-operated ears and no deterioration during follow-up in both bilateral and unilateral disease. CONCLUSIONS: This series did not provide evidence that the deterioration in bone conduction over the follow-up period in otosclerotic ears exceeds the level that can be explained by presbycusis and the Carhart effect. However, the follow-up time may have been insufficient. Stapedectomy appears to have no effect on bone conduction in this patient group. The similar bone conduction thresholds in the non-operated and operated ears in unilateral otosclerosis at the end of follow-up suggest that the thresholds in the non-operated ears approached those in the operated ones.

Cochlear implantation via round window or cochleostomy: Effect on hearing in an animal model.

OBJECTIVES/HYPOTHESIS: Cochlear implantation in patients with residual hearing has increased interest in hearing preservation. Two major surgical approaches to implantation have been devised: via the round window membrane and through cochleostomy. However, the advantages of either approach on hearing preservation have not been established. Due to the great inter- and intravariability among implantees, the current study used a normal-hearing animal model to compare the effect of the two methods on hearing. STUDY DESIGN: Animal study. METHODS: Thirteen fat sand rats were studied, in which 13 ears were implanted through cochleostomy and 13 via the round window. Hearing thresholds were determined by auditory brainstem responses to air and bone conduction at low and high auditory stimuli. RESULTS: The results indicated that each stage of the surgery, primarily the opening of the membranous labyrinth, was accompanied by significant deterioration in hearing. Hearing loss was mainly conductive, with no significant differences between the surgical approaches. CONCLUSIONS: Both surgical approaches carry similar risk of hearing loss. LEVEL OF EVIDENCE: NA Laryngoscope, 126:E375-E378, 2016.

Butterfly myringoplasty for total, subtotal, and annular perforations.

OBJECTIVES/HYPOTHESIS: The inlay "butterfly" cartilage tympanoplasty was first described as a treatment for small, central ear drum perforations. This technique can also be applied in large, marginal perforations, whereas the cartilage graft is anchored on the bony annulus. The aim of this study was to present the technique, to evaluate the results of butterfly tympanoplasty in marginal perforations, and to compare with the results of butterfly tympanoplasty in patients with nonmarginal perforations. STUDY DESIGN: Retrospective case series. METHODS: The files of patients who underwent inlay butterfly cartilage tympanoplasty for subtotal and total perforations from May 2011 to May 2013 were reviewed. Patients were followed with otoscopy and audiometry, and their results were compared with those of patients who underwent butterfly tympanoplasty for nonmarginal perforations. RESULTS: Forty-eight patients underwent butterfly tympanoplasty for subtotal and total perforations during the study period. Exclusion criteria included: active inflammation during the 3 months prior to surgery, cholesteatoma, lack of follow-up, incomplete data, ossicular chain anomaly/discontinuity, and significant sensorineural hearing loss (average bone-conduction threshold at 500,1000 and 2,000 Hz poorer than 20 dB). Thirty-three patients were included. The mean age at surgery was 34 years (range, 19-76 years); 17 patients (51%) were male. Four patients were treated previously by tympanoplasty (revision surgery), whereas the other 29 had primary surgery. None of the patients had intraoperative or immediate postoperative complications such as sensorineural hearing loss on the operated ear or facial nerve palsy. One month after surgery, two patients had a residual perforation (94% success rate), and the mean speech recognition threshold (SRT) improved from 38 dB to 24 dB. The pure tone audiogram improved from 37.7 dB to 10.6 dB, and the word recognition score improved from 97.7 to 99.75. These results are comparable with our results in nonmarginal perforations, whereas a 92% success rate and a postoperative SRT of 26 dB were achieved in a cohort of 42 patients. CONCLUSIONS: Inlay butterfly cartilage tympanoplasty is safe and effective in patients with total or subtotal perforations, and the results are comparable to those seen in nonmarginal perforations. LEVEL OF EVIDENCE: 4. Laryngoscope, 126:2565-2568, 2016.

Facial palsy associated with acute otitis media.

OBJECTIVE: Facial palsy secondary to acute otitis media is rarely encountered today. The aim of the present study was to review the characteristics of the disease and propose the proper management. STUDY DESIGN: File review. Setting University-affiliated tertiary referral center. MAIN OUTCOME MEASURES: Disease course, management and outcome were recorded. RESULTS: Sixty-five children with facial palsy were identified, of whom 13 (20%) had acute otitis media. The otitis media preceded the facial palsy in all cases by 1 to 21 days (average 5 days). House-Brackmann grade ranged from 2 to 5 (average 3.5). The recovery period was varied and unpredictable, ranging in duration from 1 to 180 days (average 68 days). Treatment was conservative, except for insertion of a ventilation tube in 2 cases. CONCLUSIONS: Considering that all the patients recovered, conservative treatment, including myringotomy and intravenous antibiotics, may be the correct approach to facial palsy associated with acute otitis media.

Hearing Loss After Vestibular Implantation in Sand Rats With Normal Hearing.

IMPORTANCE: Bilateral vestibular failure is a debilitating condition that may lead to oscillopia and adversely affect quality of life. Researchers have suggested that vestibular function might be restored with implantation of an external mechanical stimulation device. However, it is essential that such a device must not interfere with normal hearing. OBJECTIVE: To evaluate the effect of vestibular implant insertion on hearing in a sand rat model with normal hearing. DESIGN, SETTING, AND SUBJECTS: The study was conducted in a tertiary medical center in accord with the guidelines of the Rabin Medical Center Animal Care and Use Committee. The experiment was performed in 6 adult, 6-month-old, fat sand rats (Psammomys obesus), which have a unique aural anatomy that permits access to the inner ear. The study dates were March 2013 to March 2014. INTERVENTIONS: The sand rats were anesthetized and electrodes were implanted unilaterally (in 6 sand rats) or bilaterally (in 2 sand rats) in all 3 semicircular canals (lateral, then posterior, and then superior) by fenestration of the respective ampullas. To measure air and bone conduction thresholds, auditory nerve brainstem evoked responses to alternating polarity clicks and 1-kHz tone bursts were tested before surgery, at each operative stage, and after surgery. MAIN OUTCOMES AND MEASURES: Air or bone conduction threshold shifts after implantation of a vestibular implant electrode array in each semicircular canal. RESULTS: After unilateral implantation of the vestibular implant, sand rats showed a sideways head tilt, whereas after bilateral implantation, sand rats ran around in circles and were unable to stand still or walk on a treadmill. On statistical analysis, statistically significant differences from preoperative values were obtained across all stages of surgery for air conduction thresholds. The largest and statistically significant air conduction shift for 1-kHz stimuli (mean [SD, 13.7 [2.8] dB; P < .004) as well as for clicks (12.5 [2.1] dB; P < .002) was found for the superior canal electrode insertion. For the posterior canal, the air conduction thresholds to 1-kHz stimuli and to clicks shifted significantly after electrode insertion (mean [SD], 7.5 [2.3] dB; P < .01 and 7.5 [0.9] dB; P < .001). For the lateral canal, only the threshold to clicks changed significantly (mean [SD], 5.5 [1.7] dB; P < .02). Bone conduction thresholds did not change significantly after vestibular electrode insertion. CONCLUSIONS AND RELEVANCE: Implantation of a vestibular device is associated with mild to moderate conductive hearing loss in fat sand rats with normal hearing, especially when the device is placed in the posterior and superior semicircular canals. Bilateral implantation is associated with major vestibular pathologic results. Further studies are needed in animals with cochlear or vestibular disorders before it can be definitively concluded that vestibular implantation carries only a minor risk to hearing.

Esophageal incisions repair by CO2 laser soldering.

PURPOSE: This study evaluated the feasibility of fiberoptic CO2 laser soldering for the repair of esophageal injuries under tight temperature feedback control in an animal model. Healing was compared to conventional suture closure. MATERIALS AND METHODS: A CO2 soldering system equipped with infrared transmitting silver halide fibers was used. The soldered tissue temperature was monitored continuously, and laser power was adjusted to provide constant temperature. The procedure was done with 50% bovine serum albumin solder. Longitudinal incisions measuring 8 to 10 mm were made under general anesthesia in the cervical esophagus of 25 rats. Twenty rats (group I) underwent laser tissue bonding; 8 of which were tested in a preliminary study to determine optimal laser parameters. In the remaining 5 rats (group II, controls), closure was performed with 1 layer of 6/0 Vicryl sutures. The rats were sacrificed 2, 3, 4, and 6 weeks postoperatively, and the esophagus was examined histologically. RESULTS: Optimal temperature was found to be 65 to 70 degrees C and optimal exposure time, 150 to 200 seconds. Laser soldering was successful in 9 of the 12 rats (75%) treated under optimal settings; suturing was successful in 4 of the 5 control rats (80%). There were no significant differences between the groups in healing or complication rates. CONCLUSIONS: These results indicate that the CO2 laser soldering technique is a valid option for the correction of esophageal tears or incisions in rats. The confirmation and extension of these findings in further studies with larger animals may ultimately lead to the routine in vivo use of temperature-controlled laser repair for the esophagus and other organs. This method lends itself to endoscopic bonding of tissues.

Acoustic neuroma in patients with completely resolved sudden hearing loss.

Approximately 30% of patients with sudden hearing loss show complete recovery. Researchers have long questioned whether extensive evaluation is necessary in these cases. Recently, however, with the increasing widespread application of magnetic resonance imaging, a higher rate than expected of acoustic neuromas has been detected in patients with sudden hearing loss. Two studies have suggested that affected patients may even partially regain hearing. The aim of the present clinical study was to determine whether acoustic neuroma-induced hearing loss may be associated with full recovery. The files of 67 patients evaluated for sudden hearing loss at Rabin Medical Center from 1989 to 2000 were reviewed. All patients underwent pure tone audiometry, acoustic reflex tests, and auditory brain stem evoked response tests. Hearing evaluation was followed by magnetic resonance imaging scan and, 1 month later, a second hearing test. Findings were compared between patients with and without evidence of tumor on imaging, and between patients with tumor with and without full recovery. Twenty-four patients (36%) had a diagnosis of acoustic tumor, of whom 4 (16.7%) recovered hearing after 1 month. All 4 tumors were intracanalicular. Two of these patients had low-tone hearing loss, and 2 had flat curves; 3 had a pathological auditory brain stem evoked response. Of the 43 patients without tumors, 26 (60%) showed complete resolution of the hearing loss. We conclude that complete recovery of hearing loss does not exclude acoustic tumor, and these patients therefore require full evaluation. The reason for the recovery remains unclear.

Magnesium treatment for sudden hearing loss.

Magnesium treatment has been repeatedly shown to reduce the incidence of both temporary and permanent noise-induced hearing loss. We hypothesized that it might also improve the permanent threshold shift in patients with acute-onset hearing loss. In a prospective, randomized, double-blind, placebo-controlled trial, 28 patients with idiopathic sudden sensorineural hearing loss were treated with either steroids and oral magnesium (study group) or steroids and a placebo (control group). Compared to the controls, the magnesium-treated group had a significantly higher proportion of patients with improved hearing (>10 dB hearing level) across all frequencies tested, and a significantly greater mean improvement in all frequencies. Analysis of the individual data confirmed that more patients treated with magnesium experienced hearing improvement, and at a larger magnitude, than control subjects. Magnesium is a relatively safe and convenient adjunct to steroid treatment for enhancing the improvement in hearing, especially in the low-tone range, in patients with sudden sensorineural hearing loss.

Noise-induced vestibular dysfunction.

An association between noise exposure and vestibular function has long been suspected. Our wide experience in a major otologic outpatient clinic yielded six patients within the last seven years who presented with Meniere's disease and a history of long-term exposure to noise. Two of the cases are described in detail. Our evaluation in light of the data in the literature suggests that the relationship between vestibular dysfunction and exposure to hazardous noise may be more than coincidental.

[Subglottic carcinoma].

Subglottic malignancies are rare. They constitute about 1% of laryngeal cancer. Most of these malignancies are squamous cell carcinoma. In this article were describe various definitions concerning the borders of the subglottic region. A summary of pathophysiology and behavior of cancer in this location is presented. The incidence of primary subglottic carcinoma is low. The origin of most cancers in this area is the glottic cancer that extends into the subglottic region. The tumor tends to spread through lymphatic channels to the paraglottic and preglottic (delphian) nodes and secondary to the jugular chain. The delayed diagnosis is due to the lack of symptoms in the early stage of the disease and the hidden location of the tumor. The presenting symptoms are usually dyspnea and stridor. Direct laryngoscopy is essential for early detection of the tumor and the use of CT and MRI is advocated. Therapy is usually radical. Total laryngectomy and radiation therapy have both been advocated. Between 1995 and 2000, 126 patients with laryngeal squamous cell carcinoma were presented to our department. Our experience in diagnosing and treating subglottic cancer in 4 patients is hereby described. The latest literature on the subject is reviewed.