Possible clinical implications of the structural variations between the tympanic membrane quadrants.

Introduction: Retraction pockets and marginal perforations of the pars tensa of the tympanic membrane (TM) are most commonly found at superior posterior quadrant (SPQ). The patulous Eustachian tube tends to manifest in the same quadrant. Variation in the structure of the TM may explain these observations. Material and Methods: A line defined by the manubrium was used to divide the pars tensa into anterior and posterior portions. A transverse line centered on the umbo divides the pars tensa into superior and inferior parts, resulting in four quadrants. Surface areas of each of the TM quadrants were measured in a sample of 23 human adult formalin-fixed temporal bones. The TMs were completely excised, faced medially, and placed against graph paper to maintain scale measurements, photoed, and measured.TM thickness was measured on a different set of 20 human temporal bones (TB) preparations with normal external and middle ears. Four random loci were chosen from each pars tensa's TM quadrant. The thickness was measured using high-magnification power microscopy. Results: The SPQ was the largest and thinnest of the four quadrants. It occupies 31% of the pars tensa area. It is 69 µm as compared to approximately 85 µm in the other quadrants. The radial lines between the umbo and the annulus are in descending order from superior posterior toward the anterior-superior radials. Conclusion: The SPQ has the largest vibratory area and is the thinnest of the four TM quadrants. Variation in the thickness of the middle, fibrous layer accounts for the variation in the thickness of the TM. These findings may explain the tendency of pathologies related to Eustachian tube dysfunction to preferentially manifest in or originate from the SPQ.

Analysis of Sex-related Differences in Patients with Dysphagia: Using a Videofluoroscopy.

BACKGROUND: Dysphagia is a common symptom with diverse etiologies and refers to disorders of the process of swallowing food or fluids. Many studies have reported the anatomical and functional differences between men and women in swallowing in healthy patients; however, sex discrepancies in symptomatic patients have not often been studied. OBJECTIVES: To compare the performance of men and women with dysphagia using videofluoroscopy. METHODS: To compare the performance of men and women with dysphagia using videofluoroscopy. RESULTS: A total of 203 patients met the inclusion criteria, 106 men (52%) and 97 women (48%). Men complained significantly more about choking on liquids (P = 0.002) and in swallowing pills (P = 0.004) compared to women. Men had more abnormalities in the pharyngeal phase (P = 0.015) and at the upper esophageal sphincter (P = 0.056). The prevalence of aspiration, penetration, and barium residue in the hypopharynx and in the vallecula were significantly greater in men as well. CONCLUSIONS: In patients with dysphagia, women had fewer subjective symptoms and performed better than men in videofluoroscopy especially in the pharyngeal phase. These differences are probably due to different anatomical and functional swallowing characteristics. A better understanding of these discrepancies can be useful in offering tailored treatment in clinical practice.

Differences in craniofacial morphology between platybasic and nonplatybasic patients with velopharyngeal dysfunction and control subjects.

INTRODUCTION: This study aimed to identify the characteristics of cranial-base morphology in platybasic and nonplatybasic patients with palatal anomalies and velopharyngeal dysfunction (VPD) compared with control subjects to investigate structural factors related to craniofacial morphology that affect the nasopharyngeal space and may influence velopharyngeal function, and to develop precise treatments for specific patients with VPD. METHODS: Three hundred eighty-six patients with VPD and various palatal anomalies were studied retrospectively. The control group included 126 healthy patients with normal speech. Lateral cephalometric images assessed craniofacial morphology. RESULTS: Nonplatybasic patients and control subjects had larger SNA, S-Ba-Ptm, and N-Ba-PP angles (in the craniomaxillary complex), and platybasic patients had larger nasopharyngeal ANS-Ptm-Ve and Ba-S-Ptm angles and longer Ve-T and Ve-Ba distances than the nonplatybasic patients. All study patients had larger ANB, Gn-Go-Ar, and PP-MP angles (in the craniomandibular complex). Nonplatybasic patients had smaller Ba-SN angles than platybasic patients and controls because of more acute N-S-Ptm angle. Among the nonplatybasic patients, Ve-T length tended to be shorter (with no significant difference between groups) and located more inferiorly (because of the smallest ANS-Ptm-Ve angle) in relation to the maxilla. Thus, the nasopharynx was narrower horizontally but longer vertically than in patients with platybasia. CONCLUSIONS: Cranial-base flexure influences the shape of the skull base and facial-skeletal structure and may alter the pharyngeal space between them. This finding should help improve preoperative planning regarding the effect of the pharyngeal flap height relative to the nasopharynx and oropharynx ratio that affects surgical outcomes, such as resonance and residual VPD. In patients with Class III malocclusion and maxillary constriction, careful planning of presurgical orthodontic treatment is needed in maxillary advancement procedures. Orthodontic and surgical collaboration can help prevent postoperative VPD, especially in platybasic patients.

Nivolumab-induced diffuse type 2 rhinosinusitis: A case report.

BACKGROUND: Nivolumab, an immune checkpoint inhibitor is used to treat advanced metastatic malignancies. Data showed that nivolumab can cause exacerbated response of T-Helper 2 cells and lead to airway inflammation. OBJECTIVE: To present the upper airway findings of a 69-year-old woman after treatment with nivolumab. METHODS: Case report. RESULTS: A 69-year old woman with no history of chronic rhinosinusitis developed complaints of nasal congestion, rhinorrhea, sneezing, and anosmia. These symptoms started after one year of treatment with nivolumab. Pale polyps were observed on fiberoptic endoscopy examination. A gradual increase in eosinophil blood counts was noted. On histopathology, heavy infiltrates of eosinophils were seen in the tissue. CONCLUSIONS: Nivolumab is used to treat various advanced metastatic malignancies, with a good safety profile. Nevertheless, physicians must be alert to the possibility of evolving type II inflammation in patients, as appropriate therapy can be provided to improve their quality of life.

Is there a correlation between skull base flexure and palatal anomalies in patients with 22q11 deletion syndrome and velopharyngeal dysfunction?

The study aimed at assessing the relationship between skull base morphology, represented by skull base and nasopharyngeal angles, and palatal anatomy among patients with 22q11DS and velopharyngeal dysfunction. Retrospective analysis of patients with 22q11DS and velopharyngeal dysfunction. Age, sex, severity of velopharyngeal dysfunction, type of cleft (overt cleft palate, submucous cleft palate, occult submucous cleft palate, or no-CP, and cephalometric skull base angles were reviewed. Correlations between type of palatal anomaly and the angles were assessed. Among 132 patients, 71 were male (53.8%) and 61 were female (46.2%), ages 3.3-40.0 years (mean 8.3 ± 6.10). No difference in the mean cranial-base angle (P = 0.353) or in the distribution of the three types of cranial base angle sizes was found among the palatal anomaly groups (P = 0.137). More men had normal cranial base angles and more women had acute angulation (P = 0.008). A positive correlation was found between the skull base and nasopharyngeal angles (P = 0.001, r = -0.590). No direct correlation was found between cranial base morphology and palatal anomalies in patients with 22q11DS, and velopharyngeal dysfunction. This is probably because skull base and palate morphology contribute independently to velopharyngeal dysfunction.

[UNCONTROLLED PENETRATION OF THE DENTAL IMPLANT TO THE MAXILLARY SINUS - A COLLABORATION BETWEEN ENT AND ORAL AND MAXILLOFACIAL SURGERY].

INTRODUCTION: The popularity of dental implants is continuously increasing. Displacement of implants into the maxillary sinus is a well-documented complication following this treatment. AIMS: To characterize patients treated in our institution for uncontrolled penetration of dental implants into the maxillary sinus, and highlight the importance of the multidisciplinary approach in treating these cases. METHODS: The charts of all patients treated in 2018 within the Sinuses and Dental Clinic at the Meir Medical Center were reviewed. Data concerning age, gender, timing and the type of treatment performed was retrospectively analyzed. RESULTS: Fifteen patients were included in the study. Ten implants were found in the left sinus and five in the right side. Eight implants were seen in the lower medial alveolar recess. None of the patients presented with an oro-antral fistulae. Ten patients were treated endoscopically - eight through a nasal approach, and two through the mouth. All patients healed uneventfully. CONCLUSIONS: Different approaches can be used to remove implants from the maxillary sinus. DISCUSSION: Most patients in this study were referred adjacent to the displacement of the dental implant. The medial alveolar recess is the most common area of implant displacement. While either a nasal or oral approach can be used to retrieve the implant in the absence of sinus disease, a nasal approach should be preferred in the presence of such pathology. The collaboration between the otorhinologist and the maxillofacial surgeon, enables both the dental and rhinosinus considerations to be considered. This cooperation allows practitioners to design better treatment plans for patients with dental implants involving the sinuses.

FDG-PET/CT for diagnosis and follow-up of necrotizing (malignant) external otitis.

OBJECTIVE: Imaging is important for the diagnosis and follow-up of necrotizing external otitis (NEO). The best imaging modality is controversy. To suggest 2-deoxy-2-[fluorine-18] fluoro-D-glucose-positron emission tomography/computed tomography (18F-FDG-PET/CT) as an alternative to technetium-99m and gallium-67 scans for diagnosis and assessment of response to treatment for patients with NEO. STUDY DESIGN: Case series. METHODS: Tertiary referral center. From 2013 through 2017, 12 patients were diagnosed with NEO based on clinical features and positive FDG uptake within the temporal bone on PET/CT. Mean age was 74 ± 11.5; 83% of the patients were male; and 83% had diabetes. RESULTS: PET/CT scans were reviewed independently by two nuclear medicine specialists. Imaging located osteomyelitis in external ear canal, mastoid, temporomandibular joint, and nasopharyngeal region (100%, 50%, 16%, 8%, respectively). Mean follow-up was 16 months. Eight patients (67%) underwent a second PET/CT scan after active otitis resolved and after at least 6 weeks of antibiotic treatment. The scan demonstrated no or substantially reduced FDG uptake and treatment was stopped. The patients had no NEO symptoms at the end of follow-up. One patient had significant uptake, and antibiotic treatment was continued until a third scan demonstrated no FDG uptake. Two patients died before the second PET/CT, and two were lost to follow-up. CONCLUSION: 18F-FDG-PET/CT is a reliable imaging modality for diagnosis, disease localization, and decision making regarding treatment cessation. 18F-FDG-PET/CT should be considered as the imaging modality of choice for initial diagnosis and follow-up in NEO patients. Larger, controlled studies are warranted. LEVEL OF EVIDENCE: 4 Laryngoscope, 129:961-966, 2019.

Craniofacial structure variations in patients with palatal anomalies and velopharyngeal dysfunction.

PURPOSE: Cephalometric evaluation of craniofacial and craniopharyngeal morphology is important for understanding the factors affecting velopharyngeal dysfunction (VPD) in patients with palatal anomalies. MATERIALS AND METHODS: In this study, 366 patients with VPD were retrospectively stratified into cleft lip and palate (CLP), cleft palate (CP), submucous cleft palate (SMCP), occult submucous cleft palate (OSMCP), and non-CP groups. Lateral cephalometrics were used to assess craniofacial, craniopharyngeal, and velopharyngeal anatomy. RESULTS: The average craniofacial morphology in patients with VPD differed significantly according to the type of palatal anomaly. The non-CP and OSMCP groups differed from the CLP, CP, and SMCP groups in nasopharyngeal size and shape as depicted by a larger ANS-Ptm-Ve angle, a smaller S-N-Ba and NBa-PP angles, and a shorter linear value of S-Ar in the non-CP group. The CLP and CP groups had shorter ANS-Ptm, shorter Ptm-P, and smaller SNA and SNB angles. CONCLUSION: VPD patients with overt clefts have different skeletal and nasopharyngeal shapes compared to non-CP and OSMCP. Velopharyngeal function assessment should include the size and shape of the nasopharyngeal space in addition to the size and the activity of the velum and posterior and lateral walls of the nasopharynx. This should enable a more precise understanding of VPD pathology, and lead to improvements in the posterior pharyngeal flap technique in order to obtain better postoperative speech outcomes after surgical management of velopharyngeal dysfunction.

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.

Malignant external otitis: Factors predicting patient outcomes.

OBJECTIVE: Malignant external otitis (MEO) is an aggressive infection, primarily affecting elderly diabetic patients. It begins in the external ear canal and spreads to adjacent structures. This study investigated the clinical characteristics of patients diagnosed and treated for MEO and analyzed factors affecting patient outcomes. STUDY DESIGN: Historical cohort. SETTING: Tertiary medical center. METHODS: Medical records of all patients diagnosed and treated for MEO from 1990 to 2013, were retrospectively reviewed. Clinical features, laboratory, imaging and outcomes were analyzed. RESULTS: 88 patients were included, mean age was 73±11.5years, 61 (69%) were male. Of these, 75% had diabetes. Mean follow-up was 60months. The most common presenting symptoms were otalgia (89%), external ear canal edema (86%) and otorrhea (84%). Pseudomonas aeruginosa was isolated in 61% of ear cultures. All patients were treated with antibiotics, 22% had surgery and 8% hyperbaric oxygen. Overall survival rate was 38% in 5years, with disease specific mortality 14%. DM, facial nerve palsy, positive CT scan and age above 70 were found to correlate and predict disease-specific mortality. CONCLUSIONS: MEO carries a grave prognosis. The presence of two or more of the following features, DM, facial nerve palsy, positive CT scan and age above 70, predicts poor outcome, and highlights the need for prolonged, vigorous treatment.

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.

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.

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.

Predicting hearing thresholds in occupational noise-induced hearing loss by auditory steady state responses.

OBJECTIVES: Currently available behavioral tools for the assessment of noise-induced hearing loss (NIHL) depend on the reliable cooperation of the subject. Furthermore, in workers' compensation cases, there is considerable financial gain to be had from exaggerating symptoms, such that accurate assessment of true hearing threshold levels is essential. An alternative objective physiologic tool for assessing NIHL is the auditory steady state response (ASSR) test, which combines frequency specificity with a high level of auditory stimulation, making it applicable for the evaluation of subjects with a moderate to severe deficit. The primary aim of the study was to assess the value of the multifrequency ASSR test in predicting the behavioral warble-tone audiogram in a large sample of young subjects with NIHL of varying severity or with normal hearing. The secondary goal was to assess suprathreshold ASSR growth functions in these two groups. DESIGN: The study group included 157 subjects regularly exposed to high levels of occupational noise, who attended a university-associated audiological clinic for evaluation of NIHL from 2009 through 2011. All underwent a behavioral audiogram, and on the basis of the findings, were divided into those with NIHL (108 subjects, 216 ears) or normal hearing (49 subjects, 98 ears). The accuracy of the ASSR threshold estimations for frequencies of 500, 1000, 2000, and 4000 Hz was compared between groups, and the specificity and sensitivity of the ASSR test in differentiating ears with or without NIHL was calculated using receiver operating characteristic analysis. Linear regression analysis was used to formulate an equation to predict the behavioral warble-tone audiogram at each test frequency using ASSR thresholds. Multifrequency ASSR amplitude growth as a function of stimulus intensity was compared between the NIHL and normal-hearing groups for 1000 Hz and 4000 Hz carrier frequencies. RESULTS: In the subjects with NIHL, ASSR thresholds to various frequencies were significantly and highly correlated with the behavioral warble-tone thresholds; Pearson correlation coefficients ranged from 0.6 to 0.8 over the four frequencies tested. Differences between thresholds ranged from 10 to 13 dB. The configuration of the ASSR waveforms closely approximated the behavioral audiogram. The sensitivity for screening hearing thresholds was 92%; by frequency, sensitivity ranged between 92.7 and 98.4%, but specificity was lower, especially at the low frequencies. ASSR accurately predicted moderate and severe NIHL. The mean ASSR growth amplitude to increasing stimulus level for 1000 and 4000 Hz was significantly steeper in the NIHL than in the normal-hearing group, with no significant difference between frequencies. CONCLUSIONS: The ASSR test has a high sensitivity to detect moderate to severe hearing loss in subjects with NIHL. Its use can facilitate the early identification of noise-exposed workers with NIHL. It may also serve an important medico-legal function in cases of workers' compensation. The ASSR test is not, by itself, an appropriate tool for hearing screening in the general population.

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.

Effect of cochlear window fixation on air- and bone-conduction thresholds.

HYPOTHESIS: In the absence of patent cochlear windows, cochlear fluid inertia depends on the presence of a "third window" as a major component of the bone-conduction response. BACKGROUND: Studies have shown conflicting results regarding changes in air and bone conduction whenever, the round window, oval window, or both windows were occluded. METHOD: The study was performed in a tertiary university-affiliated medical center. Auditory brain responses to clicks and 1-kHz tone bursts delivered by air and bone conduction were tested in 5 adult-size fat sand rats. The round window membrane (total, 7 ears) was sealed with Super Glue, and auditory brain response testing was repeated. Thereafter, the stapes footplate was firmly fixated, and auditory brain responses were recorded for a third time. RESULTS: Round-window fixation induced a significant increase in air-conduction thresholds to clicks from 36.4 ± 0.9 to 69.3 ± 4.1 dB SPL, with no significant change in bone-conduction thresholds. When the stapes footplate was immobilized as well, air conduction increased by another 20 dB, on average, with no change in bone conduction. A similar deterioration was seen in response to 1 kHz stimulus. CONCLUSION: These findings support and complement earlier studies in the same animal model, suggesting that when the pressure outlet through the cochlear windows are abolished, still bone conduction displaces the cochlear partition probably because of a functioning "third window."

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.

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.