Can Multifrequency Tympanometry Be Used in the Diagnosis of Meniere's Disease? A Systematic Review and Meta-Analysis.

(1) Background: Ménière's disease (MD) is a disease of the inner ear, presenting with episodes of vertigo, hearing loss, and tinnitus.The aim of this study is to examine the role of multifrequency tympanometry (MFT) in the diagnosis of MD. (2) Methods: A systematic review of MEDLINE (via PubMed), Scopus, Google Scholar, and the Cochrane Library was performed, aligned with the PRISMA guidelines. Only studies that directly compare ears affected by Ménière's disease with unaffected or control ears were included. Random-effects model meta-analyses were performed. (3) Results: Seven prospective case-control studies reported a total of 899 ears, 282 of which were affected by Ménière's disease (affected ears-AE), 197 unaffected ears in patients with MD (UE), and 420 control ears (CE) in healthy controls. No statistically significant differences between the groups were observed regarding resonant frequency (RF). The pure tone audiometry average of the lower frequencies (PTA basic) was significantly greater in affected ears when compared with unaffected ears. The conductance tympanogram at 2 kHz revealed a statistically significantly greater G width of 2 kHz in the affected ears when compared to both unaffected and control ears, while control ears had a statistically significant lesser G width of 2 kHz compared to both the other two groups. (4) Conclusions: MFT, and specifically G width at 2 kHz, could be an important tool in the diagnosis of MD.

Malignant External Otitis: What the Diabetes Specialist Should Know-A Narrative Review.

AIMS: Malignant external otitis (MEO) is a special type of external otitis associated with extensive inflammation and osteomyelitis. It is believed to originate from the external auditory meatus and advance regionally to the soft tissues and the bone, eventually involving the skull base. Pseudomonas aeruginosa and diabetes mellitus are factors commonly involved in the pathogenesis of MEO. Although its treatment has changed considerably during the last decades, morbidity and mortality of the disease remain high. Our aim was to review basic aspects of MEO, a disease unknown until 1968, which attracts great interest among Ears, Nose and Throat (ENT), diabetes and infectious diseases specialists. METHODS AND RESULTS: In this narrative review we mainly include relevant papers written in English or with an English abstract. We searched PubMed and Google Scholar, using the keywords malignant external otitis, malignant otitis externa, necrotizing external otitis, skull base osteomyelitis, diabetes mellitus and surgery up to July 2022. Some of the most recent articles, with specific references to earlier articles and a book reference regarding the pathophysiology, diagnosis and treatment of MEO and its relationship to diabetes mellitus, were included. CONCLUSION: MEO is not an uncommon disease and is principally treated by ENT surgeons. Nevertheless, diabetes specialists should be aware of the disease presentation and management, since they will often encounter patients with undiagnosed MEO or will need to manage glucose levels in patients hospitalized with the disease.

Evaluation of a Dermoplasty Technique for the Control on Nasal Polyps.

To evaluate the efficacy of a dermoplasty technique in controlling nasal polyps comparing to the conventional endoscopic approach. Prospective observational study Tertiary private hospital. Twenty-nine patients underwent surgery for replacement of the middle meatus mucosa with skin. Some patients (41.4%) suffered from allergies, 44.8% from asthma, and 27.6% from aspirin intolerance. Polyps were staged according to the Lildholdt system, and patients completed a sino-nasal outcome test (SNOT-22) pre and post-operatively. Also, patients were interrogated as for medication relevant to the nose received pre and post-operatively. In twenty-six patients dermoplasty was applied in one nostril while the contralateral was treated with the conventional endoscopic technique allowing us to compare the two techniques in the same patient. Median follow-up period was 1.2 years (IQR 0.8, 2.0; range 0.4-5.8). Median drop in SNOT-22 score was 38.2 percentage units. Patients (79.3%) controlled symptoms by topical corticosteroids for 2.5-3 months per year at most. Seventy percent (70.8%) reported improvement in subjective olfaction. Results compare favorably to those reported in the literature after functional endoscopic approach. Lildholdt stage dropped post-operatively on both sides but significantly more (p value < 0.001) on the dermoplasty side comparing to the conventional endoscopic side. Dermoplasty appears to outbalance the conventional endoscopic removal of polyps and clearance of paranasal sinuses. No matter how extensive the removal of endonasal tissue, it is not sufficient for controlling nasal polyps unless mucosa is prevented from recovering the denuded areas by the use of a skin graft.

Differences in the suppression of distortion product otoacoustic emissions by contralateral white noise between patients with acute or chronic tinnitus.

OBJECTIVE: The mechanisms underlying the shift from acute tinnitus to chronic remain obscure. An association between tinnitus and medial olivocochlear bundle (MOCB) reflex dysfunction has been hypothesised by several studies. The differences between participants with acute and chronic tinnitus have not yet been investigated. DESIGN: Participants were examined with distortion product otoacoustic emissions (DPOAEs) suppression elicited by contralateral white noise. They were compared in terms of frequency regions with non-recordable DPOAEs, suppression amplitudes and the presence of DPOAE enhancement. STUDY SAMPLE: Eighteen participants with acute tinnitus, 40 age-matched adults with chronic tinnitus and 17 controls were included. All participants (aged 34.7 ± 9.6years; mean ± Standard deviation) had normal hearing. Tinnitus was bilateral in 22 participants and unilateral in 36. RESULTS: Ears with chronic tinnitus presented significantly lower DPOAE suppression amplitudes than ears with acute tinnitus (p < 0.0001). Both acute and chronic tinnitus ears present a high prevalence of enhancement, significantly different from controls (p < 0.0001, p = 0.0002, respectively). Non-recordable DPOAEs were significantly more frequent in the chronic than in the acute tinnitus and control groups (p < 0.0001). CONCLUSIONS: The differences between study groups indicate that when tinnitus becomes chronic, DPOAEs suppression presents changes that might reveal corresponding steps in tinnitus pathophysiology. Treatment implications are discussed.

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.

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.

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.

Multi-frequency tympanometry: clinical applications for the assessment of the middle ear status.

The aim of the present paper was to review the current knowledge on multi-frequency tympanometry and explore its role as a diagnostic tool in various otologic conditions. Literature review in Medline and other database sources. Prospective controlled, prospective comparative, and prospective cohort studies, animal studies, retrospective studies and systematic reviews. Multi-frequency tympanometry provides more accurate and detailed information about the middle ear dynamics than standard tympanometry. Otosclerosis and rheumatoid arthritis characteristically increase the resonant frequency (RF) of the middle ear. Ossicular chain discontinuity, atelectatic tympanic membrane, and otitis media with effusion typically decrease the RF of the middle ear. Multifrequency tympanometry can also assess the stage of rheumatoid arthritis in the presence of middle ear involvement. The RF can be affected by the mechanical impedance of the cochlea, and multi-frequency tympanometry can be helpful in the diagnostic workup of LVAS. Multi-frequency tympanometry can be a useful tool to predict the diagnosis of various middle ear pathologies preoperatively, due to the ensuing changes in the RF of the mechano-acoustic system of the middle ear, which can be accurately determined when this methodology is applied.

Effect of type I tympanoplasty on the resonant frequency of the middle ear: comparison between chondrotympanoplasty and temporalis fascia grafting.

AIMS: To evaluate the effect of type I chondrotympanoplasty on the resonant frequency (RF) of the middle ear and compare it to the respective outcomes of type I tympanoplasty using temporalis fascia grafting (TFG). Hearing results and respective graft integration rates were also assessed. MATERIALS AND METHODS: A retrospective comparative study was conducted of patients who had undergone type I tympanoplasty at a tertiary university hospital. Selection criteria included tympanic membrane perforation following chronic otitis media, trauma, or grommet insertion; an intact ossicular chain; a dry ear for at least 3 months; and normal middle ear mucosa. Patients with ossicular discontinuity, ossiculoplasty, cholesteatoma, previous ear surgery, syndromes affecting the middle ear, or younger than 16 years old were excluded. RESULTS: Sixty-nine patients met the inclusion criteria; chondrotympanoplasty was performed in 39 and TFG in 30. Three patients showed incomplete tympanic membrane closure at follow-up. The graft integration rate was 97.4% in the chondrotympanoplasty group and 93.3% in the TFG group. An air-bone gap closure within 10 dB was achieved in 73.7% of the chondrotympanoplasty patients versus 67.9% of the TFG patients. Hearing gain of 21 to 30 dB in air conduction thresholds was obtained in 65.8% of the chondrotympanoplasty patients and 60.7% of their TFG counterparts. RF was 808 ± 458 Hz in the chondrotympanoplasty group and 628 ± 256 Hz in the TFG group. The RF remained within the normal range in 73.7% of chondrotympanoplasty patients versus 42.9% of TFG patients. CONCLUSIONS: Chondrotympanoplasty has hearing results comparable to those of TFG myringoplasty. The cartilage can be used without concerns regarding its impact on the middle ear mechanics as the sound-conducive properties of the tympanic membrane remain unchanged.

Oral surgery during Byzantine times.

The Byzantine World covers the eleven-century period between 323-1453 AD and was characterized by a comprehensive system of medicine based on the fundamental principles of Ancient Greek medicine. Several clinical entities, such as epulis, parulis, constrictions of the tongue (short frenum), sublingual ranula, jaws fractures and disclocations, oral fistulae were well-known and treated during the Byzantine period with primarily surgical, but also non-surgical, interventions. Tooth extractions and operations on the uvula were also popular. The variety of these operations, for which special dental instruments were used, demonstrates the high level of surgical knowledge among physicians in Byzantine times.

Novel approaches to treating sensorineural hearing loss. Auditory genetics and necessary factors for stem cell transplant.

Sensorineural hearing loss is a chronic disease, with a serious impact on human communication and quality of life. Exposure to various factors can lead to irreversible hearing impairment, as the auditory epithelium in humans comprises terminally differentiated cells. By contrast, the inner ear of lower vertebrates and invertebrates shows regenerative capacity. Efforts to regenerate the damaged human inner ear may involve renewed cell proliferation, or transplanting cells that can differentiate into sensory cells. Literature review. Animal studies, in vitro studies, retrospective-cohort studies, community-based case-controls, clinical guidelines, and review articles. Embryonic stem cells, inner ear stem cells, and stem cells from other tissues (i.e., neural tissue, hematopoietic system) may be candidates for restoring the auditory epithelium. Transcriptional regulation of p27kip1 is the primary determinant of terminal mitosis and the final number of postmitotic progenitors of hair and supporting cells. Basic helix-loop-helix transcription factor Math1 was found to be necessary and sufficient for the production of auditory hair cells. Notch signaling seems to play a major role in the regulation of Math1, through lateral inhibition. Brn3c, Gfi1, and Barhl1 are also specific transcription factors that have been implicated in hair cell maintenance and consequent survival. Evidence concerning development, maintenance, and regeneration of hair cells is still at an embryonic stage. Combined data, as attempted in the present study, will lead to a more successful management of deafness.

Cochlear implantation in atelectasis and chronic otitis media: long-term follow-up.

OBJECTIVE: To report the long-term results of cochlear implantation in cases with chronic otitis media or atelectasis using a single surgical technique performed in a single cochlear implant center. PATIENTS: Nine patients who were implanted using the blind-pit closure of the external ear canal technique (4 patients with adhesive otitis media and 5 with radical mastoid cavities). Follow-up ranged from 18 months to 12 years (mean, 7.05 yr). INTERVENTION: The surgical procedure was performed in 2 stages. The first stage included canal wall down or lowering any high facial ridge in previous mastoidectomies, removal of all skin, and blind-pit closure of the external ear canal without mastoid cavity obliteration or eustachian tube obliteration. Cochlear implantation was performed 6 months after the first surgical procedure. RESULTS: All operations were uneventful, and during cochlear implantation, as a second stage, no epithelia or other problems were encountered. No serious complications were encountered during the follow-up period. One case had a minor disruption of the external canal closure that was reclosed successfully under local anesthesia. All patients were using the device at the last follow-up interval with no device problems. CONCLUSION: Blind-sac closure of the external ear canal without obliteration is a rather safe surgical procedure in cases with chronic otitis media or atelectasis. Meticulous surgical technique and proper patient selection are of paramount importance. However, a 2-stage procedure may not always be necessary and might best be confined to those patients who have active inflammatory disease at the primary procedure.

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.

Treating common problems of the nose and throat in pregnancy: what is safe?

Although all kinds of medications should be avoided during pregnancy, the majority of pregnant women receive at least one drug and 6% of them during the high-risk period of the first trimester. The aim of the present paper is to discuss the appropriate management of rhinologic and laryngeal conditions that may be encountered during pregnancy. A literature review from Medline and database sources was carried out. Related books and written guidelines were also included. Controlled clinical trials, prospective and retrospective studies, case-control studies, laboratory studies, clinical and systematic reviews, metanalyses, and case reports were analysed. The following drugs are considered relatively safe: beta-lactam antibiotics (with dose adjustment), macrolides (although the use of erythromycin and clarithromycin carries a certain risk), clindamycin, metronidazole (better avoided in the first trimester), amphotericin-B (especially in immunocompromised situations during the second and third trimester) and acyclovir. First-line antituberculous agents isoniazid, ethambutol, pyrazinamide, and ciprofloxacine in drug-resistant tuberculosis can be also used. Non-selective NSAIDs (until the 32nd week), nasal decongestants (with caution and up to 7 days), intranasal corticosteroids, with budesonide as the treatment of choice, second generation antihistamines (cetirizine in the third trimester, or loratadine in the second and third trimester), H2 receptor antagonists (except nizatidine) and proton pump inhibitors (except omeprazole) can be used to relieve patients from the related symptoms. In cases of emergencies, epinephrine, prednisone, prednisolone, methylprednisolone, dimetindene and nebulised b(2) agonists can be used with extreme caution. By contrast, selective COX-2 inhibitors and BCG vaccination are contraindicated in pregnancy. When prescribing to a pregnant woman, the safety of the materno-foetal unit is considered paramount. Although medications are potentially hazardous, misconceptions and suboptimal treatment of the mother might be more harmful to the unborn child. Knowledge update is necessary to avoid unjustified hesitations and provide appropriate counselling and treatment for pregnant women.

Treating common ear problems in pregnancy: what is safe?

In everyday practise, more than 80% of pregnant women receive one at least medication, often for ENT causes. The aim of the present paper is to review the literature on safety and administration of medical treatment for ear diseases, in pregnant women. The literature review includes Medline and database sources. Electronic links, related books and written guidelines were also included. The study selection was as follows: controlled clinical trials, prospective trials, case-control studies, laboratory studies, clinical reviews, systematic reviews, metanalyses, and case reports. The following drugs are considered relatively safe: beta-lactam antibiotics (with dose adjustment), macrolides (although the use of erythromycin and clarithromycin carries a certain risk), and acyclovir. Non-selective NSAIDs (until the 32nd week), nasal decongestants (with caution and up to 7 days), intranasal corticosteroids, with budesonide as the treatment of choice, first generation antihistamines, or cetirizine (third trimester) and loratadine (second and third trimester) from the second generation, H2 receptor antagonists (except nizatidine) and proton pump inhibitors (except omeprazole), can be used to relieve patients from the related symptoms. Meclizine and dimenhydrinate, as antiemetics in vertigo attacks; metoclopramide, vitamin B6 and ginger rhizome, alternatively. Low-dose diazepam and diuretics in severe cases of Meniere's disease (with caution). Systemic administration of prednisone and prednisolone can be considered in selected cases. By contrast, selective COX-2 inhibitors, betahistine and vasodilating agents are contraindicated in pregnancy. Since otologic and neurotologic manifestations during pregnancy tend to seriously affect the quality of life of the expectant mothers, ENT surgeons should familiarise themselves with the basic guidelines and safety precautions for any related medication, in order to provide appropriate treatment.

Paraganglioma of the larynx: a case report.

BACKGROUND: Paragangliomas arise from paraganglion cells as part of the diffuse neuroendocrine system. These tumors are generally considered benign. They appear rarely in the larynx and most of them are supraglottic. CASE REPORT: We present the case of a 45-year-old female patient who presented with a history of hoarseness for two months and difficulties in swallowing for twenty days. Fiberoptic endoscopic examination showed a submucosal mass involving the left side of the larynx. The subglottic area of the larynx was normal as were the base of the tongue and pharynx. The mobility of the true vocal cords was normal. There was no stridor or signs of airway obstruction and no neck lemphadenopathy. The patient underwent a direct microlaryngoscopy under general anesthesia. The tumor was entirely removed along with the left aryepiglottic fold with respect to the surrounding tissues. Histopathological examination showed a benign laryngeal paraganglioma. CONCLUSIONS: Paragangliomas of the larynx are rare neuroendocrine tumors. Most of them are supraglottic. The differential diagnosis of laryngeal paraganglioma includes typical carcinoid, atypical carcinoid, small-cell neuroendocrine carcinoma, malignant melanoma, and medullary carcinoma of the thyroid gland. Although these tumors are generally considered benign, their surgical removal with respect to the surrounding tissues and maximal possible preservation of laryngeal function is the treatment of choice.

Simultaneous and sequential bilateral sudden sensorineural hearing loss: are they different from unilateral sudden sensorineural hearing loss?

AIM: To compare bilateral (BSSHL) with unilateral (USSHL) sudden sensorineural hearing loss. METHODS AND SUBJECTS: Two hundred and thirty-two patients with USSHL, 11 with simultaneous BSSHL and 7 with sequential BSSHL, who were older than 15 years had onset of hearing loss <30 days, no head injuries or history of acoustic trauma. All patients received the same treatment (prednisolone). RESULTS: Hearing loss was more severe in simultaneous BSSHL in comparison to sequential BSSHL (p = 0.01) or USSHL (p = 0.03). Autoimmune diseases were far more common in simultaneous BSSHL (36% of patients) than USSHL. Positive antinuclear antibody was found in half of BSSHL patients and in only 8% of unilateral cases (p = 0.01). The frequency of hearing improvement was much lower in simultaneous BSSHL than in USSHL (p = 0.001). Complete or partial improvement was noted in 74% of unilateral cases versus 27% in simultaneous bilateral cases. Patients with sequential BSSHL improved in a similar way to unilateral cases. CONCLUSIONS: Simultaneous BSSHL, sequential BSSHL and USSHL may have a completely different profile and should not be managed as one disease. Hearing loss, underlying autoimmune diseases, antinuclear antibodies, and improvement/recovery of hearing loss vary in a degree that implies different pathophysiology and prognosis.

Benign paroxysmal positional vertigo and its management.

BACKGROUND: Benign paroxysmal positional vertigo (BPPV) is a common peripheral vestibular disorder encountered in primary care and specialist otolaryngology and neurology clinics. It is associated with a characteristic paroxysmal positional nystagmus, which can be elicited with specific diagnostic positional maneuvers. In recent years, specific therapeutic maneuvers have resulted in its effective treatment. In this paper the current knowledge of the pathogenesis, diagnosis, and treatment of BPPV as well as the authors' own clinical experience in treating such patients are presented. MATERIAL/METHODS: A retrospective review of the records of 204 patients with BPPV was performed. Epidemiological data and results from the audiological and neuro-otological work-up were recorded. All patients were treated with an appropriate repositioning maneuver, depending on the type of BPPV. RESULTS: Of the 204 patients, 163 had posterior canal involvement, 19 had horizontal canal involvement, and 6 had the anterior canal variant. Another 11 patients had bilateral posterior canal involvement and 5 had disease of two canals. The canalith repositioning procedure was immediately successful in 165 patients and in 23 more patients proved successful after its repetition in a second session, resulting in a total success rate of 92.1%. CONCLUSIONS: Most of the patients with BPPV responded very well to treatment. However, differential diagnosis of the type of BPPV was necessary to apply the appropriate canalith repositioning procedure. The canalith repositioning procedure is easy and safe to perform, is noninvasive, can be repeated if needed, and can provide rapid relief of vertigo.

Maturation of the auditory system: 1. Transient otoacoustic emissions as an index of inner ear maturation.

The transiently evoked otoacoustic emission amplitude of 42 preterm babies (84 ears; post-conceptional age [PCA] 30-36 weeks) was compared with the TEOAE amplitude of 39 full-term babies (78 ears; PCA 37-45 weeks) in order to trace the inner ear maturation characteristics. An ILO-92 otoacoustic emission recording system was used with linear clicks of 70 dB peak equivalent SPL. The results obtained indicated: (1) There was no statistically significant difference between preterm and full-term ears; (2) There was no significant difference between males and females; (3) There was a significant difference between left and right ear TEOAE amplitude; (4) The interaction of ear with age in relation to TEOAE amplitude was statistically significant; (5) Noise and stimulus parameters did not reveal any significant differences between right and left ears; (6) A positive correlation existed between birthweight and TEOAE amplitude; and (7) A negative correlation existed between aminoglycoside treatment and TEOAE amplitude. The results indicate subtle changes in TEOAE amplitude over time, showing a natural development of the inner ear function during the process of maturation.

Maturation of the auditory system: 2. Transient otoacoustic emission suppression as an index of the medial olivocochlear bundle maturation.

Contralateral suppression of transient otoacoustic emissions in 42 premature babies (84 ears; post-conceptional age [PCA] 30-36 weeks) was compared to that of 39 full-term babies (78 ears; PCA: 37-45 weeks). Eighteen healthy adults and ten young children (5-14 years old) were studied as controls. Risk factors for hearing loss were registered in both preterm and full-term groups. An ILO-92 otoacoustic emission recording system was used to deliver linear clicks to the ear examined and broadband noise to the contralateral ear in an alternating on and off mode. Suppression in full-term babies was statistically higher than in preterms, whereas no differences existed between children and adults and children and full-terms. Peripheral auditory lateralization was evident in adults but was observed only as a trend in newborns. Only prematurity at the time of examination and aminoglycoside treatment for more than seven days had a negative impact on suppression. The results support the conclusion that maturation of the efferent system takes place from 30 to 45 weeks PCA. The exact age at which this maturation is accomplished has not yet been clearly determined.