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PubMed1998

Positional changes and stabilization of middle ear pressure.

Middle ear pressure has been shown to increase when body position is shifted from the erect to the supine position, which is explained by an increased volume of the middle ear mucosa due to an increased hydrostatic pressure. The increase in the volume of middle ear mucosa consists of a fast major response followed by slow minor increase, which is reflected by a similar pattern in the increase of middle ear pressure. Since many otological experiments may be performed with subjects in the supine position, it is of interest to analyse these changes in middle ear pressure, as results may be affected by changes in middle ear pressure. The present study investigated the middle ear pressure changes due to a shift in body position from sitting to supine at time intervals of 15 s over a period of 120 s in a group of 20 normal adults. The middle ear pressure was found to increase 22 daPa (mean; S.D. = 12.1), whereas a stable middle ear pressure was reached after 30 s, indicating a steady state concerning the increase in volume of the middle ear mucosa. Thus, it is recommended that experiments with subjects in the supine position should be carried out only after assuming the position for 30 s. The increase in pressure did not correlate to the prevailing middle ear pressure or to the body height.

Acoustic Impedance Tests↗
PubMed1998

Multifrequency tympanometry and histopathology in chinchillas with experimentally produced middle ear pathologies.

Middle ear lesions were produced in chinchillas by introducing fascia, Gelfoam, silastic or a combination of these materials into the labyrinthine and mastoid bullae. After 1-2 months, conventional 226 Hz and multifrequency tympanometry (MFT) were performed and the animals were sacrificed for histopathological analysis of the middle ear. Specific middle ear lesions were created including abnormal tympanic membrane thickness, tympanic membrane mass, tympanic membrane adhesion, mastoid bulla obstruction, ossicular adhesions and reduced middle ear volume. Several potentially strong associations emerged between tympanometric measures and pathological conditions. The strongest were the combinations of thick tympanic membrane and irregular multifrequency tympanograms, tympanic membrane mass and notched 226 Hz admittance tympanograms, tympanic membrane adhesions and low 226 Hz admittance, and tympanic membrane adhesions and low resonant frequency. 226 Hz static admittance had a sensitivity of 0.73 and a specificity of 0.75 for detecting significant middle ear pathology. Tympanometric width was not an effective diagnostic test, separately or in combination with static admittance. The most effective test based on 226 Hz measures was the combination of low admittance or admittance notch. MFT was superior to 226 Hz tympanometry. The combination of low resonance or double resonance or irregular patterns had a sensitivity and specificity of 0.91 and 1.0, respectively. Combining 226 Hz tympanometry with MFT improved the performance relative to 226 Hz tympanometry alone but not relative to MFT alone. The results support clinical reports that multifrequency tympanometry detects some middle ear pathologies that are not detected by conventional 226 Hz tympanometry.

Acoustic Impedance Tests↗
PubMed1983

The prognostic significance of the air volume in the middle ear for the tendency to recurrence of secretory middle ear condition.

The incidence of recurrence of secretory middle ear conditions (SMEC) in the course of the first 3 months after extrusion of a grommet was evaluated in 172 tubulated patients in relation to a number of background variables in a stepwise logistic regression analysis. The background variables were: treatment period, 3-month period (season) of extrusion, sex, age, air volume in the middle ear, diagnosis (unilateral/bilateral, suppurative/non-suppurative and consequently antibiotics), other treatment apart from a grommet (paracentesis and/or adenoidectomy), and a history of allergy. There was a definite correlation between the incidence of recurrence and the air volume in the middle ear, as determined by physical volume test, after correction for age, recurrences being most common in ears with a small middle ear volume. In addition, there was a relationship, but not as marked, between the incidence of recurrence and age after correction for the middle ear volume, recurrences being less common in older patients. None of the other background variables played a statistically significant role when correction was made for age and middle ear volume. It is recommended to practise an expectant therapeutic strategy in SMEC in order to eliminate cases with spontaneous remission. In the event of recurrence, a more liberal reinsertion of grommets is recommended for patients with small middle ear volumes, while in those with larger volumes a different aetiology should possibly be considered.

Adenoidectomy↗
PubMed1987

Complicated cholesteatomas: CT findings in inner ear complications of middle ear cholesteatomas.

Patients with facial palsy and middle ear disease, which may be chronic but clinically occult, may have a cholesteatoma with extension medially along the facial canal. In two patients, axial computed tomographic (CT) scans demonstrated involvement of the medial petrous bone. Patients with vertigo and chronic middle ear disease may have a cholesteatoma with a "fistula" between the middle and inner ears. Although the fistula usually involves the lateral semicircular canal, the cholesteatoma may pass through the oval window. In two patients, coronal CT scans showed extension to the oval window in one and through it in the other.

Adult↗
PubMed2000

Middle ear volume and pressure effects on tympanometric middle ear pressure determination: model experiments with special reference to secretory otitis media.

OBJECTIVE: Middle ear pressure (P(m)) measured by tympanometry has revealed high negative values in patients with secretory otitis media (SOM) in contrast to direct measurement. This may be explained by errors in tympanometry caused by volume displacement of the tympanic membrane (TM) affecting the volume of the middle ear (V(m)) and the P(m) according to Boyle's Law. Such errors are susceptible to the size of V(m). METHODS: A realistic middle ear model based on previous clinical studies of normal pressure-volume relations of the middle ear system (MES) was constructed. In this model non-linear behaviour and hysteresis of the MES was imitated and P(m) as well as V(m) could be controlled. RESULTS: Tympanometrically estimated P(m) decreased on average 38 daPa, when V(m) was changed from 21 to 1 cm(3). The decrease was most pronounced, when V(m) became smaller than 5 cm(3). Moreover, tympanometry showed a linear numerical overestimation of P(m) by a factor 2.31 compared with model P(m). CONCLUSION: A curve fit was derived describing the tympanometric P(m) as a function of V(m). This demonstrated that tympanometric P(m) approached -infinity daPa, when middle ear volume approached 0 cm(3), which indicates that negative tympanometric recordings and B curves can be found in ears with normal P(m) entirely due to very small V(m)'s. This explains the discrepancy between direct and tympanometric measurements of P(m) in SOM, since the effusion replaces the air filled expandable volume resulting in a very small 'functional' V(m). Numerical overestimation of P(m) by tympanometry was explained by hysteresis, which reflected the viscoelastic properties of the MES. These results question the significance of negative P(m)'s as a pathogenetic factor in SOM.

Acoustic Impedance Tests↗
PubMedDate not supplied

Monitoring middle ear pressure by tympanometry. A study of middle ear pressure variation through seven hours.

The aim of this investigation was to monitor fluctuations in middle ear pressure, to study tympanometric signs of Eustachian tube functioning and to assess the validity of the tympanometric readings. In 20 patients with a low initial middle ear pressure (-150 daPa or lower) and 5 normals, impedance tympanometry was performed every 3 min through 7 h. Median pressure for the patients was -150 daPa (range 100 to -400 daPa) and for the normals 0 daPa (range 50 to -50 daPa). A remarkable pressure increase was seen after changing the body position to the supine. The patients were arranged into three groups according to the lowest middle ear pressure registered. Median pressures for the groups were running at a rather constant level. However, the individual pressure fluctuations in many patients were so great that a single tympanometric reading has to be considered unreliable when selecting patients for insertion of ventilation tubes. Thirteen patients never equalized their negative middle ear pressure, indicating that their Eustachian tube did not open during the test period. In spite of this the pressure did not decrease to lower values, indicating that maintaining a relative constant middle ear pressure is independent of opening of the Eustachian tube.

Acoustic Impedance Tests↗
PubMed1988

Aggressive papillary middle-ear tumor. A clinicopathologic entity distinct from middle-ear adenoma.

A 29-year-old woman had a middle-ear mass that resulted in hearing loss and seventh-nerve palsy. The tumor invaded the petrous bone, the mastoid, at least one semicircular canal, and then extended into the posterior fossa. Microscopically, it consisted of complex, interdigitating papillae lined by uniform, cuboidal to low columnar cells. The cells resembled the epithelium of the normal middle ear and middle-ear adenoma, but the papillary architecture distinguished this neoplasm from the latter, nonpapillary tumors. Papillary middle-ear tumors are locally invasive. We propose the term "aggressive papillary middle-ear tumor" (APMET). Nine other examples of APMET have been reported under various diagnostic terms. All have been locally destructive with frequent intracranial invasion. Although none of the tumors has metastasized, one patient died of uncontrolled local disease. For this reason, APMET must be distinguished from nonpapillary middle-ear tumors.

Adenocarcinoma↗
PubMed2001

Selective expression of aquaporin 1, 4 and 5 in the rat middle ear.

The middle ear cavity is an air-filled space that must be maintained for effective sound transmission to the inner ear. To examine the mechanisms of water homeostasis in the middle ear, we investigated whether aquaporins (AQPs), a family of water-permeable channels, were expressed in the middle ear. Reverse transcription-polymerase chain reaction and immunoblot analyses revealed that mRNAs encoding AQP1, 4 and 5 (but not 2 or 3) subtypes were expressed in rat middle ear epithelium; AQP1, 4 and 5 were detected as 28-, 30- and 30-kDa proteins, respectively. Immunohistochemical analysis showed that AQP1 was localized at capillary endothelial cells and fibroblasts in lamina propria mucosae; AQP4 was present solely at the basolateral membrane of ciliated cells, whereas AQP5 was on the apical surface of ciliated cells as well as of flat and columnar epithelial cells. The characteristic different localizations of AQP1, 4 and 5 subtypes in the middle ear suggest that middle ear water homeostasis requires the coordinated operation of these AQPs.

Animals↗
PubMed1998

Influence of the gas exchange function through the middle ear mucosa on the development of sniff-induced middle ear diseases.

To investigate the influence of gas exchange function through the middle ear mucosa on the development of sniff-induced middle ear diseases, the authors examined the mastoid pneumatization among patients with sniffing habit using computed tomography, and also examined the change of negative middle ear pressure induced by sniffing using tympanogram. In 20 ears with cholesteatoma or adhesive otitis media, the areas of mastoid cavity measured at the level of the lateral semicircular canal were significantly smaller than those in 26 ears with otitis media with effusion (OME) or attic retraction and in eight normal ears with sniffing habit (P < .01 and P < .0001, respectively). In 26 ears with OME or attic retraction, the areas of mastoid cavity were significantly smaller than those in eight normal ears with sniffing habit (P < .0001). By contrast, in the four ears with sniff-induced middle ear disease, the recovery of negative middle ear pressure in 5 minutes without swallowing was less than 10 mm H2O, whereas in all seven ears with normal eardrum, negative middle ear pressure recovered by more than 20 mm H2O in 5 minutes. These findings suggested that impairment of gas exchange function through the middle ear mucosa, as well as eustachian tube dysfunction, might be closely related to the development of sniff-induced middle ear diseases.

Adolescent↗
PubMed1991

Primary ciliary dyskinesia and the middle ear.

The middle ear cavity and the eustachian tube contain a well-functioning mucociliary clearance system. To learn more about the importance of this mucociliary clearance, we studied patients with primary ciliary dyskinesia, in whom mucociliary clearance is absent. Thirty-six patients were investigated by means of a questionnaire; in 16 of these patients, otological and audiological studies could be performed. In patients with primary ciliary dyskinesia, a discrepancy was found between subjective ear complaints and the actual middle ear function. Moreover, it appeared that for the middle ear system, mucociliary clearance is of importance only in the first 3 decades of life. With aging, however, a deficient mucociliary clearance system in the middle ear and eustachian tube can be fully compensated for.

Acoustic Impedance Tests↗
PubMed1988

Relation between the onset of chronic middle ear inflammation and the development of the middle ear air cell system.

The relation between the onset of chronic middle ear inflammation and the degree of pneumatization was investigated in porcine tympanic bullae, which closely resemble the human mastoid air cell system. Pneumatization was inhibited in all inflamed ears, and the later the induction of otitis media, the lesser the degree of inhibition of pneumatization. It was concluded that chronic middle ear inflammation inhibits the development of the middle ear air cell system, and the time of onset plays an important role in the degree of pneumatization.

Animals↗
PubMed1991

Chloral hydrate and middle ear pressure.

Middle ear pressure and tympanic membrane compliance were measured in 34 infants and young children (66 ears) with normal middle ears under oral choral hydrate hypnosis. Tympanograms were performed before and 40 to 60 minutes after administration of the drug. Results showed that the middle ear pressure increased significantly in all cases and in both sexes. This increase ranged between +19 and +219 mm H2O. In all cases the pressure returned to its prehypnotic values after recovery. Results of tympanic membrane compliance showed significant increase in males and not significant decrease in females.

Acoustic Impedance Tests↗
PubMed1992

[Mechanics and function of the middle ear. 2: Hearing physiologic comments on middle ear surgery].

The reconstruction of the destroyed ossicular chain has the purpose to re-establish an unhindered sound reception and transmission. With respect to the hydraulic factor, the reconstructed chain should be attached to a large effective area of the drum membrane, ideally to the malleus handle. The sensitivity is furthermore diminished in a linear relationship with increasing mass and stiffness. Therefore, cartilage cannot represent an acoustically ideal material for a drum membrane replacement. The reconstructed chain must vibrate without restraint for an unhindered transmission. Furthermore, the interposed prosthesis must be secured firmly to the remnants of the ossicular chain; the reconstructed chain must vibrate like one solid body. A loose contact attenuates the transmission and might result in a dislocation of the prosthesis with excessive ambient air pressure induced displacements of the drum membrane. A solid anchoring might be created by glueing, bony adhesion, special design of the prosthesis or with a wire connection. With unfavorable middle-ear conditions, the piston-like vibrational mode of the footplate has to be met with a direct driving of the stapes by a T-like prosthesis in the extension of the stapedial's vertical (high) axis. Ineffective rocking movements of the footplate are thus reduced. The almost perfect hearing result of the stapesplasty demonstrates that the impedance-matching middle-ear function is determined by the area ratio between the drum membrane and the width of the cochlear scala. Both components are not altered by the operation.(ABSTRACT TRUNCATED AT 250 WORDS)

Ear Ossicles↗
PubMed1988

Sensory innervation of the ear drum and middle-ear mucosa: retrograde tracing and immunocytochemistry.

The distribution and origin of nerve fibers of presumed sensory nature in the ear drum and middle-ear mucosa of the rat were studied by a retrograde tracing technique in combination with immunocytochemistry. Application of True Blue (TB) on the ear drum or on the middle-ear mucosa labeled nerve cell bodies in the jugular, trigeminal, geniculate and cervical dorsal root ganglia (C2-C4). Judging from the number of TB-labeled nerve cell bodies the jugular and trigeminal ganglia contributed the major component to the sensory innervation of the ear drum and the middle-ear mucosa, while the contribution from the geniculate and cervical dorsal root ganglia was relatively minor. The majority of the TB-labeled nerve cell bodies contained calcitonin gene-related peptide (CGRP), whereas minor populations stored substance P (SP) and neurokinin A (NKA). Nerve fibers containing SP, NKA and CGRP were moderate in number in the middle-ear mucosa and few in the ear drum. Double immunostaining revealed that SP invariably coexisted with NKA in nerve cell bodies in the ganglia examined. The SP/NKA-containing nerve cell bodies constituted a subpopulation of those storing CGRP. The findings indicate that several ganglia project to the ear drum and middle-ear mucosa and that many neuropeptides are involved in the mediation of middle-ear sensitivity.

Afferent Pathways↗
PubMed1989

[Movement of the ear ossicles by middle ear muscle contraction].

Up to now, the function of the middle ear muscles has mainly been investigated from an acoustical point of view. However, the primary function of the middle-ear muscles, namely the induction of ossicular movements, has never been investigated systematically. For this purpose, the displacements of the ossicles, as induced by simulated muscle contractions, were measured microscopically in 13 fresh temporal bone preparations. Both muscles move all ossicles. The tensor tympani muscle pulls the umbo inwards about 100 microns. Due to the gliding motion in the malleus-incus joint, the stapes is thus pushed inwards by at the most 10 microns and, additionally, displaced anteriorly, antagonistic to the pull of the stapedius muscle. This muscle pulls the stapes backwards, lifting the anterior crus outwards and pushing the posterior crus inwards. This reduces the pressure on the cochlear fluids significantly as compared to our former concepts of the movement of the footplate, tilting outwards as a whole around an axis at the posterior pole. Furthermore, this outward displacement of the stapes is not prerequisite for the outward movement of the malleus-drumhead complex, which typically appears at the contraction of the stapedius muscle. The basic motion of the stapes is the movement backwards, which is 5 times greater and which matches the anatomic direction of the pull of the stapedius muscle. This explains the otherwise unlogical position of the stapedius muscle parallel to the footplate. Due to the gliding movement in the malleus-incus joint, this motion changes at the umbo into outward rotation, counteracting the tensor tympani muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Ear Ossicles↗
PubMed1997

A minimally invasive technique for endoscopic middle ear surgery.

Middle ear endoscopy should be considered a useful adjunctive or alternative method to microscopic surgical exploration for middle ear pathology. This minimally invasive technique provides excellent visualization for viewing the surgical micromorphology and pathological findings of the middle ear. Selected patients underwent middle ear endoscopy using a transtympanic approach. Rigid endoscopes of 2.7 mm and 1.9 mm caliber and 0 degrees, 30 degrees and 70 degrees viewing angles were introduced into the tympanic cavity through small tympanostomy incisions. The indications and technique with video monitoring are discussed.

Adult↗
PubMed2003

Efficacy of the 26-kilodalton outer membrane protein and two P5 fimbrin-derived immunogens to induce clearance of nontypeable Haemophilus influenzae from the rat middle ear and lungs as well as from the chinchilla middle ear and nasopharynx.

The rat middle ear and lung clearance model has been used to show that the nontypeable Haemophilus influenzae 26-kDa outer membrane protein OMP26 is highly efficacious as a mucosal immunogen, inducing significantly enhanced clearance in immunized rats upon direct challenge of these two anatomic sites. Similarly, the chinchilla model of middle ear and nasopharyngeal clearance has been used to show that two P5 fimbrin adhesin-derived immunogens, LB1 and lipoprotein D (LPD)-LB1(f)(2,1,3), are highly efficacious as parenteral immunogens. Both induced significantly augmented clearance of nontypeable H. influenzae upon challenge of these sites. Here, these three nontypeable H. influenzae immunogens in addition to six bovine serum albumin and keyhole limpet hemocyanin conjugates of the synthetic peptide LB1(f) were assayed for relative efficacy in the reciprocal rodent model system. OMP26 was assayed in the chinchilla host by a parenteral immunization route, with clearance of the middle ear and nasopharynx used as outcome measures. Both LB1 and LPD-LB1(f)(2,1,3) were assayed in the rat host with a mucosal immunization route and clearance of nontypeable H. influenzae from the lungs and middle ears as outcome measures. Both of the immunogens were found to induce a high-titered and specific immune responses in the heterologous host system. Moreover, each was found to be highly efficacious in the reciprocal host system, providing strong support for the continued development and inclusion of both OMP26 and P5 fimbrin-derived peptides as candidate vaccine antigens directed at otitis media caused by nontypeable H. influenzae.

Amino Acid Sequence↗
PubMed2001

[Carcinoma of the external ear canal and middle ear as interdisciplinary challenge for ear surgery and radiotherapy].

BACKGROUND: Carcinoma of the external auditory canal are tumours considered to have a poor prognosis. Improvement of the survival rate by surgical means alone is not possible. Individual therapy modalities as a result of an interdisciplinary approach between otosurgeon and radiotherapist are necessary. PATIENTS AND METHODS: A series of 30 patients (3 patients pretreated at other institutions) with carcinoma of the external auditory canal and middle ear treated between 1978 and 1997 in our institutions was analysed with particular reference to tumour size and its relation to surrounding tissues, patterns of neck node involvement, surgical procedures, and radiation techniques. Clinical endpoints were freedom from local failure, overall survival, disease-free survival. The mean follow-up was 4.7 years (range: 0.1 to 18.8 years), median 3 years. RESULTS: Treatment by surgery and radiotherapy resulted in an overall 5-year survival rate of 51%. According to Pittsburgh classification the 5-year survival rate for early disease (T1- and T2-tumours) was 89%, for stage III 67% and for stage IV 39%. Most important prognostic factors were dural infiltration (all patients with dural invasion died within 2.2 years) and the infiltration of surgical margins (the 5-year survival rate of patients with complete tumour resection was 100%, but 54% in patients with tumour beyond surgical margins). 192-iridium HDR afterloading brachytherapy based on 3D CT-treatment planning is an effective tool in the management of local recurrences following surgery and a full course of external beam radiotherapy. CONCLUSIONS: Surgical resection followed by radiotherapy adapted to the stage of disease and grade of resection is the preferred treatment of cancer of the external auditory canal and middle ear.

Adult↗