Patient with audible popping sounds emanating from the ear canal

We describe a most unusual case of a 40-year-old male who presented with audible popping sounds emanating from his left ear canal. The process of identifying the source of the sounds and treating the underlying cause is presented in detail.

[Pressure relations between endocranial and intracochlear fluid spaces in patients with inner ear diseases]

Intracranial pressure is transmitted to the perilymph of the cochlea via the cochlear aquaeduct and via Reissner's membrane to the endolymph. The "Tympanic Membrane Displacement Analyser (TDA)" is a new device that may be a useful non-invasive method to show intracranial and intracochlear pressure changes indirectly measured by tympanic membrane displacement during stapedial reflex contraction. The TDA was utilised in 20 normal persons and in 29 patients with unilateral diseases of the inner ear. No significant differences in the tympanic membrane displacement were found between patients with sensorineural hearing loss, patients with Ménière's disease, and normal persons.

Cochlear vascular pathology and hydrops in otosclerosis

Three ears with otosclerosis were found incidentally in a series of human temporal bones examined to evaluate cochlear sensorineural degeneration. Otosclerosis was identified with microdissection, surface preparation technique and transmission electron microscopy. Vascular abnormalities were present in all ears, and otosclerosis involved the cochlear endosteum extensively, mainly in the scala tympani of the basal turn. In the scala tympani of the lower half of the basal turn, shunts had formed so that venules deviated abruptly from their normal radiating course towards the spiral vein, left the scala and entered into otosclerotic foci. There was a marked loss of radiating venules in areas where otosclerosis affected the endosteum of the scala. In the pair of bones capillaries in the stria vascularis were extremely dilated, the widest being 80 microns in diameter. The third single bone from a patient with Meniere's disease had severe cochleo-saccular hydrops. Ten serially sectioned temporal bones with known otosclerosis were reviewed. Two of the bones, one of which had cochleo-saccular hydrops, displayed vascular shunts in the scala tympani and enormously dilated strial capillaries with a maximum diameter of 139 microns.

[Noninvasive assessment of intracochlear pressure. III. Case reports of patients with intracochlear hyper- and hypotension]

It was the scope of two previous papers to outline the basics and possible neurotological applications of the tympanic membrane displacement technique (TMD). The present paper is aimed at briefly reviewing five distinct cases where a sudden sensorineural hearing loss with/without tinnitus could be monitored by the TMD technique. These features include a sudden hearing loss upon lumbar puncture, the audiological manifestation of an internal hydrocephalus, stapes gusher and the round window rupture. All symptoms are based on a change in intracranial and intracochlear pressure which in turn leads to the manifestation of the previously unknown sensorineural hearing loss and/or tinnitus.

Shape and displacement patterns of the gerbil tympanic membrane in experimental otitis media with effusion

This study assesses the visco-elastic properties of the tympanic membrane (TM) in isolated gerbilline temporal bones as a function of time after inducing experimental otitis media with effusion (OME). To do this we measured the TM displacements produced by application of sequences of static pressures across the TM, with a high resolution, real-time, differential moiré interferometer, and the results were compared with measurements on healthy ears. Two methods of producing OME were used: in one group tubal plugging was performed to produce mild OME (the 'TP group'); in the other group electro-cauterization of the nasopharyngeal orifice of the Eustachian tube was used to cause a severe form of OME (the 'EC group'). The measurements were performed from one day up to ten weeks after surgery. In the TP group the displacement fringe patterns were normal, i.e. qualitatively they resembled the patterns of the control group. Quantitatively there was a significant decrease of displacement for a given pressure on the first day after surgery, followed by a trend of increase with time; after seven to ten days the displacement was larger than in the control group. In the EC group the displacement was significantly reduced after half a week, followed by a trend of increase with time, similar to what was found in the TP group; at one week the displacement was larger than in the control group, and at ten weeks the largest displacement was recorded. In the EC group the displacement patterns were often irregular; in some cases with changes suggesting the presence of weak spots in the TM where retraction pockets most likely could develop. OME seems to affect the stiffness of the TM promptly so that it is a potential parameter for early diagnosis. The stiffness changes may, if measurable in the clinical situation, become prognostic parameters in the treatment of OME.

Tympanic membrane and otitis media

The tympanic membrane participates in several ways in the middle ear defense system. It may act as a baroreceptor, contains an important neural network with neurogenic inflammatory mediators, and is particularly rich in mast cells. Histological changes of the tympanic membrane in purulent, serous and chronic otitis media are discussed.

[Effect size on resonance of the outer ear canal by simulation of middle ear lesions using a temporal bone preparation]

By means of a model of the external and the middle ear it is possible to simulate various, exactly defined pathological conditions of the middle ear and to describe their influence on ear canal resonance. Starting point of the investigations are fresh postmortem preparations of 8 human temporal bones with an intact ear drum and a retained skin of the ear canal. The compliance of the middle ear does not significantly differ from the clinical data of probands with healthy ears. After antrotomy it is possible to simulate pathological conditions of the middle ear one after the other at the same temporal bone. The influence of the changed middle ear conditions on ear drum compliance, ear canal volume and on the resonance curve of the external ear canal was investigated. For example, the middle ear was filled with water to create approximately the same conditions as in acute serous otitis media. In this middle ear condition a significant increase of the sound pressure amplification was found, on an average by 4 decibels compared to the unchanged temporal bone model. A small increase in resonance frequency was also measured. The advantages of this model are the approximately physiological conditions and the constant dimensions of the external and middle ear.

Tympanic membrane. Retraction pocket

The author attempts to analyse the pathogenesis of the retraction pocket. Middle ear pressure, behaviour of both the tympanic membrane lamina propria and the stratified squamous epithelium are considered. Predisposing factors are presented. A conservative surgical treatment is suggested in cases of non-fixed retraction pockets; a radical surgical treatment is reserved for the fixed pockets. The management of mastoid cavities is discussed.

[Noninvasive evaluation of intracochlear pressure. II. Study findings in patients with Meniere's disease, fluctuating deep tone hearing and peripheral vestibular vertigo]

The tympanic membrane displacement technique (TMD) is aimed at evaluating intracochlear and intracranial pressure changes non-invasively. Therefore, the present paper describes the findings in patients with Ménière's disease where an increase in volume of the endolymphatic spaces is discussed. It should be investigated to which extent a change in the intracochlear pressure corresponds to different stages of the disease. It could be described that the intracochlear pressure does change over a certain period of persisting Ménière's, but that there is no extensive increase in intracochlear pressure between the attacks. The glycerol test as well as the acute attack (case report on one patient) are, however, characterised by distinct patterns. The same holds true for the late-stage Ménière's. It could be demonstrated that the functional patency of the cochlear aquaeduct in patients with long-term Ménière's history is reduced. This finding is surprising and should be investigated further. In essence, the TMD technique enables to better characterise Ménière patients, but it should not be a tool of routine diagnosis of the disease. In some audiological patients, it can also be beneficially applied (10).

Epidermal growth factor and basic fibroblast growth factor are induced in guinea-pig tympanic membrane following traumatic perforation

Epidermal growth factor (EGF) and basic fibroblast growth factor (bFGF or FGF-2) have been shown to enhance the healing of traumatic tympanic membrane (TM) perforations. The action of EGF and bFGF in the TM repair process remains unknown. This study was designed to determine the expression of EGF and bFGF in normal and injured TM by immunohistochemistry. EGF was detected in normal TM mainly in the annulus tympani area. After a perforation in the TM posterior/superior quadrant, EGF was detected around the perforated area in polynuclear cells, in pericytes and in basal epithelial cells. EGF was also detected in the antero/superior quadrant in basal epithelial cells and pericytes. The peak of EGF detection was observed 3 days after the perforation. bFGF was not detected in normal TM, but it was expressed 3 days after a traumatic perforation mainly in the perforated area in pericytes and in polynuclear cells. This study suggests that EGF and bFGF are involved in the control of TM acute perforation repair. These findings help to explain the accelerated healing of TM perforations that are seen after application of FGF or EGF, and suggest that antibodies against these growth factors would retard the healing process.

Influence of tympanic membrane changes on audiometric and immittance findings in school-aged children

Six-hundred-and-eighty-seven 6 to 15-year-old children were examined for the association between tympanic membrane (TM) changes and audiometric or immittance findings. The hearing thresholds were between 20 and 30 dB in ears with amber TM, but between 25 and 45 dB in ears with adhesive TM. When the TM was retracted or the mobility decreased, the hearing thresholds were about 10 dB poorer than in ears with normal TM position or mobility. Thick TM caused hearing loss in the high-frequency areas. The hearing loss was only marginal (3-4 dB) in ears with retracted pars flaccida compared with ears with normal position of pars flaccida. The mean and median middle ear pressure value was lower than -200 da Pa in ears with dull, amber, retracted, poorly movable, adhesive or thick TM. It was between -100 and -200 da Pa in ears with red TM, locally retracted pars tensa or retracted pars flaccida. Stapedius reflex thresholds were higher in ears with one or several abnormal findings than in normal ears.

Current considerations in the etiology and diagnosis of tympanosclerosis

Current concepts of formation of tympanosclerosis in the middle ear are reviewed, as are various clinical considerations. Ultrastructural changes are discussed. A differential diagnosis includes disorders affecting middle ear sound conduction, with the most prevalent involving otosclerosis and cholesteatoma.

[Calculated displacements of the middle ear ossicles in static load]

To investigate the dynamic properties of human hearing, experiments in vivo and with cadaver specimens can be carried out. Furthermore, electrical or mechanical models can also be used to study specific phenomena and parameter sensitivities. Present electrical and mechanical models are often based on crude structural and kinematic simplifications in which testing is restricted to static loading or simplified investigations. To investigate both static and dynamic behavior of normal and pathological ears spatial mechanical models have to be established. The different parts of sound transmission--i.e., airborne sound, elastic membranes, fluids, and ossicles have to be represented by different mechanical systems. In this investigations, a rigid body model of the middle ear was investigated. For verification, simulation results with respect to static loads were compared with measurements reported previously by Hüttenbrink. In further investigations, the dynamic behavior of the model will be evaluated. Models for the tympanic membrane and inner ear will also be formulated in order to create a compositive model that describes the whole hearing process. By so doing the successful development of prostheses as well as diagnostic methods will be supported.

Tympanic membrane atrophy, scarring, atelectasis and attic retraction in persistent, untreated otitis media with effusion and following ventilation tube insertion

Two hundred and twenty two children with persistent bilateral otitis media with effusion (OME) were treated with unilateral ventilation tube insertion and no treatment to the contralateral ear. The tympanic membrane changes in the operated and unoperated ears were compared during a 12 year follow-up. Segmental atrophy resulted from tube insertion whereas minor scarring and thickening of the pars tensa was related to the middle ear condition. Eight three percent of untreated ears and 85% of those treated with tubes did not develop atelectasis. Sixty percent of untreated ears and 64% of treated ears did not develop attic retraction. Very few cases (1.5 and 2%) in untreated and treated ears, respectively developed severe atelectasis. The overall duration of OME was assessed from the pre-operative history of hearing loss, the 3 month period of pre-operative observation and the post-operative time with effusion. There is a relationship between duration of the disease and development of both atelectasis and attic retraction.

Progression of tympanometry and acoustic reflectometry. Findings in children with acute otitis media

The presence of middle ear effusion (MEE) following acute otitis media (AOM) has been assessed by impedance tympanometry and acoustic reflectometry but has not been assessed serially from the time of presentation for AOM in the same group of patients. This descriptive study examined serial measurements by tympanometry and reflectometry in children with clinical AOM at the time of diagnosis, 3 to 5 days later, and at final follow-up 12 to 15 days after diagnosis. The study entry criteria were conservative in order to represent obvious cases of AOM and included 90 patients representing 107 ears. The objective was to describe the evolution of instrumental findings and to attempt to identify unique patient subpopulations with differing prognoses. We found that combined use of initial tympanometry and reflectometry, while yielding intriguing results, does not allow for identification of subpopulations with good or poor progression for MEE clearance at 2-week follow-up. It is our conclusion that initial tympanometry and reflectometry add to the cost of AOM diagnosis without clear benefit for the individual patient.

[Noninvasive assessment of intracochlear pressure and patency of the cochlear aqueduct in normal probands with TMD (tympanic membrane displacement) analysis]

The intracochlear pressure cannot yet be evaluated in patients with certain audiological neuro-otological diseases. However, it seems to be of importance in the diagnosis and pathogenesis of Ménière's disease and related disorders. The present paper is aimed at introducing a setup to indirectly assess intracochlear and intracranial pressure changes and the design and philosophy of this technique. It is possible to describe a normal range of the measured values in healthy controls although large interindividual variations occur. In addition, the positional changes of the registered parameters enable assessment of the patency of the cochlear aquaeduct. This seems to be important in some diseases, such as stapes gusher.

Tympanic membrane changes in experimental otitis media with effusion

A tympanometric in vitro model was used to measure the mechanoacoustic properties of the tympanic membrane. Impedance measurements were made during the early course (1-21 days) of experimentally induced otitis media with serous effusion in the Mongolian gerbil. A more severe form of otitis media with mucoid effusion was produced by electrocauterization of the nasopharyngeal orifice of the eustachian tube. The dynamic peak values of the acoustic susceptance were significantly reduced early in the course of serious otitis media, indicating increased stiffness of the tympanic membrane. In mucoid otitis media, the same reaction of the tympanic membrane was predominant, but the reverse reaction also was recorded in a few ears. These results indicate that alterations of the mechanoacoustic stiffness of the tympanic membrane occur during otitis media with effusion. Such changes may play an important role in the further course of the disease. The clinical implications of the tympanic membrane stiffness changes are discussed. Significant histopathologic changes were encountered in all cell layers, whereas the collagen fiber layer of the pars tensa appeared intact until 4 weeks of disease.

Multifrequency tympanometry. Preliminary experiences with a commercially available middle-ear analyzer

Normal ears and ears affected by various pathologies were studied with a clinical middle-ear analyzer according to the multifrequency tympanometric concept, by which the resonance frequency of the tympanic membrane/middle-ear system can be determined. This frequency varies considerably in normal ears with a mean value close to 1 kHz. Ears with pathologies in the tympanic membrane and otosclerotic ears have resonance frequencies differing significantly from those of normal ears. The effects may be explained by considering mass and stiffness components.

Evaluation of basic fibroblast growth factor in tympanic membrane repair

Basic fibroblast growth factor (bFGF) has been shown to enhance speed of wound repair at a number of anatomic sites. This study presents an evaluation of bFGF in a model of acute tympanic membrane (TM) perforation in order to assess rate of healing as well as structural and functional outcome. Perforations were created in the tympanic membranes of rats, then allowed to heal in the presence of topically applied bFGF with the opposite ear serving as a control. The growth factor was applied in repeated doses beginning 2 days after creation of the TM defect. The treated ears healed faster by an average of 4.0 days. The healed tympanic membranes were assessed using tympanometry and light microscopy. Structurally and functionally, the healed tympanic membranes were similar to the controls. The observed results indicate that bFGF promotes accelerated healing and restoration of normal architecture in acute TM defects.

[Measuring vibrations by laser doppler vibrometry of the human tympanic membrane after stapes fixation]

At times preoperative diagnosis of otosclerosis can prove difficult. Even the objective measurement of the stapes reflex is not very conclusive in patients suffering from more severe hearing loss. Laser-Doppler vibrometry measures the velocity or amplitude of the tympanic membrane (umbo) vibrations. Laser-Doppler vibrometry has a sensitivity that is highly by the factor 10(4) than tympanometry. The herewith presented examinations show, that there is a correlation between the frequency patterns of the displacement amplitudes and experimentally simulated otosclerosis.

Chronic otitis media after tympanostomy tube placement caused by Mycobacterium abscessus: a new clinical entity?

Infections with nontuberculous mycobacteria (NTM) are being identified with increasing frequency, but the otologic manifestations of NTM infection are not well defined. Mycobacterium abscessus is a ubiquitous rapidly growing mycobacterium (RGM) known to cause disease by inoculation after trauma. Though reported following open heart and breast augmentation surgery, it is not recognized as a cause of sporadic post-tympanostomy tube otorrhea. This report presents detailed clinical information on six sporadic cases and partial information on 15 additional cases of ear infection caused by RGM over the past 7 years. Of these, 20 of 21 cases (95%) were attributable to M. abscessus, 14 of 21 (67%) subjects lived in a southern coastal state and 16 of 16 with available histories had previously undergone placement of tympanostomy tubes. Each isolate exhibited resistance to many antibiotics, with 50 percent exhibiting high level mutational resistance to aminoglycosides related to prior topical aminoglycoside use. Therapy was difficult, requiring debridement and prolonged antibiotic therapy. M. abscessus is a problematic infection requiring specific diagnosis and treatment and should be sought as a cause of refractory post-tympanostomy tube otorrhea.