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At least 325 records · Page 18Linked to original sources
PubMed1977

Ear canal hyperostosis--surfer's ear. An improved surgical technique.

The increased populatiry of surfing has produced a marked augmentation in the incidence of ear canal exostosis. However, when it becomes moderately severe, I prefer to call it "hyperostosis." Exposure to cold ocean water for many years can be an important etiologic factor in hyperostosis. There is a serious risk, and a high incidence of tympanic membrane perforations during the removal of large external canal hyperostosis. This injury can be prevented by placing a sheet of Silastic against the tympanic membrane beforehand. I describe the method. Serious degrees of hyperostosis, causing transient hearing loss and otitis externa, are increasingly common in coastal towns, where cold-water surfing is a popular year-around sport.

Adult↗
PubMed1984

Programmable auditory stimulus generator and electro-acoustic transducers--measurements of sound pressure in an artificial ear and human ear canal.

The measurement of sound pressure wave forms of different headphones resulted in considerable differences in an artificial ear and in the external auditory canal in man. This concerns, in particular, the pattern of stimuli used to elicit the auditory nerve and brain-stem auditory evoked potentials. By varying the electrical input to the headphones by means of a programmable stimulus generator, it can be shown that the sound pressure wave form can be influenced considerably.

Brain Stem↗
PubMed1999

Bilateral middle ear squamous cell carcinoma and clinical review of an additional 5 cases of middle ear carcinomas.

We reported a retrospective review of the clinical records for a 64 year old male patient with bilateral middle ear squamous cell carcinoma (MESCC), and for the five other patients with MESCC treated at our institution during the last 20 years. The patient with bilateral MESCC has survived and remained tumor free for more than 1.5 years after extended radical resection of the secondary tumor combined with intra-arterial and systemic chemotherapy, radiotherapy and immunotherapy. Four patients with unilateral MESCC were treated with multidisciplinary treatment (induction chemotherapy, surgery and radiotherapy), and the remaining patient was treated with radiotherapy and mastoidectomy. Five of the six patients are alive with no evidence of disease. The patient treated with radiotherapy and radical mastoidectomy died of local recurrence 3 years after diagnosis. We suggest that MESCC should be considered when refractory granulation, long-standing otorrhea, otalgia and facial paralysis are observed. Multidisciplinary treatment, including intra-arterial chemotherapy and en bloc resection of the temporal tumor is useful for the treatment of MESCC and will improve the prognosis of patients with this disease.

Adult↗
PubMed1980

A syndrome with mixed deafness, Mozart ear, middle and inner ear dysplasias.

A 10-year-old boy presenting a disorder of multiple malformations with an otologic component consisting of mixed deafness, Mozart ear, thin stapes, small oval window and agenesis of the semicircular canals, was studied. A comparative analysis of similar malformation-entities has permitted the delineation of a previously undescribed syndrome.

Abnormalities, Multiple↗
PubMed1988

The ear wigglers: tics of the ear in 10 patients.

The author describes 10 patients with tics of the ear. The pathogenesis of this disorder is uncertain, but psychological factors may play an important role. This may be the first report of this disorder in the English literature.

Adolescent↗
PubMedDate not supplied

Effects of middle ear pressure on the inner ear.

It was demonstrated in experiments on normal subjects that moderate ambient pressure changes, creating overpressure in the middle ear, may induce a vestibular reaction. In other experiments on subjects suffering from acute attacks of Meniere's disease, relief of symptoms was achieved by means of ambient pressure changes of the same magnitude.

Ear, Inner↗
PubMed1997

Effect of middle ear pressure change on middle ear mechanics.

The effect of graded variations in middle ear pressure on ossicular vibration was measured in 15 normal human temporal bone specimens. The displacement amplitude of the umbo and stapes head was measured at 16 frequencies between 0.2 kHz and 3.5 kHz at a constant sound pressure of 134 dB SPL at the tympanic membrane (TM) using a non-contacting video measuring system. Both negative and positive pressures decreased umbo and stapes vibration at low frequencies and slightly increased the vibration at higher frequencies. The effects were greater for negative pressure than for positive pressure. The change in stapes vibration was less than that of the umbo at low frequencies, but increased at higher frequencies. In some temporal bones, a small positive pressure produced improvement in stapes vibration at all frequencies. These effects were thought to be primarily due to an increased stiffness of the TM and a damping of ossicular vibration, due to stretching of the ossicular suspensory ligaments and the annular ligament of the footplate.

Aged↗
PubMed2000

The nasopharynx and the middle ear. Inflammatory reactions in middle ear disease.

The host-parasite interactions in the nasopharynx with bacterial colonization and antigen uptake in the lymphoid tissue, the adenoid, has an impact on the maturation of local and systemic immunity. The adenoid is a part of mucosa associated lymphoid tissue and is responsible for both effector and inductor functions in the nasopharynx. Increasing evidence supports the role of serum antibody in protecting the middle ear cavity from disease. There is evidence for a minor immunologic defect in a number of children with recurrent episodes of AOM.

Adenoids↗
PubMed2000

Inner ear and lateral line expression of a zebrafish Nkx5-1 gene and its downregulation in the ears of FGF8 mutant, ace.

An orthologue of the mouse homeobox gene Nkx5-1 was cloned and characterized in the zebrafish. As in the mouse and chick, the zebrafish Nkx5-1 gene is expressed in the ear placode and vesicle and in cells forming the vestibulo-acoustic ganglion. In addition, a novel expression domain, the lateral line, appears in the zebrafish, supporting a common precursor hypothesis for these two organs. In the FGF8 zebrafish mutant ace, expression of Nkx5-1 in the otic structures is diminished. The most significant reduction of zfNkx5-1 expression was observed in cells of the vestibulo-acoustic ganglion.

Amino Acid Sequence↗
PubMed1989

Static acoustic-admittance measures in normal ears: a combined analysis for ears with and without notched tympanograms.

A preliminary database of acoustic-immittance measures in normal adults was provided in an earlier publication (Wiley, Oviatt, & Block, 1987). Here, an additional analysis of static acoustic-admittance measures, based on the original database, is provided. Specifically, compensated static acoustic-admittance data for a 220-Hz probe signal are provided for 239 ears including those that did (N = 55) and did not (N = 184) demonstrate tympanometric notching for a 660-Hz probe signal.

Acoustic Impedance Tests↗
PubMed1998

Ear reconstruction in cases of typical microtia. Personal experience based on 352 microtic ear corrections.

The aim of this paper is to report my experience of 352 ear reconstructions to correct microtia with Brent's technique (n = 184) and Nagata's technique (n = 144). The remaining 24 were atypical presentations reconstructed in a one-stage procedure. Brent's technique is a safe, step-by-step, four-stage reconstruction and Nagata's technique involves only two stages. Nagata's innovations include transposing the lobule of the auricle during the first stage, carving a framework that includes the tragus, and constructing the posterior wall of the concha during the second stage. Cases of typical microtia have been selected to illustrate the advantages and pitfalls of both techniques.

Adolescent↗
PubMed1976

Symposium: Congenital anomalies of the middle ear. II. Vascular anomalies of the middle ear.

Of all the abnormal situations that one encounters in performing a tympanotomy, probably the last one to be thought of is vascular anomalies, and yet, potentially, this is one of the most hazardous of anomalous problems with which we have to deal. Most of the anomalies which have been reported concern the persistent stapedial artery. This artery arises from the stump of the second aortic arch (stapedio-hyoid artery), it traverses the developing stapes bone, leaving behind a monument to its existence - the obturator foramen of the stapes. The artery exits from the middle ear along the horizontal portion of the facial nerve, traversing this area for a variable distance and then usually divides into an intra-cranial branch and a sphenoidal branch. The stapedial artery in its development before its regression, gives rise to the anlage of many important cranial arteries. These vessels are usually anastomosed with and distributed by the branches of the internal maxillary artery and the ophthalmic artery. The hyoid artery is represented in the adult by the carotico tympanic artery. Anomalies involving the internal carotid artery are much more rare. The anomalies that have thus far been reported are: 1. Absence of the internal carotids. 2. Aneurysms. 3. Unusual courses. Venous anomalies are generally uncommon and are usually represented by an abnormally placed jugular bulb which can simulate a glomus jugulari tumor.

Aneurysm↗
PubMed1997

Increases in middle ear pressure resulting from counter-diffusion of oxygen and carbon dioxide into the middle ear of monkeys.

The mechanism of middle ear (ME) pressure regulation is incompletely understood. Previously, Hergels and Magnuson reported an unexpected increase in ME pressure for human subjects who partially evacuated their relative positive ME pressures by swallowing. They suggested that a novel, but unknown mechanism for the generation of gas was responsible for the pressure increase. In this experiment, the MEs of rhesus monkeys were inflated with N2 via the eustachian tube and post inflation ME pressures were recorded for up to three hours. Eleven of 20 experiments showed an initial increase in ME pressure caused by the inflation followed by stable pressures for the remainder of the followup period. In 9 of the experiments, a rapid and temporally discrete decrease in ME pressure was observed during the course of followup. Following the observed pressure decrease which was interpreted as a transient eustachian tube opening, ME pressures showed a progressive increase characterized by a kinetic pattern similar to that of the human experiment. To understand the mechanism responsible for this effect, the monkey experiment was simulated using a mathematical model of ME pressure regulation. Free parameters of the model were taken from experimental data for monkeys. The model accurately predicted the time course of pressure change documented in the monkey experiments. The effect is driven by a decrease in the preexisting ME partial pressures of CO2, O2 and H2O consequent to tubal openings at relative positive pressures, with the subsequent counter diffusion of those gases from blood to ME causing the observed increase in total ME pressure. The results reported by Hergels and Magnuson can also be explained by this mechanism.

Animals↗
PubMedDate not supplied

Preliminary observations on isotretinoin-induced ear malformations and pattern formation of the external ear.

Retinoic acid is a morphogenic substance capable of inducing a variety of limb malformations, including duplications and reduction-type defects. Whether retinoic acid plays a similar role in controlling pattern formation of other vertebrate structures is unclear. Many fetuses and infants exposed to isotretinoin (13-cis-retinoic acid) in utero have a characteristic pattern of anomalies, chiefly involving brain, craniofacial, and thymic morphogenesis. Among the craniofacial anomalies, external ear malformations are common and the specific types of auricular malformations include partial duplications, and tissue reductions and displacements. These similarities to the types of limb malformations that retinoic acid can induce suggest that retinoic acid may play an important role in controlling pattern formation of facial structures.

Ear, External↗
PubMed1976

[The effect of ear surgery to the immunologic defense system of the middle ear during chronic otitis media (author's transl)].

Alpha-1-antitrypsin and alpha-2-macroglobuline are very important proteinase inhibitors for the healing process in chronic otitis media, because they can inhibit numerous bacterial and leukocytic proteinases: Alpha-2-macroglobuline can block the malignant proteinases of pseudomonas aeruginosa, staphylococcus aureus and proteus vulgaris. In 58 cases in the middle ear secretion was examined and the level of alpha-1-antitrypsin and alpha-2-macroglobulin investigated pre- and postoperatively. By these investigations we could demonstrate that the postoperative level of these two inhibitors is higher than preoperatively. In a couple of cases with cholesteatoma the postoperative concentration of alpha-2-macroglobuline was nearly three times higher than prior to the tympanoplasty. We believe that one of the causes for this high inhibitor level is the liberation of alpha-2-macroglobuline by injuring blood vessels during a tympanoplasty. It is our opinion that the increase of the inhibitor level in the postoperative phase is one of the prerequisites for the healing process in chronic otitis media.

Antibody Formation↗
PubMed1995

[Effect of variations in middle ear pressure on ruptures of the round window membrane of the inner ear of the guinea pig (Cavia porcellus)].

The electrical activity of the inner ear before and after rupture of the round window membrane was monitored in guinea pigs under different pressure conditions with the aid of electrocochleography. Following studies were conducted weekly over a period of 4 weeks. Findings showed that overpressure below the pressure needed to open the Eustachian tube caused strong temporary functional disturbance of the cochlea, especially at high frequencies. Irreversible changes that were pressure-dependent were observed and occurred mainly at high frequencies. Application of low pressure to the round window membrane caused a functional loss comparable to changes after overpressure. Animals with a predamaged cochlea reacted to overpressure that was below opening pressure of the tube and to corresponding low pressure with a longer lasting functional loss than did animals with an undamaged cochlea.

Acoustic Impedance Tests↗