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At least 343 records · Page 19Linked to original sources
PubMedDate not supplied

Necrotizing ("malignant") external otitis histopathologic processes.

The histologic findings in a serially sectioned temporal bone, from a patient who succumbed to brain abscess secondary to necrotizing ("malignant") external otitis, are described. The mechanism of invasion of the ear canal appears to be due to local bone necrosis. This in turn extends to the submucosal vasculature of the pneumatic spaces. The infective process extends submucosally, establishing one or several sites of bone destruction. The lumen of the pneumatic space is not involved. In this process, the periphery of the fibrous inflammatory tissue formation is the site of active bone destruction. In pneumococcal petrositis, the peripheral fibrous elements are protective. The process in malignant external otitis may extend directly to adjacent central nervous system structures inoculating the structure with Pseudomonas. Development of Pseudomonas brain abscesses can be slow, allowing for new bone closure of the site from which the infection spreads as demonstrated in this specimen. Therefore, apparent local control of the disease can be established while a central infective process progresses.

Aged↗
PubMed1997

Perilymphatic fistula: a Washington, DC, experience.

One hundred ninety-seven patients who underwent surgical repair for a presumed unilateral perilymphatic fistula were reviewed. Of those patients, 87% with vestibular symptoms reported complete or near-complete relief of their symptoms. Forty percent of the patients with sudden hearing loss had an improvement in their hearing levels. An analysis of several diagnostic tests revealed their sensitivity and specificity ratings. A review of the patients' operative records showed a marked disparity between the visual identification of an actual fluid leak during surgery and their postoperative outcome. This review supports the premise that at the present time, the patient's surgical outcome is the best way of documenting a successfully repaired perilymphatic fistula.

Adolescent↗
PubMed1994

Beta 2-transferrin confirms perilymphatic fistula in children.

beta 2-Transferrin is a protein that is unique to the cerebrospinal fluid and aqueous humor. On the basis of this information and a recent study from our institution that demonstrated that beta 2-transferrin was also unique to human perilymph, a prospective, double-blind study to evaluate perilymphatic fistula in children was performed. Attending otolaryngologists at Children's Hospital of Pittsburgh evaluated and recommended surgery for 10 children (10 ears) who were suspected of having a congenital perilymphatic fistula. During the operation, the surgeon decided whether a perilymphatic fistula existed, on the basis of otomicroscopic findings, and then separate pieces of gelatin sponge were placed on the oval and round windows, respectively, and sent to the immunopathology laboratory where they were analyzed for beta 2-transferrin. Ten patients (10 ears) undergoing tympanoplasty or tympanomastoidectomy were used as controls and tested in a similar fashion. During the study, both the surgeons and patients were blinded from the results of the test. Of the 10 control patients, none was observed to have a perilymphatic fistula, and all were negative for beta 2-transferrin. Of the 10 patients undergoing exploratory tympanotomy for perilymphatic fistula, 1 ear was thought to be negative for perilymphatic fistula on microscopic visual examination, whereas 9 were considered to be positive for perilymphatic fistula. No beta 2-transferrin was identified from the ear that was considered not to have a perilymphatic fistula, whereas six of the nine ears that were thought to have perilymphatic fistula tested positive for beta 2-transferrin.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1976

Symposium: Congenital anomalies of the middle ear. IV. Management of profuse perilymph leak.

Profuse perilymph leak during an otological operation can be controlled by inserting an epidural teflon cannula into the lumbar subarachnoid space and draining away the excess spinal fluid. After about 100 cc is removed the perilymph leak stops, and the oval window can be sealed with a living seal, such as vein, and the operation completed. The catheter is left in the subarachnoid space for about four days, with a bottle on the distal end positioned to remove no more than 150 cc of spinal fluid per day. Results with two patients in which this maneuver was used to control profuse perilymph leak are reported.

Catheterization↗
PubMed1982

Computed tomographic anatomy of the temporal bone.

With the recent development of high-resolution computed tomography (CT), there is a growing need to explore the full potential of this new method in demonstrating the detailed anatomy of the temporal bone. For this purpose, dry skulls with intact ossicles were scanned in axial and coronal projections. The detailed CT anatomy of the temporal bone was documented, complemented by images from live patients. Because of its superior contrast resolution, CT was able to demonstrate numerous structures, such as the tympanic membrane, ossicles, and supporting structures, hitherto never or poorly visualized by any other method. In addition, the ease by which axial sections of the temporal bone could be obtained is of great benefit in displaying several structures previously difficult to evaluate.

Adult↗
PubMed1979

Effects of local application of ototoxic antibiotics on cochlear potentials in guinea pigs.

The effects of neomycin, kanamycin and dihydrostreptomycin on the cochlear microphonic, the action potential of the auditory nerve and the endocochlear potential were studied in guinea pigs in which these drugs were locally administered by perfusion. These drugs suppressed the cochlear responses markedly when applied to the endolymph but were less effective when applied to the perilymph. The mechanisms of action of antibiotics on the hair cells of the organ of Corti are discussed.

Action Potentials↗
PubMedDate not supplied

The early postnatal development of the cochlear vasculature in the gerbil.

The blood vessels of the cochlea were studied from birth up to adult age in the gerbil. Even at birth the principal vascular arrangement could be identified in the external wall. However, the early circulatory mainstream appeared even more predominantly radial apico-basal over radiating arterioles-arteriovenous anastomoses-collecting venules than at later stages. At birth, only small sections of capillaries could be observed in the stria vascularis. Stria vascularis achieved its adult vascular appearance rapidly between 8-10 days after birth (DAB). The rapid development of stria vascularis immediately preceded the development of cochlear function and may have been related to the development of the ionic composition of endolymph. At birth the vessel of the basilar membrane showed many large vascular connections with the collecting venules in the scala tympani of the external wall but very few supplying and draining ramifications on the medial side of the vessel. This suggests that the vessel of the basilar membrane originates from the external wall vessels, not from the spiral lamina vessels as has previously been supposed. The peripheral vascular connections degenerated rapidly after birth. The vessel, being very large at birth, degenerated completely by 15 to 20 DAB, ultimately disappearing in the basal turn. The degeneration suggests that its major importance may be during embryonic stages, with great probability for the development of the organ of Corti.

Aging↗
PubMed1988

Rapidly progressive sensorineural hearing loss (rapid deafness).

28 ears of 28 patients, aged 15 to 60 years, whose sensorineural hearing loss had developed over a period of a few hours to 3 days, were defined as having rapidly progressing sensorineural hearing loss (rapid deafness), in comparison with so-called sudden deafness with instantaneous onset. For other criteria, their hearing loss was idiopathic and the rate of hearing loss was confirmed by reliable means. The rate was greatest within the first 1-3 days. Of the 28 patients, 12 (43%) recovered completely, while another 12 improved markedly. The prognosis in rapid deafness was relatively good, but the recovery time was longer than in spontaneously healing sudden deafness. Sensorineural hearing loss in contralateral ears more often preceded rapid deafness (9 cases, 32%). No clear-cut difference could be found between rapid deafness and sudden deafness.

Adolescent↗
PubMed1988

Development of pressure monitoring and controlling system for quantitative analysis of experimentally induced perilymph fistula.

The cause of perilymph fistula, a subgroup of sudden deafness, has not been clearly understood. To study its etiology quantitatively, the inner ear pressure monitoring system with a computer controlled pressurizing device and three types of low-pressure monitoring sensors was constructed and utilized in ex vivo experiments using white guinea pigs. Hypothesizing that cerebrospinal pressure increases cause rupture of the round window membrane, direct and indirect pressurization to cerebrospinal region and simultaneous measurement of inner ear and cerebrospinal pressures were carried out. Ruptures of the round window membranes were seen in the experiments with direct saline infusion into the cochlea when the increment of inner ear pressure exceeded 500 mmH2O. There was no sign of rupture when squeezing abdomen was employed as an indirect pressurization, although cerebrospinal pressure increased.

Animals↗
PubMedDate not supplied

Bone modeling in the otic capsule of the rat.

Bone modeling determines postuterine gross bone architecture. During growth the shape and proportion of all bones are continuously adapted to function by surface resorption and surface formation. This process is responsible for exchange of most primary endochondral type bone with lamellar endosteal or periosteal bone. By a combination of microradiography, tetracycline fluorescence and osteoid staining of undecalcified material bone modeling in the otic capsule of the rat was studied and compared to well-known modeling patterns in rat long bones. Perilymphatic spaces were found to be enclosed in a layer of primary bone resistant to resorption associated with surface modeling. It is proposed, that this drift barrier is maintained by a control mechanism present inside the perilymphatic space.

Animals↗
PubMed1999

Beta-2 transferrin assay in the identification of perilymph.

HYPOTHESIS: Western blot assay for beta-2 transferrin protein is a clinically useful method for the detection of human perilymph and should be used for the diagnosis of perilymph fistulas (PLFs). BACKGROUND: Considerable controversy exists regarding the diagnosis of PLF. Recent studies suggest that the detection of beta-2 transferrin protein may be useful in the identification of perilymph. METHODS: To evaluate the usefulness of the beta-2 transferrin assay for identifying human perilymph, paired perilymph samples and negative controls were collected on Gelfoam pledgets from 20 patients who had surgery that opened the inner ear. Blinded immunoelectrophoretic assay (Western blot) for beta-2 transferrin was performed on each specimen. RESULTS: Only one (5%) of the known perilymph samples and none of the control specimens were definitely positive for beta-2 transferrin. Combined with historical data, this assay has 29% sensitivity, 100% specificity, 100% positive predictive value, and 31% negative predictive value. CONCLUSIONS: These findings suggest that the beta-2 transferrin protein assay may not be a reliable method for detecting human perilymph when performed using this technique.

Cochlear Aqueduct↗
PubMed1998

Congenital and acquired perilymph fistula: review of the literature.

Perilymph fistula is caused by an abnormal communication between the perilymph space and the middle ear. The etiology is either congenital or acquired. The congenital fistula can be associated or not with clinical symptoms or radiologically detectable abnormalities of the temporal bone. In patients presenting congenital fistula without symptoms or radiologically detectable abnormalities, little malformations of the middle ear may be detected during surgery. The acquired fistula can be caused by iatrogenic trauma, physical injury or erosion. As far as therapy is concerned, surgical treatment can be performed and the perilymph fistula thus represents one of the few causes of sensorineural hearing loss that can be treated surgically. However, the main challenge is the identification of those patients that need to undergo an exploratory tympanotomy, since there are no clinical-audiologic symptoms or radiographic indicators that can be considered pathognomonic of perilymph fistula. The aim of this review of the literature is to define the guidelines for preoperative diagnosis to indicate exploratory tympanotomy both in children and in adults. On the basis of our results, exploratory tympanotomy should be performed in patients with vertigo and/or progressive, sudden or fluctuating hearing loss in association with one or more than one of the following elements: a history of cranial trauma, radiographically detectable abnormalities of the inner ear, congenital malformations of the head, recurring meningitis, positive fistula test. The surgical treatment consists in placing a graft of temporalis fascia or tragal perichondrium and it usually results in a significant improvement of vestibular symptoms and sometimes of the hearing function as well.

Cochlear Aqueduct↗
PubMed2000

A case of barotrauma-induced pneumolabyrinth secondary to perilymphatic fistula.

We report the case of a 62-year-old woman who experienced pneumolabyrinth associated with a perilymphatic fistula. Her condition was diagnosed with the help of computed tomography, which detected the presence of an air bubble in the labyrinth, and middle ear exploration, which revealed that clear fluid was emanating from the round window niche in a manner consistent with the presence of a perilymphatic fistula. The niche was repaired with tragal perichondrium and bolstered with Gelfoam.

Barotrauma↗