Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Perilymph”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1989

Perilymph fistulas in children: experience of the Otologic Medical Group.

We reviewed records of 86 consecutive fistula explorations over 12 years. Four cases were children under age 18. There were 35 fistulas, all in adults. Since this series, we have identified five more children with fistula explorations for a total of nine patients. Two had bilateral explorations. Presenting symptoms were hearing loss and dizziness. None of the children had a definite fistula. Of the nine patients, one patient had a significant improvement in hearing postoperatively, five had no change, and two had worse hearing. There was no follow-up in two patients or in the second ear of a bilateral case. We feel that a fistula should be considered in any case of progressive or fluctuating sensorineural hearing loss, especially in cases with a congenital inner ear deformity. In such cases, an exploration may be reasonable to rule out a fistula. Otherwise, we are hesitant to explore patients for fistulas regardless of whether they are children or adults. Sudden, progressive, and fluctuating sensorineural hearing loss, dizziness, and meningitis have been attributed to perilymph fistulas in both adults and children. The literature reports fistulas in all types of conditions. The incidence and degree of success of treatment have varied widely. When Goodhill first reported round window rupture as a cause of sudden sensorineural hearing loss (SNHL), the Otologic Medical Group (OMG) began routine exploration of all cases of sudden SNHL for the presence of fistulas. After 50 consecutive cases were explored and no fistulas were found, we became selective in our exploration candidates.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1979

Perilymph fistulae.

A small series of 14 post-stapedectomy fistulae illustrates the varied aetiology. The long-term competence of the oval window seal may be ensured by making a small hole in the footplate. Contraction of ageing fibrous tissue contributes to late stapedectomy failures. Long-term follow-up is important, for any deterioration in hearing after stapedectomy may result from a perilymph leak.

Female↗
PubMed1983

Effects of perilymph viscosity on low-frequency intracochlear pressures and the cochlear input impedance of the cat.

Cochlear model calculations are shown to be in reasonable agreement with recent low-frequency measurements of intracochlear pressures and the cochlear input impedance of the cat [V. Nedzelnitsky, J. Acoust. Soc. Am. 68, 1676-1689 (1980); T. J. Lynch, III, V. Nedzelnitsky, and W. T. Peake, J. Acoust. Soc. Am. 72, 108-130 (1982)]. Included in the cochlear model are perilymph viscosity, the measured variation of the area of the scala vestibuli with distance from the stapes [P. Dallos, J. Acoust. Soc. Am. 48, 489-499 (1970)], and finite impedance of the round window membrane. The WKB approximation and its extension to the low-frequency region is used in order to exhibit explicitly the dependence of the model results on the cochlear parameters.

Acoustic Impedance Tests↗
PubMed1983

Gentamicin persistence in rat endolymph and perilymph after a two-day constant infusion.

The kinetics of gentamicin in the inner ear fluids of rats were studied up to 15 days after cessation of a 2-day constant infusion of 10 micrograms/min. In endolymph, the concentration of gentamicin persisted at about 1 microgram/ml for up to 15 days, precluding the determination of the half-life of the drug in this fluid. In perilymph, gentamicin cleared more slowly than after a shorter period of infusion. These results suggest that the tissues of the inner ear could bind the aminoglycoside and then slowly release it into the surrounding fluids.

Animals↗
PubMed1977

Hereditary deafness in the cat. Free amino acid and sugar content in the perilymph.

The free amino acid and sugar content of cat perilymph was studied from 11 normal and 17 deaf ears, and compared with simultaneous estimations from cerebrospinal fluid and serum. Each fluid has a distinctive amino acid composition, whilst glucose was the only saccharide demonstrable. The functional status of the cochlea did not influence the biochemical parameters studied.

Amino Acids↗
PubMed1986

Perilymph fistulas caused by myringotomy.

Two cases of rupture of the round window membrane verified by operation are presented. Both cases arose in connection with myringotomy and were presumably caused by a violent force acting directly on the tympanic membrane and the ossicles. This would result in a strong movement of the stapes and an acute change in the perilymph pressure, thereby causing an indirect injury to the round window. Symptoms and treatment are briefly discussed.

Acute Disease↗
PubMed2004

"Spontaneous" perilymph fistula: a case report.

A surgically documented case of barotrauma-induced perilymph fistula is presented in this case report. A brief review of the literature on this entity confirms the difficulty of making a definitive preoperative diagnosis in most instances. Clinical, audiometric, radiologic, and intraoperative findings are presented, and the classic presumed mechanisms for this uncommon cause of sudden sensorineural hearing loss are discussed. The presence of intact evoked otoacoustic emissions in an ear demonstrating a severe cochlear-type loss was considered helpful in narrowing the differential diagnosis in this case, and may suggest a productive avenue for future study.

Adult↗
PubMedDate not supplied

Role of perilymph in the early stage of serous otitis.

After injection of an electron-dense tracer into the cerebrospinal fluid (CSF) the particles can be seen within the lymphatic spaces of the middle ear mucosa after a few minutes. They find their way via the well known communication routes from CSF to the perilymphatic spaces of the inner ear. From there they enter through open fluid spaces into the fibrocytic network of the round window membrane which stands in open relationship to the extracellular fluid spaces of the middle ear mucosa. They were drained to the regional lymph nodes by lymphatic vessels. When inducing a serous otitis by experimental obstruction of the Eustachian tube it could be demonstrated that the fluid within the middle ear cavity is partly coming from the CSF and perilymph. Later the healing process of the middle ear epithelium was studied after the onset of serous otitis with and without artificial ventilation of the middle ear.

Animals↗
PubMedDate not supplied

Surgical treatment of recurrent perilymph fistula with anacusis.

A woman with substantiated well-preserved premorbid cochlear function developed right-sided anacusis due to a perilymph fistula twice at an interval of 20 months. The fistula was presumably a sequel to previous operative damage to the stapes footplate. On both occasions she was treated surgically with a good result.

Audiometry↗
PubMedDate not supplied

Antibody activity in perilymph from rats with type II collagen-induced autoimmune inner ear disease.

Rats were immunized with native type II bovine collagen to induce autoimmune inner ear disease, and the antibody activity in the inner ear fluid was measured. Antibody activity against type II collagen was detected in the perilymph at about 10% to 20% of serum level. Thus, the presence of antibody against type II collagen in inner ear fluid may imply an immune injury mechanism in inner ear diseases.

Animals↗
PubMedDate not supplied

Perilymph fistula: the Stanford experience.

Seventy-eight tympanotomies were performed to determine the presence of perilymph fistulas (PLFs); of these, 51% were found. The oval and round windows of all patients were grafted, whether PLFs were present or not. Of those patients with PLFs, 64% had resolution of their major symptom; when no PLF was found, 44% had a similar outcome. We concluded that 1) PLFs often behave as if they are epiphenomena in relation to hearing and balance, 2) PLFs can be intermittent, 3) PLF surgery is disappointing for restoration of hearing in sudden hearing loss when compared to the rate of spontaneous recovery, 4) stabilizing a fluctuating or progressive loss is a more realistic goal, and 5) establishing preoperative criteria for exploration is still a problem.

Adolescent↗
PubMed1993

Accumulation of potassium in scala vestibuli perilymph of the mammalian cochlea.

Movements of potassium (K+) were monitored during perfusion of either the scala tympani (ST) or the scala vestibuli (SV) of the guinea pig cochlea with a solution containing 15 mmol/LK+. A highly asymmetric clearance of K+ was observed, with K+ rapidly being taken up from the ST and allowed to accumulate in the SV. Under some conditions the SV K+ concentration could exceed that in the perfused ST. These observations are believed to result from the distortion of passive K+ diffusion by the high circulating current of K+ that is part of the transduction process. Calculations are presented to demonstrate that circulating fluxes are of sufficient magnitude to generate the results observed. The high rate of circulating K+ current is probably also responsible for the difference in physiologic K+ concentration between the ST and SV, in which the ST perilymph K+ concentration is typically found to be half that of the SV. A clearance of K+ from the ST and its eventual accumulation in the SV could play a role in how the ear responds to abnormal ion concentrations, such as may occur in Meniere's disease. It is proposed that an accumulation of K+ in the SV would result in vestibular dysfunction that might contribute to the vestibular symptoms of the disease.

Animals↗
PubMed1983

Perilymph fistulas in infants and children.

During the years 1975 through 1981 we performed exploratory tympanotomies on 33 infants and children (44 ears) to verify the presumptive diagnosis of perilymph fistula (PLF). A PLF was identified at the round window, oval window, or both in 29 (66%) of the 44 ears explored. After surgery hearing was unchanged in 86%, improved in 5%, and worsened in 9% of the ears in which PLFs had been observed. Complaints of vertigo subsided in all children in whom a PLF was repaired. Preoperative factors determined to be highly suggestive of the presence of a PLF included the following: sudden onset of sensorineural hearing loss (SNHL), congenital deformities of the head, and abnormal findings on tomograms of the temporal bones, especially Mondini-like inner ear dysplasias. Middle ear abnormalities (primarily congenital) were observed in 20 of the 44 ears. Abnormal results of preoperative vestibular function studies, which included a fistula test, and sex were not consistently found to be associated with an observed PLF at tympanotomy.

Adolescent↗
PubMed1986

Diagnosis and treatment of perilymph fistulas without hearing loss.

In 1978, I reported on the diagnostic criteria and therapy based on the treatment of 34 cases of perilymph fistula. Of that group, 20 patients had no hearing loss associated with the fistula. Since that time, an additional 30 cases of fistula--15 without hearing loss--have been seen and treated operatively. The 30 significant variables of history and physical findings identified in the first study were statistically reviewed, along with a new finding that seems highly significant. Twenty-three of the 26 new cases so evaluated had a positive "eyes-closed turning test" (staggering when turning to the side of the lesion after walking with eyes closed). A further finding has been the presence of an abnormally placed round window membrane, in most cases involving the round window. The total operative population of fistulas, both those with and without hearing loss, is reviewed to identify the operative technique best suited for each window and the graft material most likely to succeed. Perichondrium is the choice tissue for graft material, except for very small fistulas at the annular ligament. The graft must be held firmly in place, with either a prosthesis or appropriate packing, carefully avoiding adhesions between the round window and the tympanic membrane.

Adolescent↗
PubMed1986

Results of surgical repair of inapparent perilymph fistulas.

In patients who are thought to have a perilymph (PL) fistula, careful inspection of the round and oval windows during exploratory tympanotomy may be normal. The decision must then be made either to terminate the procedure--knowing that the patient's symptoms will probably continue or deteriorate--or to repair both windows as if PL fistulas were present, risking further damage to the inner ear. From a series of 14 patients explored for possible PL fistulas, we report on 6 patients with preoperative diagnoses of PL fistula, based on history, physical examination, and audiometry. Symptoms resulting from trauma were present from 10 days to 23 years before surgery. During exploratory tympanotomy, no fistulas were evident; however, both the oval and round windows were repaired with tissue grafts. Follow up--for 1 to 5 years--revealed that vertigo was relieved in all patients. Postoperatively, one patient had a mild conductive hearing loss; yet no patient sustained a sensory neural hearing loss. We conclude that patch grafting of both the oval and round windows is a safe and effective method of treating suspected, but inapparent fistulas. Patient selection, surgical technique, and results shall be detailed.

Fistula↗
PubMed1987

Hydrostatic pressure measurements of endolymph and perilymph in a guinea pig model of endolymphatic hydrops.

The primary histologic correlate of Menière's disease is endolymphatic hydrops. From this, many investigators have postulated the existence of endolymphatic hypertension, although there have been no measurements published to substantiate this concept. Seventy guinea pigs, surgically treated with right endolymphatic duct obstruction, were later assessed by use of a micro-electrode technique that measured their endolabyrinthine hydrostatic pressures. For 21 of these animals, the pressures of both scala tympani (Pst) and scala media (Psm) of both ears of each animal were successfully measured. Similar measurements were made in a control group of 25 guinea pigs that had not undergone any previous surgery. For normal ears--as well as those with hydrops-pressure differences between perilymph and endolymph (Psm - Pst) varied around 0 +/- 2.0 mm Hg. When only the right (obstructed) ears were considered, there appeared to be a slight, relative pressure elevation (p less than 0.05) in scala media during the first 7 days after endolymphatic duct obstruction-and in those ears with EP, less than 70 mV. The magnitude of this pressure difference that can be attributed to the state of endolymphatic hydrops-and not to natural variability-is calculated (within 95% confidence limits) to be less than 0.5 mm Hg.

Animals↗
PubMed1991

Repair of a cerebrospinal fluid perilymph fistula primarily through the middle ear and secondarily by occluding the cochlear aqueduct.

A 35-year-old man had a 5-year history of fluctuating hearing loss in his only hearing ear. History and diagnostic tests indicated a perilymph fistula, a diagnosis subsequently confirmed by exploration. Primary and secondary repairs temporarily ameliorated symptoms. A spinal fluid to middle ear fluid pathway was identified by radioactive tracer. A patent cochlear aqueduct indicated on computed tomography scan was found and repaired through a posterior cranial fossa approach. Hearing was preserved, remaining relatively stable during the 2-year follow-up period.

Adult↗
PubMed2001

Perilymph fistula associated with pulse-synchronous eye oscillations.

Three-dimensional eye movements (scleral search coil system) were recorded in a patient with a surgically acquired perilymph fistula of the left horizontal semicircular canal. Spontaneous horizontal pendular nystagmus was found to be related to the heart rate and may be caused by pressure transfer of blood pulses to the labyrinth. In addition, a contralesional horizontal jerk nystagmus was elicited by Valsalva maneuver, indicating that Ewald's first law may not only be valid for excitation but also for inhibition.

Aged↗