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PubMed1980

The blood-perilymph barrier.

Freeze fracture replicas of the guinea pig inner ear were studied under the electron microscope to define the blood-perilymph barrier morphologically. This barrier is represented basically by the continuous endothelium of the inner ear capillaries. The endothelial cells contain only a few micropinocytotic vesicles in contrast to those of the stria vascularis vessels. The cochlear plexus also exhibits some special differences. Tight junctions of the continuous mesothelial type connect the endothelial cells of the inner ear capillaries. Cell membranes of these cells possess a lower particle density than those of the stria vascularis vessels. In general, the blood-perilymph barrier is morphologically similar to the blood-brain barrier.

Animals↗
PubMed2001

Surgery of otosclerosis in the elderly.

Auditory results following stapes surgery in 26 patients with otosclerosis >60 years of age at the time of surgery were compared with those obtained in 140 patients <60 years undergoing stapes surgery during the same time period. Stapedotomy was performed in all cases. The mean follow-up period was 29 months. Hearing results as judged by postoperative air-bone gaps were as good in the older age group as in the younger patients. Moreover, complications of surgery, such as postoperative formation of perilymphatic fistula, did not occur more frequently in elderly vs younger patients. On the basis of the results obtained, it is concluded that stapes surgery should be offered to elderly patients with the same indications as younger patients with otosclerosis.

Adult↗
PubMed2001

Perilymphatic pressure measurement in patients with Menière's disease.

The MMS-10 Tympanic Displacement Analyser is a new device for measuring perilymphatic pressure in humans. This instrument was used in 70 patients with Menière's disease (44 affected ears) and a group of 50 young normal hearing subjects. No significant differences in perilymphatic pressure measurements were found between the groups. Although measurement parameters showed large inter-individual variation in a subgroup of 25 patients, the intra-individual correlation in the subgroup was good. In patients with Meniere's disease no relationship was found between perilymphatic pressure, hearing thresholds, blood pressure, gender or age. There was no difference between unilaterally and bilaterally affected patients.

Adult↗
PubMed2001

[Rupture of the round window--detection with fluorescence endoscopy].

Rupture of the round window membrane as a special cause of inner ear deafness is widely accepted after changing pressure levels, e.g. in diving. However, even without a barotrauma before, the spontaneous rupture of the round window membrane is suspected occasionally in patients with sudden hearing loss and/or vertigo and tinnitus. To carry through the tympanotomy is decided by ENT surgeons often in cases of progressive hearing loss despite infusion therapy. Perilymph fistulas have been detected relatively seldom, compared to the number of reported operations by several authors. However, covering the round niche with connective tissue leads to the improvement of symptoms sometimes even in cases without microscopical evidence of fistula. Within the last 3 years 14 patients suffering sudden hearing loss of one ear underwent tympanotomy in our department. Of these patients 8 reached restitution of the hearing ability. Especially 2 patients with sudden deafness caused by spontaneous rupture of the round window membrane are reported in the following article. Perilymph fistulas were detected in these cases by IV-application of fluorescein and fluorescence endoscopy of the middle ear. Both patients obtained a normal hearing curve within 1 week after surgical intervention and obliteration of the round niche.

Adolescent↗
PubMed2003

Can low frequency sound stimulation during posturography help diagnosing possible perilymphatic fistula in patients with sensorineural hearing loss and/or vertigo?

Perilymphatic fistula (PLF) is often difficult to diagnose because of the similar symptomatology, such as vertigo, tinnitus and hearing loss, which is found in several inner ear diseases. We attempted to correlate a positive result of low frequency sound (LFS) stimulation tests in posturography with the presence or absence of a PLF confirmed by transtympanic endoscopy in 209 patients with various inner ear diseases (Meniere's disease ( n=128), vestibulopathy ( n=41), cochleopathy ( n=28) and sudden deafness ( n=12). LFS provoked unsteadiness in posturography without PLF in 24 patients with Meniere's disease, in 5 patients with vestibulopathy, in 3 patients with cochleopathy and in 2 patients with sudden deafness. In one patient, tympanoscopy revealed fistula in the round window membrane that was covered with a fibrinous layer. In four cases there was abnormal light reflex in the round window but without PLF. In eight cases, Hennebert's sign was present with nystagmus, without PLF. We conclude that pathological responses to the LFS test in posturography can also be encountered in other inner ear diseases without PLF.

Acoustic Impedance Tests↗
PubMed2003

Hearing preservation in perilymphatic fistula due to a congenital fistula in an adult.

Congenital fistula in the stapedial footplate usually can be diagnosed by the recurrence of meningitis caused by spontaneous cerebrospinal fluid (CSF) in infants or young children. We report the case of a 65-year-old woman, who was initially diagnosed as having an acquired perilymphatic fistula caused by aural barotrauma and demonstrated episodic vertigo and fluctuant sensorineural hearing loss in the right ear after air travel. Surgical exploration showed a congenital circular defect in the peripheral part of the stapedial footplate with leakage of CSF. The fistula was closed by inserting a tiny piece of fascia attached to both the tympanic and perilymphatic side of the stapedial footplate utilizing the back-pressure of perilymphatic fluid and fibrin glue; hearing was preserved.

Aged↗
PubMed2004

Evaluating patients with vertigo: bedside examination.

Dizziness and vertigo are common complaints in patients referred for neurological evaluation. With a basic understanding of vestibular physiology and proper examination techniques, a correct diagnosis can generally be made at the bedside. This article reviews the most common peripheral and central vestibular syndromes as well as the key elements of the bedside vestibular system examination.

Cerebellar Diseases↗
PubMed2001

Perilymphatic fistula.

A perilymph fistula is an abnormal connection between the inner and middle ear that allows escape of perilymph fluid into the middle ear compartment. The clinical symptomatology that follows leakage of fluid is by and large indistinguishable from a number of other pathologies that affect inner ear function. Definite diagnostic proof of a perilymph fistula remains elusive, and methods of diagnosis remain controversial. Traumatic tears in the oval or round windows remain a major cause of perilymph fistula, yet an index of suspicion in traumatic brain injury frequently remains low. The diagnosis of perilymph fistula must always be considered in the appropriate clinical setting of head trauma, barotrauma, and in patients with unresolved and undiagnosed episodes of recurrent vertigo or hearing loss. Surgical treatment with patching of oval and round windows remains the mainstay of therapy for this condition.

Cochlear Aqueduct↗
PubMed1996

Perilymph detection by beta 2-transferrin immunoblotting assay. Application to the diagnosis of perilymphatic fistulae.

beta 2-Transferrin, the asialotransferrin, is found in cerebrospinal fluid (CSF) and inner ear perilymph, but is absent from serum and other body fluids or secretions except the aqueous humor. The detection of this asialo-fraction of the transferrin in ear fluid microsamples with an immunoblotting technique is of great interest when a perilymphatic fistula (PLF) is suspected. beta 2-Transferrin was detected on microsamples collected by syringe or on micro-collagen sponges from 30 patients undergoing ear surgery. The problem is reviewed, the technique and sample preparation are explained and the results discussed. beta 2-Transferrin detection in the ear fluid allows the identification of perilymph, except in the CSF oto- or rhinorrheal context, and is proposed as a promising test to confirm perilymphatic fistula.

Blotting, Western↗
PubMed1988

Early effects of gentamicin on inner ear glycocalyx cytochemistry.

The early effects of gentamicin treatment on the inner ear glycocalyx were investigated using two cationic probes, colloidal thorium and cationized ferritin. Gentamicin treatment resulted in a diminished thorium reactivity of both the endolymphatic and perilymphatic glycocalyx of the hair cells after 1 day and complete abolishment of reactivity after 5 days. Cationized ferritin reactivity of the perilymphatic and endolymphatic glycocalyx was not significantly influenced. The cytochemistry of the inner ear glycocalyx and the possible biochemical changes induced by gentamicin are discussed.

Animals↗
PubMed1992

Circadian and menstrual rhythms in frequency variations of spontaneous otoacoustic emissions from human ears.

This paper reports hourly and daily monitoring of the frequencies of spontaneous otoacoustic emissions. Regular circadian variations in frequency were found in two of three subjects. Consistent monthly variations, in step with the menstrual cycle, were seen in three of four women. The circadian cycle typically showed a rise in frequency of 0.6-1% while asleep and a similar fall while awake. The monthly cycle typically saw frequencies rise and fall by 0.4-0.6%, reaching a minimum near the onset of menstruation, and rising to a peak close to ovulation. A review of the literature revealed that certain cardiovascular parameters such as arterial blood pressure follow, over both daily and menstrual cycles, a broadly similar time course to SOAE frequency. Further experiments produced data supporting a relationship between blood pressure and SOAE frequency, and it is therefore suggested that much of the circadian-linked, menstrual-linked, and background variation in SOAE frequency may arise from cardiovascular changes. A likely causal mechanism, involving cerebrospinal fluid, is discussed.

Acoustics↗
PubMed1995

Persistent dizziness following head trauma and perilymphatic fistula.

A growing body of evidence supports the idea that dizziness that persists for months and even years can be caused by an unsuspected perilymphatic fistula. Perilymphatic fistulas are abnormal ruptures that allow perilymph to leak out of the inner ear into the middle ear space. Most commonly, these ruptures occur secondary to a traumatic event. The term postconcussive syndrome has been used to describe a myriad of symptoms following head trauma. Some of these symptoms, such as cognitive changes, tinnitus, neck stiffness, and dizziness, are also commonly caused by active perilymphatic fistulas. This article discusses the typical history and diagnostic tests for patients with perilymphatic fistula. Common diagnostic tests include audiograms, electronystagmograms, electrocochleograms, and subjective and platform fistula tests. Also, the surgical treatment for the perilymphatic fistula (ie, repair of the oval and round windows) is reviewed, along with the results produced by this relatively minor ear operation. Suggestions are made to help the medical professionals involved in rehabilitative care to be aware of perilymphatic fistulas and seek proper consultations from inner ear specialists if they suspect the existence of this easily cured disorder.

Adult↗
PubMed2000

Syndrome of recurrent meninigitis due to congenital perilymph fistula with two different clinical presentations.

Recurrent meningitis secondary to a congenital labyrinthine anomaly is a rare clinical entity, diagnosis of which is dependent upon certain clinical, radiological and intraoperative features. In the following report we describe two children with congenital labyrinthine fistula and recurrent meningitis whose clinical presentation, radiological features and intraoperative findings were dissimilar and thus, illustrative of two different ways of presentation of this rare disorder. While one had a classical Mondini defect and unilateral hearing loss, the other had normal audiometric and radiographic findings. The fistulae were successfully closed via a tympanotomy approach in both the patients.

Adolescent↗
PubMedDate not supplied

Petrous high jugular bulb: a histological study.

PURPOSE: A high jugular bulb (JB) is thought to affect structures of the inner ear and possibly cause symptoms there, but clear histological findings of an anatomical relationship between a high JB and the inner ear have not yet been described. MATERIALS AND METHODS: We surveyed horizontal sections of 1,591 temporal bones from the collection of the Otopathology Laboratory at the University of Minnesota in Minneapolis, Minnesota, defining a high JB as a JB extending above the inferior margin of the basal cochlear turn. RESULTS: In 65 specimens (16%), we found a high JB with its vascular wall obviously thinner than that of a low JB. Bony resorption was occasionally observed around high JBs. Sixteen specimens showed a bony deshiscence between the JB and the endolymphatic sac. Clinical charts showed no obvious symptoms associated with a high JB. CONCLUSIONS: Our findings suggest that the JB may have potential to expand upward postnatally. Although our study confirmed occasional bony dehiscence between the JB and the endolymphatic sac, JBs with this involvement may have only a minor effect on function in the inner ear.

Adolescent↗
PubMed2001

Electrically evoked otoacoustic emissions from apical and basal perilymphatic electrode positions in the guinea pig cochlea.

Stimulation of the cochlea with sinusoidal current results in the production of an otoacoustic emission at the primary frequency of the stimulus current. In this study we test the hypothesis that the wide frequency response from round window (RW) stimulation is due to the involvement of a relatively large spatial segment of the organ of Corti. Tonotopically organized group delays would be evident from perilymphatic electrode locations that restrict the spatial extent of hair cell stimulation. Monopolar and bipolar-paired stimulus electrodes were placed in perilymphatic areas of the first or third cochlear turns and the electrically evoked otoacoustic emissions (EEOAE) produced by these electrodes were compared to that from the RW monopolar electrode in the anesthetized guinea pig. Current stimuli of 35 microA RMS were swept across the frequency range between 60 Hz and 100 kHz. The EEOAE was measured using a microphone coupled to the ear canal. It was found that the bandwidth of EEOAEs from RW stimulation extended to at least 40 kHz and was a relatively insensitive to electrode location on the RW. The group delay of the EEOAE from stimulation at the RW membrane (corrected to stapes motion) was about 53 micros. First and third turn stimulations from electrode placements in perilymph near the bony wall of cochlea yielded narrower band EEOAE magnitude spectra but which had the same short group delays as for RW stimulation. A confined current (from a bipolar electrode pair) applied close to the basilar membrane (BM) in the first turn produced the narrowest frequency-band magnitude emissions and a mean corrected group delay of 176 micros for a location approximately 3 mm from the high frequency end of the BM (corresponding to about the 18 kHz best frequency location). Bipolar electrodes in the third turn scala tympani produced low pass EEOAE magnitude functions with corrected group delays ranging between approximately 0.3 and 1 ms. The average phase slopes did not change with altered cochlear sensitivity and postmortem. These data indicate that the EEOAE from RW stimulation is the summed response from a wide-tonotopic distribution of outer hair cells. A preliminary model study indicates that short time delayed emissions are the result of a large spatial distribution of current applied to perilymphatic locations possibly giving rise to "wave-fixed" emissions.

Animals↗
PubMed2002

A model for perilymphatic fistula induced hearing loss in the guinea pig cochlea.

In cases of sudden, reversible hearing loss where perilymphatic fistulas are thought to be the cause, a multitude of causes have been postulated. These include perilymphatic pressure changes, Simmons' double-break theory, perilymphatic hemorrhage, pneumolabyrinth, and others. This study was proposed to explore the role pneumolabyrinth may have in this pathology. Guinea pigs were fitted with cochlear perfusion pumps pumping artificial perilymph into the left scala tympani. One group of animals received a bubble ( approximately 1.5-2 microl) introduced into the scala tympani while the other group of animals received continuous infusion of artificial perilymph. The animals' cochlear function was monitored using distortion product otoacoustic emissions (DPOAEs) while the animals' behavior was assessed to evaluate for vestibular dysfunction. While unaffected by pump surgery, animals that received air into the scala tympani had their DPOAEs eliminated by day 2 after pump placement. On day 6, positional changes in the DPOAEs were observed where the left lateral decubitus position showed a sharp demarcation at 4 kHz, where lower DPOAE frequencies were abolished and higher ones minimally affected, with DPOAEs normal in the prone position. By days 8 and 20, DPOAEs recovered to normal amplitudes. Vestibular dysfunction was never detected in any animal that received a pneumolabyrinth. All control animals receiving a continuous perilymph infusion exhibited no loss of cochlear function throughout the testing period. The reversible nature of pneumolabyrinth induced hearing loss and the pneumolabyrinth's sole presence (without other possible causes of hearing loss, such as pressure differentials or round window membrane perforations) are powerful indicators of the role of air in the pathology of perilymphatic fistulas. In addition, the fluctuation of the hearing loss with positional changes supports the use of positional audiometry when evaluating perilymphatic fistulas.

Air↗