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PubMed1973

Meniere's disease study: three-year progress report.

The results of a three-year study of 120 patients with Meniere's disease has revealed multiple but specific etiology for 48 percent of the patients: (1) Allergy-14 percent (2) Congenital or acquired syphilis-7 percent (3) Adrenal pituitary insufficiency-6 percent (4) Hypothyroidism-3 percent (5) Stenosis of the internal auditory canal-3 percent (6) Trauma, acoustic or physical-3 percent (7) Combination of the above-12 percent. Emotional or psychiatric factors are not involved in the etiology of this disease. The vestibular and cochlear aqueduct on both temporal bones of patients with Meniere's disease could not be visualized in a significantly greater number than a normal control group suggesting an anatomic predisposition to the development of Meniere's disease. Preliminary immunologic viral investigation suggests the possibility of viral etiology in the remaining group considered idiopathic. It is hoped that this study will encourage other investigators to criticize and help intensify our efforts to solve the questions remaining about Meniere's disease.

Adrenal Insufficiency↗
PubMed1983

Clinical implications of experiments on alteration of the labyrinthine fluid pressures.

Hearing is affected by changes in hydrostatic pressure of the perilymph, but very high pressures are required to produce a significant loss. Among the observed findings in cats are a rapidly reversible decrease in the sensitivity of the cochlear microphonic that is greater for low frequencies, harmonic distortion and reduction of dynamic range as measured by the input-output function for the cochlear microphonic, and a change in the summating potential from negative to positive. These changes are attributed to a temporary reduction in the size of the cochlear duct due to a shift of water molecules out of the cochlear duct into the blood until the resulting increase in osmotic pressure balances the increase in hydrostatic pressure. Consequently, the organ of Corti is biased "upward" away from the scala tympani. Increasing the hydrostatic pressure of the endolymph produces a "downward" biasing of the organ of Corti and has an opposite effect upon the summating potential. Presumably this is what happens in Meniere's disease. Because of the presence of the perilymphatic canaliculi, the locus of the hydrostatic pressure effect is assumed to be in the region of the reticular lamina. A theory has been developed to explain why cochlear function is very sensitive to relative differences between the hydrostatic pressures of the perilymph and the endolymph but is resistant to large variations in the absolute magnitudes of those pressures. Some of the clinical implications of this theory are discussed.

Animals↗
PubMed1978

Spontaneous perilymphatic fistula.

Sudden hearing loss from spontaneous perilymphatic fistula in a child managed by prompt surgical intervention and with recovery of hearing has not previously been reported. The historical and contemporary theories of fistula formation are reviewed. A child with spontaneous oval window rupture associated with a congenital malformation of the stapes and cochlear aqueduct is described together with his complete recovery of hearing following surgical repair. Some rationales explaining the mechanism of oval window rupture in this patient are suggested.

Adolescent↗
PubMed1978

Rupture of the round window membrane.

The mechanism of development of rupture of the round window membrane appears to be an increase in pressure in the cerebrospinal fluid transmitted to the inner ear via the cochlear aqueduct. Two cases of rupture of the round window membrane in divers are described in detail. One diver had ruptures of both round window membranes following difficulty in autoinflating when diving, and the other had a rupture of one round window membrane, having presented with acute prostating vertigo and normal hearing. Surgical repair restored the hearing in the former case and preserved normal hearing in the latter. The similarity between ruptures of the round window membrane and poststapedectomy fistula is emphasized, and it is suggested that spontaneous healing of ruptures may well occur. A case history supporting this hypothesis is presented. The technique of repair of ruptures of the round window membrane is described as well as postoperative management. Normal nasal function in divers is essential if inner ear barotrauma and ruptures of the round window membranes are to be avoided.

Adult↗
PubMed1981

Inner ear pathology in deaf mutism.

This is a report of the inner ear pathology found in a pair of temporal bones from a deaf mutism case. This patient's spouse and four of six children were deaf mutes. Some members in the succeeding generation were also known to be deaf mutes. The temporal bones (horizontally sectioned) showed the cochleo-saccular degeneration with exactly similar extent bilaterally. The scala media and the saccular space were atrophied, and displaced membranes were attached onto the degenerated sensory epithelia in many areas, but some portion of the scala media exhibited an ectatic view. The cochlear and saccular nerves were severely reduced. In addition to the pathology found in the pars inferior, the internal auditory canal and the cochlear aqueduct were enlarged. All end organs and nerves in the pars superior were intact.

Aged↗
PubMed1995

[Stapedectomy in congenital stapes fixation].

Because several cases of cerebral-spinal fluid leakage (perilymph gushers) have been reported during stapedectomy for congenitally fixed stapes in children, many otologists advise against surgical intervention. The pathophysiologic mechanism of the gusher and its association with a congenitally fixed stapes is, however, poorly understood. This study was designed to examine the pre-operative presentation and hearing results of 10 children undergoing stapedectomies for congenital fixation. No perilymph gushers of significant sensorineural hearing loss was encountered. All but one case resulted in closure of the air-bone gap and speech frequencies to within 20 dB. The average air-bone gap was 11.2 dB. Minor congenital abnormalities of the stapes suprastructure were seen in 3 cases. Review of case reports in the literature indicate that gushers in association with surgical manipulation of the congenitally-fixed stapes occur almost exclusively in males and that pathophysiology involves a defect in the internal auditory canal (as opposed to a patent cochlear aqueduct). A pre-existing sensorineural hearing loss may also be a risk factor for perilymph gusher.

Adolescent↗
PubMed1994

[Hearing loss following lumbar puncture: case report and literature study].

This report describes a patient with permanent hearing loss after spinal anesthesia. The literature is reviewed, particularly concerning incidence and possible causes. The incidence is surprisingly high and related to the size of the needle. The role of the cochlear aqueduct as a transmitter of a decreased fluid pressure in the subarachnoid space to the perilymph of the labyrinth is discussed.

Aged↗
PubMed1994

Perilymphatic fistula--the value of diagnostic tests.

Perilymphatic fistula (PLF) remains one of the most challenging problems in otological practice. Fifty-two consecutive patients (53 ears) who underwent explorative tympanotomy for suspected PLF between 1985-1992 were included in this study. The clinical picture, history, patients' complaints and laboratory tests were analysed and compared with the operative findings. The conclusions of our work are that the diagnosis of PLF is based mostly on the clinical picture and a battery of laboratory diagnostic tests, but no one test is truly diagnostic for PLF.

Adult↗
PubMed1993

[Reversible hearing loss in the contralateral ear after surgery of acoustic neurinoma].

In a prospective study of 12 patients undergoing operation for acoustic neuromas, the hearing on the contralateral ear was tested before and systematically after operation. In 11 cases a perceptive loss of at least 20 dB was found at one or more frequencies during the first two postoperative weeks. The maximal average threshold decrease was 16.5 dB in the treble and 19.6 in the low frequencies. After three months the hearing had normalized in all cases. The loss of cerebrospinal fluid during operation diminishes the CSF pressure, which is then transmitted to the perilymph via the cochlear aqueduct, producing a transitory perilymphatic hypotonia and a relative endolymphatic hypertension mimicking an endolymphatic hydrops.

Adult↗
PubMed1994

Cochlear dysplasia and meningitis.

Congenital dysplasias of the labyrinth of the inner ear are associated with varying degrees of hearing loss. There is a risk of a fistulous communication between the subarachnoid space and the middle ear cavity in some cases that present either as cerebrospinal fluid otorhinorrhea or as recurrent attacks of meningitis. The types of deformity where such a fistula is likely have not been clearly defined. The authors correlated the hearing state with the imaging assessment in 20 patients with congenital malformation of the labyrinth and, in particular, the cochlea. In addition the postmortem histologic findings from one patient with severe cochlear dysplasia who died from otogenic meningitis are described. The key to the assessment is the basal turn of the cochlea. If the basal turn is present and of normal caliber then some hearing is possible and there is no risk of a major fistula. However, if the basal turn is wider than normal or replaced by an undeveloped sac then there is anacusis and very real risk of fistula. In such cases the deformed labyrinth needs to be packed with fibrofatty tissues after just one attack of meningitis.

Adolescent↗
PubMed1995

Stapedectomy for congenital fixation of the stapes.

Because several cases of profuse cerebrospinal fluid leakage (perilymph gushers) have been reported during stapedectomy for congenitally fixed stapes in children, many otologists advise against surgical intervention. The pathophysiologic mechanism of perilymph gusher and its association with congenital fixation of the stapes is, however, poorly understood. This retrospective study was designed to examine the preoperative presentation and hearing results of children undergoing stapedectomy for congenital fixation of the stapes. Stapedectomy was performed on 10 ears for this condition. No perilymph gushers or significant sensorineural hearing loss were encountered. All but one case resulted in closure of the air-bone gap at the speech frequencies to within 20 dB, with the average air-bone gap being 11.2 dB. Minor congenital abnormalities of the stapes superstructure were seen in three cases. A review of case reports in the literature would seem to indicate that the perilymph gusher in association with surgical manipulation of the congenitally fixed stapes occurs almost exclusively in males, and that the pathophysiology involves a defect in the internal auditory canal as opposed to a patent cochlear aqueduct. A pre-existing sensorineural hearing loss may also be a risk factor for perilymph gusher.

Adolescent↗
PubMed1997

Surgical anatomy of the transtemporal approaches to the petrous apex.

HYPOTHESIS: This study was undertaken to compare the subcochlear and infralabyrinthine approaches to the petrous apex. BACKGROUND: Both approaches are advocated to drain cholesterol granuloma or biopsy lesions of the petrous apex. There is little data directly comparing these approaches. METHODS: Anatomic dissections were performed on 20 preserved temporal bones. The anatomic distances were measured to the nearest quarter millimeter using a two-point needle caliper. Measurements were repeated three times and averaged. RESULTS: The average window created through the subcochlear approach was 9.41 x 7.33 mm. The approach is performed between the carotid artery, jugular bulb, and basal turn of the cochlea, and gives a roughly triangular window in most cases. The cochlear aqueduct and glossopharyngeal nerve may be exposed during this approach. The subcochlear approach provided a more consistent exposure (SD of 3.5 x 1.9) and was always possible. Still, the exposure obtained through this approach may be limited if the hypotympanic air cell tract is sclerotic. The infralabyrinthine approach gave adequate exposure in most cases, but a high-lying jugular bulb obstructed this approach completely in eight of 20 cases. The average window created was 4.99 x 7.23 mm (SD 4.4 x 1.3). CONCLUSIONS: The availability of a particular approach to the petrous apex and the exposure obtained varies considerably in individual cases. The choice of a surgical approach to the petrous apex should be influenced by the location of disease, the type of disease, the existing anatomy, and the experience of the surgeon.

Cochlea↗
PubMed1997

[Non-invasive monitoring of intracranial pressure changes through the ear].

Otoacoustic emissions are low energy vibrations generated by the inner ear during the physiologic process of hearing. The authors measured transiently evoked otoacoustic emissions in normal hearing individuals placed in Trendelenburg position and during diagnostic elevation of intracranial pressure in neurosurgical patients. In Trendelenburg position and at elevated intracranial pressure and reproducible phase shift of otoacoustic emissions could be observed. This phase shift was linear to the pressure increase of intracranial liquids. According to the hypothesis of the authors intracranial pressure increase is transmitted to the inner ear (possibly by the cochlear aqueduct) and thereby the mechanical load on the stapes footplate is elevated. This, in turn, causes a stiffening of the annular ligament which changes the angle of the impedance vector and thereby the phase of the whole vibrating system. By measuring the phase of otoacoustic emissions it is possible to monitor intracranial pressure in various clinical states.

Ear, Inner↗
PubMed1976

[A case of spontaneous CSF otorrhea associated with recurrent meningitis (author's transl)].

A 5-year-old girl was admitted to our hopsital on June, 1972, because of meningitis and CSF otorrhea. She had not suffered from head trauma or otological infective disease. Right temporal craniotomy was carried out on October, 1972, but no pathological findings on the anterior surface of the petrous bone was detected, so, the right middle ear bottom was packed with fascia graft by otologist, which stopped the CSF otorrhea for seven months. But the otorrhea recurred on June, 1973, when she caught cold. She was readmitted to our hospital because of recurrent meningitis. On November 7, 1973, when the meningitis abated, posterior fossa exploration was performed microsurgically. Strong arachnoid adhesion due to recurrent meningitis and enlargement of the right internal auditory meatus was observed. Probe could be inserted into the internal auditory meatus easily at a depth of 1.5 cm. Saline which was injected into the meatus from the probe flowed into the right middle ear. So the internal auditory meatus was packed with Gelfoam and muscle piece. By means of this procedure, CSF otorrhea was healed completely. Spontaneous CSF otorrhea, which was initially reported in 1897 by Escat, is a very rare disease. Only 15 cases have been reported in the literature. Two main possible routes of CSF leakage were reported, the one is via the internal auditory meatus, the other is via the cochlear aqueduct (Fig. 3). The former cases were more frequent than the latter. Our case belongs to the former type. (Fig. 4)

Cerebrospinal Fluid Otorrhea↗
PubMed1998

Hearing loss with cochlear modiolar defects and large vestibular aqueducts.

OBJECTIVE: Defects of the cochlear modiolus have been found to be associated with most cases of large vestibular aqueduct. The clinical significance of these modiolar defects has not been studied previously. The purpose of this article is to correlate clinical (functional) parameters, such as hearing outcomes, with the severity of the radiographic findings in these dysplastic inner ears. STUDY DESIGN: The study design was a retrospective chart review, supplemented with telephone interviews and clinic visits. SETTING: The study was conducted at an academic, tertiary care center. PATIENTS: Thirty consecutive patients with large vestibular aqueducts participated. RESULTS: Scores of modiolar deficiencies yielded inconsistent correlations with hearing loss. Vestibular aqueduct morphology and thickness correlated very strongly with the severity of hearing loss. CONCLUSIONS: These observations support the hypothesis that large vestibular aqueduct-related hearing loss may be caused by transmission of subarachnoid pressure forces into the inner ear. However, the thickness and morphology of the vestibular aqueduct may simply be markers for more subtle cochlear dysplasia manifest by modiolar deficiency.

Adolescent↗
PubMed2002

Cochlear implantation with large vestibular aqueduct syndrome.

OBJECTIVES: In this investigation, we report the outcomes of 14 adults (age >18 y) and 9 children (age <18 y) with radiographically proven large vestibular aqueduct syndrome (LVAS) who received cochlear implants at Indiana University School of Medicine. STUDY DESIGN: This is a retrospective case-control study detailing the outcomes of 23 patients with LVAS and 46 control patients implanted with Nucleus (Cochlear Corp., Englewood, CO), Clarion (Advanced Bionics Corp., Sylmar, CA), or Med-El (MED-EL Corp., Innsbruck, Austria) cochlear implants. METHODS: Performance data on pure-tone averages, speech detection thresholds, and a variety of auditory and speech recognition tasks from these patients with LVAS were compared with performance data obtained from a matched group of 46 cochlear implant users who did not have LVAS. Specific patient characteristics used in matching included the age of the patient, the age at implant of the patient, and whether the patient was pre- or postlingually deafened. Data for the adult group was analyzed using the Student t test, and data for the pediatric patient group was compared using a chi2 test. RESULTS: The results indicated positive outcomes for both pediatric and adult groups. With both adult and pediatric groups, auditory and speech recognition performance did not differ significantly between those patients with LVAS and control subjects. CONCLUSIONS: This study adds further support for the use of cochlear implantation in patients with LVAS. Cochlear implantation is beneficial and can be offered as an eventual treatment of LVAS if hearing loss progresses to profound levels in these patients.

Audiometry↗
PubMed1997

Large vestibular aqueduct syndrome and its implication for cochlear implant surgery.

The large vestibular aqueduct syndrome (LVAS) is commonly found when presurgical computed tomography is performed in advance of cochlear implantation. We present data on two patients with LVAS, in whom computed tomography (CT) and magnetic resonance imaging (MRI) was performed. Cochlear implantation when these malformations are present may be complicated by an intraoperative gusher, but it appears to be safe and produces a favorable outcome.

Child, Preschool↗