Bulging of the Oval Window in Common Cavity Deformity: A Possible Predictor of Meningitis

OBJECTIVE

To investigate the prevalence-rate of oval window bulging in the common cavity and its association with bacterial meningitis.

PATIENTS

CT and clinical files of 29 children with preliminary diagnosis of common cavity deformity were collected from 13 Italian centers.

INTERVENTION

A retrospective case review study was conducted with a centralized evaluation of the temporal bone CT imaging was performed at Azienda Ospedale - Università Padova, Padova, Italy.

MAIN OUTCOME MEASURE

Diagnosis of common cavity was reviewed; in addition, a fluid protrusion into the middle-ear cavity through the oval window at CT imaging was considered as oval window bulging. Its association with the history of bacterial meningitis was investigated.

RESULTS

Common cavity deformity was confirmed in 14/29 children (mean-age 11.4 ± 3.8; age-range 5-20; nine females) referred with this diagnosis. In 7/14 patients, the common cavity deformity was bilateral (i.e., 21 common cavities). Oval window bulging was found in 3/19 common cavities (concomitant middle-ear effusive otitis hampered the evaluation in two cases), while the internal acoustic meatus fundus was defective in 10/21 cases. History of bacterial meningitis was found in three children (21%) and two of them had oval window bulging at CT. In the case unrelated to oval window bulging, meningitis occurred late at the age of 12 during acute otitis contralateral to common cavity deformity (ipsilaterally to incomplete partition type 1).

CONCLUSION

Patients harboring common cavity deformity have a high risk of meningitis in their first years of life. Oval window bulging seems to be associated with a higher risk of meningitis. This information might be important for appropriate surgical planning.

Hyaluronate Gel Stapedotomy

OBJECTIVE: To evaluate hearing results and postoperative dizziness after stapedotomy with application of sodium hyaluronate gel (HG) to the oval window niche during fenestration of the footplate.

STUDY DESIGN: Case-control study comparing 27 stapedotomies with HG and 32 stapedotomies without HG.

OUTCOME MEASURE: Preoperative and postoperative audiometric data, postoperative dizziness (vertigo or dysequilibrium), and nystagmus.

RESULTS: Postoperative hearing results were not statistically different for the 2 groups. There were no cases of postoperative sensorineural hearing loss greater than 10 dB. Early postoperative dizziness (χ2 = 4.08, P = 0.043) and nystagmus (χ2 = 5.05, P = 0.024) were reduced in the HG group.

CONCLUSIONS: HG stapedotomy is safe and effective and results in less early postoperative dizziness and nystagmus when compared with the standard technique of stapedotomy. The application of HG to the oval window niche to prevent blood from entering or perilymph from escaping the vestibule during fenestration of the stapes footplate may contribute to a quicker recovery in outpatient otosclerosis surgery.

EBM rating: B-3b

Functional outcomes of Vibrant Soundbridge applied on the middle ear windows in comparison with conventional hearing aids

CONCLUSION

Vibrant Soundbridge (VSB) application to the middle ear windows yields better functional outcomes than conventional hearing aids. However, speech discrimination scores obtained with VSB and conventional hearing aids are similar.

OBJECTIVE

To assess audiological outcomes of round and oval window applications of VSB in comparison with conventional hearing aids.

METHODS

Nineteen adult patients were included in the study. The patients had mild to moderate, moderate or moderate to profound conductive or mixed hearing loss. During surgery the floating mass transducer (FMT) was placed on the round (n = 14) or oval (n = 5) window. After the surgery, audiometric evaluation and free field audiometric evaluation of both ears was carried out.

RESULTS

The hearing thresholds in the low frequencies were not significantly different between the conventional hearing aids and VSB. The functional gains obtained with oval and round window approaches were similar except for 500 Hz. The hearing thresholds in the mid and high frequencies were significantly better with VSB than the conventional hearing aids. The functional gain in the low frequencies was not significantly different between VSB and conventional hearing aids. The functional gain in the other frequencies was significantly better with VSB than conventional hearing aids.

Initial experiments to develop a MEMS transducer for a new implantable audioprosthesis to substitute the tympanic-ossicular system

CONCLUSION

We tested one prototype of a new audioprosthesis including the audioprocessor, the implemented algorithms and fitting platform in a small group of selected patients with mixed hypoacusis due to earlier bilateral radical mastoidectomy. It was effective to compensate the conductive and the neurosensory components of those patients. Results regarding the energy, frequency and other requirements of the output transduction make it possible to develop a suitable actuator with the available Micro-Electromechanic-Machine-System (MEMS) technology to substitute the conventional transducer of the prototype.

OBJECTIVES

The objectives were: a) to evaluate the effectiveness of the whole fitting system, and b) to obtain information about the required energy to design the MEMS actuator.

MATERIALS AND METHODS

The experiments were conducted with the A prototype of the prosthesis equipped with an output transducer coupled to the oval window. Two algorithms and three cases were tested.

RESULTS

The audioprocessor with the implemented FIR filter-67 coefficients paradigm algorithms, and the fitting system were shown to be adequate for clinical use. Effectiveness parameters were: pure tone average gains 20-33.3 dB; gap closure 25.5-31.8 dB; speech reception thresholds improvement 15-20 dB. Required gain: 5-40 dB. Subjectively, patients considered the results very satisfactory.

Dehiscences of the horizontal segment of the facial canal in otosclerosis

Dehiscences of the bony horizontal segment of the facial canal are rather common in human adults. These facial canal dehiscences occur most often in the region of the oval window. This study presents the observations of the facial canal in the oval window region in 427 operations for otosclerosis. The incidence of dehiscences in the facial canal to the middle ear space in otosclerosis was studied. Dehiscences were observed in 14 of the 427 patients (3.27%) who had a stapedotomy. This incidence is very low compared to the anatomical studies of the facial nerve in human cadaver temporal bones. Dehiscences of the facial canal are a variation of the normal anatomy of the facial nerve and these dehiscences occur sporadically in otosclerosis.

Morphometric and ultrastructural findings on human vestibular ganglion cells

Eight human temporal bones (4 patients) were fixed within 2 h after death by perilymphatic perfusion through the oval and round windows. After preparation, 30-micron-thick sections were cut for light microscopy and ultrathin sections for ultrastructural evaluation. Under the light microscope, the diameter, the circumference and the area of the vestibular ganglion cells were measured. The data were statistically analyzed. The histograms of cell measurements showed two maxima. When observing the diameter of cells, one was at 40 microns and the other at 28 microns. Under the light microscope, we could distinguish two cell types, which mainly differed in size and content of granules in the cytoplasm. Ultrastructurally we identified also two cell types: larger cells with many mitochondria, dark clusters of endoplasmic reticulum and a varying amount of dark-stained lysosomes in the cytoplasm and smaller cells with only few mitochondria, no lysosomes and an extended rough endoplasmic reticulum. None of the ultrastructurally analyzed ganglion cells were myelinated.

Validity of spontaneous perilymphatic fistula

In response to recent articles questioning the validity of some perilymphatic fistula diagnoses, another small series is presented, reconfirming the enigmatic clinical appearance of perilymphatic fistula. Histologic evidence and experimental pathophysiology that explain the varied symptoms are reviewed. A pressed-fat fibrin-glue technique that seems to prevent recurrences is described, as well as a technique that may be helpful in confirming the presence of inapparent fistulas in surgery. Argument is advanced that this is a safe, minor surgical procedure helpful in alleviating vestibular and/or auditory symptoms in more than 70% of patients.

Correlation of beta-2 transferrin and middle ear abnormalities in congenital perilymphatic fistula

Congenital perilymphatic fistula (PLF) as a diagnosis for progressive, fluctuating, or sudden sensorineural hearing loss with or without vertigo is still controversial. Beta-2 transferrin is a protein that is unique to cerebrospinal fluid, aqueous humor, and perilymph. A recent pilot study demonstrated that beta-2 transferrin may be an objective test to determine the existence of a congenital PLF. The authors prospectively evaluated and recommended surgery for 43 children with suspected PLF over the past 3 years. A prospective, blinded study was performed by having the attending otolaryngologist evaluate the middle ear at the time of surgery for a PLF and any middle ear abnormalities. Samples of fluid were collected from the oval and round windows and were tested for beta-2 transferrin. Of 16 patients undergoing tympanoplasty or tympanomastoidectomy who served as controls, none were positive for beta-2 transferrin. Of the 43 patients undergoing exploratory tympanoplasty for PLF, 20 (46.5%) were considered to be negative for PLF on microscopic visualization; 23 (53.5%) were found to be positive. Of the 20 patients thought to be negative for PLF, 18 (90%) tested negative for beta-2, but 2 of these patients were positive for beta-2, and both had a congenital middle ear abnormality. Of the 23 patients found to have a PLF at surgery, 6 (26.1%) tested positive for beta-2, and all of these 6 had middle ear abnormalities. Of the 17 patients negative for beta-2, 9 had normal anatomy; 6 had middle ear abnormalities, and 2 had erosive changes. The authors conclude that beta-2 transferrin, an objective test, confirms the existence of congenital PLF in children, which is associated with middle ear abnormalities.

A case of Tullio phenomenon in a subject with oval window fistula due to barotrauma

The Tullio phenomenon is defined as vertigo that occurs as a result of extremely high acoustic stimuli. Stimulation of the system of semicircular canals and otoliths causes nystagmus, reflex head tilt and body sway, and vertigo to occur. This condition is quite rare. The Tullio phenomenon was diagnosed in a patient with a fistula of the oval window due to barotrauma. It was diagnosed after a careful examination by Frenzel's glasses. The complaints of vertigo disappeared after the fistula had been closed surgically.

[Granuloma of the oval window after stapedectomy]

A case report is presented of a female patient who underwent stapedotomy with bad functional results Reoperation revealed a dislocated prosthesis and there was no successful hearing. Besides conduction deafness perceptive deafness occurred as well. The second reoperation disclosed reparative granuloma around the prosthesis, while histological analysis showed foreign-body granuloma. Foreign-body granuloma by stapedectomy is extremely rare and it was the first case in our 810 surgically treated ears.

Treatment and management of perilymphatic fistula: a New Hampshire experience

From August of 1975 to June of 1990 the author managed 45 cases of spontaneously occurring perilymphatic fistula. Twenty-nine of the 45 cases were reported in 1988. In the series there were eight patients with bilateral involvement, seven with involvement of both oval and round window in the same ear, and seven with fistulas believed to be of congenital origin. Seventeen patients (38%) required revision surgery. Occasionally adjunct modalities (endolymphatic shunt, labyrinthectomy, blocking a cochlear aqueduct, and streptomycin ablation) were used for symptom control. Diagnosis, treatment, and management of these patients is discussed.

Stapes surgery: complications and airway infection

From a group of 1,111 patients who had stapedectomy or stapedotomy performed in a 10-year period, a thorough investigation was made of 11 patients who had a total hearing loss and 8 patients who developed a partial sensorineural hearing loss after operation. The data obtained indicate that postoperative infection with influenza virus may be responsible for unexpected complications following stapedectomy. A close relation was found between the appearance of complications and periods of epidemics of influenza.

[Physical separation of the populations of cochlear and vestibular efferent somas. A study using horseradish peroxidase]

We have physically separated cochlear and vestibular end organs, and after injecting horseradish peroxidase two different populations of efferent somas have been described belonging to the cochlea and vestibule.

Perilymph fistula--a diagnostic dilemma

A retrospective series is presented of 51 cases operated on for suspected perilymph fistula. In 26 ears a fistula was identified at surgery. A positive fistula test was found to strongly indicate a perilymph fistula but was more often negative than positive in surgically demonstrated fistula ears. Other vestibular tests were found to be of little value in the pre-operative diagnosis. Ears with a surgically demonstrated fistula and sensorineural hearing loss had either flat or downward-sloping audiograms. Difficulties in diagnosing a perilymph fistula at tympanotomy are discussed. At follow-up, vestibular symptoms were found to be eliminated or improved in 96 per cent of cases with surgically demonstrated fistulae and in 68 per cent of cases in which no fistula was detected at tympanotomy but hearing improved significantly in only one ear (4 per cent) of the former group and in five ears (20 per cent) of the latter group.

Round window reflex and oval window fistulae

The round window reflex is normally absent in stapedial fixation. In this study, six cases of oval window fistula are described in which the round window reflex was absent. This is probably because there is insufficient pressure transmitted to the round window membrane through the perilymph because of leakage from the oval window. This is considered as an important diagnostic sign of oval window/stapes footplate ligament disruption.

ECoG results in perilymphatic fistula: clinical and experimental studies

Patients with perilymphatic fistula have been described as having symptoms similar to Meniere's disease and endolymphatic hydrops. Direct clinical or experimental evidence linking the two inner ear disorders has been lacking. An enhancement of the summating potential observed with electrocochleography suggests a diagnosis of ELH in both of these inner ear disorders. In this study, ECoG results of 27 patients with surgically confirmed PLF are reported. Fourteen patients with surgically confirmed spontaneous PLF had abnormal ECoG. Six of these 14 patients had normal hearing. The ECoG changes in patients with Meniere's disease and those with surgically confirmed PLF are identical, indicating the underlying pathologic change in both is hydrops. But there is no specific diagnostic abnormality on ECoG that differentiates these two inner ear disorders. Also, an experimental model of PLF was developed and studied in guinea pigs. "Inactive" PLF is defined as "an opening was made into the cochlea, but if no perilymph moved out through the fistula, it was defined as inactive" An "active" PLF occurs when perilymph actually moves from the inner ear out to the middle ear. ECoGs were recorded before and after creation of an "active" PLF. ECoG abnormalities were seen in "active" PLF and correlated with histologic data demonstrating ELH. An abnormally enhanced summating potential was demonstrated after active removal of perilymph through the experimentally created fistula. Cochlear duct histology showed hydropic distention of Reissner's membrane in the experimental ears and no changes in the membranous labyrinths of the unoperated, control ears.(ABSTRACT TRUNCATED AT 250 WORDS)

Perilymph fistula: an important cause of deafness and dizziness in children

This study underscores the importance of considering a perilymph fistula, an abnormal communication between the inner and middle ear, in any child with a progressive sensorineural hearing loss. A concomitant complaint of intermittent dizziness or observed spells of imbalance (56%) is another indication of the disease. Six of 16 patients (37.5%) with proven fistulas were less than 2 years of age at the onset of symptoms. Unless the fistula is identified and repaired by grafting, the ear may become totally deaf. This would be disastrous in the presence of bilateral fistulas, which occur commonly in children (56% of patients had symptoms of bilateral disease). Our experience in recognizing and treating fistulas and thereby saving and restoring hearing is described.

Two emerging perilymph fistula "syndromes" in children

This paper proposes two relatively common "syndromes" seen in children with perilymph fistulas using illustrative case reports. One, a 2 1/2-year-old child with bilaterally symmetric progressive sensorineural hearing loss, was found to have bilateral oval and round window fistulas. The other was a child who presented originally with an unexplained unilateral sensorineural loss. It was only when hearing deteriorated in the opposite ear several years later that a perilymph fistula was suspected and confirmed by tympanotomy. The clinical presentations and other details of these cases diverge widely, but may represent two emerging syndromes of perilymph fistulas in children: 1. a congenital or hereditary predisposition, and the other, 2. sudden hearing loss in the "good" ear of children with an unexplained sensorineural hearing loss in the opposite ear.

Delayed onset hearing loss in a two-year old

This paper describes a delayed onset sensorineural hearing loss in a baby known to have normal hearing until at least 13 months. A mild high-frequency loss was discovered quite by accident at 25 months. The bilaterally symmetrical loss progressed over the next 6 months to no measurable high-frequency hearing and a 70 dB threshold at 500 Hz. To our knowledge this is the youngest completely documented case of what has been called hereditary delayed onset hearing loss. However, in this instance, and perhaps unsuspected in others, this child had bilateral oval and round window fistulas whose repair may have not only arrested the progression of her loss, but even improved her residual hearing sensitivity.

Conservative management of inner ear barotrauma resulting from scuba diving

Fourteen patients who experienced inner ear barotrauma (IEBT) while scuba diving were examined shortly after the episode and were followed up until symptoms resolved or stabilized. On the basis of these observations and a review of the literature, three types of IEBT are hypothesized that usually result from forceful autoinflation of the middle ear: (1) hemorrhage within the inner ear, (2) labyrinthine membrane tear, and (3) perilymph fistula through the round or oval window. Presenting symptoms, treatment regimens, and final results are detailed.

Bilateral congenital oval window microfistulae in a mother and son

This article details case histories of a son and his mother who were studied over a seven-year period before making the diagnosis of bilateral oval window microfistulae in both of them. The boy demonstrated a slowly progressive bilateral and symmetrical sensorineural hearing loss closely resembling that of his mother. The case reports emphasize their respective histories, diagnostic evaluation, surgical observations, and treatment.

Stapedectomy revision following sensorineural hearing loss

This study analyzes 71 stapedectomies that resulted in a sensorineural hearing loss, followed by a revision stapedectomy on the suspicion of an oval window fistula. The cases were divided between two primary stapedectomy techniques: a stainless steel Robinson prosthesis on a vein graft and a wire prosthesis with Gelfoam. The major differences between the surgical findings of the two groups were the fistula rate with the wire prosthesis was 10 times that with the Robinson prosthesis; the wire prosthesis was longer than necessary in 21% of the cases in which it was used; there was no finding of excess length with the Robinson prosthesis; and after revision stapedectomy, dizziness was lessened in 20% of the patients in the Robinson prosthesis group, in 60% of those in the wire prosthesis group, and in 75% of those with fistula. Surgical directions are given for revision stapedectomy following a sensorineural hearing loss.

Perilymphatic fistula--a definitive and curable cause of vertigo following head trauma

Vertigo or disequilibrium occurring in patients after concussive and nonconcussive head trauma may be due to a pathologic perilymphatic fistula from the inner ear through the oval and round window areas of the middle ear. Of 33 patients who had successful grafting of the fistulous area at middle ear exploration, 32 had resolution of vertigo, and 12 of 23 who had an associated hearing loss had improved hearing. Perilymphatic fistulas associated with vertigo and hearing loss after head trauma can be diagnosed with great certainty and are surgically curable in the great majority of cases. Patients with post-concussive syndrome, whose symptoms include vertigo or disequilibrium, should have a thorough otologic evaluation for the possibility of a perilymphatic fistula.

Distribution of HRP in the inner ear after injection into the middle ear cavity

The distribution patterns of horseradish peroxidase (HRP) reaction products in the inner ears of guinea pigs were studied after injections into the middle ear cavities and perilymphatic and subarachnoid spaces. The normal round window membrane resisted HRP penetration from the middle ear side, but when it became pathological after repeated applications, its permeability increased. HRP deposits were found in the cochlear and vestibular sensory cells and in the lumen of the endolymphatic sac. HRP reaction products were minimal at the cochlear apex even after long survival times, suggesting that perilymph flow, if it exists, is rather weak toward this direction. Whereas the stria vascularis is impermeable to HRP, the vestibular dark cells were accessible; thus, the metabolic activity of the dark cells can be more readily controlled by drug applications through the middle ear cavity. The finding of HRP deposits on the scala vestibuli surface of Reissner's membrane and the absence of HRP in the upper portion of the spiral ligament at the basal turn suggests that the oval window is a secondary route of passage for these particles from the middle ear cavity to the inner ear. In order to determine the route of HRP into the endolymphatic sac from the middle ear cavity or scala tympani, the cochlear and/or vestibular aqueducts were obliterated singly or together. The route of HRP was determined to be the vestibular aqueduct. HRP is believed to enter the sac lumen through Reissner's and saccular membranes and the sac epithelium. Drugs and other large molecular substances instilled in or gaining access to the middle ear cavity may reach the endolymphatic sac causing its functional alteration.

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.

Recurrent meningitis, congenital anacusis and Mondini anomaly

Temporal bone polytomography should be performed in cases of recurrent meningitis, anacusis and vestibular areflexia. The finding of a Mondini-type anomaly is indicative of an oval window fistula. A further case is described, and scanning electron microscopic views of the defect in the stapedial footplate presented. Dysplasia of the otic capsule is considered to be the probable cause of this syndrome.

Failures in surgery for stapedial otosclerosis

The causes for failure in surgery for stapedial otosclerosis are many. Most of these occur in the early postoperative period. Failures occurring later are due to either a breakdown of the reconstructed transformer system or to a labyrinthitis due to failure of the vestibular seal. The role of cochlear otospongiosis in producing late failures has not been sufficiently emphasized. This clinical review of 105 surgical failures examined consecutively during the years of 1975 through 1979 will demonstrate the importance of cochlear otospongiosis in this consideration. The fate of the unoperated-on ear in unilateral surgical failures will be demonstrated. Control of the progressive sensorineural hearing loss in these instances can be gained by the use of sodium fluoride therapy.

The case for small fenestra stapedectomy

Eight hundred stapedectomies were analyzed to evaluate the long-term results with four prostheses. It was concluded that limitation of fenestra size played a most important part in the outcome of stapedectomy, especially in regard to the preservation of high-frequency bone conduction response over prolonged periods. Other advantages deriving from small fenestra stapedectomy included significantly fewer fistulae and severe sensorineural losses.