A ventilation capacity test for the Eustachian tube using a soundproof pressure chamber

Using a soundproof pressure chamber, we performed Békésy air conduction audiometry at 1000 Hz under the following pressure conditions: 1) from atmospheric pressure (AP) to 200 mmH2O below AP, 2) AP to 200 mmH2O above AP, 3) AP to 700 mmH2O below AP, and 4) AP to 700 mmH2O above AP. In conditions 1) and 2), the patient was instructed not to swallow until the pressure change was complete, then to swallow once every 15 seconds. The number of swallows required for hearing to return to the baseline level was counted. In conditions 3) and 4), the patient was told to swallow as many times as possible both before and after completion of the pressure change; maximum hearing level and the time needed for return to the baseline level were measured. Although all except one of the seven patients with suspected tubal dysfunction showed normal results with catheter insufflation and tympanometry, six of the seven showed abnormality and one reported the disappearance of ear stuffiness after the ventilation capacity test. We concluded that this test is useful not only for the diagnosis of tubal dysfunction but also as a possible therapy for aiding adaptation to changing environmental pressure.

Measurement of cochlear basilar membrane traveling wave velocity by derived ABR

Auditory brainstem response (ABR) can be used to measure the basilar membrane traveling wave velocity (TWV). Traveling wave velocity was calculated from the latency difference between wave V of different derived ABR and the cochlear location distance between the appropriate derived band center frequency. The latency of wave V of derived ABR produced by 6 noise-masked ABR using high pass filtered noise and the location of the corresponding cochlear partition (distance from the stapes foot-plate) were measured, and five traveling wave velocities were estimated based on this parameter. Ten subjects with normal hearing, 7 patients with Meniere's disease, and 8 patients with sensorineural hearing loss were used in this study. The traveling wave velocity in the sensorineural hearing loss group was within normal limits at all frequencies, whereas the traveling wave velocity at 8 kHz in the Meniere group greatly exceeded that of the normal and sensorineural hearing loss group.

Frequency analysis of transiently evoked otoacoustic emissions in sensorineural hearing disturbance

Transiently evoked otoacoustic emissions (TEOAE) are present in nearly all normal hearing ears and recognized as useful for objective auditory screening. In the spectral analysis of TEOAE with click stimuli, the normal power spectrum of TEOAE has yet to be obtained. In this study, the normal range of the power spectrum was determined for 42 adults with normal hearing and compared with sensorineural hearing disturbance data. The power spectrum of TEOAE in normal hearing adults sloped down at high frequencies and was the same for right and left ears in both males and females. For comparison with sensorineural hearing disturbance, a significant correlation between the audiogram and power spectrum of TEOAE was sought. Frequency specificity was noted in the power spectrum of TEOAE with click stimulation.

Tinnitus evaluation using the tinnitus grading system

We developed a system to help evaluate the likelihood of a particular patient requiring intensive tinnitus treatment. The system is based on Vernon's tinnitus grading system, in which patients assign values from 1 to 5 to each of the three subjective complaints of loudness, annoyance, and interference with life activities. In our study, we collected data from 346 of our tinnitus patients and analyzed the relationship between the three values. On the basis of these results the patients were divided into five tinnitus-type groups. Scores on a tinnitus severity scale were also determined by adding the three values together. We similarly evaluated 87 patients whose tinnitus was severe enough to require hospitalization. It was found that patients who had high values for annoyance and life interference and who showed tinnitus severity scores of 9 or more tended to require careful observation and intensive treatment. These patients also tended to have physical and psychological problems in addition to their tinnitus.

Pressure test for the diagnosis of Menière's disease

In the last 15 years, a pressure chamber able to generate negative air pressure has been used to treat patients with Menière's disease. In this study we sought to clarify whether the underpressure chamber can be used to diagnose Menière's disease. We studied 45 ears from patients with neurotological diseases. The subjects were placed supine in a soundproof pressure chamber. The pressure was first decreased to -500 mmH2O, and after 5 min to -700 mmH2O. The pressure was kept at this level for another 5 min and then increased to 0 mmH2O. This procedure was done three times in succession. While the chamber pressure was below 0 mmH2O, the subjects were instructed to abstain from actively equilibrating middle ear pressure. When the chamber pressure was raised to 0 mmH2O, they were instructed to equilibrate middle ear pressure, and if necessary Politzerization or catheterization of the Eustachian tube was done. As a result, hearing was improved after this procedure only in patients with Menière's disease (50%) and/or cochlear Menière's disease (32%) in which endolymphatic hydrops was suspected.

Effect of atmospheric pressure on hearing in patients with Menière's disease

Hearing in patients with Menière's disease improved when they were treated in an underpressure chamber. In this study 46 patients with neurotological diseases, including 32 cases of Menière's disease, were tested in an overpressure chamber. As a result, hearing in 32% of the patients with Menière's disease improved, although this was lower than the 50% rate of improvement in Menière's disease patients tested in an underpressure chamber.

Menière's disease

Menière's disease is one of the most common etiologies for dizziness in the United States. The mainstay of therapy for Menière's is medical therapy. Symptomatic treatment is employed, but long-term prophylaxis is emphasized, with salt restriction and diuretic administration as needed. A prophylactic approach can prevent many attacks and ameliorate those that do occur. Patients with moderate to severe symptoms who fail medical therapy may be candidates for endolymphatic sac surgery, since this procedure is successful in a majority of patients and has low morbidity. Those patients in whom an endolymphatic shunt fails and who continue to have severe symptoms may undergo selective sectioning of the vestibular nerve, while patients with no residual hearing may be offered translabyrinthine nerve section.

Factors influencing results with streptomycin perfusion of the labyrinth

Streptomycin perfusion of the labyrinth is the logical choice of treatment for the third stage of Meniere's disease with intractable vertigo. The results of streptomycin perfusion of the labyrinth are comparable to those of other treatments, including endolymphatic shunt and vestibular nerve section. Refinements must be made in the process of selecting candidates for the operation. To study the factors influencing the results of streptomycin perfusion of the labyrinth, 144 patients who had streptomycin perfusion of the labyrinth and were followed for 1 year were studied using the 1972 AAOO classification of results. The findings of this study indicate that only a low dosage of streptomycin and a small volume of perfusate are required to obtain good results. Patients who have long lasting severe endolymphatic hydrops with poor hearing preoperatively are less likely to achieve good results.

An electrocochleographic study of acute low-tone sensorineural hearing loss

Twenty-four patients with acute low-tone sensorineural hearing loss (ALHL) were examined using electrocochleography. The negative summating potential (SP) amplitude and the summating potential/action potential (AP) ratio were significantly greater in the ALHL patients than in normals. The SP/AP ratio was smaller in the ALHL patients than in patients with known Meniere's disease and moderate hearing loss, although the SP amplitude was somewhat greater in the former. An abnormal increase in the SP amplitude following click stimuli was found in 54% of the ALHL patients, while the SP/AP ratio was increased abnormally in 63% of these patients. These findings suggest that the pathophysiology of ALHL may be similar to that for endolymphatic hydrops.

Sensory interaction platform posturography in patients with Ménière's syndrome

INTRODUCTION

The influence on balance by the peripheral vestibular disturbance in Ménière's disease is studied. The influence of visual and proprioceptive support in balance is evaluated.

MATERIALS AND METHODS

Patients with recurrent spontaneous vertigo attacks (n = 134) were studied, 90 with Ménière's disease and 44 with recurrent vestibulopathy. A post-urographic technique was applied with the patient standing on a force plate in four test conditions: (1) eyes open, (2) eyes closed on a stable platform, and the same two conditions on a foam rubber platform. Postural sway was measured for each test and the normality of the results were evaluated by a scoring system. Sensory interaction on balance was assessed by comparing the values of the test results obtained with and without interfering influences on the vestibular-visual-proprioceptive sensory input.

RESULTS

The results of the posturographic data were used to subdivide the patients into normal and abnormal groups. Comparison of the tests with and without visual input as well as of the tests with undisturbed and disturbed proprioceptive input were used to evaluate the effect of each sensory input and to determine which effects were dominant. In this way a "pattern" was defined. The interaction effect, thus defined, was most frequently positive, however, it could also be negative (negative patterns). Visual effects were most frequent. There was no significant difference for findings between patients who were stabilized and nonstabilized. Negative patterns suggest a complex interaction of the sensory inputs.

CONCLUSION

In these patients with spontaneous vertigo attacks, sensory interaction posturography showed an influence upon balance in the erect position. Different patterns of sensory interaction were found. There was no specific pattern for this category of patients. There was no significant difference related to the "stabilization" of the syndrome.

Electrocochleography with postural changes in perilymphatic fistula and Menière's disease: case reports

Perilymphatic fistula can be difficult to diagnose differentially prior to exploratory surgery. In this study, we investigated a new test technique in four case studies of subjects with perilymphatic fistula and compared our findings to results obtained in 20 normally hearing subjects with no history of vertigo and 10 subjects with Meniere's disease. Recordings from an eardrum electrode were obtained with the subject in an upright position, after the subject had been lying in a horizontal position for 30 minutes with the test ear up and after 15 minutes with the test ear down. Stimuli consisted of high level clicks and tonebursts. Neither the summating potential (SP) and action potential (AP) amplitudes nor the SP/AP amplitude ratio were significantly affected by postural change in either the normal or Meniere's disease group. The perilymphatic fistula subjects, in general, showed greater changes in the SP/AP, particularly for the 6000 Hz tonebursts, than did the other two groups. More data will be needed to determine if these findings are consistent in a large population of perilymphatic fistula patients.

[Transtympanic electrocochleography in Menière's disease]

In order to examine the usefulness of the electrocochleography (ECoG) in the diagnosis of Menière's disease and establish the diagnostic criteria in Chinese, transtympanic ECoG was performed on 18 normal ears, 22 Menière's ears and 14 ears with cochlear type sensorineural hearing loss other than Menière's disease. Although the Menière's ears had larger mean summating potential (SP) than the normal ears, the difference between both groups was not statistically significant. The mean amplitude and latency of the action potential (AP) in Menière's ears decreased and elongated significantly, but neither was sensitive enough in diagnosing Menière's disease. The SP/AP amplitude ratio not only made significant difference among 3 groups, but also had good diagnostic sensitivity (59.1%) and specificity (92%) in diagnosing Menière's disease while using the 95% upper confidence limit of the normative data (i.e., 34%). The SP/AP amplitude ratio of Menière's ears tended to increase while the mean hearing level of 4-8 KHz deteriorated. Also, abnormal enlargement of the SP/AP amplitude ratio in Menière's disease tended to be the result of decreased AP amplitude.

[Acoustic distortion products. Recordings from patients with normal hearing and those with sensorineural hearing loss]

Distortion product otoacoustic emissions (DPEs) are a subtype of evoked otoacoustic emissions that represent a class of cochlear response. Because of their frequency specificity and the wide range of frequencies explored DPEs have a great potential for clinical use. DPEs studies include DP-audiograms and input/output functions. We recorded 27 DPEs, 24 of them from normal ears and 3 from pathological ears. This report resumes methods and results.

Neuro-otology

New techniques for the assessment of vestibulospinal, neck-afferent, and viscerograviceptive function may show future clinical applications for a broader assessment of balance function in neuro-otological patients. Magnetic resonance imaging studies revealed that many intralabyrinthine disorders (labyrinthitis, hemorrhage, schwannomas) can be adequately visualized. Perceptual and oculomotor clinical studies improved our understanding of vestibular disordered function in the roll (coronal) plane. Therapeutic studies highlight the importance of a team approach, with individually tailored programs for the rehabilitation of patients with vestibular disorders. Reasonable agreement on the criteria for attempting hearing preservation during acoustic neuroma surgery seems to have been reached.

Vestibular evaluation--electronystagmography, rotational testing, and posturography

This report describes a battery of tests that is utilized by several clinical laboratories to investigate vestibular and balance function. The electronystagmogram evaluates eye movements, inner ear function, brainstem function and cerebellar function. Sinusoidal vertical axis rotation is a sensitive measure of horizontal semicircular canal function that is often complimentary to the caloric stimulation portion of the electronystagmogram. Visual-vestibular interaction rotation testing is designed to evaluate brainstem, cerebellar and oculomotor function. Dynamic posturography facilitates measurement of standing balance and permits a quantification of the role of proprioception, vision and the vestibular system in the maintenance of standing balance.

Autorotation test of the horizontal vestibulo-ocular reflex in Menière's disease

Sixty-four patients with the diagnosis of Menière's disease were tested at the House Ear Clinic with an active head-rotation test system, the Vestibular Autorotation Test (VAT). The VAT is a portable, computerized test that measures the horizontal vestibulo-ocular reflex (VOR) with the use of high-frequency (2 to 6 Hz) active head movements to obtain gain and phase. The purpose of this study was to characterize the horizontal VOR at high frequencies in patients with Menière's disease. At frequencies from 5 to 6 Hz, all patients demonstrated horizontal phase greater than 180 degrees and 85% showed abnormal VAT results. The most common patterns were decreased gain or increased phase values, or both, relative to normative data. No significant differences in the degree of abnormality in gain and phase were noted among groups of patients when the patients were clinically staged. We conclude that, in our test population of patients with Menière's disease, the VAT shows common gain and phase patterns and abnormalities of the horizontal VOR. This may contribute to high retinal image velocities, which render the patient unable to stabilize retinal images during locomotion (visual field image slip), in as many as 85% of the patients tested, regardless of clinical stage. Such high-frequency testing can reveal abnormalities of the horizontal VOR not apparent from conventional vestibular testing. Thus VAT provides additional information about the functioning VOR when combined with the present vestibular test battery.

Immunoperoxidase study of the endolymphatic sac in Menière's disease

A growing body of evidence suggests that some cases of Menière's disease may be mediated by immune mechanisms. Because endolymphatic sac dysfunction is believed to be an underlying cause of Menière's disease, this study used immunohistochemical techniques to demonstrate the presence of immune complex deposition in the sacs of patients with Menière's disease. Positive immunoglobulin G (IgG) staining was noted in 10 of 23 sac biopsies from Menière's patients, with 2 specimens showing perivascular deposition. Only 1 of 5 control specimens was only slightly positive for IgG. Clinical correlation showed a statistically significant increase in disease bilaterality (P < .05), larger summating potential/action potential (SP/AP) ratios with electrocochleography (ECoG), and a tendency toward worse hearing and more progressive disease among the immunopositive Menière's patients. The results provided histological evidence of immune injury in the endolymphatic sacs of patients with Menière's disease.

Cortical evoked potential criteria in the objective assessment of auditory threshold: a comparison of noise induced hearing loss with Ménière's disease

Amplitude of the N1 component of the cortical response was used to objectively determine threshold of hearing at 1 kHz and 4 kHz in a series of consecutively referred medicolegal cases with alleged occupational noise induced hearing loss and a control group of patients with Ménière's disease who were not seeking compensation for their hearing loss. The cortical response thresholds were compared with the subjective pure tone audiometric (PTA) thresholds at the same frequencies. The cortical and PTA thresholds were 'within 10 dB' for 84 and 92 per cent of the cases of noise induced hearing loss (NIHL) and Ménière's disease respectively, confirming the validity of CERA as a means of defining accurately the frequency specific thresholds and the audiometric configuration. Of the remaining 16 per cent of NIHL, 13 per cent exaggerated their PTA thresholds at 1 kHz and 10 per cent at 4 kHz whilst the error in cortical threshold estimation was beyond the 10 dB level for three and six per cent of cases at those frequencies respectively. The median exaggeration of threshold was 25 dB. For eight per cent of the Ménière's patients, thresholds exceeded 10 dB at both 1 and 4 kHz, four per cent of whom exaggerated their PTA thresholds and four per cent had a test error greater than 10 dB. A similar percentage (four per cent) of both groups revealed a cortical test error greater than 10 dB whereas three times as many cases of noise induced hearing loss (13 per cent) revealed exaggeration of their subjective audiometric thresholds compared with the Ménière's group (four per cent).(ABSTRACT TRUNCATED AT 250 WORDS)

Experimental endolymphatic hydrops and glycerol. Electrophysiologic study

The object of the present study was to evaluate electrophysiologically the therapeutic effect of glycerol on the cochlear function of guinea pigs in which experimental hydrops had been surgically induced. Fifteen albino guinea pigs were used. Each animal was chronically implanted to follow the evolution of hearing. The experimental protocol considered 3 groups of guinea pigs (5 animals each). Group 1 received no drug treatment, while groups 2 and 3 were given glycerol orally at 0.75 and 0.50 g/kg of body weight once a day for 4 months. The audiograms of the animals treated with glycerol showed a statistically significant hearing improvement compared with the control group. Clinically, our results seem to support the view of those who favor the use of glycerol for the medical treatment of Meniere's disease at an early stage.

[Otorhinolaryngologic aspects of diving sports]

ENT disorders are the most common of all medical problems of diving. This review summarizes the specific conditions and ENT diseases in Scuba diving. During compression failure to equalize the pressure of air-filled cavities surrounded by bone deprives the middle ear or sinuses of aeration. Middle ear barotrauma is the most common barotrauma encountered in divers while sinus barotrauma and especially inner ear barotrauma (with rupture of the round or oval window) are less common. Decompression sickness in primarily the result of inert gas bubbles; deafness and vertigo may result if the inner ear is involved. The ENT examination necessary for assessment of diving fitness focuses on the middle and inner ear as well as the nose, sinuses and larynx. A list of ENT contra-indications is presented that mandate temporary or permanent disqualification from diving.

Long-term efficacy of endolymphatic sac surgery for vertigo in Menière's disease

The long-term efficacy of endolymphatic sac procedures for control of vertigo in Menière's disease has been controversial. We evaluated results of sac shunt surgery for 234 patients having at least 10 years followup (mean, 13.5 years). All patients had persistent vestibular symptoms despite medical therapy. All underwent endolymphatic subarachnoid shunt as their original operation. Data were collected by chart review and questionnaire regarding: (1) the number of additional surgical procedures to control vertigo, (2) remaining dizziness, and (3) level of disability. One hundred forty-seven of the patients (63%) did not undergo any further surgery to control vertigo, and an additional 17% had only revisions of the endolymphatic sac shunt. Thus, 80% never required a destructive procedure. Long-term effectiveness of surgery in regard to dizziness and disability was determined from the questionnaire. Of the 147 patients with only the original sac shunt surgery, 93% reported no dizziness or mild to no disability. Of the group who underwent only revisions of the original shunt, 96% stated they had no more dizziness or mild to no disability. We conclude that endolymphatic sac shunt operations are effective as initial surgical procedures for long-term control of disabling vertigo of Menière's disease.

Bilateral vestibular neurectomy for treatment of vertigo

The effects of bilateral vestibular neurectomy on equilibrium and vestibular function were clinically evaluated in two patients more than 15 years after surgery. Both patients had bilateral Menière's disease and their vertiginous spells were permanently resolved after the second vestibular neurectomy. Symptoms of disequilibrium were absent in one patient and mild in the other. Reflexive horizontal eye movements on whole body rotation in darkness were absent on low angular accelerations (2 degrees/s2), but could be elicited with angular accelerations of 20 degrees/s2 or higher. Extravestibular cues generating these eye movements seemed to be unlikely because a "control" patient with complete peripheral vestibular ablation after bilateral subtotal petrosectomy did not present reflexive eye movements under the same stimulus paradigms. An incomplete deafferentiation of the vestibular end organ (rather than regeneration of vestibular nerve fibers) and a consecutive impairment of the central velocity storage mechanism may explain the good functional outcome in our bilateral neurectomized patients.

Endoscopic transcutaneous mastoidoscopy for evaluation of residual epitympanic/mastoid cholesteatoma

It is generally agreed that patients subjected to an intact canal wall mastoidectomy to excise mastoid/epitympanic cholesteatoma should undergo a "second-look" operation to rule out residual cholesteatoma. The morbidity of this second operation can be significantly reduced with endoscopic mastoidoscopy, when compared to the traditional postauricular (open) incision approach. Details, benefits, and limitations of endoscopic mastoidoscopy are discussed.

[Clinical significance of cervico-ocular reactions]

Cervically induced eye movements consist of a nystagmus and a deviation of the mean eye position (shift). They show in relation to different neck torsion velocities maximum reactions at slow velocities. The clinical significance of these cervico-ocular reactions is discussed controversially. Therefore we investigated 40 healthy subjects without any neurootological findings, who, in addition, underwent a manual examination. The neck torsion test was performed automatically with quantifiable stimulus parameters and a complete head fixation by means of individual dental casts. It could be shown that at a constant chair velocity of 5 degrees/s every healthy subject exhibits cervical nystagmus and/or shift deviations. In comparison a group of 30 patients with an upper cervical spine syndrome also showed similar cervico-ocular reactions without significant difference. It can be concluded that a muscle hypertonus in the deep neck region does not lead to pathological, cervically induced eye movements and that the cervical nystagmus itself is not a pathognomonic sign for cervical, proprioceptive vertigo.

Functional changes associated with experimentally induced endolymphatic hydrops

A guinea pig model with surgically induced endolymphatic hydrops of the inner ear has been developed and studied over the past thirty years. The aim of such studies is to obtain insight into physiological processes associated with endolymphatic hydrops in man and in particular in Menière's disease where endolymphatic hydrops is systematically encountered at post-mortem examination of the temporal bones. The present review attempts to draw together the data pertaining to functional modifications of inner ear function in the animal model. For simplicity the data are categorised under five main titles: electrochemical modifications, electrophysiological modifications, pressure and hydrops, sensitivity to other insults and vestibular dysfunction. One of the most striking observations that can be made is that the data originating from different authors are very variable. There is, however, some evidence suggesting that the evolution of the auditory dysfunction could be considered as consisting of a series of different phases. This kind of information could serve as a basic framework for future research on the animal model.