Middle ear pressure and dysfunction of the labyrinth: is there a relationship?

Risk of Sensorineural Hearing Loss in Patulous Eustachian Tube

OBJECTIVE

To investigate whether the long-term presence of a patulous Eustachian tube (PET) is associated with sensorineural hearing loss (SNHL).

STUDY DESIGN

Retrospective chart review.

SETTING

Tertiary referral center.

PATIENTS

Ears (n = 100) were classified into two groups based on duration of PET symptom(s), i.e., Short (≤3 mo; n = 47 ears) and Long (≥48 mo; n = 53 ears). Contralateral ears without PET (n = 28 ears) were classified as the Contralateral group.

MAIN OUTCOME MEASURES

We used ISO 7029 to calculate the hearing thresholds of an age- and sex-matched population at a given frequency. Hearing loss was defined as >25% of these calculated values.

RESULTS

At 4 kHz, the Long PET group showed a higher prevalence of hearing loss (47%) at 4 kHz than did the Contralateral (21%) and Short PET (19%) groups (p = 0.0280 and 0.0043, respectively). Ears with breathing autophony or a sonotubometric low probe tone level showed a higher prevalence of hearing loss at 4 kHz than those without this symptom or with a high probe tone level (p = 0.0329 or 0.0103, respectively). At low frequencies, ≥89% of the ears in all groups showed mild hearing loss.

CONCLUSION

Chronic PET was associated with SNHL at 4 kHz. PET patients showed low-frequency hearing loss regardless of disease duration. Further studies are needed to better understand the pathophysiology of SNHL in patients with PET.

Structural Analysis of Tensor Tympani Muscle, Tympanic Diaphragm, Epitympanum, and Protympanum in Menière's Disease: a Human Temporal Bone Study

HYPOTHESIS

We hypothesized that there would be significant anatomic differences of the tensor tympani muscle (TTM), tympanic diaphragm, epitympanum, and protympanum in patients with versus without Menière's disease.

BACKGROUND

The effects of tenotomy on Menière's disease suggested it relieves the pressure on the inner ear of the contraction of the TTM and of negative middle ear pressure.

METHODS

Using human temporal bones from patients with Menière's disease, two studies were conducted. We examined the presence of otitis media, cholesteatoma, and endolymphatic hydrops, the length, diameter, configuration, the volume of the TTM and tendon, and the area of the tympanic isthmus (Study 1). We examined the presence of otitis media, cholesteatoma and endolymphatic hydrops, and the area and volume of the protympanum (Study 2).

RESULTS

In study 1, we observed no significant differences between the two groups. In study 2, we did not observe a small and narrow protympanum in the Menière's disease group. None of the ears in the Menière's or control groups had otitis media or cholesteatoma in either study. We observed hydrops in all the temporal bones of the Menière's disease group and none in the control groups.

CONCLUSION

The position, configuration, and size of the tensor tympani muscle and tendon do not seem to play a role in the pathogenesis of Menière's disease. Because the tympanic isthmus and protympanum in Menière's disease are not smaller than controls and that none of the temporal bones had otitis media or cholesteatoma, it is unlikely that there was dysventilation in the middle ear.

Recent surgical options for vestibular vertigo

Vertigo is not a well-defined disease but a symptom that can occur in heterogeneous entities diagnosed and treated mainly by otolaryngologists, neurologists, internal medicine, and primary care physicians. Most vertigo syndromes have a good prognosis and management is predominantly conservative, whereas the need for surgical therapy is rare, but for a subset of patients often the only remaining option. In this paper, we describe and discuss different surgical therapy options for hydropic inner ear diseases, Menière's disease, dehiscence syndromes, perilymph fistulas, and benign paroxysmal positional vertigo. At the end, we shortly introduce the most recent developments in regard to vestibular implants. Surgical therapy is still indicated for vestibular disease in selected patients nowadays when conservative options did not reduce symptoms and patients are still suffering. Success depends on the correct diagnosis and choosing among different procedures the ones going along with an adequate patient selection. With regard to the invasiveness and the possible risks due to surgery, in depth individual counseling is absolutely necessary. Ablative and destructive surgical procedures usually achieve a successful vertigo control, but are associated with a high risk for hearing loss. Therefore, residual hearing has to be included in the decision making process for surgical therapy.

Eustachian tube function in patients with inner ear disorders

The influence of Eustachian tube (ET) dysfunction on the inner ear fluid pressure and thus on the inner ear function in Meniere's disease has been discussed controversially. So far, most of the studies examining ET function in inner ear disorders indirectly analyzed ET function by tympanometric methods. The present study directly studied ET function in inner ear disorders by sonotubometry. Healthy subjects and patients with Meniere's disease, sudden sensorineural hearing loss, cholesteatoma and chronic suppurative otitis media were examined by sonotubometry. Mean increase of sound pressure intensity (dB) and mean duration of sound pressure increase (s) were analyzed. Highest mean increase of sound pressure intensity was seen in healthy subjects when using >5 dB peaks (11.6 ± 0.7 dB) and >0 dB peaks (9.6 ± 0.6 dB). Comparative analysis including bilateral ears showed decreased ET function in patients with cholesteatoma (p = 0.002) and in patients with Meniere's disease (p = 0.003) when using >0 dB peaks. Examination of each specific ET opening maneuver showed impaired ET function in pathological ears of patients with cholesteatoma and with Meniere's disease, during yawning (p = 0.001; p < 0.001), dry swallowing (p = 0.010; p = 0.049), Toynbee maneuver (p = 0.033; p = 0.032) and drinking (p = 0.044; p = 0.027). Mild ET dysfunction is detected in patients with Meniere's disease by direct sonotubometric assessment of ET function.

Inadequate opening capacity of the eustachian tube in Meniere's disease

CONCLUSION

In this physiological study subjects with Meniere's disease (MD) had high resistance to opening of the eustachian tube (ET) in three of four provocation tests. These subjects can be exposed to pressure deviations in the middle ear (ME) above their equalizing capacity. Transmission of the pressure deviations to the inner ear fluids and influence of the symptoms of MD are feasible.

OBJECTIVE

The aim of the study was to reveal potential inadequacy in the ET equilibration capacity and deviations in ME pressure in patients with MD.

METHODS

Direct ME pressure measurements were made during provocation tests of the ET, and continuously during the daytime and night-time in 21 patients with unilateral, definite and active MD. Twenty subjects with healthy ears (HEs) were used for comparison.

RESULTS

In all, 15/21 subjects could not equilibrate an induced positive and/or negative pressure in the ME by deglutition; 9/21 subjects were not able to perform Valsalva's manoeuvre. All the controls could effectively perform these manoeuvres. However, the continuous measurements showed a similar pressure pattern in patients with MD and the controls, i.e. a slightly negative mean ME pressure during the daytime and positive pressure during sleep.

Middle ear pressure in patients with dizziness

The middle ear pressure was analyzed in 112 patients with dizziness. In 37 patients with Meniere's disease, the middle ear pressure on the low-pressure side was significantly lower, the middle ear pressure difference (between the high and low sides) was significantly larger, and the maximum compliance on the low-compliance side was significantly lower than in normal volunteers. The middle ear pressure difference was significantly larger during periods of dizziness or recurrent dizziness than at the time of remission. In patients with Meniere's disease, a middle ear pressure difference of more than 50 decapascals was significantly more common among those with abnormal blood gas levels than among those with normal blood gas levels. In 27 patients with cervical vertigo and 15 patients with vertebrobasilar insufficiency, the middle ear pressure difference was also significantly larger than in normal volunteers. These results suggest that the middle ear pressure difference might be closely related to dizziness in Meniere's disease and less closely related in cervical vertigo or vertebrobasilar insufficiency. The middle ear pressure difference might also be related to abnormal blood gas levels in patients with dizziness.

Funktionsuntersuchungen der Tuba Eustachii

The Eustachian tube regulates the homeostasis of the middle ear. Problems with its function are predominantly found in childhood. As a consequence, otitis and hearing impairment occur. The most important muscle is the tensor tympani muscle. The complexity of the functional anatomy and physiology are reasons why no function test alone is capable of fulfilling all diagnostic needs. The predictive value of the various Eustachian tube function tests for the outcome of a tympanoplasty is not yet clear. An overview of clinically and scientifically relevant tests for the Eustachian tube function is provided.

Insertion of tympanic ventilation tubes as a treating modality for patients with Meniere's disease: a short- and long-term follow-up study in seven cases

OBJECTIVES

As a treatment for patients with Meniere's disease, insertion of a ventilating tube in tympanic membrane was carried out, and the effect of the therapeutic modality was analysed.

METHODS

Seven patients (four males and three females, age ranged 35-62 years) with active Meniere's disease were placed with ventilating tubes in the affected ear and postoperative change in symptoms, i.e. incapacitating vertigo and hearing loss were investigated. Disease severity was scored and evaluated pre- and postoperatively under the guidelines proposed by the Committee on Hearing and Equilibrium in the American Academy of Otolaryngology-Head and Neck Surgery (AAO-HNS, 1985).

RESULTS

Of the seven cases, the number of patients and the degree in controlling vertigo after the treatment were: at 24 months (short-term) five cases with substantial, one with limited and one with insignificant control, then at 42 months (long- term) four cases with substantial, three with limited control, respectively. The degree of disability in patients at 24 and 42 months of the treatment was compatible with the level of vertigo controlling. On the other hand, patients' hearing level was not affected by the treatment.

CONCLUSIONS

Exact explanation for the effect of ventilating tubes in tympanic membrane is vague and its therapeutic effect was limited. However, at least this treatment might represent a short-term effect for the reduction of persistent vertigo in some patients with Meniere's disease and so it might become a treatment option because of its simple and less-invasive procedure.

The non-specific effect of endolymphatic sac surgery in treatment of Meniere's disease: a prospective, randomized controlled study comparing "classic" endolymphatic sac surgery with the insertion of a ventilating tube in the tympanic membrane

A prospective, randomized study was carried out comparing the effect of two surgical modalities in the treatment of patients with Meniere's disease: insertion of an endolymphatic sac shunt and insertion of a ventilating tube in the tympanic membrane. A total of 29 patients, 12 males and 17 females, age 27-71 years, were operated on in two ear, nose and throat (ENT) departments. Of these patients, 15 had an endolymphatic shunt inserted and 14 had a ventilating tube inserted in the tympanic membrane. Postoperative follow-up was carried out in the department in which the patients had not been operated. The severity of the disease was scored pre- and postoperatively, and the results evaluated under the guidelines of the Committee on Hearing and Equilibrium (1995) for the diagnosis and evaluation of therapy in Meniere's disease. The patients in both groups had a statistically significant reduction in dizzy spells, measured 6 and 12 months postoperatively, and there was no difference between the groups. The pathophysiological explanation for the reduction in dizzy spells in each of the treatment modalities is debatable and the effect is non-specific. The patients' hearing and tinnitus were statistically unaffected by the treatment in both groups, though 2 patients in the shunt group developed severe hearing loss (anacusis/70 dB).