Steven D. Rauch

Superior semicircular canal dehiscence presenting as conductive hearing loss without vertigo.

Objective: The objective of this study was to describe superior semicircular canal dehiscence (SSCD) presenting as otherwise unexplained conductive hearing loss without vestibular symptoms. Study Design: Retrospective. Setting: Tertiary referral center. Patients: The study comprised 8 patients (10 ears), 5 males and 5 females aged 27 to 59 years. All 10 ears had SSCD on high-resolution computed tomography scan of the temporal bone. Diagnostic Tests and Results: All 10 ears had significant conductive hearing loss. The air–bone gaps were largest in the lower frequencies at 250, 500, and 1000 Hz; the mean gaps for these 3 frequencies for the 10 ears were 49, 37, and 35 dB, respectively. Bone-conduction thresholds below 2000 Hz were negative (−5 dB to −15 dB) at one or more frequencies in 8 of the 10 ears. There were no middle ear abnormalities to explain the air–bone gaps in these 10 ears. Computed tomography scan and laboratory testing indicated lack of middle ear pathology; acoustic reflexes were present, vestibular evoked myogenic potentials (VEMPs) were present with abnormally low thresholds, and umbo velocity measured by laser Doppler vibrometry was above mean normal. Middle ear exploration was negative in six ears; of these six, stapedectomy had been performed in three ears and ossiculoplasty in two ears, but the air–bone gap was unchanged postoperatively. The data are consistent with the hypothesis that the SSCD introduced a third mobile window into the inner ear, which in turn produced the conductive hearing loss by 1) shunting air-conducted sound away from the cochlea, thus elevating air-conduction thresholds; and 2) increasing the difference in impedance between the oval and round windows, thus improving thresholds for bone-conducted sound. Conclusion: SSCD can present with a conductive hearing loss that mimics otosclerosis and could explain some cases of persistent conductive hearing loss after uneventful stapedectomy. Audiometric testing with attention to absolute bone-conduction thresholds, acoustic reflex testing, VEMP testing, laser vibrometry of the umbo, and computed tomograph scanning can help to identify patients with SSCD presenting with conductive hearing loss without vertigo.

Idiopathic Sudden Sensorineural Hearing Loss

A healthy 58-year-old woman answers the telephone and realizes that her hearing is diminished on the left side. She notices aural fullness and loud tinnitus in the affected ear. Self-administered ear cleaning with the use of an over-the-counter kit does not relieve the symptoms. How should she be evaluated and treated?

Vestibular evoked myogenic potentials show altered tuning in patients with Ménière's disease.

Objective: Acoustic stimulation of the saccule gives rise to a vestibulocollic reflex, the output of which can be measured in the neck as inhibition of activity in the ipsilateral sternocleidomastoid muscle. This vestibular evoked myogenic potential has been promoted as a means of assessing integrity of saccular function. In this study, we test the hypothesis that the cochleosaccular hydrops of Ménière’s syndrome leads to alterations in saccular motion that change the dynamics of the vestibular evoked myogenic potential. Study Design: Prospective cohort study. Setting: Large specialty hospital, department of otolaryngology. Subjects: Fourteen normal adult volunteers and 34 consecutive consenting adult patients with unilateral Ménière’s disease by American Academy of Otolaryngology–Head and Neck Surgery diagnostic criteria. Interventions: All subjects underwent vestibular evoked myogenic potential testing using ipsilateral broadband click and short tone-burst stimuli at 250, 500, 1,000, 2,000, and 4,000 Hz. Main Outcome Measures: Threshold, amplitude, and latency of vestibular evoked myogenic potential responses in normal and Ménière’s affected and unaffected ears. Results: Vestibular evoked myogenic potential was present in all ears tested. Normal subjects show a frequency-dependent vestibular evoked myogenic potential threshold, with best response (“frequency tuning”) at 500 Hz. Compared with normal subjects and unaffected ears of Ménière’s subjects, affected Ménière’s ears had significantly increased vestibular evoked myogenic potential thresholds. Affected Ménière’s ears showed threshold shifts at all frequencies and there was less tuning apparent at 500 Hz. Unaffected ears of Ménière’s subjects also showed significantly elevated vestibular evoked myogenic potential thresholds compared with normal subjects. Analyses of vestibular evoked myogenic potential thresholds for effects of age, hearing loss, and audiometric configuration showed no significant differences. Conclusions: Ménière’s ears display alterations in vestibular evoked myogenic potential threshold and tuning, supporting our hypothesis of altered saccular motion mechanics arising from hydropic distention. Unaffected ears of unilateral Ménière’s subjects show similar changes, though to a lesser degree. This finding may be because of occult saccular hydrops in the asymptomatic ear or binaural interactions in the vestibular evoked myogenic potential otolith–cervical reflex arc.

Meniere's Syndrome and Endolymphatic Hydrops: Double-Blind Temporal Bone Study

A systematic double-blind assessment of case histories and histopathologic findings in temporal bones in the collection at the Massachusetts Eye and Ear Infirmary was performed to test the hypothesis that clinical Menieres syndrome is associated with endolymphatic hydrops demonstrated histopathologically at death. Thirteen of 13 cases of clinical Menieres syndrome were found to have endolymphatic hydrops not attributable to other causes. However, some patients with idiopathic endolymphatic hydrops did not exhibit clinical Menieres syndrome as revealed in their medical records. These results challenge the dogma that endolymphatic hydrops per se generates the symptoms of Menieres syndrome.

Oral steroid treatment of sudden sensorineural Hearing loss: A ten year Retrospective analysis

Objective To describe ten years of experience with Sudden Sensorineural Hearing Loss and compare the outcomes with and without treatment with oral corticosteroids. Study Design Retrospective review of medical records. Setting Large specialty hospital, Department of Otolaryngology. Patients Patients presenting with sudden onset (72 hours) unilateral sensorineural hearing loss, with no evidence of Ménières Disease, acoustic injury, retrocochlear disease, and other specifiable disorders. Interventions The majority of patients received a standard course of oral corticosteroids (Prednisone 60mg and taper). A smaller group declined treatment. Main Outcome Measures Recovery of hearing sensitivity was measured using standard audiometry and reported as change in Pure Tone Average. Word recognition scores were also analyzed. Results When severe-to-profound cases are analyzed, a significant improvement (p < .01) in Pure Tone Average is seen in cases treated with steroids versus those untreated. When milder cases are included, a statistical floor effect prevents differentiation of these groups. Word recognition scores were significantly improved (p < .05) in the treated group. Conclusions Application of steroid medication significantly improves the recovery outcomes in cases of Severe Sudden Sensorineural Hearing Loss.

Decreasing Hair Cell Counts in Aging Humans

Abstract: Deterioration of balance with advancing age is a well‐known fact of life. Some investigators have reported a 50% prevalence of dizziness in the elderly. Clinically, progressive dysequilibrium of aging presents as gradually worsening balance due to age‐related decline in function of the peripheral vestibular system, central nervous system, vision, and musculoskeletal system. Vestibular function testing has shown clear evidence of age‐related changes in peripheral and central sites. Histopathologic changes in the vestibular sensory organs include progressive hair cell degeneration, otoconial degeneration in the otolith organs, and decreasing number of Scarpas ganglion neurons. Recently, a new quantitative method of assessing vestibular otopathology has been described, utilizing Nomarski differential interference contrast microscopy. This technique has been applied to 67 human temporal bones of individuals from birth to age 100 to create a normative database of total, type I, and type II hair cell counts as a function of age. Results show a highly significant continuous decrease in all counts from birth to age 100, best fit by a linear regression model. Type I hair cell counts in all three semicircular canal cristae decrease at a similar rate, significantly faster than the degeneration observed in type I hair cells of the maculae. Type II hair cell counts decline at the same rate for all 5 sensory epithelia. These normative data provide the basis for comparisons to hair cell counts made in temporal bones from subjects with known vestibular disorders. They also provide a basis for drawing correlations between vestibular function testing and vestibular otopathology.

Vestibular evoked myogenic potentials (VEMP) can detect asymptomatic saccular hydrops.

Objective: The objective of this study was to explore the useful of vestibular evoked myogenic potential (VEMP) testing for detecting endolymphatic hydrops, especially in the second ear of patients with unilateral Ménière disease (MD).

Intratympanic Gentamicin for Treatment of Intractable Meniere's Disease: A Preliminary Report†

Topical administration of aminoglycoside antibiotics in the middle ear can achieve “chemical labyrinthectomy” in patients with intractable Menieres disease. Herein we report our results of intratympanic gentamicin therapy in 21 patients using two different dosing protocols, twice weekly and twice daily(b.i.d.). Both hearing and vertigo outcome were evaluated. Complete control of episodic vertigo was achieved initially in 20 of 21 patients (95.2%). However, 6 of 20 responders (30%) developed relapsing symptoms within 12 months. Retreatment was successful in 75% of these patients. Overall, hearing was preserved or improved in 62% of cases, worse in 24%, and not yet tested in 14%. When the cumulative dose of gentamicin was ≤4 injections in the first week, only 1 of 14 (7.1%) lost hearing. Intratympanic gentamicin offers better risk/benefit outcome than other invasive therapies for intractable Menieres disease.

Temporal Bone Studies of the Human Peripheral Vestibular System: 1. Normative Vestibular Hair Cell Data

Quantitative studies of the vestibular system with serially sectioned human temporal bones have been limited because of difficulty in distinguishing hair cells from supporting cells and type I from type II hair cells. In addition, there is only a limited amount of normative data available regarding vestibular hair cell counts in humans. In this study, archival temporal bone sections were examined by Nomarski (differential interference contrast) microscopy, which permitted visualization of the cuticular plate and stereociliary bundle so as to allow unambiguous identification of hair cells. The density of type I, type II, and total numbers of vestibular hair cells in each of the 5 sense organs was determined in a set of 67 normal temporal bones that ranged from birth through 100 years of age. The mean total densities at birth were 76 to 79 cells per 0.01 mm2 in the cristae, 68 cells per 0.01 mm2 in the utricle, and 61 cells per 0.01 mm2 in the saccule. The ratio of type I to type II hair cells at birth was 2.4:1 in the cristae and 1.3:1 in the maculae. There was a highly significant age-related decline in all sense organs for total, type I, and type II hair cell densities that was best fit by a linear regression model. The cristae lost type I cells with advancing age at a significantly greater rate than the maculae, whereas age-related losses for type II cells occurred at the same rate for all 5 sense organs. Hair cell densities in the cristae were significantly higher at the periphery than at the center. There were no significant sex or interaural differences for any of the counts. Mathematical models were developed to calculate the mean and 95% prediction intervals for the total, type I, and type II hair cell densities in each sense organ on the basis of age. There was overall good agreement between the hair cell densities determined in this study and those reported by others using surface preparation techniques. Our data and related models will serve as a normative database that will be useful for comparison to counts made from subjects with known vestibular disorders.

Temporal bone studies of the human peripheral vestibular system. Meniere's disease.

Quantitative assessments of vestibular hair cells and Scarpas ganglion cells were performed on temporal bones from 24 patients with well-documented Menieres disease. Of these, 18 had unilateral disease and 6 had bilateral disease. Vestibular hair cell counts were made in each of the 5 sense organs by Nomarski (differential interference contrast) microscopy. Hair cell counts were expressed as densities: number of cells per 0.01 mm2 surface area of the sensory epithelium. The results were compared with age- and sex-matched normal data. The type I hair cell densities for all vestibular sense organs were within the range for normative data. On the other hand, there was a significant loss (p < .01) of type II hair cells for all 3 cristae and both maculae. There was also a significant loss of Scarpas ganglion cells (p < .001) when compared with normative data. The findings indicate a selective loss of type II hair cells and Scarpas ganglion cells in Menieres disease. These new observations have implications regarding the pathophysiological mechanism and clinical manifestations of Menieres disease.