Approach Considerations
Laboratory tests, though not specific for Ménière disease, should be directed at differentiating the disease from other causes on the basis of associated symptoms. More extensive testing is typically reserved for outpatient or inpatient workup and is not performed in the emergency department (ED), including the following otologic tests:
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Audiometry
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Brainstem auditory evoked potentials
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Electrocochleography (ECOG)
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Otoscopy
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Caloric testing/electronystagmography (ENG)
A patient with a history classic for Ménière disease normally does not need imaging studies performed. If there is concern about the presence of other intracranial disease processes, then magnetic resonance imaging (MRI) or computed tomography (CT) can be obtained.
Laboratory Studies
No blood test is specific for Ménière disease. However, the following studies may be ordered to exclude obvious metabolic disturbances, infections, or hormonal imbalances:
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Thyroid-stimulating hormone (TSH), T4, and T3 to rule out hyperthyroidism and hypothyroidism
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Glucose level to rule out diabetes
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Erythrocyte sedimentation rate (ESR) and antinuclear antibody (ANA) test to rule out autoimmune disorders
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Urinalysis to rule out proteinuria and hematuria and indicators of otorenal syndrome
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Complete blood count (CBC) to rule out anemia and leukemia
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Electrolyte levels to rule out salt/water imbalance
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Venereal Disease Research Laboratory test (VDRL) and fluorescent treponemal antibody (FTA-ABS) to rule out neurosyphilis and Lyme disease
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Allergy testing for allergy-mediated Ménière syndrome
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C-reactive protein (CRP)
MRI and CT Scanning
Although usually unnecessary when the patient has a classic history indicative of Ménière disease (MD), MRI or CT may be useful when it is deemed important to identify or exclude other potential disease processes.
MRI of the brain should be done to rule out abnormal anatomy or mass lesions. Specifically, acoustic neuromas or other cerebellopontine angle lesions are sought. Other lesions, such as multiple sclerosis or Arnold-Chiari malformations, also can be ruled out. [25] Note that mass lesions rarely are found but are important to exclude.
Using 3-dimensional fluid-attenuated inversion recovery MRI (3D-FLAIR MRI), quantitative assessments of endolymphatic hydrops (EH) were found to correlate with the severity of hearing impairment in patients with Ménière disease. In this study, 41 ears were analyzed in 21 subjects (12 ears with MD, 29 without MD). EH was better evaluated on 3D maximum intensity projections (MIPs) than on 2D images. [26]
In another FLAIR study, delayed 3D FLAIR and fused 3D FLAIR-CISS (constructive interference steady state) color map images of the inner ears after intravenous contrast administration were found to be potentially useful diagnostic tools in the evaluation of patients with suspected Ménière disease. The gray-scale 3D FLAIR images demonstrated 68.2% sensitivity and 97.4% specificity, and the fused color map images demonstrated 85.0% sensitivity and 88.9% specificity in the identification of endolymphatic hydrops in 10 patients with MD and 5 controls. [27]
CT scans should be normal. They are obtained to detect possible dehiscences of the semicircular canals, congenital abnormalities, widened cochlear and vestibular aqueducts, and subarachnoid hemorrhage. Whereas CT scans are useful at imaging the anatomy of temporal bone structures, specific findings and their association with Ménière disease remain subject to debate. [28]
Audiometry
Audiometry is particularly helpful for documenting present hearing acuity and detecting future change. In any given patient, the audiogram may have a broad spectrum of results that ranges from normal hearing to profound hearing loss, reflecting the fluctuating nature of the impairment. From patient to patient, there is also a wide range of different types of hearing loss.
The patient may not notice a loss at specific frequencies. Low-frequency or mixed low- and high-frequency insufficiency may be observed. Typically, however, the lower frequencies are affected more severely. This is due to preferential sensitivity of the apex to the hydrops.
Multiple hearing tests, which document fluctuating hearing loss, are helpful in diagnosing Ménière.
Electrocochleography
ECOG is an electrophysiological test that reflects elevation of inner ear pressure. Specifically, it detects distention of the basilar membrane of the inner ear. This distortion is presumably due to elevated endolymph pressure associated with hydrops. The pressure may cause the membranes to tear and the inner ear to misfire, causing vertigo.
ECOG measures the ratio of the summating potential (probably from the movement of the basilar membrane) and the nerve action potential in response to auditory stimuli. Hydrops (elevated pressure) is suggested when this ratio is greater than 35%. The test is most accurate when Ménière disease is active.
Electronystagmography
ENG is a test of inner ear function (particularly the horizontal semicircular canals). The test determines inner ear responsiveness to movement and caloric stimulation. It tests central and peripheral function and can help localize the site of the lesion.
Administer the test when the patient has an empty stomach and after discontinuing meclizine (Antivert), antihistamines, and sedatives for 2 weeks. These drugs may alter test results.
The caloric portion of the test is performed by “irrigating” the ear with warm air and then cold air, with the patient in a supine position. The temperature differential causes the fluid within the horizontal semicircular canal to move, triggering a nystagmus response. The response on one side is compared with the opposite side. As with any reflex, one would expect equal reactions on each side. Usually, anything that would cause a weakened response would be considered pathological.
Typically, endolymphatic hydrops causes a reduced vestibular response in the affected ear, although response may be paradoxically increased secondary to an irritative lesion. The patient may feel dizzy or nauseated.
The direction of the spontaneous nystagmus during or after an attack of Ménière disease is not always a reliable indicator of the site of the lesion. In general, the nystagmus points away from the affected ear because Ménière's disease typically weakens the vestibular response in the affected ear. However, an irritative phase may occur during the attack (fast phases directed toward the involved ear), followed by a paretic phase (fast phases directed toward opposite ear). Since the examiner may not know exactly what phase the patient is in, it is difficult to definitively determine this side of lesion.
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Transtympanic instillation device is used to administer drugs to inner ear.
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Intraoperative view of the left ear treated with labyrinthectomy; endolymphatic sac can be seen in this view.
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Tinnitus model. Two phenomena in auditory cortex are associated with peripheral deafferentation: (1) hyperactivity in lesion projection zone and (2) increased cortical representation of lesion-edge frequencies (here, C6) in lesion projection zone. These 2 phenomena are presumed to be neurophysiologic correlates of tinnitus. Red letters correspond to octave intervals of fundamental frequency.
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- Overview
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- Treatment
- Approach Considerations
- Principles of Medical Management
- Pharmacologic Therapy
- Meniett Device
- Principles of Surgical Management
- Endolymphatic Sac Decompression or Shunt
- Vestibular Nerve Section
- Labyrinthectomy
- Cochlear Implant
- Transtympanic Perfusion of Medication
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