Meniere's Disease ( Endolymphatic Hydrops )Meniere's Disease is a disorder characterized by dizziness and/or vertigo, hearing loss, ringing in the ear, and/or a feeling of fullness in the ear.
Diagnosis for Meniere's Disease
Beyond a thorough history and physical examination, some diagnostic tests can be of some value.
Blood tests to rule out thyroid dysfunction, diabetes, high cholesterol, syphilis, and autoimmune disorders are helpful. Other tests that can provide additional evidence for Meniere’s disease include an audiogram (hearing test), an electronystagmogram (ENG, balance test), an electrocochleogram (ECoG), an auditory brainstem response (ABR), and a magnetic resonance image (MRI).
An audiogram is a hearing test conducted in a soundproof room by a qualified audiologist.
An electronystagmogram (ENG) is a balance test that involves placement of recording electrodes around the eyes. Movements of the eyes are recorded while the head is put in changing positions with respect to the earth’s gravitational field. The eye movements are also recorded while cool and warm air or water is blown into the ear canal. The semicircular canals of the inner ear are sensitive to changes in temperature. When the inner ear is cooled or warmed, the effect is to lessen or heighten activity within the horizontal semicircular canal of the inner ear. The normal response is to feel vertigo during changes in temperature. The level of response to cool and warm stimuli is compared to the other ear. Asymmetry between the two ears in response to stimulation suggests the diagnosis of Meniere’s disease.
An electrocochleogram (ECoG) is a specialized test for Meniere’s disease. Here, electrodes are inserted into the ear canal while tones or clicks are presented to the hearing mechanism. The waveform generated from the inner ear (summating potential, SP) and the waveform generated from the nerve behind the inner ear (action potential, AP) are compared. In endolymphatic hydrops, the summating potential is enhanced and the action potential is unaffected, thereby enhancing the SP/AP ratio.
An auditory brainstem response and an MRI are tests done to rule out the presence of an acoustic neuroma.