In 1861, the French physician Prosper Ménière described a condition which now bears his name. Meniere’s disease is a disorder of the inner ear that causes episodes of vertigo, ringing in the ears (tinnitus), a feeling of fullness or pressure in the ear, and fluctuating hearing loss. In Figure 1, the area of the ear affected is the entire labyrinth, which includes both the semicircular canals and the cochlea.
A typical attack of Meniere’s disease is preceded by fullness in one ear. Hearing fluctuation or changes in tinnitus may also precede an attack. A Meniere’s episode generally involves severe vertigo (spinning), imbalance, nausea and vomiting. The average attack lasts two to four hours. Following a severe attack, most people find that they are exhausted and must sleep for several hours. There is a large amount of variability in the duration of symptoms. Some people experience brief “shocks,” and others have constant unsteadiness. The majority of people with Meniere’s disease are over 40 years of age, with equal distribution between males and females.
A particularly disabling symptom is a sudden fall that may occur without warning. These are called otolithic crisis of Tumarkin, from the original description of Tumarkin (1936). These are attributed to sudden mechanical deformation of the otolith organs (utricle and saccule), causing a sudden activation of vestibular reflexes. Patients suddenly feel that they are tilted or falling (although they may be straight), and bring about much of the rapid repositioning themselves. This is a very disabling symptom as it occurs without warning and can result in severe injury. Often destructive treatment (for example labyrinthectomy or vestibular nerve section) is the only way to manage this problem. See here for more information about drop attacks.
Meniere’s episodes may occur in clusters; that is, several attacks may occur within a short period of time. However, years may pass between episodes. Between the acute attacks, most people are free of symptoms or note mild imbalance and tinnitus.
Meniere’s disease usually starts confined to one ear but it often extends to involve both ears over time so that after 30 years, 50% of patients with Meniere’s have bilateral disease (Stahle et al, 1991). There is some controversy about this statistic however; some authors suggest that the prevalence of bilaterality is as low as 17% (Silverstein, 1992). We suspect that this lower statistic is due to a lower duration of follow-up and that the 50% figure is more likely to be correct. Other possibilities, however, are selection bias and different patterns of the disease in different countries. Silverstein suggested that 75% of persons destined to become bilateral do so within five years.
In most cases, a progressive hearing loss occurs in the affected ear(s). A low-frequency sensorineural pattern is commonly found initially, but as time goes on, it usually changes into either a flat loss or a peaked pattern (click here for more information about hearing testing). Although an acute attack can be incapacitating, the disease itself is not fatal.
An acute attack of Meniere’s disease is generally believed to result from fluctuating pressure of the fluid within the inner ear. This is called “hydrops”. A system of membranes, called the membranous labyrinth, contains a fluid called endolymph. The membranes can become dilated like a balloon when pressure increases. One way for this to happen is when the drainage system, called the endolymphatic duct or sac is blocked. In some cases, the endolymphatic duct may be obstructed by scar tissue, or may be narrow from birth. In some cases there may be too much fluid secreted by the stria vascularis. Recently, some have pointed out that this “central hypothesis” of Meniere’s is questionable, as many normal people without Meniere’s have evidence of increased pressure in the inner ear too.
Abnormally enlarged fluid pathways into the ear, such as the vestibular aqueduct or cochlear aqueduct, may also be associated with Meniere’s-like symptoms, but recent evidence is against a relationship between the cochlear aqueduct and Meniere’s disease (Yilmazer et al, 2001).
Recently, attention has been mainly focussed on the immunologic function of the endolymphatic sac; thus, immune disease may contribute to a substantial percentage of Meniere’s disease. However, for the most part, the underlying cause of Meniere’s disease is unknown. It is most often attributed to viral infections of the inner ear, head injury, a hereditary predisposition, and allergy. Click here for more about the causes of Meniere’s disease.
Meniere’s disease can cause hair cell death, as well as mechanical changes to the ear.
Hair Cell Death
The periodic admixture of perilymph and endolymph often kills hair cells in the inner ear. This is a gradual process over years, but frequently resulting in unilateral functional deafness. Cochlear (hearing) hair cells are the most sensitive. Vestibular (motion sensing) hair cells seem more resilient but there is also a slow decline in the caloric response in the diseased ear over roughly 15 years (Stahle et al, 1991).
Mechanical disruption of the inner ear is also likely, with dilation of the utricle and saccule of the ear being a well known pathological finding. The saccule may dilate so that, in later stages, it is adherent to the underside of the stapes footplate. This mechanical disruption and distortion of normal inner ear structures may result in the gradual onset of a chronic unsteadiness, even when patients are not having attacks. The periodic dilation and shrinkage of the utricle is also a reasonable explanation for periodic attacks of another inner ear disorder, BPPV. Finally, it also seems likely that there may be a rupture of the suspensory system for the membranous labyrinth. This might create some mechanical instability of the utricle and saccule and consequently some chronic unsteadiness.
There is presently no evidence that Meniere’s disease kills the cochleovestibular nerve (Kitamura et al, 1997).
How is Meniere’s Disease Diagnosed?
Diagnosis is based on a combination of the right set of symptoms (usually episodic dizziness and hearing disturbance); hearing tests, which document that hearing is reduced after an attack, and then gets better; and exclusion of alternative causes. The differential diagnosis is broad and includes perilymph fistula, recurrent labyrinthitis, migraine, congenital ear malformations of many kinds, syphilis, tumors, Multiple Sclerosis, etc. The process of diagnosis usually includes hearing testing (audiometry), an ENG test, several blood tests (ANA, FTA), and an MRI scan of the head. Electrocochleography (ECOG) is helpful in difficult cases.
Hearing tests often begin with showing a fluctuating low-frequency sensorineural hearing loss. Over years, this gradually progresses to a “peaked” pattern with both low- and high-tone reduction, and finally a “flat” pattern, typically 50 db loss (110 db would be completely deaf). While some people have hearing that fluctuates like this without any further symptoms of dizziness or tinnitus, in most cases, this does not progress to Meniere’s disease (Schaaf et al, 2001)
At the present time there is no cure for Meniere’s disease, but there are ways to manage the condition and help you control symptoms. Treatment for Meniere’s disease falls into the following categories:
- Diet cases, a unit of the patient’s own blood can be stored before surgery for later use.