In the early stages of Ménière’s disease, patients may report only the vertigo symptoms, as the fluctuations in hearing thresholds are minor and may go unnoticed. However, as the disease progresses the fluctuating hearing loss (generally affecting low tones) becomes more marked, and a permanent hearing loss may persist between attacks (middle stages of the disease). Later in the disease course, the hearing loss becomes permanent and nonfluctuating. At this stage, the attacks of vertigo usually lessen, and hearing loss becomes the dominant symptom (‘burnt out’ Ménière’s disease). The sensation of tinnitus similarly may be less noticed in the early stages, only to become more prominent in the later course of the disease.
Late in the disease, patients may experience drop attacks (caused by dysfunction of the vestibulospinal reflex), where a sudden loss of balance control causes them to drop to the ground without losing consciousness.
The natural history of Ménière’s disease is highly variable. Attacks of vertigo can occur daily in clusters over periods of several weeks or as isolated episodes interspersed with variable periods of remission, sometimes lasting many months or several years. In the later stages of the disease, the episodes of vertigo tend to ‘burn out’, and severe hearing loss dominates the clinical picture. In long-term follow-up studies of patients with Ménière’s disease, 30% to 45% developed the disease in the contralateral ear within a period of 30 years.
There are many variants of classical Ménière’s disease, in which vertigo precedes the fluctuations in hearing loss. The reverse occurs in Lermoyez syndrome: hearing loss precedes vertigo and improves following vertigo attacks. Some patients experience a fluctuation in their hearing thresholds (usually low tone) accompanied by tinnitus and fullness but no vertigo. This has been labelled ‘cochlear hydrops’.
Several epidemiological studies of Ménière’s disease have been performed over the past few decades with widely contrasting results. Estimated prevalence rates range from as low as 3.5 per 100,000 population to as high as 513 per 100,000 population. The wide range is likely to result from methodological differences, changes over time in criteria for the diagnosis of Ménière’s disease, difficulty in distinguishing Ménière’s disease from related conditions such as migraine-associated vertigo, and differences in the populations surveyed. However, it is clear that Ménière’s disease is more common in women, and the prevalence increases dramatically with age, peaking in the 60 to 69 years age group.3,4 It is very rare in people younger than 20 years.
Before Ménière’s description of the disease in 1861 correctly attributed it to a disorder of the inner ear, vertigo attacks were thought to be due to a form of epilepsy.1 Ménière suggested the mechanism could be similar to migraine or vasospasm within the inner ear. Early treatments, including cervical sympathectomy and vasodilators such as nicotinic acid, were based on this understanding.
In 1938, the first reports of temporal bone histology in patients with Ménière’s disease were published, showing an increased fluid volume in the endolymph compartment of the cochlea, termed endolymphatic hydrops. It was assumed that increased endolymphatic volume led to the attacks of Ménière’s disease. However, further histological analysis of human temporal bones showed many examples of endolymphatic hydrops in patients with no clinical symptoms of Ménière’s disease.