Ménière Syndrome, Benign Paroxysmal Positional Vertigo, and Vestibular Neuritis
Ian S. Storper
INTRODUCTION
Three of the most common causes of peripheral vertigo are Ménière syndrome, benign paroxysmal positional vertigo, and vestibular neuritis. Each syndrome has its own distinct type of vertigo. The purpose of this chapter is to explain the clinical presentation and current treatment principles of each syndrome to aid the clinician in diagnosis and management.
MÉNIÈRE DISEASE
Although Ménière disease was described over 140 years ago, little about it is understood. The condition is often progressive; with medical and surgical treatment options, however, disability may be averted or ameliorated. A recent study using health claims data from 60 million patients in the United States reports prevalence as 190 per 100,000 with a female-to-male ratio of 1.89:1 [Level 1].1 The prevalence increases with age.
This disease was first reported by Prosper Ménière in Paris in 1861 [Level 1].13 As described, patients typically suffered recurrent attacks of vertigo lasting from hours to days. Coincident with the attacks were episodes of unilateral hearing loss and roaring tinnitus. At first, the hearing loss and tinnitus occurred only with the attacks, but as the disease progressed, they became permanent. In 1943, Cawthorne added a fourth symptom: fullness in the affected ear. Table 59.1 lists the clinical features of Ménière disease. Although the cause of Ménière disease still remains unknown, it was postulated by Knapp in 1871 that symptoms were caused by dilatation of the endolymphatic compartment of the inner ear during attacks and renormalization afterward [Level 1].11 This idea is still widely accepted, as the vast majority of patients respond to sodium management.
DEFINITIONS
Ménière disease is defined as the idiopathic occurrence of attacks of vertigo, hearing loss, tinnitus, or fullness in the affected ear. If a cause is assumed, the term is Ménière syndrome. The causes of Ménière syndrome are listed in Table 59.2.
Episodes typically last from hours to days. After an attack, the patient often feels “foggy” or tired. Initially, only one or two symptoms may be present; for example, a patient may experience only episodic vertigo; the hallmark is fluctuation. In the early stages, patients are often asymptomatic between attacks. With progression, low-frequency hearing loss can become permanent and may progress to all frequencies. Tinnitus is usually loud and roaring. Vertigo can be severe, a true spinning sensation of the patient or surroundings. Nausea, vomiting, sweating, and pallor are typical, as the vertigo arises in the inner ear rather than in the brain. Some describe a linear motion or feel as if they are on a boat. Rarely, vertigo is noted only with change of position, mimicking benign paroxysmal positional vertigo. It is distinguishable because positional vertigo of Ménière disease occurs in attacks. If left untreated, disequilibrium may persist between attacks of vertigo. Most Ménière sufferers are women, attributable to hormonal causes of increased water retention. Symptoms may be worse prior to the menstrual cycle.
TABLE 59.1 Ménière Disease Clinical Features | ||
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TABLE 59.2 Some Causes of Ménière Syndrome | |||||
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Typically, attacks become less frequent and less severe over time, with or without medical management. Within about 2 years of diagnosis, more than half of all patients are better, even without treatment. Treatment decreases the frequency and severity of attacks and minimizes permanent hearing or balance loss. Only 5% of medically treated patients progress to surgery.
About 10% of patients never experience vertigo; their disorder is termed cochlear Ménière disease. Ten percent of patients never experience auditory symptoms. The term burned out Ménière disease applies to the patient who has totally lost auditory and vestibular function. There is no loss of consciousness during Ménière attacks; if it occurs, neurologic disease is likely. A rare entity associated with Ménière disease is referred to as drop attack or crisis of Tumarkin; the patient suddenly drops to the ground. Head injury may ensue.
DIAGNOSIS
Ménière disease is diagnosed clinically; no test has sufficient sensitivity and specificity to be pathognomonic. Tests are used to rule out other disorders and to help confirm the diagnosis. Careful history and physical examination are essential. Ménière disease should be considered in any patient without other obvious cause who suffers episodic vertigo, hearing loss, tinnitus, or fullness in the ear. Ménière disease is not diagnosed unless symptoms have occurred at least twice. Between attacks, the examination is often normal, especially early in the disease. During an attack, a patient typically
appears acutely vertiginous, with horizontal nystagmus beating toward the affected ear. If nystagmus is vertical, central nervous system (CNS) disease is considered.
appears acutely vertiginous, with horizontal nystagmus beating toward the affected ear. If nystagmus is vertical, central nervous system (CNS) disease is considered.
Tests that aid in the diagnosis of Ménière disease include audiometry (complete audiologic evaluation [CAE]), videonystagmography (VNG), and magnetic resonance imaging (MRI). If the symptoms are bilateral, blood tests for autoimmune inner ear disease and infections are ordered. Early in the disease, the CAE is often normal. Later, low-frequency sensorineural hearing loss can develop. Ultimately, hearing loss may also involve high frequencies. Rarely, the hearing asymmetries may be in the high frequencies rather than the low frequencies. During an attack, there may be hearing loss in the affected ear, which may resolve afterward. If conductive hearing loss is found, other diagnoses, such as superior semicircular canal dehiscence or cholesteatoma, should be considered.
Early in Ménière disease, the VNG is usually normal because vestibular function recovers between attacks. As the disease progresses, caloric testing often yields a unilateral vestibular weakness. If testing is inadvertently performed during an attack, hyperfunction of the affected ear is usually seen. In end-stage disease, there is complete weakness (100%) in the affected ear. If central pathology is the cause of vertigo, caloric test results are usually normal. Gaze and positional testing, as well as optokinetic nystagmus testing, are often abnormal.
MRI is recommended for every patient with recurrent vertigo, asymmetric sensorineural hearing loss, or unilateral constant tinnitus. The study should include the brain and internal auditory canals, with and without gadolinium. This test evaluates intracranial pathology such as vestibular Schwannoma, stroke, or demyelination, which can cause these symptoms. If symptoms begin after age 60 years, Doppler examinations are performed to evaluate possible cerebrovascular disease. Electrocochleography is helpful in diagnosing Ménière disease. The test demonstrates high ratios of the summating potential/action potential in Ménière patients; sensitivity and specificity are not high enough for routine use. Once other causes are excluded, the most accurate way to establish the diagnosis is to determine whether it responds to treatment.
MEDICAL TREATMENT
Therapy begins with diet and medication. Approximately 85% of patients respond very well, with significant decrease in frequency and severity of attacks. About 5% of patients find that therapy with diet and medication is inadequate and requires middle ear injections or surgery.
The standard for medical management is a low-sodium diet and thiazide diuretic. First, it should be ascertained that this is safe for the patient by consultation with their internist. A new patient should be started on a diuretic between attacks of vertigo. Diet should be a strict 1,500 mg/day sodium regimen; the patient should be informed that this requires checking labels carefully. If patients eat outside the home, it should be in places where they can limit the amount of sodium. Sodium intake should be even with each meal to avoid surges in pressure. Patients are advised to drink copious amounts of water to help flush out the sodium and maintain blood pressure. They are urged to avoid caffeine and alcohol, which are thought to aggravate symptoms. Emotional stress can also aggravate Ménière disease, and psychiatric consultation may be necessary.
Because sodium levels are hormonally regulated, adding a diuretic is useful. Typically, the patient is started on hydrochlorothiazide 37.5 mg/triamterene 25 mg once daily. This diuretic sheds sodium well and is required only once daily. Triamterene typically protects the potassium level. Electrolyte levels and renal function should be monitored periodically while this diuretic is being taken. Discontinuation or dose adjustment may be required. Patients should be advised that it can take a few weeks to know if this regimen is beneficial.
TABLE 59.3 Medical Treatment of Ménière Disease | ||||||||||||||
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