What Is Meniere’s Disease;Diagnosis,Treatment And Causes

Meniere’s disease is the most common cause of true vertigo. The term vertigo strictly refers to an illusion of bodily movement involving either the person or the environment. It does not include the more prevalent but non rotatory sensations of light­headedness or giddiness.In 1861 Prosper Meniere first described the triad of explosive vertigo, fluctuating hearing loss, and tinnitus. The disease begins in middle life, although patients younger than age ten and in late years have been reported. It affects both sexes about equally, and, rarely, may be a familial condition.

The same perfectionistic, striving tendencies that characterize migrainous persons are often present in those with Meniere’s disease, and appear to intensify the expression of the illness. Many variations in the order of ap­pearance of the classic symptom triad have been described. Pseudo-Meniere’s syndrome refers to explosive attacks of vertigo without hearing loss or tinnitus. However, most patients eventually develop the complete symptom triad. Lermoyez syndrome consists of gradual, progressive hearing loss that strangely remits after the first attack of recurrent vertigo.

Clinical Manifestations Of Meniere’s.

Intermittent, explo­sive attacks of vertigo lasting minutes to hours are the hallmark of Meniere’s disease. The vertigo is of the peripheral type with sudden onset and an illusion of movement so violent that the patient cannot walk. The attacks may occur several times weekly, but long remissions of several years’ duration are frequent.

Between attacks the patient has no disorder of equilibrium or nystagmus. During the attack, there is nystag­mus with the slow phase usually toward the in­volved ear. Severe nausea, vomiting, and pallor are frequent because of involvement of the vagal and vasomotor areas of the brainstem that receive vestibular inputs. Loss of consciousness occurs occasionally, perhaps because the vestibular dis­turbance is transmitted to the brainstem reticular activating network that maintains consciousness. Half of the patients notice a feeling of fullness in the ear or head during attacks. Cold and warm water irrigation of the ear canal reveals in over half the patients at least a partial loss of thermal- induced nystagmus on the involved side.

The hearing loss with Meniere’s disease starts either before or after the onset of vertigo and initially usually affects the low tones. Commonly, there is a decrement in hearing during an attack of vertigo, and recovery is incomplete so that pro­gressive stepwise unilateral hearing loss occurs. The vertigo often ceases when hearing loss is com­plete. Total unilateral deafness occurs in only 10 per cent of patients, and the disease is bilateral in only 12 per cent. Associated auditory phenomena are sound distortion, diplacusis, and recruitment. Diplacusis is the hearing of a pure tone at a dif­ferent pitch in the involved ear. Recruitment is an abnormal increase in loudness evoked by a very slight increase’ in sound intensity.

Audiometry reveals a “perceptive” (sensorineural) deafness, with air and bone conduction equally depressed on the involved side. Speech reception is impaired to a degree appropriate for the severity of hearing -loss. Refined testing reveals the deafness to be more typical of sense organ (cochlear) damage than of nerve trunk (retrocochlear) damage with: (1) hearing thresholds that are nearly similar on the continuous and interrupted tone audiogram (Bekesy type I or II), (2) no decay in loudness (adaptation) during prolonged pure tone stimula­tion, (3) an enhancement of ability to judge small changes in sound intensity during the short in­crement sensitivity index (SISI) test, and (4) loudness recruitment. Tinnitus persists between attacks and most commonly is a roaring noise, but higher pitched types may occur. It usually predominates in the involved ear and is not abol­ished by carotid artery compression.

Pathology.

The few reports on Meniere’s dis­ease confirm the original findings of Hallpike and Cairns in 1938 of dilatation of the membranous sacs of the labyrinth and cochlea. Rupture of the sacs and degeneration of the sensory elements are seen occasionally. The abnormalities suggest a chronic elevation in intraluminal endolymphatic pressure. The postulated pressure increase may produce the sensation of fullness noted during attacks. The acute hearing loss and vertigo could result from sudden rupture of the membranes after a prolonged increase in pressure, but some investigators believe that sudden rupture of the sac may actually terminate the attack.

Lesser fluctuations in hearing could result from small clusters of cases of a clinical entity which re­sembles the foregoing description of vestibular fluctuations in endolymphatic pressure without rupture. Studies of cochlear models subjected Soil increased fluid pressure reveal Changes in basilar] membrane elasticity that would explain the majai 11 audiologic findings in Meniere’s disease except fan recruitment, which may be related to sensory] hair-cell degeneration. Autonomic or vascular theories of symptom production have also been popular, but remain unproved.

You Must Know The Treatment of Meniere’s Disease.

The medical therapy of Meniere’s disease consists of antivertiginous agents (Dramamine, Bonamine) every four hours during the acute attack and for several days thereafter. Sedatives or tranquilizers may be added. Nicotinic acid, 50 to 100- mg. four times daily, is recom­mended by many for acute attacks and for chronic usage, in an attempt to dilate the vessels of the inner ear. A low-salt diet with or without diuretics is often prescribed in an attempt to increase endolymph fluid absorption.

Many authorities prohibit:: smoking. No single medical regimen has beer, uniformly successful. In those patients with severe vertigo, surgical intervention should be considered. If hearing on the involved side ha~ deteriorated severely, labyrinthectomy is pre­ferable. If useful hearing remains, various endo­lymphatic drainage procedures such as sacculot­omy or shunts to the CSF have been employed. Selective vestibular nerve section may be advis­able in some cases.

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