• Definition :

• Meniere’s disease is also called Endolymphatic hydrops.
• Moreover it is a disorder of the Inner ear where the endolymphatic system is distended with the endolymph.

Characteristic features of Meniere’s disease :

• Vertigo
• Sensorineural hearing loss
• Tinnitus
• And also sense of aural fullness

Pathology:

• The main pathology of this disease is distension of endolymphatic system.
• It mainly affects the Cochlear duct (Scala media) and the Saccule.
• And to some lesser extent it also affects the Utricle and Semicircular canals.
• Moreover the dilatation of cochlear duct is such that it may completely fill the scala vestibuli.
• It also presents with bulging of Reissner membrane.
• This may herniate through the helicotrema into the apical part of the scala tympani.
• The distended saccule may lie against the stapes footplate.
• Moreover the utricle and saccule may show outpouchings into the semicircular canals.

Aetiology or Causes :

• The distension of the endolymphatic system is due to increased volume of the endolymph.
• It can be either the result of increased production of endolymph or its faulty absorption or both.
• Moreover, Stria vascularis secretes the endolymph.
• This endolymph fills the membranous labyrinth.
• Finally the endolymphatic sac absorbs the endolymph.

Theories for the Aetiology of Meniere’s disease:

• Defective absorption by endolymphatic sac :
  • The endolymphatic duct carries the endolymph to the sac where it is absorbed.
  • Defective absorption of the endolymph stands as the reason for the increased pressure of the endolymph.
  • Moreover the experimental obstruction of the endolymphatic sac and its duct also produces Hydrops.
  • Ischemia of the endolymphatic sac also leads to Meniere’s disease.
  • This happens in cases of Meniere’s disease undergoing sac surgery, indicating poor vascularity and thus poor absorption by the sac.
  • Distension of membranous labyrinth leads to rupture of the Reissner membrane.
  • Thus it leads to mixing of the Perilymph and Endolymph.
  • There is belief that this mixing of the perilymph with endolymph brings about an attack of Vertigo.
• Vasomotor disturbance :
  • According to this theory there is sympathetic overactivity.
  • This results in spasm of internal auditory artery and or its branches, thus interfering with the function of cochlear or vestibular sensory neuroepithelium.
  • Thus this is responsible for the hearing loss and Vertigo.
  • Anoxia of capillaries of stria vascularis also causes increased permeability, with transudation of fluid and increased production of endolymph.
• Allergy :
  • The allergen may be either foodstuff or an inhalant.
  • So in case of allergy, the inner ear acts as the ” shock organ ” producing excess of endolymph.
  • Nearly 50 percent of the people with Meniere’s disease are associated with the Food or Inhalant allergy.
• Sodium and water retention :
  • Excessive amounts of fluid retained due to either obstruction or increased production leads to endolymphatic hydrops.
  • Hence there arises a need to avoid excessive salt intake.
• Hypothyroidism :
  • Nearly 3% of the cases of Meniere’s disease are due to hypothyroidism.
  • Such cases usually benefit from thyroid replacement therapy.
• Autoimmune and Viral Aetiologies :
  • The above two causes are also suggestive of the Meniere’s disease.

Clinical features :

• Age and Sex : Usually it is prevalent in age group of 35-60 and also most commonly in males.
• Usually the disease is unilateral but after few years both the ears get affected by the disease.

Cardinal symptoms of Meniere’s disease :

• Episodic vertigo
• Fluctuating hearing loss
• Tinnitus
• And also sense of fullness or pressure in the involved ear.
• Vertigo :
  • Usually presents as an attack.
  • The onset is usually sudden.
  • The patient feels like rotation of his own head or his/her environment.
  • Sometimes it also presents with to and fro movements or up and down movemnts.
  • Attacks usually comes in clusters with periods of spontaneous remission lasting for weeks or months or years.
  • Usually the attacks are accompanied by nausea and also vomiting with ataxia and nystagmus.
  • If the attack is severe it may be accompanied by the vagal disturbances such as abdominal cramps, diarrhoea, cold sweats, pallor and bradycardia.
  • There is no warning symptoms for the oncoming attacks of vertigo but sometimes the patient may feel the fullness in the ear, change in character of tinnitus oor discomfort in the ear which herald an attack.
  • In some cases of the Meniere’s disease there may be presence of Tullio phenomenon.
  • It is a condition where the loud sounds or noise produce vertigo and is due to the distended saccule lying against the stapes footplate.
  • And this phenomenon is also seen when there are three functioning windows in the ear.
  • For e.g a fenestration of horizontal canal in the presence of mobile stapes.
• Hearing loss :
  • It usually either accompamies vertigo or precedes vertigo.
  • Hearing improves after the attack and may be normal during the periods of remission.
  • Moreover this fluctuating character of the hearing loss is a characteristic feature of the disease.
  • With the recurrent attacks of the disease, improvement in hearing during the remission may not be complete.
  • Moreover some hearing loss will be always added up in every attacks leading to slow and progressive deterioration of hearing which becomes permanent as the time passes by.

Specific complaints in hearing loss :

• Distortion of sound :
  • Some of the patients suffering from this disease may complaint of distorted hearing.
  • Particular frequency of sound may appear normal in one ear and also of higher pitch in the other ear for them.
  • This leads to Diplacusis.
  • And also music appears discordant.
• Intolerance to loud sounds :
  • Patients suffering from Meniere’s disease cannot tolerate amplification of sounds due to recruitment phenomenon.
  • Moreover they are the poor candidates for the hearing aids because even the amplification of the sounds produced by the hearing aids cannot be tolerated.

• Tinnitus :
  • Roaring type of low-pitched sound and it is mainly aggravated during the acute attacks.
  • Sometimes it has a hissing ( To make a sharp or sibilant sounds ) Characteristic.
  • This condition may persist during the remission of the attacks.
  • Moreover, change in the intensity and pitch of the tinnitus may be the warning symptom of the attack.
• Sense of fullness or pressure :
  • As like all other symptoms, it also fluctuates.
  • This may either accompany or precede an attack of Vertigo.
• Other features :
  • Patients suffering from Meniere’s disease also suffer from emotional stress due to apprehension of the repetition of attacks.

Examination :

• Otoscopy :
  • Tympanic membrane is usually normal.
• Nystagmus :
  • Nystagmus ia only seen during acute attack.
  • Moreover the quick component of nystagmus is towards the unaffected ear.
• Tuning fork tests :
  • Mostly they indicate the sensorineural hearing loss.
  • Rinne test is positive.
  • Moreover absolute bone conduction is reduced in the affected ear and also Weber is lateralized to the better ear.

Investigations :

• Firstly, Pure tone audiometry
• Secondly, Speech audiometry
• Special audiometry tests
• Electrocochleography
• Caloric test
• And also Glycerol test

Results of various tests to differentiate a cochlear from a retrocochlear lesion :

	Normal	Cochlear lesion	Retrocochlear lesion
Pure tone audiogram	Normal	Sensorineural hearing loss	Sensorineural hearing loss
Speech discrimination score	90% – 100%	Below 90%	Very poor
Roll over phenomenon	Absent	Absent	Present
Recruitment	Absent	Present	Absent
SISI score	0% – 15%	Over 70%	0% – 20%
Threshold tone decay test	0 – 15dB	Less than 25dB	Above 25dB
Stapedial reflex	Present	Present	Absent
Stapedial reflex decay	Normal	Normal	Abnormal
BERA	Normal interval between I and V	Normal interval between wave I and V	Wave V delayed or absent

Variants of Meniere’s disease :

• Cochlear hydrops
• Vestibular hydrops
• Drops attacks
• And also Lermoyez syndrome

• Cochlear hydrops :
  • Usually the cochlear symptoms and also signs of Meniere’s disease are present.
  • Moreover vertigo is usually absent initially.
  • It is only after several years that vertigo will appear.
  • And also it is believed that in these cases, there is a block at the level of Ductus reuniens and thereby confining the increased endolymph pressure to the cochlea only.
• Vestibular hydrops :
  • The patients gets attacks of episodic vertigo while the cochlear functions remain normal.
  • It is only after sometime that a typical picture of Meniere’s disease will develop.
  • Moreover many of the cases of vestibular Meniere’s disease are labelled ” recurrent vestibulopathy ” as endolymphatic hydrops cannot be demonstrated in the study of temporal bones in such cases.
• Drops attacks ( Tumarkin’s otolith crisis ) :
  • In these cases there is a sudden drop attack without the loss of conciousness.
  • Moreover there is no vertigo or fluctuations in hearing loss.
  • The patients gets a feeling of having been pushed to the ground or poleaxed.
  • It is an uncommon manifestation of Maniere’s disease and also occurs either in the early or late course of the disease.
  • The possible mechanism lies in the deformation of the Otolith membrane (Macula) of the Utricle or saccule due to changes in the endolymphatic pressure.
• Lermoyez syndrome :
  • Here the symptoms of the Meniere’s disease is seen in the reverse order.
  • Firstly, there is progressive deterioration of hearing.
  • Secondly, followed by an attack of Vertigo at which time the hearing recovers.

Meniere’s disease versus Meniere’s syndrome :

• Meniere’s disease is an idiopathic condition while Meniere’s syndrome is clinically results from variety of reasons such as trauma, viral infections, syphilis, Cogan’s syndrome, Otosclerosis or autoimmune disorders.
• It is also called secondary Meniere’s disease.

Diagnosis of Meniere’s disease :

• According to American Academy of Otolaryngology – Head and neck Surgery classified the diagnosis of Meniere’s disease as follows :
• Certain :
  • Definite Meniere’s disease is confirmed by histopathology.
• Definite :
  • Two or more definitive spontaneous episodes of vertigo lasting for more than 20 mins or longer.
    • (a) Audiometrically documented hearing loss on atleast one occasion.
    • (b) Tinnitus or Aural fullness in the affected ear.
    • (c) All other causes excluded
• Probable :
  • (a)One definitive episode of vertigo
  • (b)Audiometrically documented hearing loss on atleast one occasion.
  • (c)Moreover Tinnitus or Aural fullness in the treated ear.
  • (d) All other causes excluded
• Possible :
  • (a) Episodic vertigo of Meniere’s type without documented hearing loss ( vestibular variant )
  • (b) And also it can be Sensorineural hearing loss, fluctuating or fixed, with disequilibrium but without definitive episodes (Cochlear variant)
  • (c) All other causes excluded

Staging of Meniere’s disease :

Stage	Pure tone average in dB in previous 6 months
1	</= 25
2	26-40
3	41-70
4	>70

• This staging can be done in certain and definite cases of Meniere’s disease.
• And also it is based on the average of pure tone thresholds at 0.5, 1, 2 and 3kHz ( rounded to the nearest whole) of the worst audiogram during a period of 6 months before treatment.

Treatment :

A) General measures

• Reassurance :
  • Firstly to reduce the anxiety of the patients by giving reassurance.
  • And also it is important to explain the true nature of the disease.
  • This is particularly important in case of acute attack.
• Cessation of smoking :
  • Nicotine causes vasospasm.
  • And therefore smoking should be completely stopped.
  • This holds very much important because for some patients just cessation of smoking stands as the necessary treatment.
• Low salt diet :
  • Firstly, patient must be advised to take low salt diet intake.
  • Secondly, no extra salt intake must be permitted.
  • Moreover the salt intake should not exceed 1.5 -2.0g/day.
  • Avoid excessive intake of water
  • And also avoid overintake/indulgence of in coffee, tea and alcohol.
• Mental stress :
  • Avoiding stress and bringing a change in the lifestyle.
  • And also Mental relaxation exercises and yoga are helpful to decrease stress.
• Regarding activities :
  • As the attack of Meniere’s disease is abrupt, sometimes with no warning symptom, professions such as flying, underwater diving or working at great heights should be avoided.

B) Management of Acute attack :

• During the acute attack of Meniere’s disease, there is severe vertigo with nausea and also vomiting.
• The patient will be usually apprehensive.
• And also Head movements provoke giddiness.
• Therefore the treament would consist of:
  • Reassurance and also psychological support to allay worry and anxiety.
  • Bed rest – in such a way preventing head movements.
  • Intravenous fluids and also electrolyte administartion to combat their loss due to vomiting.
  • Vestibular sedatives to relieve vertigo.
  • Vasodilators improves labyrinthine circulation.

C) Management of Chronic use :

• When patient presents after Acute attack, the treatment consists of :
  • Vestibular sedatives
  • Vasodilators
  • Diuretics
  • Propenthaline bromide
  • Elimination of allergen
  • Hormones
  • And also Intratympanic Gentamicin therapy

D) Surgical Treatment :

• During the failure of medical treatment the surgical treatment is carried out.
• Conservative procedures :
  • These are useful in cases of vertigo is disabling but hearing is still useful and needs to be preserved.
  • A) Decompression of the endolymphatic sac.
  • B) Endolymphatic shunt operation
  • C) Sacculotomy ( Fick’s operation )
  • D) Selective section of vestibular nerve
  • E) And also Ultrasonic destruction of Vestibular labyrinth
• Destructive procedures :
  • They totally destroy the function of the cochlear and vestibular function
  • And also the method is only opted when the cochlear function is not serviceable.
  • Moreover labyrinthectomy is usually done.
• Intermittent low-pressure pulse therapy ( Meniett device therapy )