Mnires Disease


General Discussion


Mnires Disease is a disorder of inner ear. There is commonly episodic vertigo, imbalance, nausea and vomiting, tinnitus, and a feeling of fullness or pressure in the ear. Fluctuating hearing loss. Attacks can be typically preceded in one or both ears by aching or feeling of fullness. Average attack can be two to four hours followed by a period of tiredness and a need for sleep for several hours. Weeks, months or even years may pass between episodes, usually free of symptoms but may note mild imbalance or tinnitus. Around 75% confined to one ear and most cases have a progressive hearing loss in the affected ear. This disease is considered to result from fluctuating pressure of a fluid (endolymph) within the inner ear. The cause of the disease is unknown. The loss of hearing is over time. There are periods of vertigo or dizziness with tinnitus (ringing, buzzing, humming in the ear) with the feeling of fullness or pressure in affected ear.


Initially, hearing may return to normal then get worse, get better and so on. Hearing may never return to normal limits but changes go back and forth between mild/moderate hearing loss. Usually the loss is greater in the low frequencies. May complain of some or all of the following:


                                                                                                     Greater sensitivity to noise or sounds



                                                                                                     Rapid heart action

                                                                                                     Rapid pulsation of heart

                                                                                                     Complete mental or physical exhaustion

                                                                                                     Hearing one sound as two

                                                                                                     General weakness



Symptoms may occur together or separately. For some, symptoms exist to some degree at all times. Episodes usually occur suddenly and are often preceded by a decrease in hearing, increased fullness feeling, tinnitus in affected ear and change in quality of the pre-existing symptoms. An attack may go within one hour or may continue for hours or days. Some have long periods between episodes - some more frequently. Mnire's disease refers to amount of one of the inner ear fluids (approx 50% cases of unknown cause). Associated with physical trauma (fracture of temporal bone or concussion of balance organ), elevated blood fat, viral infection.


There are four subvarieties of Mnire's disease - improved hearing during and immediately following attack (Lermoyezs syndrome). Sudden falling down that lasts for short time only (Tumarcinn's syndrome). Low frequency hearing loss, but no dizziness (Cochlear hydrops). Dizziness, but no hearing loss (Vestibular hydrops). Audiologist often consulted to complete hearing and balance evaluation, electrocochleography (ECOG), electronystagmography (ENG), posturography and Auditory Brainstem Response (ABR). Mnire's disease also called idiopathic endolymphatic hydrops. One of most common causes of dizziness originating in inner ear - typically between 20 to 50 years of age. Men and women equally affected.

Vertigo defined as sensation of movement when no movement occurring. May also occur in CNS disorders.


Dysequilibrium (off-balance sensation). This lasts 20 mins to two hours or more. Off balance may last several days afterwards. May be intermittent hearing loss early in disease, especially low frequencies, but fixed hearing loss involving tones of all pitches commonly develops in time. Loud sound may be uncomfortable and appear distorted in affected ear. Tinnitus pressure feeling may come and go with changes in hearing, occur during or just before attacks or be constant. Symptoms of Mnire's disease may be minor nuisance or become disabling, especially if attacks of vertigo are severe, frequent and occur without warning. Audiometric examination typically indicates sensory type hearing loss in affected ear. ENG to evaluate balance function. Darkened room. Eyes and ears work in coordinated manner through nervous system. Eye movements used to test balance system. In about 50%, balance reduced in affected ear (ie. 50% it is not). CT or MRI to rule out tumour (rare) on hearing or balance nerve but symptoms similar to Mnire's disease. acoustic neur(in)oma.


Endolymphatic shunt or decompression procedure - inner ear operation directs fluid from inner ear into cerebrospinal fluid around brain or into mastoid and done to improve inner ear drainage. Usually preserves hearing. Vertigo controlled ;n half to two-thirds cases. Control not always permanent but recovery time short. Selective vestibular neurectomy - major procedure, working next to brain stem. Like 'unplugging phone' - cuts nerve sending faulty information. Balance nerve cut as it leaves inner ear to brain. Vertigo commonly cured and hearing preserved in most cases. Labyrinthectomy and Vlllth nerve section - balance and hearing mechanism destroyed in inner ear on one side. Only considered if poor hearing in affected ear. Results in highest rate of control of vertigo attacks.


Head noise - Annoying but rarely a sign of a serious problem. Causes of tinnitus (ringing in the ear/s):


Common source of dizziness is Mnire's disease. Sudden attack or 'spell' includes vertigo (often with nausea and vomiting). May occur once a year or every day and may last 20 mins to one-day. Usually begins in adulthood and equally among men and women. May return to normal after a spell and may gradually worsen with repetitive episodes. Most people ultimately lose much if not all hearing in affected ear. Can develop into other ear to some degree. Problem of tiny fluid-filled semicircular canals (vestibular labyrinth) of inner ear that controls balance. Only a few drops of fluid in these canals so balance of pressure and electrolytes in the fluid is critical. Too much fluid produced or isn't reabsorbed quickly enough - or combination of both. Build up of fluid and pressure causes vestibular nerve to send false signal to brain indicating spinning or falling. Cause unknown. Diagnosis tends to be by exclusion.




Wide variation of symptoms, difficult to diagnose. Inner ear and not brain (Mnire 1861). Four major symptoms - vertigo, hearing loss, tinnitus and pressure in ears. All symptoms tend to occur intermittently and are variable in severity. Sometimes, only two or three of symptoms are present. Vertigo my last minutes to hours, leaving patient feeling tired and unsteady. Most middle aged but can occur in very young and elderly. Symptoms do not always correspond to medical text book description. Underlying cause unknown but fluid pressure build up of inner ear results in symptoms of Mnire's. Also fluid pressure build up can occur in spinal fluid (hydrocephalus) and in the eye (glaucoma) or arteries (high blood pressure). As fluid pressure increases over time damage occurs to nerve endings of the inner ear.


Many cases referred to ear specialist. Audiogram, ENG, ABR (tumour may mimic Mnire's disease). ECOG - most specific test for endolymphatic hydrops or Mnire's disease. SHA (sinusoidal harmonic acceleration, rotary chair). Posturography - helpful in diagnosis of inner ear membrane rupture (perilymph fistula). Two surgical procedures - Shunt Endolymphatic Mastoid Shunt Valve. Non destructive. Small incision behind ear and brain not involved. RVS (Retrolabyrinthine Vestibular Nerve Section). All symptoms are unpredictable - vertigo, tinnitus, hearing loss. Frequency, duration and intensity vary. Some may feel slight vertigo several times a year, or tinnitus while sleeping. Hearing tends to recover after attack but over time becomes worse.


Change in fluid volume within portion of inner ear known a labyrinth. Two parts - bony labyrinth and membranous labyrinth. Latter encased by bone necessary for hearing and balance and is filled by fluid called endolymph. Head motion causes endolymph to move. This causes nerve receptors in membranous part to send signals to brain about body motion. The increase in endolymph can cause the labyrinth to balloon or dilate.  Condition known as endolymphatic hydrops.


Possible that rupture of the membranous labyrinth allows endolymph to mix with perilymph - another inner ear fluid occupying space between membranous labyrinth and the bony inner ear. This mixing may cause symptoms of Mnire's disease. Possibly also viral infection implicated? Symptoms can suddenly arise daily or once a year. Vestibular nerve serves balance and sends distorted messages to brain. Balance nerve very close to facial nerve. Hearing loss can be sensory arising from inner ear or neural arising from hearing nerve. ABR measures electrical activity in hearing nerve and brain stem can differentiate and be useful between two types of hearing loss. An ECOG (records electrical activity of inner ear in response to sound) can help confirm diagnosis.


To test vestibular or balance system, calric testing done. Flood ears with warm and cool water. Results in nystagmus (rapid eye movements) that can help diagnose balance disorder. Tumour growth can produce symptoms similar to Mnire's disease so MRI useful test to determine whether tumour causing vertigo and hearing loss. In USA about. 0.2% population affected. Two in three cases affect one ear only. Progressive hearing loss in affected ear - not fatal. Acute attack believed to result from fluctuating pressure of fluid within inner ear. Most often attributed to viral infection of the inner ear or head injury.


Periodic admixture of perilymph and endolymph often kills hair cells in the inner ear. Gradual process over years. Results frequently in unilateral deafness. Cochlear (hearing) hair cells are most sensitive. Vestibular hair cells seem more resilient. Mechanical disruption also likely an effect with dilation of the utricle (upper chamber of the inner ear from which arise the semicircular canals) and saccule (lower chamber of the auditory vescicle, small cavity containing fluid) of the ear being a well known pathological finding. This may result in gradual onset of a chronic unsteadiness, even when not having an attack. Also reasonable explanation for periodic attacks of BPPV (Benign Paroxysmal Positional Vertigo - causes severe vertigo when head held in certain position). Also likely that may be rupture of the suspensory system for the membranous labyrinth. No evidence t.hat diseases kills cochleovestibular nerve. Most people with this disease are over 40 - equal to male/female. No cure but manageable. There are several blood tests which can be used to identify this disease along with hearing testing. ENG test and MRI head scan. Acute symptoms of Mnire's disease are episodic.


Hydrops diet - fluid-filled hearing and balance structures of inner ear normally function independent of the body's overall fluid/blood system. Normal ear fluid maintained at constant volume and contains specific concentrations of sodium, potassium, chloride and other electrolytes. This bathes sensory cells of inner ear and allows normal function. Injury or degeneration of these structures, independent control lost and volume and concentration of inner ear fluid fluctuates with changes in body's fluid/blood. This fluctuation causes symptoms of hydrops - pressure or fullness in the ears, tinnitus, hearing loss, dizziness and imbalance.