DRGANOF.CORTIMeniere'’ s Disease
Meniere’s Disease
DefinitionMeniere's Disease,alsocalled endolymphatichydrops,is a disorder oftheinnerearwheretheendolymphaticsystemisdistendedwithendolymph.It is characterized by(i) vertigo,(ii)sensorineural hearingloss,(ii)tinnitus,(iv) aural fullness
Definition Meniere' s Disease, also called endolymphatic hydrops, is a disorder of the inner ear where the endolymphatic system is distended with endolymph . It is characterized by (i) vertigo , (ii) sensorineural hearing loss， (iii) tinnitus ， (iv) aural fullness
BackgroundIn 1861,oProsperMenieredescribedasyndromeIn1938oHallpikeandYamakawareportedthefindingofendolymphatichydropsintemporalbonefrompatientswithMDCross.section.of.cochleaScataTectorialmediamembraneScalaVestibuliSpiralganglion.ScalatympaniInnerOuterhaircllshaircellsBasilarmembrano
Background In 1861, ◦ Prosper Meniere described a syndrome In 1938, ◦ Hallpike and Yamakawa reported the finding of endolymphatic hydropsin temporal bone from patients with MD
PrevalenceEpidemiology4/100000inJapan.15/100000inUS,-46/100000inSweden,100/100000inUKThelargedifferencesaredueto- Geographic, genetic, ethnic or environmental factors,or different diagnostic criteria
Prevalence Epidemiology – 4/100000 in Japan. – 15/100000 in US, – 46/100000 in Sweden, – 100/100000 in UK. The large differences are due to – Geographic, genetic, ethnic or environmental factors, or different diagnostic criteria
PathologyEndolymphatichydropsThehydropsprincipallyinvolvesthecochlearductandsacculebutwerenotobviousintheutricleandampullaeofsemicirclarcanals.Decreaseintheamountoflooseconnectivetissuearoundtheendolymphaticsachypoplasiaofvestibularaqueduct,anddecreasedsacand perisaccularfibrosiswerealsoobserved
Pathology Endolymphatic hydrops ◦ The hydrops principally involves the cochlear duct and saccule but were not obvious in the utricle and ampullae of semicirclar canals. Decrease in the amount of loose connective tissue around the endolymphatic sac, hypoplasia of vestibular aqueduct, and decreased vascularization of the sac and perisaccular fibrosis were also observed
+Figure15.1(A)Normalcochlearduct.(B)CochlearductisdistendedwithendolymphpushingtheReissner'smembraneintoscalavestibuli?
Aetiology1.Defectiveabsorptionbyendolymphaticsao2.Vasomotordisturbance3.Allergy4.Sodiumandwaterretention5.Hypothyroidism6.Autoimmuneandviral aetiologies
Aetiology 1. Defective absorption by endolymphatic sac 2. Vasomotor disturbance 3 . Allergy 4 . Sodium and water retention 5. Hypothyroidism 6. Autoimmune and viral aetiologies
Clinical FeaturesRecurringepisodeofVertigovertigoisusuallysuddenwithoutlossofconsciousnessoCompaniedwithnauseavomitingandnystagmusPersistfor2Omintoseveralhours
Clinical Features 1. Recurring episode of Vertigo vertigo is usually sudden – without loss of consciousness ◦ Companied with nausea vomiting and nystagmus ◦ Persist for 20min to several hours
EveEeNe& Thsut HospitaCharta#83fenyangRoadwedbday0ceoter20.20041025200032377134-545TL2.FluctuatingHearinglossRR字58R#乐8号PTAEarlyfluctuationoflowfrequenceyhearingloss andlaterinvolvementofthehighChanttfrequencies.EAneventual declineover5-10yearsand subsequentstabilizationwithaflat国共品零品moderatetoseverehearingloss
2. Fluctuating Hearing loss PTA – Early fluctuation of low frequencey hearing loss and later involvement of the high frequencies. – An eventual decline over 5-10 years and subsequent stabilization with a flat moderate to severe hearing loss
3.Tinnituslow-pitchedaggravatedduringattacks
3. Tinnitus low-pitched aggravated during attacks