Rupture of Reissner's membrane during acute endolymphatic hydrops in the guinea pig: a model for Ménière's disease?
CONCLUSIONS
The changes in cochlear function during a destructive acute endolymphatic hydrops were relatively small. This might be consistent with the hypothesis that an endolymphatic hydrops is a marker of disordered inner ear homeostasis rather than the cause of the clinical symptoms of Ménière's disease.


OBJECTIVE
Assessment of cochlear function during induction of a destructive acute endolymphatic hydrops.


METHODS
During repetitive microinjections of 0.5 microl of artificial endolymph at a rate of 50 nl/s the 2f1-f2 and f2-f1 cochlear microphonics distortion products (CMDP) and 2f1-f2 distortion products otoacoustic emissions (DPOAE) were recorded in the guinea pig.


RESULTS
A 'catastrophe' occurred in the inner ear when 2.5-3.5 microl of artificial endolymph was injected. A rupture of Reissner's membrane was then found, most often in the apical turn of the cochlea. This rupture had only minor effects on the endocochlear potential, whereas it caused a marked decrease in 2f1-f2 DPOAE amplitude. The 2f1-f2 and f2-f1 CMDP amplitude increased during each injection prior to the rupture. After the rupture the f2-f1 CMDP amplitude decreased during each injection, possibly due to a shift of the cochlear transducer operating point position.
Valk
W L
WL
Department of Otorhinolaryngology, University Medical Center Groningen, Groningen, The Netherlands. w.l.valk@kno.umcg.nl
Wit
H P
HP
Albers
F W J
FW
D000818:Animals; D003051:Cochlea / Q000503:physiopathology; D003053:Cochlear Duct / Q000293:injuries*; D003055:Cochlear Microphonic Potentials / Q000502:physiology; D004195:Disease Models, Animal; D004710:Endolymph / Q000502:physiology; D018159:Endolymphatic Hydrops / Q000209:etiology / Q000503:physiopathology*; D006168:Guinea Pigs; D008575:Meniere Disease / Q000209:etiology* / Q000503:physiopathology*; D008845:Microinjections; D017084:Otoacoustic Emissions, Spontaneous / Q000502:physiology; D011312:Pressure; D012421:Rupture