Rare. Malformation of the inner ear due to an interruption of the development of the neural tube towards the 7th week of gestation: the causes may be genetic or exogenous (rubella). It is the most frequent radiologically visible cochlear malformation: there is a dilation of the aqueduct of the vestibule and of the vestibule itself as well as an incomplete division of the cochlea (reduced number of coils).

A communication between the perilymphatic fluid and the subarachnoid spaces is possible, allowing the CSF to penetrate into the middle ear ('ear geyser') in case of abnormal permeability of the internal acoustic meatus. A platinar fistula can lead to recurrent meningitis.

This anomaly can be associated with Wildervanck, Klippel-Feil, Pendred, Duane or Di George syndrome.

Clinical signs: perception deafness, sometimes clear otorrhea or recurrent meningitis.

Anesthetic implications:

deafness an signs of the accompanying syndrome if any; avoid temperature measurement in the affected ear.

References : 

-         Hafsa C, Kriaa S, Ommezine SJ, Ben Achour N et al. 
Une cause de méningite récurrente chez l’enfant: la dysplasie cochléaire. 
J Radiol 2008 ; 89 : 60-3. 

-         Lien C-H, Chang H-Y, Liu Y-P, Chi H, Chiu N-C, Lin C-Y. 
There is something in the ear : Mondini dysplasia. 
J Pediatr 2014; 165: 638.

Updated: January 2019