[Cochlear Implant Mini-System 22 for the management of deaf preschool children]

The long-term reliability and the overall good results achieved with cochlear implants in adults have led us to consider whether this method could also be applied in small children. This though was supported by the work of House, who has been providing children with cochlear implants for many years, although using a monochannel device with only one electrode, which is inserted only a few millimetres into the scala tympani. Our considerations were also prompted by technical progress which has resulted in the so-called Mini System 22. In this system, the implant is only 6 mm thick with a speech processor of a mere 9 x 6 x 1.9 cm and weighs not more than 100 g. From the point of view of the surgical technique, small children do not present any specific difficulties, except for the necessity of fixing the array of electrodes as closely as possible to the cochlea, in order to avoid its slipping out of the cochlea during skull growth. Positive results with single reimplantations indicate that such patients will also be able to benefit from technical progress in future decades. To differentiate between inner ear and nerve deafness the promontory test has to be replaced by electrocochleography. This indicates a neural genesis of the hearing impairment in cases of cochlear microphonics of more than 50-60 nHL and possibly even a summation potential can be recorded. Additionally, we consider it mandatory to use objective parameters as a basis for the first tune-up of the speech processor.(ABSTRACT TRUNCATED AT 250 WORDS)