[Development of different linguistic systems in children with a cochlear implant]. / Développement des différents systèmes linguistiques chez les enfants porteurs d'un implant cochléaire.

The authors have studied a population of 21 pre-lingually deaf children equipped with a cochlear implant for at least 24 months. Their linguistic progression after implantation has been compared with the standard language development in normally hearing children, using a model published by Marie Therese Le Normand in 1996. 3 types of development can be distinguished: Profile 1 (shown by 9 children) in which language development after implantation is rapid and homogeneous: profile 2 (shown by 8 children), in which it is slower and more heterogeneous, with a longer pre-linguistic phase; Profile 3 (shown by 3 children) in which there are diverse problems with development. The authors then searched to establish the influence of the age at implantation and the mode of communication on this development.

Selection criteria for cochlear implants in children.

OBJECTIVE: To determine the selection criteria for cochlear implantation in children. SETTING: Hospital pediatric implant center. PATIENTS AND INTERVENTIONS: Selection of patients depends on medical evaluation, audiometric data, speech discrimination, communication skills, cognitive skills, and psychosocial factors. Patient selection is based on tonal audiometry, computed tomography, magnetic resonance imaging, and electrophysiologic tests. Side of implantation is chosen according to cochlear structure, duration of deafness, and dominant handedness. RESULTS: Ninety-eight cochlear implantations with the Nucleus multichannel implant have been performed at this center since 1990. CONCLUSION: The selection of children for cochlear implantation require close collaboration between the pediatric surgical team, the educational team, and the family.

Criteria for selecting the side for cochlear implantation.

Choice of the side for cochlear implantation should take into account peripheral (extracortical) factors and central (cerebral dominance) factors. From 111 patients implanted with a Nucleus device, the authors found that significant peripheral factors were the degree of cochlear ossification, the duration of deafness before cochlear implantation, and the preoperative promontory test dynamic range (degree of response on the promontory test in decibels); cause of deafness and residual hearing were not correlated with speech discrimination. Cerebral dominance was indirectly determined by handedness. Handedness laterality was determined by a questionnaire. There was no significant difference in results between patients implanted on their dominant side and patients implanted on their nondominant side. When ears are different according to their peripheral factors, the authors suggest implanting the better ear, provided there is no significant hearing in that ear. When both ears are identical, the side of implantation should be the side of handedness laterality to facilitate device manipulation (a practical reason).