Prognostic factors in cochlear implantation.

Predicting outcomes in cochlear implantation has preoccupied many researchers,. In this thesis we focussed our attention on prognostic factors related to electrophysiology, anatomy, and imaging techniques. First we evaluated electrophysiological variables such as the electrode impedance and the electrically evoked action potenatial (ECAP). Secondly we investigated the audiological performance of children with inner ear (IE) abnormalities, their outcome is comparable to that of prelingually deaf cochlear implant recipients. Thirdly we introduced an imaging protocol to investigate the intracochlear position relative to the scala tympani and scala vestibuli. This protocol was evaluated in a clinical study in which we found a correlation between electrode distance and modiolus against the ECAP. The electrode-modiolus distance is thus of importance in the stimulation of the auditory nerve fibers.