Evaluation of the slope of amplitude growth function changes of the electrically evoked action potential in three months after receiving the device in children with cochlear implant

In neural response telemetry, intracochlear electrodes stimulate the auditory nerve and record the neural responses. The electrical stimulation send to the auditory nerve by an electrode and the resulted response, called electrically evoked compound action potential, is recorded by an adjacent electrode. The most important clinical applications of this test are evaluation and monitoring the intra and postoperative responses of auditory nerve and help to primary setting of speech processor. The aim of this study was evaluating of the potential's slope of amplitude growth function changes in three monthes after receiving the devise in pediatric cochlear implant recipients. This longitudinal study evaluated the potential's slope of amplitude growth function changes in four given electrodes in four sessions after receiving the devise by approximately one month's intervals in all of the children who implanted in Amir Alam and Hazrat-e-Rasoul hospitals in 2007, July to December. Friedman test used to analysis of results. Electrically evoked compound action potential's mean slope of each electrode was more in later sessions relative to first session, while there was significant difference between the 1st and the other electrodes’ responses in every session(p<0.05). The reliabiliy of the responses result in more certainty of clinician to fit the speech processor for along time. Better responses in apical electrodes may lead to develope an effective coding strategy.