EVOKED cO MPOUND a ctI ON POtE NtIaL (Ec aP ) OF tH E aU DItI VE NErV E rEcOrD ED FrO M a GrO UP OF cH ILDrE N UsI NG PULs ar cI 100

Introduction: The electrically evoked compound action potential (ECAP) of the auditory nerve can be recorded in cochlear implants and the obtained thresholds can be used to predict threshold levels for speech processor maps. The aim of the study was to determine how often the ECAP can be recorded using the auditory response telemetry (ART) system of MedEl cochlear implants and to find correlations with the deafness etiology, hearing loss duration, auditory rests and electrode array position. Material and methods: According with the established protocol, we have recorded the amplitude growth function of the ECAP on the Pulsar CI100 cochlear implants. This study included intraoperatively recordings in 10 children under general anesthesia immediately following the implantation. The X-ray control followed the surgery for each patient in order to localize the implant's electrodes. Results and conclusions: The amplitude growth function was obtained in the majority of measured intracochlear channels. The auditory response telemetry may vary depending of the position of the electrodes along the cochlea. The response was recorded better for the electrodes situated in the middle region of the cochlea and lesser in the basal part. We found thresholds values bigger in the basal group of electrodes than in the middle or apical group. No correlation can be established between the ART measurements and the hearing Introducere: La pacien]ii implanta]i cu implant cohlear MedEl se poate nregistra poten]ialul de ac]iune compus al nervului auditiv (ECAP) pentru ob]inerea pragurilor care s\ fie utilizate n reglajul implantului. Scopul studiului a fost s\ determin\m n ce m\sur\ nregistrarea intraoperatorie a ART (Auditory Response Telemetry) a avut rezultate, rela]ia dintre ART [i etiologia surdit\]ii, durata acesteia, resturile auditive [i pozi]ia electrodului intracohlear. Material [i metod\: Am stabilit un protocol de evaluare a celor 10 copii implanta]i cu sistem MedEl tip Pulsar CI 100. Am nregistrat ECAP intraoperator, imediat dup\ implantare, sub anestezie general\, apoi am verificat radiologic la fiecare caz pozi]ia intracohlear\ a portelectrodului. Rezultate [i concluzii: ART a putut fi nregistrat n condi]ii bune la majoritatea pacien]ilor pe electrozii intracohleari. Calitatea r\spunsului variaz\ n func]ie de pozi]ia portelectrodului intracohlear. Am ob]inut r\spunsuri ale nervului auditiv mai bune pentru electrozii situa]i n por]iunea medie cohlear\ [i mai pu]in ample pentru por]iunea bazal\. Am determinat praguri auditive constant mai mari n grupul electrozilor bazali dect ale celor din regiunea medie [i apical\ cohlear\. Nu a putut fi stabilit\ nici o dependen]\ a ART fa]\ de durata priv\rii auditive, dar am observat un r\spuns ART mai deteriorat n hipoacuzia de cauz\ meningitic\. Cuvinte cheie: implant cohlear, ECAP