Retrospective analysis of intraoperative ECAP (electric compound action potentials) data from 812 patients treated with cochlear implants

Cochlea implant fitting is based on ECAP measurements (electrically evoked sum action potentials). It is claimed that ECAP profiles differ depending on the electrode array and its position as well as the time of deafening and patient age. Retrospectively, the Auto NRT (Neutral Response Telemetry) data from 812 patients who had received a cochlea implant between 11/05 and 11/21 were evaluated. The intraoperative data of children and adults was compared relative to the electorde array and its position.

There is a significant difference in mean ECAP values between children and adults (F (8.722)  = 1961.406, p <.000). For the different types of electrodes, there are significant differences in the level of ECAPS between CI512 (M  = 179.47, SD  = 18.0, n =165) and CI522 (M  = 188.75, SD =12.94, n =111) (t (272)  = -4.97, p  =  < .01) and between CI522 and CI532 (M  = 181.26, SD  = 13.19, n  = 61) (t (170)  = 3.6, p = <.01). If one differentiates between the electrodepositions, there are highly significant differences between the basal (M  = 181.29, SD  = 18.69, n  = 165) and medial (M  = 184.09, SD  = 20.64, n  = 165) electrodes in CI512 and CI522 (basal M  = 197.43, SD  = 14.45, n  = 111; medial M  = 190.03, SD  = 14.07, n  = 107), (p  < .01) as well as the apical electrodes in CI522 (M  = 177.13, SD  = 15.54, n  = 108) and CI523 (M  = 164.95, SD  = 18.54, n  = 61) (p  < .01). Children's ECAPs are significantly lower in CI422 (t (103)  = 2.443, p=0.016).

The hypotheses regarding ECAP differences depending on age, duration of hearing loss and position of the electrode array can be confirmed here in one of the largest published patient collective. In a follow-up study, we used and compared smaller stimulation increments (Advanced NRTs).

Das Projekt wurde von Cochlear Research and Development Limited finanziell unterstützt.

Publication History

Article published online:
24 May 2022