[Electrically evoked compound action potential thresholds of pediatric cochlear implant recipients and its clinical application].
OBJECTIVE
To investigate the possibility of using pediatric cochlear implant mapping protocol, to estimate the psychophysical levels based on the electrically evoked compound action potential (ECAP) threshold measured with the neural response telemetry (NRT) capabilities of cochlear corporation's CI24M device.


METHODS
ECAP amplitude growth functions were regressed via NRT 3.0 software to determine ECAP threshold. 6 pediatric cochlear implant recipients' ECAP thresholds 1, 2 and 3 months after surgery were compared, meanwhile, intraoperative and postoperative ECAP thresholds in 7 pediatric recipients were compared.


RESULTS
The ECAP amplitude growth functions were not linear when ECAP was close to threshold or saturation. There were no significant difference among the ECAP thresholds 1, 2 and 3 months after surgery. The average intraoperative ECAP threshold of 22 electrodes was 15 CL greater than postoperative threshold. It showed high relationship between them (R2 = 0.9154).


CONCLUSIONS
ECAP threshold should be determined by regression of data from linear part of amplitude growth function. Only one NRT trial should be assessed when mapping protocol based on ECAP threshold to estimate pediatric map parameter. The intraoperative ECAP threshold can act as C-level at the initial mapping. Key words cochlear implant, electrically evoked compound action potential, mapping.
Xi
Xin
X
Department of Otolaryngology-Head & Neck Surgery, Chinese PLA General Hospital, Beijing 100853, China. xxi@163bj.com
Hong
Meng-di
MD
Han
Dong-yi
DY
Huang
De-liang
DL
Yang
Wei-yan
WY
D000200:Action Potentials; D001309:Auditory Threshold; D002675:Child, Preschool; D019929:Cochlear Implantation; D003054:Cochlear Implants; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D011601:Psychophysics; D013686:Telemetry