Electrically Evoked Auditory Brain-Stem Response in Pediatric Patients With Cochlear Implants

Abstract

OBJECTIVE: To study the feasibility and clinical applicability of preoperative, transtympanic electrically evoked auditory brain-stem response (EABR) in a pediatric patient population with cochlear implants. DESIGN: A descriptive study using repeated measures analyses of variance to determine if EABR measures were affected by response configuration or cochlear status. SETTING: The operating room before cochlear implant surgery. PATIENTS: A population-based sample of 43 patients aged 2.5 to 14.5 years who were candidates for cochlear implantation. INTERVENTION: Stimuli consisting of brief balanced biphasic current pulses were provided by a transtympanically placed promontory needle electrode; EABR was recorded with subdermal needle electrodes on the forehead and contralateral mastoid. MAIN OUTCOME MEASURE: Presence or absence of postoperative electrical excitability with a cochlear implant. RESULTS: Electrically evoked auditory brain-stem responses were available from 41 of the 43 patients tested. Mean EABR threshold was 406.5 microA (SD = 118.1) for 31 patients with patent cochleas and 472 microA (SD = 91) for 10 patients with cochlear ossification. Mean wave V latency at threshold was 4.69 milliseconds (SD = 0.57). CONCLUSION: Preoperative EABR is an integral component of the preoperative selection process for pediatric patients with cochlear implants.