ELECTRICALLY-EVOKED AUDITORY BRAIN-STEM RESPONSE IN PEDIATRIC-PATIENTS WITH COCHLEAR IMPLANTS

Objective: To study the feasibility and clinical applicability of preo perative, transtympanic electrically evoked auditory brain-stem respon se (EABR) in a pediatric patient population with cochlear implants. De sign: 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 impla nt surgery. Patients: A population-based sample of 43 patients aged 2. 5 to 14.5 years who were candidates for cochlear implantation. Interve ntion: Stimuli consisting of brief balanced biphasic current pulses we re provided by a transtympanically placed promontory needle electrode; EABR was recorded with subdermal needle electrodes on the forehead an d 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 fro m 41 of the 43 patients tested. Mean EABR threshold was 406.5 mu A (SD =118.1) for 31 patients with patent cochleas and 472 mu A (SD=91) for 10 patients with cochlear ossification. Mean wave V latency at thresho ld was 4.69 milliseconds (SD=0.57). Conclusion: Preoperative EABR is a n integral component of the preoperative selection process for pediatr ic patients with cochlear implants.