Clinical portrait of cochlear implantation in patients with incomplete partition type-III malformation

Objective: To investigate the clinical characteristics and postoperative speech development in children with incomplete partition type III (IPIII) cochlear malformation. Methods: A retrospective analysis was conducted on 6 patients (12 ears) diagnosed with IPIII cochlear malformation, all patients underwent preoperative high-resolution CT (HRCT), middle ear and cranial MRI, and audiological evaluations. Intraoperative cochlear imaging was performed to confirm electrode placement, there was also 1 types of comparison: IP III patients with matched CI patients without inner ear malformations, questionnaires were used to evaluate auditory and speech perception. Results: All 6 patients were male, with 3 undergoing bilateral cochlear implantation and 3 undergoing unilateral implantation (1 left, 2 right). The surgical age ranged from 8 months to 12 years, with a median age of 17 months. HRCT findings in all 12 ears (100%) showed a grossly normal cochlear shape with bony cochlear partitions present but an absent modiolus. Ten ears (10/12; 83.3%) exhibited enlarged internal auditory canals (6.13 ± 0.395 mm), 9 ears (9/12; 75%) had profound sensorineural hearing loss, 4 ears (4/12; 33.3%) showed significant vestibular dilation with a cystic appearance, and 4 ears (4/12; 33.3%) had enlarged vestibular aqueducts. All patients had normal auditory nerve development (100%). intraoperative neural response telemetry (NRT) responses were successfully elicited in all cases, and all patients experienced gusher phenomenon (6/6; 100%). Intraoperative cochlear imaging preliminarily confirmed electrode placement. Follow-up ranged from 3 months to 1 year, with preoperative CAP scores 0.83 ± 0.41 and postoperative CAP scores 6 ± 1.55, p