Audit of 5-year post-implantation routine integrity tests performed on paediatric cochlear implantees.

Abstract

The Nottingham Paediatric Cochlear Implant Programme (NPCIP) specializes in the implantation of children under 5 years of age. Subsequent tuning of the device and identification of changes in device function for these young children, who may have additional disabilities, can often be challenging. Thus, an objective measure to assess the integrity of the device is desirable. This study compares the device function by both objective and behavioural techniques in 30 children (age at implantation 3-11 years) at five years post-implantation. All children were implanted with the Nucleus Mini 22 device. Objective data were collected from integrity testing (IT) which allowed examination of the functioning of the implant by measuring the electrical stimulus artefact. This does not require the child to give a behavioural response. A protocol for a five-year post-implantation IT is suggested which examines common ground, monopolar and bipolar modes of operation. Behavioural data in the form of threshold (T) and comfort (C) levels were obtained by use of developmental age-appropriate techniques at 5 years post-implantation. Results demonstrate that 43.3% of patients had no electrode faults, 23.3% had potential faults on both behavioural and integrity testing, 6.7% were difficult to assess in terms of defining electrode faults due to partial electrode insertions, 13.3% had potential faults on behavioural testing only and 13.3% of patients had potential faults on IT only. In conclusion, IT is valuable in the identification of faulty electrodes, especially in young children and those with additional disabilities. Implementation of the five-year routine IT affected the management of 30% of patients. This study demonstrates that objective and behavioural techniques are complementary procedures in the ongoing management of paediatric patients.