ABSTRACT
Background: Cochlear Implantation (CI) has become an important modality of treatment for children with severe to profoundpre-lingual sensorineural hearing loss who do not benefit from hearing aids (HAs). The final outcome is not totally predictable,as there are a large number of factors which either alone or in combination will play their roles in the final outcome of CI.Aim of the Study: This study aims to evaluate prospectively the relative impact of multiple pre-, peri-, and post-operative factorson the final outcome of the CI in pre-lingual hearing impaired children aged 5 years under “Sruthitharangam” free cochlearimplant program of Government of Kerala.Materials and Methods: This study was conducted at Government Medical College, Kozhikode (GMC-KKD), Kerala, fromJanuary 2014 to January 2015. The study group consisted of 60 patients screened from the patients who have attendedAuditory verbal habilitation (AVH) categories of Auditory Performance (CAP) test, Meaningful auditory integration scale (MAIS)and Speech intelligibility rating test (SIR) at GMC-KKD, Kerala. Counseling of parents was done regarding regular follow-upsand therapy/support to the child at home.Observations and Results: Pearson correlation test and Spearman correlation test were done to check the correlation betweenage at which HA was first fitted and MAIS scores. Correlation between the age at which HA first fitted and MAIS was negative.As the age at which HAs were fitted increases, the MAIS score decreases. This indicates the significance of using the residualhearing and stimulation of auditory nerve as early as possible. Pearson correlation and Spearman correlation tests were appliedto check the correlation between age of surgery and MAIS score and found that there was negative correlation existing betweenage of surgery and MAIS scores. This meant, as the age at which surgery was done increases, the MAIS score decreases.Pearson correlation test and Spearman correlation tests were applied to check the MAIS scores and duration of AVH with HAs.Conclusions: A Cochlear implant was not a passive sensory aid or sensory substitution device that simply replaces a damaged ordefective cochlea to restore normal hearing but requires prolonged period of aural rehabilitation that involves perceptual learning,adaptation, and readjustment of their attention. The various risk factors that affect the auditory gain and speech perception eitheracting singly or in combination and the statistical analysis of the present study showed are the age at implantation, duration ofauditory deprivation, and the residual hearing which have a direct impact on the outcome over a period of 1 year.
ABSTRACT
OBJECTIVES: The objective of this study was to compare the long-term auditory performance and language skill depending on the age of cochlear implantation in the Korean population. We especially tried to separate the effect of maturation/development from that of the age at implantation. METHODS: Eighty-six pre-lingual children with profound hearing loss who underwent a cochlear implantation before the age of six and had been followed for more than 3 yr were included in this study prospectively. Categories of Auditory Performance (CAP) and Korean Picture Vocabulary Test (K-PVT) were serially followed up. In order to separate the age at implantation effect, K-PVT results were readjusted to the child's chronological age in the normal hearing population. RESULTS: When the CAP and K-PVT scores were directly compared without chronological readjustment, we failed to show a significant difference for improvements according to the age at implantation. Early cochlear implantation was associated with better language development, only when the K-PVT scores were readjusted to percentile scores of their chronological age. CONCLUSION: Early cochlear implantation was associated with better language development even within the critical period. This advantage may be recognized only when the effect of the age at implantation is separated from the effect of maturation/development.