Evaluation of auditory perception skills development in profoundly deaf children following cochlear implantation

Cochlear implant is a medical treatment option for individuals with severe to profound sensori-neural hearing loss on account of non-functioning cochlea or part thereof. Technology is ever evolving and the candidacy criteria are widening. Appropriate selection of patient, successful implantation of an appropriate device and adequate post-implantation rehabilitation protocol are the key factors that dictate the eventual outcome. Bilateral cochlear implantation in children and combined electro-acoustic stimulation are the new developments in this field of rehabilitation for the deaf. Pakistan Cochlear Implant Programme was started in year 2000 and one hundred and fifty subjects have undergone cochlear implant surgery so far at Karachi, Lahore and Peshawar since. This prospective study was designed to evaluate the development of auditory perception skills and language in children, over a twelve months period, following cochlear implantation. Twenty-one patients were enrolled in this evaluation. These were divided into three groups as per age factor. Group 1 included eleven children of ages less than five years, Group 2 included eight children of ages between five and nine years whereas, Group 3 included two eleven years old children. Furthermore, subjects in Group 1 and 2 were pre-lingual whereas those in Group 3 were post-lingual. The three groups were evaluated using "Evaluation of Auditory Responses to Speech" [EARS]. Improvement in performance on all measures was noticed in all the groups over a twelve months period following implantation. Dynamics of improvement in auditory skills suggested more and rapid development in younger age group. Children of varying ages, both pre and post lingual, did show improvement in the development of auditory perception skills, that was evident more in the younger age group

Preservation of residual hearing in cochlear implanted patients

Aim of this study is to investigate the preservation of residual hearing after the cochlear implant surgery. Lahore and Peshawar during the period 2001 to 2007. Eighteen patients out of an overall of 150 subjects, who underwent Cochlear Implant surgery in Lahore and Peshawar during the period 2001 to 2007, were enrolled for this study. Hearing threshold has been measured in this group of patients following cochlear implantation with Medel Combi 40+ device for the last six years. The assessment was carried out within the first post-operative month as well as at later stage, between six and 72 months, post-operatively. All Eighteen patients in our cochlear implant program who could give good pure tone audiometry results used hearing aids before implantation. The pure tone acoustic thresholds at 250, 500, 1000, 2000 and 4000 Hz were obtained using the standard audiometrical procedures before and after cochlear implantation. Hearing preservation could be achieved in 16/18 patients [86%]. In two patients partial preservation was possible [14%]. These results indicate that it is possible to partially preserve residual hearing during cochlear implant surgery