الفهرس | Only 14 pages are availabe for public view |
Abstract Cochlear implant is an auditory prosthesis that electrically stimulates the primary auditory nerve fibers to elicit sound perception in individuals with severe to profound sensorineural hearing impairment. A substantial number of studies have demonstrated that the use of CI can facilitate the development of speech and language skills of children who are prelingually deaf (born deaf or become deaf before 3 years of age) (3). In clinical field, persons involved with CI always (patients, caregivers, professionals) face a challenge in choosing which ear to be implanted (better or poor hearing ear). As the implantation of the poorer ear allows the possibility of bimodal stimulation by utilizing a contralateral hearing aid. However, implantation of the poorer ear has raised concerns that the implant could be less beneficial in an auditory system that has been long deprived of stimulation And implantation in the better ear gives better speech discrimination and better language outcome as it contains residual neural tissues (5). So, the aim our study is to know the effect of the preimplant degree and duration of hearing loss on side selection to be implanted, by evaluating language outcome, in order to reach the better decision of the site to be implanted for better language and speech outcome. This retrospective study was conducted on (30) patients with bilateral a symmetrical sever to profound SNHL who had been implanted. The study was carried out by evaluating 30 patients who had complete recorded files. These patients fitted with their first HA before the age of 3 years with for least 6 months with extensive auditory training but without any benefits. The patients were divided into three groups according to the degree and the duration of hearing loss of the implanted ear before implantation. The first group has been implanted in the worse and short duration of deafness. The second group has been implanted in the worse and long duration of deafness. The third group has been implanted in the better ear regardless the duration of deafness. Every case was subjected to the protocol of phoniatric assessment for hearing impairment. This protocol was applied to detect which group shows the better language outcome by applying PLS-4 Arabic form (116). This study declared that children in each group suffering from delayed language. While the third group is the best comparing with the other because, it is the better functional ear contain some residual hearing and it is important for better speech discrimination and so on better language outcome. The first group is better than the second group due the short duration of deafness in the first group. The short duration of deafness provides more residual neural tissue for electrical stimulation that leads to better speech recognition. The long duration of deafness leads to degradation of peripheral neural structures, spiral ganglion cells and the cochlear nucleus. This study revealed positive correlation between functionality of the ear and language outcome (implantation in the better function ear gives better language outcome) and negative correlation between the duration of deafness and language outcome ( as the duration of deafness increases the language outcome will be poor) |