EFFECT OF AGE Time of Cochlear implantation IN CHILDREN FUNCTION OF HEARING

EFFECT OF AGE
Time of
Cochlear implantation IN CHILDREN
FUNCTION OF HEARING

By:
Tutut SRIWILUDJENG T.
Dr. Wahidin Sudiro Husodo Mojokerto

INTRODUCTIONCochlear implant is a very important development in the handling yanga very severe deafness in the last century. Hearing Helper Tool (APM) acoustics can indeed help most people with deafness, but not much use for most besat patients with very severe deafness (profound Deafness). Effect of very severe deafness very large in early childhood - childhood, because it will hinder development of language and speech. For children - children like this, cochlear implant is one - the only way to be able to hear the speaking voice, so it is very significant in developing kemampan oral personal communication.Cochlear implants are designed to to replace the function of the middle ear, cochlear mechanical motion, and cells - sensory cells, convert sound energy into electrical energy that generates implus in the auditory nerve.Factors - factors that determine the outcome of cochlear implantation, namely:○ The duration of deafness○ Age at the start of amplification, language stimulation, and implantation diakukannya○ The experience of hearing and ability perception previous○ cognitive and attention condition○ The use of language to speak in da house school environment.In this reference will be discussed the influence of age at cochlear implantation in children did on hearing function, as this will greatly determine the recommended age for cochlear implantation done.
1. HEARING ON CHILD DEVELOPMENT
1.1 DEVELOPMENT OF STRUCTURAL AND PHYSIOLOGICAL HEARING SYSTEM PrenatalOtic placode can be performed at 23 days gestation. Corti organ differentiation started in the tenth week keahamilan. Structural developments follow the gradient from base to apex, associated with your area of ​​low and high on corti organ. Hair cell differentiation, membrane separation tektoria of corti organ, and cochlear innervation occurred in the twentieth week four of pregnancy, and with it kokklea started functioning. Action potential arising from the N. VIII at 27 weeks gestational age in premature infants showed that the cochlear nerve was functioning and relationships already exist at the time
1.2 FUNCTIONS OF HEARINGWhat is meant by primary auditory processing is the extraction and encoding of physical attributes of sound, while the secondary auditory processing is the selection of a combination of quantitative and qualitative atrtibut sound to detect sound, distinguishing beramcam - suaru kind, and understand the conversation. Sound physical attributes include frequency, timing, and intensity.Resolution or frequency tuning in the auditory system is specificity, with a structure where the structure - the structure of the auditory system response to sound at certain frequencies. It is important to distinguish frequencies. In the prenatal period, cochlear and neural maturation has the largest role in the development of frequency resolution. Tuning in the cochlea is mature, but in the neural structure, the tuning is still developing until age 6 months. After that, attention is a primary factor in the development of frequency resolution during childhood - childhood.Resolution time is the ability to detect perubaahn in tuning the sound, such as cessation of sound, distinguishing between - kind of sound duration. The resolution time was longer than the growing frequency and intensity resolution, estimated as it depends on attention and memory. In perkembangnya Initially, the factors - factors such as myelisin, diameter nerve fibers and the efficiency of the synapse plays an important role in the development of temporal resolution.Intensity resolution is the ability to detect changes in sound intensity or loudness difference. More detailed data regarding the development of intensity resolution is still unknown.From research on the development of hearing obtained a period of rapid growth in the threshold of hearing since a new baby is born until the age of 6 months, followed by a slower growth until the age of 10 years.Maturation outer and middle ear structures play an important role in hearing sensitivity.
1.3 SYSTEM DEVELOPMENT sensoryIn all animals, sensory systems evolved in the following order: somatosensoris, vestibular, smell, hearing and vision. Animal studies have shown the existence of interactions between structures - structures and environmental hearing noemal important for development.Settings neurons - neurons in the auditory areas of cerebral cortex in groups occur in response to stimulation tehadap. Sensitive period is the period when the development of sensory areas in the cerebral cortex can be affected by the conditions of stimulation, occurred at the age of 23 months of pregnancy until the month - the early months of life. Critical period of language development is on the first two to three years of life. During that period speak adequate stimulus is needed. Children with congenital deafness who do not get early amplification will be at risk to changes in structural and functional development of the permanent.
 2. Cochlear implantCochlear Implant is a device implanted through a surgical procedure that provides hearing sensation to persons with severe to profound deafness who do not benefit from the use of APM. Generally in orng with severe to profound hearing loss are severe problems in the cells - sensory cells in the cochlea. Pad normal ear, sound energy converted into mechanical energy by the middle ear, and then converted into mechanical motion of fluid in the cochlea. In the cochlea, cells - sensory cells (hair cells inside and outside) is a sensitive transducer that converts mechanical movement of fluid into electrical implus in the auditory nerve.Dirnacang cochlear implant to replace the function of the middle ear, cochlear mechanical motion, and cells - sensory cells, convert sound energy into electrical energy that generates implus and auditory nerve.Didsarkan cochlear implantation based on the fact that many fibers - the auditory nerve fibers that are still alive (viable) in patients with type cochlear deafness. Neurons N, VIII surviving can be stimulated by providing electric current from outside the force, duration and the proper orientation, with the result of the emergence of neural implus actively. This neural electrical potential will reach the temporal lobe cortex as neural implus generated by an acoustic signal transmitted through the cochlear hair cells. The brain receives this artificial electric potensia as sound.Cochlear implants consist of enternal and external components. External components, which are used in the head, above or near the ear, including:1. Microphones, which convert sound into electrical signals.2. speech processor, which manipulate and transform these signals into a special code.3. transmitter / transimiting coil, which sends electrical signals that have been encoded into the internal components.Internal components (the implanted) include:1. receivers that decode seinyal from specch processor2. electrode array, which stimulates the cochlea with electrical current.System is getting power from the battery located in the speech processor.Cochlear implants work in this way are as follows:1. The sound captured through the microphone2. The voice then forwarded to the speech processor3. speech processor filters, analyzes and encodes the sound into electrical signals.4. The signal sent to transmiting coil via a cable.5. Transmiting coil sends the signal through the skin into ireceiver.6. Receiver to decode the electrical signal.7. The signal was taken ken electrodes to stimulate nerve VIII8. Signals captured the brain as sounds, sensations arise hearing















Figure 1: How a cochlear implant3. Cochlear implantation IN CHILDRENInitially the FDA (Food and Drug Administration) allows only the cochlear implantation in 1986 aged 2 to 17 years with very severe deafness. Northern in 1986 to provide a minimum restriction kendidat cochlear implants in children as follows:• Minimum age 2 years• Deafness or severe sensorineural bilateral total• Already menyeleseikan prevalence procedure• IQ at least in the normal range• There were no other disability (eg autism or significant learning disabilities) that can affect the success of cochlear implantation.• Strong support from family• There were no satisfactory progress has been made despite an active training and installation of APM.Once the implants are more developed and the development of data obtained from children - children who were implanted, the advantages and disadvantages of implantation in children to be large compared with the conventional amplification system. Moreover, children - children who were implanted early development menunnjukkan better speech perception than children implanted at an older age. Based on these observations it is clear that observation implantas better to optimize the development of speech and language. Since 2002 criteria for cochlear implant candidates for kids - children according to the FDA are as follows:• Ages 12 months to 17 years• very severe bilateral sensorineural Deafness, but children - children with severe hearing loss is also considered as a candidate.• Benefits of using a hearing aid is limited Kinley cochlear implant candidates mentioned criteria are very severe bilateral sensorineural deafness with the threshold of hearing with hearing aids (APM) is not less than 60 dB.• No progress in the development of speech, language, and hearing by APM.
 Attempted use of APM during a certain period to assess the development of communication with the APM.• Undertaking a parent to follow activities: engaging in speech therapy, language and hearing as well as control sesusai schedule.• There were no medical contraindications in the installation of electrodes and a receiver.• home environment and educational support teerhadap use cochlear implants.While factors - factors that determine the outcome of cochlear implantation, among others:• The duration of deafness• Age at dimujlainya amplification, language stimulation, and does implantation• The experience of hearing and speech perception ability before.• Kedaan cognitive and attention.• Use of language to speak in the home environment and school.
4. EFFECT OF AGE WHEN THE CHILDREN DO cochlear implantationTo be able to hear very well have to buffer the sound information reaches the central auditory path in the right shape and the central auditory system must be able to process the central development of speech perception is inhibited even though the input to the peripheral auditory system to be improved. The problem is what sparked many clinics to perform cochlear implantation as early as possible. Central auditory system's ability to process speech sounds did not develop with asdekuat when the input does not exist. Early childhood - childhood is a time of development and production of speech perception and the ability to communicate. The earlier dierbaiki auditory input, the better the child will use that information. It is assumed that the central auditory system's ability to evolve and change the appropriate age. This assumption is supported by the results of speech perception in children - children who get cochlear implants.Early diagnosis of disorders that cochlear implantation provides an opportunity to do early in the case - kasusu with severe hearing loss to severe sting auditory stimulation produced by the implant kolea in infancy allows maturation point of near-normal hearing. Sensitive period of neural perkembagnan is a critical period of language development conversation. Yoshinaga-Itano and Apuzzo and Down's and Yoshinaga-Itano, as quoted by Hammes et al stated that the children - children who diagnoses hearing loss (from mild to very severe) and begin intervention within the first 6 months of life will achieve proficiency in a more suitable premises age compared with that diagnosis and intervention after the age of 6 years. Hammes et al concluded that the best results in language and speech was found in cochlear implantation is performed at the age of 18 months or less.














Figure 2: The ability to capture the language to talk to children who get cochlear implants.In line with Hammes et al, Kirk et al in his study of the effects of age at implantation in children do get that language development in children - children who receive cochlear implants before age 3 years faster than with cochlear implants who get slower.Sensory disturbance effects caused by congenital deafness on auditory channels is still unknown as clearly. Sharma et al stated that the degenerative changes in the sensory path takes time. Nervous system arrives young show high levels of neural plastistas. Therefore, implantation before or shortly after the onset degenaratif changes will not cause delayed maturation of central auditory system. So it is recommended to perform cochlear implantation in children - children with hearing senteral new system degenerate minimum and / or highly plastic, so the development of central auditory path can occur. New central auditory path degenerate minimal after a hearing loss for 2-3 years. This period is closely linked to intrinsic sinaptogenesis period dikorteks hearing. From his study of 18 children with prelingual deafness was found that children - children who underwent cochlear implantation before the age of 3.5 years showed that age-appropriate cortical response. So are advised to perform cochlear implantation before the age of 3-4 years.
SUMMARY● Cochlear Implant function convert sound into electrical signals are transmitted to the brain via the N. VII.● Criteria for cochlear implant candidates children aged 12 months to 17 years old, deaf severe to profound sensorineural bilateral, do not get the benefits of using APM, there was no progressive development of speech, language and hearing after the use of APM, there is a strong family support, no contra indications obtained medical, environmental support● The success of cochlear impantasi influenced by: the length of deafness, age at start of ampifikasi, language stimulation and does implantation, the experience of hearing and speech perception ability before, the state of cognitive and attention and use of language to talk at home and school environment.● In an earlier implantation will get the ability to speak and speak better than on a slower implantation.● degenerative changes in sensory path takes time.● The nervous system of children is still very plastic.● implantation before or some time after the onset of degenerative changes do not cause delayed maturation of central auditory system.● cochlear implantation should be performed when the new central auditory system degenerate minimum and / or sting plastic.
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