The Parents' Guide to Cochlear Implants

2. Candidacy Evaluation

17 CANDIDACY EVALUATION Candidacy Evaluation Chapter 2 Once a family enters the pre-implant period, they must then pass through a number of substages. The question of candidacy is crucial since it determines whether the child will continue through the process. A multidisciplinary team of professionals with expertise in the areas of audiology,speech,language, education, and medicine conducts the pre-implant evaluation. These professionals perform multiple tests within their individual disciplines to provide a comprehensive candidacy assessment. The sequence of appointments made for the pre-implant evaluation may vary from facility to facility as well as from patient to patient within a facility. In some cases,the parent may first meet with the cochlear implant surgeon who then refers the child for audiological testing. In other cases, the audiologist may be the point of entry into the implant protocol. Regardless of which professional is seen first, the child must meet certain audiological criteria in order to continue the process, thus making the audiologist the “gatekeeper” for candidacy. Once the audiological criteria have been met,teams perform additional evaluations to add to their pre-implant knowledge of the candidate. Evaluating the Whole Child One approach that has proved useful for many centers is a “whole child” orientation to implant candidacy. To assist in this undertaking,an evaluation tool known as the Children’s Implant Profile, or ChIP, was developed in 1989 by the cochlear implant 18 CHAPTER 2 team at Manhattan Eye, Ear, and Throat Hospital. This profile assesses children across a variety of factors that have been shown to contribute to implant success. Each factor is rated along a continuum of concern ranging from“no concern”to “great concern .” The ChIP provides the team and the family with a structured method of reviewing the components that may contribute to the child’s performance with the device. The factors evaluated by the ChIP are explained in the following sections. Age at Time of Implantation and Duration of Deafness Two of the primary factors evaluated by the ChIP are age at time of implantation and duration of deafness. These are critically important because they identify the period of auditory deprivation and the point at which auditory stimulation begins.Children with short duration of profound deafness tend to perform better with cochlear implants than children with long duration of deafness. Thus congenitally deaf,or prelinguistically deafened children implanted at young ages, perform better than the same children implanted when they are older. Children born with mild or moderate hearing loss, progressing to profound hearing loss have been found to demonstrate good auditory skills with an implant. Hearing children who become profoundly deaf due to some cause like ototoxic drugs or head trauma will also perform well as long as they are implanted soon after losing their hearing. In an effort to keep the duration of deafness as short as possible , more parents are seeking implantation for their infants as soon as the age criterion is met. In June 2000, the U.S.Food and DrugAdministration (FDA) approved implantation in profoundly deaf children twelve months of age or older. Universal Newborn Hearing Screening has contributed to the phenomenon of infant implantation since identification can be made within days of an infant’s birth. Many of the children identified at birth are then followed until they reach the criterion age. However,under cer- 19 CANDIDACY EVALUATION tain medical circumstances,surgeons have the discretion to implant children under one year of age. This requires medical necessity and is not standard procedure at this time. Medical/Radiological Assessment Another category on the ChIP, medical/radiological assessment ,is evaluated by the implant surgeon. Children must be able to undergo surgery and sustain at least two hours of general anesthesia . Therefore, surgery may have to be delayed in children with serious health issues until the other medical condition is resolved. For example,a child with a heart problem will not undergo implant surgery until his or her heart condition is addressed. The radiological evaluation ensures that a cochlea is present. A small percentage of children are born without a cochlea, rendering them unable to benefit from cochlear implant technology. In other cases,the cochlea may be malformed or not fully developed . Malformations of the cochlea are often referred to as “Mondini deformities.” These deformities can range in severity from a cochlea with fewer than the normal two-and-a-half turns Factors Evaluated on the Children...