Postoperative management and habilitation for children with CI

2.1.2.3 The implantation surgery

The surgery is performed under general anesthesia. Since placement of the internal components within the inner and middle ear requires drilling near the facial nerve, this nerve must be monitored to ensure that it is not compromised during surgery. The surgery takes about four hours. The child usually stays overnight at the hospital.

Although the rate of complications associated with cochlear implant surgery is very small and post-implant complications are rare, there are certain risks involved in both the surgical procedure and postoperative period. As with any type of surgery, there is always the risk of a problem with general anesthesia, or other risks such as immediate postoperative bleeding and/or infection. The implant surgery may also result in injury to the facial nerve, postoperative dizziness, and other rare complications. There are also some long-term considerations. Despite the fact that cochlear implants are extremely reliable and designed to last a lifetime, device failures do occur in less than 2% of the population. They can result in either a change in hearing status or a total lack of auditory stimulation. If device failure is confirmed, re-implantation should occur as soon as possible. Post-reimplantation results are typically good (American Speech-Language-Hearing Association [ASHA], 2004; Cohen, 1998; U.S. Food and Drug Administration [FDA], 2007).

2.1.2.4 Postoperative management and habilitation for children with CI

About three to four weeks following surgery, the patients return to the audiologist for initial programming of the cochlear implant. By then, the swelling around the incision is reduced and healed. This enables the magnet to adhere properly. The implant activation’s procedures depend on the patient’s age and the type of device that was implanted. The initial programming for all types of devices starts with determination of the softest sounds that can be heard from each of the electrodes. This level threshold is recorded on the computer software program. This procedure is followed by determining the upper level of stimulation for each active electrode. Depending upon the type of device used, level of stimulation is increased until the patient reports the sound is “more comfortable” or is loud but comfortable. This is true for adults.

With little children, it is almost impossible to get precise mapping data because they

typically cannot report what they hear. Many clinics use electrophysiological data (often times gathered in the O.R. at the time of the surgery) to establish the initial maps. The audiologists then rely on careful observation and tedious "play audiometry" or visual localization responses to fine tune the map. Their goal is to determine the softest sound the child can hear with each electrode (or group of electrodes) and then find the highest stimulation level that will not cause obvious discomfort (by observation and parent/teacher reports). The final psychophysical data are then used in the program for the speech-processing strategy. In most cases, the patients can begin using the CI after the initial programming session (Katz, 2002).

This session is usually very exciting, especially for the parents. Since this is the first time the child has experienced hearing, the responses vary from one child to another and can range from laughter to tears, from panic to joy, and from surprise to indifference (Sternberg, 1998). For the next three months, children return for continuing programming their speech processor twice a month (most of the time), once a month for the next three months, and then every six to twelve months.

According to Barker, Dettman, and Dowell (1997), rehabilitation aims to encourage reacquisition of lost communication skills. For the adult who acquired hearing loss, the CI might be expected to assist rehabilitation by restoring an auditory percept. This differs from providing a habilitation program for a young child who received a CI. The clinician’s role is then “to facilitate acquisition of listening, speech and language in a normal development order” (p. 171). The importance of a multidisciplinary habilitation process for children with CI cannot be overstated. Its aims are complex and holistic and it and must be meticulously implemented if the child is to obtain maximum benefit from the device. There must be collaboration between a clinical facility providing medical and technical support and the educational and training facilities. The habilitation includes training in the perception of speech and non-speech acoustic signals, speech production, and receptive and expressive language enrichment. Strong parental involvement as well as coordination among all of the child's teachers, therapists and care givers is essential. In general, the habilitation procedures used with children with CI are similar to those used with children who have hearing aids. Two primary differences between techniques used with children with hearing aids and with children with CI is that material used with implanted children often contain high-frequency information. Additionally, therapists often have greater expectations for children with CI (Allum, 1996; Christiansen &

Leigh, 2002).

The ultimate goal of all speech and language habilitation programs after pediatric cochlear implantation is to have a hearing-speaking individual. The outcomes after cochlear implantation vary due to uncontrolled factors such as the intactness of pathways at and beyond the auditory nerve as well as decisions of parents and professionals such as the implant technology, age of implantation, pre-implantation reinforcement of residual auditory sensitivity, and choice of language modality (Marschark & Spencer, 2003).

Barker, Dettman, and Dowell (1997) state that the habilitation approaches used with children with hearing impairments range along a continuum from highly visual (such as sign language) to highly auditory (such as auditory-verbal). They write:

Sign Language of the Deaf is a gestural system that has a unique syntactic structure and no spoken correlate. Signed English encodes language with a specific sign for every individual word and morphological marker. Total communication involves the use of Signed English, lip-reading, and listening for the hearing-impaired person to perceive language. Cued speech employs a series of hand signals to indicate certain phonetic features (e.g., tongue position for vowels) which are not visible when lip-reading. The Oral/Aural approach emphasizes the optimum use of residual hearing in conjunction with lip-reading cues. The Auditory-Verbal approach emphasizes learning language and speech through the exclusive use of residual hearing and the deemphasis of lip-reading cues (p. 173).

In Israel, the oral/aural approach, auditory-verbal, and total communication are the only ones in use in the different educational settings. Pre-implantation, each child will have been educated according to one of these educational procedures. As with the old oral versus manual controversy in the education of the deaf (Connor, Hieber, Arts,

& Zwolan, 2000), there has been a debate whether children with CI will benefit most from a program that offers spoken language only (such as oral or auditory-verbal), or from a program that includes sign language which provides redundant linguistic speech to facilitate comprehension (Marschark & Spencer, 2003). Marschark and Spencer (2003) indicate that the findings in the research literature are controversial regarding this issue (for review see p. 438 in their book) and summarize that children

with CI improve their speech and language skills regardless of the type of language intervention. When compared to their hearing peers however, most children with CI whether in an oral, auditory-verbal, or total communication environment tend to lag in language skills after implantation. The authors add that the identification of interaction between language mode and factors such as age at implantation, as well as emerging reports of the progress of children using cued speech, suggest a need for continued objective assessment of this issue. Additionally, the status of the child's unimplanted ear has been receiving increasing attention in the audiology literature as another important element in speech and language development.

In an unpublished paper on educational audiology submitted to the Board of Education in Israel, Halpern (2004)⁷ relates to the considerations in choosing the habilitation program for children with CI, and points out that children who were orally educated pre-implantation, will obviously continue to be educated by the same approach post-implantation. The dilemma arises in regard to children who were educated in a total communication program before the implantation:

1. For those below two years, the oral approach is recommended. However, it is of paramount importance to monitor the pace of communicative development and remain prepared to change the communicative approach if the oral method doesn't allow for appropriate language development.

2. For those who relied mainly on sign language pre-implantation, it is recommended to gradually integrate the use of oral communication while emphasizing auditory learning of speech and environmental sounds.

Halpern states that the functional level of a child with CI is unpredictable, but the probability of successful speech and language development will be enhanced by the following factors:

1. Short duration of deafness;

2. Early diagnosis of the hearing impairment followed by an immediate use of amplification and language stimulation (spoken or signed);

3. Early implantation;

4. Early and extensive auditory experience;

5. Good cognitive and attention skills;

7 Dr. Orly Halpern, Ministry of Education, Israel; Tel Aviv University, Israel (personal communication, March 16th, 2009). E-mail: hpinny@012.net.il

6. Educational and home environment which provide intensive exposure to spoken language;

7. Intensive auditory-oral training.

Further perspectives and research related to these issues can be found on http://convention.asha.org/handouts/1420_0162Scott_Susanne_059135_Nov14_2008 Time_011840PM.pdf