The cochlear implant is one of the most amazing technological advances for children who are deaf and hard of hearing. Combined with universal newborn hearing screening and early hearing detection and intervention programs, the device has dramatically influenced developmental outcomes, with few other innovations having such positive effects.
Implantation by 12 months of age is now the standard of care for children born with profound sensorineural hearing loss. Professionals who work with these children have become more comfortable moving infants through the candidacy process.
On the other hand, decisions about when to transition older children with more residual hearing from amplification to cochlear implantation are challenging, but they are greatly important for ensuring auditory access.
In a common scenario for pediatric hearing healthcare, a child is diagnosed with moderate to severe hearing loss via auditory brainstem response and is fit with hearing aids during infancy. At that time, the child is not considered to be a candidate for cochlear implantation because hearing aids provide adequate audibility for speech.
Perhaps the child has a gradual progression of hearing loss, or behavioral audiometric assessment reveals poorer thresholds than initially evident from the auditory brainstem response test.
The child may start to experience delays in the development of auditory skills or of speech and language. Compared with other children who use amplification, the child may be developing more slowly.
When we examined these issues in our own clinic to determine the best time to send a child for cochlear implant evaluation, we discovered that, unlike the rapidly expanding literature on early cochlear implantation, research on assessing cochlear implant candidacy in older children who are not advancing despite amplification is much more limited.
What factors do we consider when deciding whether to send a child with hearing aids for a cochlear implant evaluation?
DON'T WAIT FOR FAILURE
If we wait for children who use amplification to show developmental delays before considering them for cochlear implantation, we miss a golden opportunity to help. As a result, we must err on the side of referring children if there is any evidence that amplification may not be effective.
While not all evaluated families will end up being cochlear implant candidates, I would argue that this proactive approach is preferable given the consequences of waiting for children to demonstrate significant developmental challenges before referral.
DOCUMENT AUDITORY SKILL
Questionnaires that document auditory skill development, such as LittlEARS Auditory Questionnaire (Int J Pediatr Otorhinolaryngol 2009;73:1761-1768http://www.ijporlonline.com/article/S0165-5876(09)00523-0/abstract) and Parents’ Evaluation of Aural/Oral Performance of Children (PEACH; J Am Acad Audiol 2007;18:220-235http://www.ncbi.nlm.nih.gov/pubmed/17479615), can help put the child's progress in context compared with their peers who also use hearing aids.
Performance that is consistently outside the normative range should prompt conversations with families about the potential need for a cochlear implant candidacy evaluation.
PAY ATTENTION TO AIDED AUDIBILITY
Research suggests that children with an aided Speech Intelligibility Index less than .65 may be at risk for delays in vocabulary development ( J Speech Lang Hear Res 2012;55:764-778http://jslhr.pubs.asha.org/Article.aspx?articleid=1811737)
If aided audibility is .65 or less for average conversation in quiet, it is likely to be much lower across realistic listening situations where the talker is more than one meter away or there is noise and reverberation.
If audibility is poor despite our best efforts to adjust the child's amplification, cochlear implant candidacy may be considered, even if audiometric thresholds are better than those typically expected for children with cochlear implants.
Children whose aided speech recognition is much poorer than anticipated based on their aided audibility should also be considered for evaluation if such deficits cannot be attributed to developmental comorbidities.
Many parents whose children have worn hearing aids for an extended period of time or have more residual hearing assume their children are not candidates for cochlear implants, even though candidacy criteria or the child's hearing may have changed since infancy.
Conversations about transitioning from amplification to cochlear implants should occur if concerns arise, but families may need time to consider these new options or adjust to the idea of a cochlear implant. Those with young children may still be adjusting to the hearing loss diagnosis itself.
RESPECT FAMILY DECISIONS
We frequently encounter children who, based on their clinical data, appear to be excellent candidates to transition to cochlear implants but are not interested in doing so.
Conversations with children and their families about cochlear implants should be documented in the medical record, including whether or not the family or child would like to revisit the topic at a later date.
If families determine they are not interested in cochlear implantation, professionals should keep them informed about treatment options while trying to respect their preferences.
OVERCOMING THE GRAY AREA
Armed with clinical data and a willingness to share information about potential treatment options, clinicians can help families make informed decisions about whether or not to transition from amplification to a cochlear implant.
Future research may help identify early risk factors that indicate whether or not amplification is likely to benefit children who are in the gray area for cochlear implant candidacy.