Those benefits, which are documented by years of research on CI in infants with bilateral deafness, “support implanting a child as early as possible,” Dr. Holcomb said. “In the U.S., indications are as low as 9 months of age [for children with bilateral hearing loss]; however, there is substantial literature to support implantation in children who are younger than 9 months.”
Explore This IssueAugust 2022
Dr. Park echoed the need for early intervention. “There is a window of time when you can rehabilitate that auditory pathway,” she said. There is evidence that SSD may impede binaural central integration perhaps as early as 2 years after onset (Trends Neurosci. 2012;35:111-122). “We have no reason to think that children with SSD would be any different than children with bilateral hearing loss. So, for now, younger is better.”
Then there’s the question of when to test very young infants with SSD who are being considered for CI. According to the guidelines, infants younger than 12 months of age should have objective measures (auditory brainstem response/ auditory steady state response testing) of sensorineural hearing loss with confirmatory audiometric results, when possible, prior to implantation.
Given all the debate over how early to intervene, it’s important to also consider the age and length of deafness at which a CI implant would not be helpful. “We aren’t ready to say that there’s a cut-off age when a patient would not benefit from CI,” Dr. Park said. “We have seen children with greater than 10 years of hearing deprivation who have benefited from CI. A teenager may not want to wear an implant, so that’s where the counseling has to come in— the teenagers have to have buy-in to have the best outcomes.”
One of the main features of the new guidelines is an in-depth review of the medical and audiological considerations for CI. The current FDA labeling for SSD includes a four-frequency pure tone average > 80 dB HL or > 90 dB HL, depending on which cochlear implant is being used. “These criteria may be too restrictive for children,” noted Dr. Park. According to the guidelines, “a CI evaluation is recommended for children with a unilateral 3-frequency pure tone average of > 60 dB HL and/or an aided SII < 0.65 because these children are unlikely to receive adequate benefit from traditional amplification.”
The FDA set the criteria as a profound hearing loss. “But that doesn’t always meet the needs of everyone with SSD, who may have a severe or steeply sloping hearing loss,” Dr. Park said. “Our view is that if a child can’t benefit from a hearing aid, they have an auditory nerve, and they want to hear from both ears, then they should be considered for a cochlear implant,” she said.