Do you think it's possible to use a TM electrode on a naturally sleeping baby? I'm wondering if this might greater inform interpretation with an infant when ANSD is suspected?
I've never tried using a tympanic membrane (TM) electrode on a sleeping baby, but I think it would be quite challenging. It's likely the pressure of a well-placed electrode on the TM would create enough discomfort to wake a naturally sleeping baby. It certainly would be important to check and verify if the TM electrode is FDA-approved for use with infants and young children. My suspicion is that the electrode is approved only for adults.
For audiologists, a simple electrode option for ECochG in infants is a pediatric-sized TIPtrode but the ear canal would need to be prepared in advance with abrasive substance (e.g., NuPrep). Infants will not willingly tolerate that process due to some discomfort so the prep would need to be done before the child fell asleep. The TIPtrode option would be feasible with an anesthetized child.
With otology support at a children’s hospital, the best ECochG approach to use (if you really wanted test results for decisions about a CI) would be a trans-tympanic needle recording with a sub-dermal needle.
This Ask the Expert was asked as a follow up question to Dr. Hall's course, Clinical Applications of Electrocochleography Today, which can be accessed in the AudiologyOnline Course Library.