Hybrid CI Flashcards
What are the candidacy criteria for a hybrid CI?
Sharply-sloping high-frequency SNHL
Implanted ear: 10-60% CNC words PTA @ 2, 3, 4 kHz ≥75 dB HL
Non-implanted ear: ≤80% CNC words PTA @ 2, 3, 4 kHz ≥60 dB HL
What are the contraindications for a hybrid CI?
- Fluctuating HL
- Hearing loss with duration ≥30 years
- Progressive hearing loss
What additional testing would you complete for the patient?
- CNC words to see if hybrid candidate (can be done in quiet or noise)
- AzBio + 5 dB noise so that have something to compare pre/post-op
What are the expected results for AzBio + 5 dB noise?
Bilateral: 60%
Aided right: 55%
Aided left: 46%
What are the expected results for CNC words?
Bilateral: 54%
Aided right: 48%
Aided left: 40%
Recommendations
1) reprogram current hearing aids which are very old
2) purchase new hearing aids and/or assistive technology
3) Hybrid cochlear implant + continued use of hearing aid in right ear with consideration of implant in future
What is a hybrid cochlear implant?
A cochlear implant that is designed to preserve low frequency hearing, while allowing the user to have access to high frequency regions where there is a severe to profound hearing loss.
How does a hybrid cochlear implant work?
Provides electrical and acoustical stimulation ipsilaterally through one device eliminating the need for simultaneous use of an ITE hearing and and a CI in the same ear.
What is the difference between a traditional CI and a hybrid CI?
Cosmetically, there is a receiver instead of an earhook attached to the processor. This receiver is identical to that used in a hearing aid.
The electrode array implanted int he cochlea is also sorter than that of a conventional array in order to preserve more of the low frequency hearing.
What are the benefits of low frequency hearing?
(Gantz & Turner, 2003)
- Improved sound quality
- Improved music perception
- Improved speech-in-noise performance
What is your recommendation for this patient?
My recommendation for this patient is a hybrid implant in the left ear with continued use of a hearing aid in the right ear.
Ultimately it is the patient’s decision what option they want to pursue.
Combined condition vs. electric only
Better speech recognition in noise (Lenarz et al., 2013)
Why should he use a hearing aid in the right ear?
Keeps the auditory nerve stimulated, should he decide to pursue a second implant later.
Prevents further atrophy of spiral ganglion nerves, as more spiral ganglion nerves results in better performance with a CI post-op (Gantz et al., 1993)
Expectations for outcome should the patient follow recommendation of a CI
Because of his extended duration of deafness he will not do as well as someone who has had a shorter duration of deafness due to further atrophy of the spiral ganglion neurons (Gantz et al., 1993; Nadol et al., 1989).
However, since he has been a hearing aid user and has kept the nerve stimulated, he should notice an improvement with the devices following lots of auditory training. He needs to get his brain tuned and trained to hearing again.
Counseling for a CI
Important since pre-operative expectations shape post-operative satisfaction
Make sure that patient understands what the device is, otherwise they will not do well.
Counsel about outcome of hearing status following surgery:
1.) Some degree of hearing maintained, but may be up to 30 dB drop 6 months to 3 years post-op (Lenarz et al., 2013)
2.) No hearing preservation, so wouldn’t attach the receiver to the sound processor and would listen only electrically as with a traditional CI
