Auditory Brainstem Implants

I read an interesting article this morning about a study starting up in Boston that uses Auditory Brainstem Implants (ABI) on infants that are not eligible for Cochlear Implants. This was particularly interesting to me because (1) I had no clue what an Auditory Brainstem Implant actually was and (2) the possibility that Fiona might not be eligible for a Cochlear Implant hadn’t yet occurred to me (cue latest mini-freakout).

So I did some research and here’s what I found: In less then 1% of deaf individuals, the actual auditory nerve from the cochlea to the brain is damaged or nonfunctional (from wikipedia). If you saw my post on Cochlear Implants, you’ll see that the CI works by connecting electrodes into the inner ear and through the cochlea, bypassing the damaged ear “hair cells” and stimulating the auditory nerve directly, which then carries the signal to the brain. If the auditory nerve is damaged, then a CI can’t work.

This is where Auditory Brainstem Implants (ABI) come in. They work very similarly to the CI, but instead bypass the cochlea and auditory nerve to stimulate the brainstem directly, as shown below:

Auditory Brainstem Implant

Auditory Brainstem Implant

So why don’t people just do the ABI?

Well first of all, you’re now talking brain surgery so the complexity, risk and cost of the procedure is much higher. Secondly, the effectiveness (in terms of spoken word understanding) is at best equal to CI, and often less. So in other words, more risk for less results. But, if no other options exist, this may be a last hope.

The scope of ABIs done is far less then CI: 1000 adults worldwide for ABI vs. 200,000 for CI. Also, until recently ABIs were only FDA approved for children over 12 years old. The study cited above is new in that it is being performed on infants, which should be interesting to watch.

As of today we don’t know the cause of Fiona’s deafness or if she would not be eligible for CI. Tomorrow we visit the ENT (Ear, Nose, Throat) doctor for the first time, and while we don’t expect to have all the answers then, we do expect to know the next steps.

Fiona At 6 Weeks

Fiona At 6 Weeks (Yesterday)

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6 thoughts on “Auditory Brainstem Implants

  1. Muriel Lindsay

    Fiona looks very present and fully engaged. And not to mention, she is lovely. The plot thickens. Possibilities just keep expanding. What a time to be alive.

  2. Sheri

    Best wishes today. I was also wondering… In the picture Fiona is turning her head and concentrating. Did you say she had any stimulation in one ear. Andrew could not hear a certain pitch and would turn his head to listen better and concentrate when he was young. They said he would out grow it and at 17 he chooses what to hear now. It may be my wishful thinking on my part that one ear is getting some sort of stimulation. See what the doctor says. It was the ear nose throat doctor that finally found Evan and Andrew’s problems. I hope you get a lot of answers today.

    1. Mark Isham Post author

      Hi Sheri, it was very very slight in just one ear at high volume and low frequency. So slight the audiologist wasn’t sure if it was an artifact of the testing or not. We haven’t seen any clear cause/effect responses in our day to day experiences with her unfortunately, but she is still very young so maybe things will change as she grows older.

      I know you mentioned Andrew had tubes done in his ears – did he ever wear hearing aides out of curiosity?

  3. Anonymous

    Fiona is adorable! 🙂 Best of luck tomorrow at the ENT, I’m confident you will get more info on the path that’s right for you all.

  4. Pingback: Auditory Brainstem Implants in the News | Profoundly Strong - Fiona's Journey

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