Category Archives: Education

Genetic Therapy for Deafness?

My Google Alerts have been lighting up the last two days with all the news around a new research study released by Professor Gary Housley of Univeristy of New South Wales Australia, who’s team has successfully regenerated cells in the cochlea of a guinea pig using a combination of electrical stimulation from a cochlear implant and injected DNA cells.

Here’s one of the better articles from Wired: Genetic Tricks Could Make Bionic Ears Hear Better.

(From Wired): Cochlear nerve neurons (green) before (bottom) and after (top) gene therapy in the same animal. UNSW Australia Translational Neuroscience Facility, J. Pinyon and G. Housle

(From Wired): Cochlear nerve neurons (green) before (bottom) and after (top) gene therapy in the same animal. UNSW Australia Translational Neuroscience Facility, J. Pinyon and G. Housle

The articles are laden with medical technical jargon that I don’t pretend to understand. This one may be the worst, I just had to include it for laughs:

In the study, Professor Housley and colleagues used the cochlear implant electrode array for novel “close-field” electroporation to transduce mesenchymal cells lining the cochlear perilymphatic canals with a naked complementary DNA gene construct driving expression of brain-derived neurotrophic factor and a green fluorescent protein reporter. The focusing of electric fields by particular cochlear implant electrode configurations led to surprisingly efficient gene delivery to adjacent mesenchymal cells.

Woah.

Regardless of the jargon, its easy to jump on the hope bandwagon here. Cochlear implants, while a miraculous invention, are still very clunky devices. They are still quite limited in their abilities to reproduce pitch at levels equivalent to a functional ear, and much too bulky. For our techie friends, its like we’re living in the age of Apple II computers when we want an iphone instead.

I blogged about this quite some time ago that the “true” fix needs to be at the biological level – actual regeneration of the damaged cells. While I’m sure the actual realization of this dream is still far out, its awesome that research is proceeding so quickly in this direction. I’m 100% optimistic a solution will be available for Fiona in her lifetime.

Some other night time reading to help put you to bed…

 

 

A Tour of the Neptune Sound Processor

So now that we have a little more experience with Fiona’s new implant, I wanted to do a quick tour on how it all works.

Fiona is currently wearing the Advanced Bionics Neptune sound processor. It’s quite compact as you can see here:

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While the Neptune is first and foremost designed to be waterproof (bath time approved), the chief advantage at her age is the ease in which it can attach to her clothing:
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The sound processor is “a miniature computer that converts sound picked up by the microphone into electrical signals that are used by (the) cochlear implant to enable hearing.” (straight from the manual).

You can mix and match various color covers to personalize the appearance.

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The Neptune runs off a standard rechargeable AAA battery, although you’ll see further down this post that the “over the ear” processors use custom, smaller batteries.

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Attached to the sound processor is the headpiece. Embedded inside the headpiece is a very small microphone, look for the tiny black dot in this picture:

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The headpiece is also customizable with different cover colors as well. Fiona is sporting pink.

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On the back side of the headpiece is a magnet. You can add and remove additional magnets to adjust the strength. We’ve also further McGuyvered Fiona’s by adding some toupee tape to help keep her from pulling it off. (No, not from my private stash…)

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The head piece attaches to the processor on one side (connector plug) and the cochlear implant on the other, via a small magnet that was embedded inside Fiona’s head at her surgery. We have both standard headpieces and thicker waterproof variants. If she pulls off the headpiece, the processor starts beeping. Useful and maddening at the same time.

Here’s how it works: the sound picked up by the microphone in the headpiece transmits down the wire to the processor, is converted into an electrical signal, then transmitted back up the wire, across the gap from the magnets, into the implant and down into the auditory nerve inside the cochlea.

ear_diagram

In a very real sense, its reproducing what the functioning cells inside the cochlea of a hearing child would otherwise do:

ear canal

The Neptune processor has 3 different “programs” that are programmed by our (fantastic) audiologists to stimulate different frequencies at different levels. Fiona has already gone back once for her first reprogramming, and has several more to come. She’s currently on her 4th program. Think of this like easing yourself into the hearing world: you start with an empty room, then a quiet library, soon a restaurant and then someday a Rush concert. Neil Peart!!!

To switch programs, we attach a special device called the “Neptune Connect” to the processor to switch the mode, then detach again to keep the profile of the device small. Fortunately we don’t have to do this very often – maybe once every few days.

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For her implant surgery, Advanced Bionics provided us with 2 processors: a primary and a spare.

We chose to start with the Neptune as it’s easier to manage with a small child, but our second processor is the “over the ear” Naida processor. The over ear processors are even smaller then the Neptune and are easier for older children and adults to manage, but are more challenging for certain infants who like to constantly constantly constantly pull things off their ears…

Still we have her Naida on deck, still in the packaging:

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Yes that’s a remote control you see as well. We’ll get to live the parents dream and directly control how loud our child plays her music, mwuhahahaha!

Actually its kindof cool as these implants can connect straight into bluetooth and other wireless techs, i’m a little jealous. Maybe i should start getting some Advanced Bionics kickbacks from this free PR…

accessories

And of course last but not least, we’re the first kids on the block with a stuffed monkey with its own Cochlear Implant:

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So Mom and Dad are learning besides Fiona, but she’s already acclimating quite well to the change. Kids are so resilient!

(Insert your own caption here)

(Umm, insert your own caption here…)

Great Podcost on the New Internal CI

Ran across this great 12 minute audio podcast this morning from Physics Central describing the basic operation of Cochlear Implants as well as the new MIT research I blogged about two weeks ago on the Internal Cochlear Implants. It also delves into the wireless power charging and research around how sound location can be determined with newer CIs. Very interesting stuff.

What I particularly liked about this podcast is how they explained technically complex ideas in basic, easy to follow lay terms. A great way to understand the basic physics of CIs without requiring an advanced degree. If you’re still not totally clear about how CIs work, give this explanation a try.

In other news, we’re continuing to appeal the CI surgery denial from Blue Cross I blogged about earlier this week. No news yet, but we’ve received incredible support and are continuing discussions. Hopefully we’ll hear more soon. (no pun intended)

And now for a gratuitous Fiona picture. This is Fiona in front of a giant redwood from our recent vacation last month. Pretty amazing.

Redwoods National Park

Redwoods National Park

 

 

One Step Closer to Internal Cochlear Implants

Back in July I posted about The Future of Hearing Correction, in which I mentioned a logical next step would be a totally implantable Cochlear Implant. Well it looks like recent research from MIT has made another step forward towards this dream.

In this recently published article, researchers at MIT’s Microsystems Technology Lab created a CI processor that can theoretically operate entirely internal to the ear.

Internal CI Processor

Internal CI Processor

Existing CI processors, while smaller now then ever, are still bulky and worn externally in quite a noticeable manner.

processor on ear

While it could be argued this is pure vanity and it shouldn’t matter if the processor is visible, I tend to be a realist and think the presence of CI hardware could lead to discrimination and exclusion in some social circumstances. Especially for children.

The internal processor is an interesting and natural evolution of the technology. Its amazing to me to think that through technological innovation, a child born deaf could interact with hearing peers in a manner that those peers would never know that child was deaf. We’re not there yet, but I can see this happening within Fiona’s lifetime.

This research is currently just that, research. As far as I’m aware, this new processor has not yet been implanted into a live subject, and it looks like there are still some challenges to work out on the power side of things:

“The idea with this design is that you could use a phone, with an adaptor, to charge the cochlear implant, so you don’t have to be plugged in,” says Anantha Chandrakasan, the Joseph F. and Nancy P. Keithley Professor of Electrical Engineering and corresponding author on the new paper. “Or you could imagine a smart pillow, so you charge overnight, and the next day, it just functions.”

A “smart pillow” gives me the willies – something about running electrical induction so close to the brain, but I have to assume smarter people then myself have this all figured out.

Still, exciting to see progress move forward so quickly.

 

Retinal Implant for Blindness

Short Friday post today. A few months ago I blogged about the future of heading correction, pointing out the similarities between hearing loss and vision loss. In that blog I had mentioned that hearing correction was in some ways ahead of vision correction, but its only a matter of time before vision catches up.

Well wouldn’t you know it today I came across new research on retinal implants, which look in many ways very similar to Cochlear Implants. Below is a good illustration that shows how it works.

retinal_implant

My family has a broad history of vision problems, so when Fiona was diagnosed with profound hearing loss it was a total shock. You never want any harm to come to your child, but if there was ever to be a problem I would have bet on vision problems instead.

While the retina implant still has a long way to go, its fantastic to see research is making progress on this front.

Booth Testing

Tonight the Isham clan braved 2 fantastic hours of rush hour traffic to take Fiona to her first booth testing session. Booth testing is one of the final stages in our journey to prepare Fiona for the Cochlear Implant procedure, and is typically not started until the baby is at least 6 months old. Today Fiona is 6 months and 2 weeks old.

The process is pretty interesting. First you have a soundproof room equipped with speakers and TV flat panels located at strategic locations. Here’s the booth from the outside:

Come on in!

Come on in!

Inside the booth there are speakers immediately to the left and right of the subject, and TV screens located in close proximity to the speakers.

Inside

Inside the booth

During the test, Eliza sat in the booth with Fiona on her lap, facing the front of the room with the speakers and TVs directly to her left and her right. Our audiologist Lauren sat directly in front of Eliza with various hand puppets to distract Fiona and keep her attention focused forward.

On the outside, Dad stood in the dark with Lauren’s assistant Jenny, looking in through the observation window as the test was underway. The goal of course is to keep hidden from Fiona so she does not get distracted by her dad’s incredibly handsome looks.

Somebody's Watching You...

Somebody’s Watching You…

Jenny then proceeded to introduce sounds at different locations in the room, looking for a repeatable response from Fiona. Similar in some ways to the ABR test, she would vary the frequency (high pitch to low pitch), volume (75 dB to 95 dB) and location (left or right). (Check out my earlier post on Frequencies of Familiar Sounds for more information on the sound spectrum).

What makes this fun for children are the TV screens. Whenever the child positively responds to the sound (by looking in the direction of the sound), a short flash of a movie displays on the TV nearest to the sound. In this case, it was good ‘ol Nemo.

Here was the display in the control room (to keep dad entertained during the interludes)

Everyone Loves Nemo

Everyone Loves Nemo

This process is called Visual Reinforcement Audiometry. Here’s a short (1 min 30 second) youtube video that shows this process really well.

To score a positive result, Fiona had to respond conclusively twice to the same frequency/volume/location. While she did have a couple “single responses” at high volume and middle frequencies, she did not have a repeatable result. This was as expected given her prior testing – we did not expect a miraculous change. Still, this level of validation is an important milestone to confirm her candidacy for the CI procedure.

Fiona will be booth tested again at least once or twice more before her surgery on March 7th, but this first test was definitely interesting to watch.

How Hearing Aids Actually Sound (Video)

This is a clever video Eliza found recently, prepared by the Vermont Center for the Deaf and Hard of Hearing. In this video, they recorded the actual sound received by a hearing aid under 4 different scenarios:

  1. Close by with no background noise (the “ideal”)
  2. Far away with no background noise
  3. Close by with background noise
  4. Far away with background noise

This is a great way to “walk in the shoes” of the listener. Scenario 4 is very common in the classroom setting, and very challenging to cope with. I have no doubt it’s exhausting!

After the exposition, they then repeated the same 4 scenarios using an FM transmitter, showing significant improvements. Good stuff.

Here’s the video, keep your eye on the student with the red hat – an Oscar winning performance…

While this video demonstrates hearing aids, I do know many of the Cochlear Implants out there now offer similar integration with transmitter systems. I’m expecting (perhaps wrongly?) a similar experience for CI users.

Regardless of the technology, clearly the teacher and school system have to be on board with this for it to succeed, so we’ll definitely need to weigh our options on schools when Fiona gets to the appropriate age. Fortunately we still have a few years there.

If anyone reading this has firsthand experience on this topic they’d like to share, we’d love to learn more. Especially with school systems in the Atlanta area.

The Genetic Tests Are In!

Close View of a DNA Strand

It’s hard to believe, but it’s been over 3 months since we first learned of Fiona’s deafness. We’ve come so far.

When this journey first began, we had 2 big fears: would Fiona be eligible for the Cochlear Implant and would this prevent us from having a second child?

A month later, our first fear was laid to rest: Fiona was pronounced eligible for the Cochlear Implant. I blogged about this on July 16th.

Yesterday we received the answer to our second fear: Fiona’s deafness does not appear to be genetic.

This is great news as it lays to rest our concerns about having a second child. It’s also good news for adult Fiona as she likely will not pass on hearing loss to her children (if she so chooses to have any).

We couldn’t be happier!

Yippee!

Yippee!

How Did They Test?

About two months ago, Fiona’s doctor drew blood to conduct the genetic testing. Apparently there are 3 known genetic mutations that are common to infant profound hearing loss.

Before I go further, i’ll put out the disclaimer that this information is very technical and difficult to understand. To make matters worse, the websites I found were very heavy in “Doctor-talk” so was hard for me to follow. I did my best to understand the high level concepts, but it’s very possible I missed some key details.

Connexin 26 and Connexin 30

Connexin 26 and 30 are 2 proteins used by the inner ear to communicate from cell to cell. A defect in the “GJB2” gene (good ‘ol GJB2!) can cause these 2 proteins to disrupt communication across the cells in the ear, leading to the inability of the ear system to function properly. Here is one of the better articles I found on the topic from the California Ear Institute.

For two hearing parents to have a deaf child with the Connexin mutation, both parents must have the Connexin mutation. This means the mutation is passed recessively to the child (since neither of the original parents were deaf). Fiona’s testing did not indicate this mutation, clearing her and her children of this possible cause.

Mitochondrial DNA Defect

Mitochondrial DNA defects are the other common genetic cause of hearing loss. Mitochondria are cellular structures that help “power” the activity of cells in your body. A specific genetic defect in the Mitochondria can lead to premature death of some of the cells specifically used for the process of hearing. For a medical layman this is somewhat hard to follow, but here’s a good article I found here: Yale Study.

And here’s a good but technical 4 minute video on the topic:

The mitochondrial DNA defect is only passed on maternally, meaning it can only come from the mother. Fiona did not have this defect either.

So What’s Next?

It should be stressed that medical research is still evolving quite a bit in this area, so its very possible there are other genetic factors at work here of which we’re simply not aware. We can’t know for sure, but as of today all known genetic factors appear to be clear.

At this point it’s unlikely we’ll ever know the root cause of her hearing loss, but we’ve been told that’s the case more then 50% of the cases. Perhaps medicine will shed some new light on this in the years to come, but at least for now we know the odds are low in a recurrence in future children.

Drinks all around!

Sound Association Therapy

Today we had our second speech therapy session for Fiona at the Audio Verbal Center, and our first full session with our new therapist Aneesha. In our first session we spent the majority of the hour answering a questionnaire and learning about the program, so we were excited to get down to some hands on therapy today.

Because Fiona is only 3 1/2 months old, there is only so much we can do at this stage, but its still good to start off with the basics. We began with Sound Awareness – testing her response to various sounds throughout the room, much like we did in the last session. As expected we didn’t get much response there, so moved on to Sound Association.

The key for Sound Association is to train Fiona to mentally connect something visual with the introduction of a new sound. This is valuable because it will speed up her recognition of sounds down the road once she gets her implant. While you’d think this would be obvious, remember up to that point she will have never known the concept of sound. The visual cue is a shortcut to prompt her to seek out and associate this new sensation to the meaning of sound we take for granted. The beating sound of a drum means something, I should pay attention. Etc.

The process works basically like this:

  1. You introduce an upcoming new sound in your best silly baby talk voice: “Here comes the bell!”
  2. You make a noise and point to your ear. This is the association. (Ring! Ring!)
  3. You reinforce the new sound and show excitement. “That was a bell, yay!”

Eliza is a natural:

Sound Association

Sound Association

While Fiona likely can’t hear the sound, she does pick up on the excitement and notices the ear pointing means something special just happened. “This is exciting, I should pay attention to that!”

After her implant, the same exercise will now be more effective because she will already have learned to associate the finger to the ear motion with the introduction of something new and noteworthy.

It’s pretty neat to learn the basic cognitive foundations of skills we take for granted. Over the next 2 weeks our homework is to continue the sound association exercises with sounds of different frequencies. Dad has the bass tones covered.

Cochlear Implants and Music

Ludwig van Beethoven -

Ludwig van Beethoven

Did you know Beethoven began losing his hearing at the age of 26? I actually did know this “Before Fiona”, but the meaning is now more inspiring than ever.

Dr. Charles Limb of John Hopkins recently presented a TED Talk speaking to the perception of music for Cochlear Implant users. While CIs represent an amazing technological breakthrough for basic speech recognition, music perception is still primitive at best.

I found this talk highly informative and entertaining. Don’t let the 16 minute length discourage you, it’s littered with humor and multimedia goodness. I think you’ll find it worth your time.

Dr. Limb ended with an interesting sentiment: while restoration of basic function (language, safety sounds) is critical, the “perception of beauty” is what life is all about. If you were to lose your hearing tomorrow, would you want to just hear speech again? You’d want it ALL!

This is not sour grapes, but a call to keep pushing on. We’ve come a long way, but we’re not there yet.

I couldn’t agree more.