- Hi guys, Cliff Olson, Doctor of Audiology
and founder of Applied Hearing Solutions
in Phoenix, Arizona.
And, in this video, I'm talking about using stem cells
to cure hearing loss and tinnitus, coming up.
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It is no secret that individuals with hearing loss
and tinnitus would prefer a cure for these conditions
rather than having to treat them with hearing aids,
cochlear implants, or a variety
of different treatment methods.
And with nearly 500 million people
throughout the entire world having hearing loss
and tinnitus there is definitely incentive
for researchers to find a cure.
Now, hearing loss and tinnitus can be caused
by a variety of different things, including head trauma,
genetics, noise exposure, chemical exposure, and age.
Each of these can either cause damage to,
or lead to improper development
of inner and outer hair cells inside of the cochlea
which, ultimately, results in hearing loss and tinnitus.
Outer hair cells are, basically,
your ears' natural amplifiers.
There are three rows of these hair cells embedded inside
of the basilar membrane, which amplify
the vibration of incoming sounds.
A single row of inner hair cells are
also embedded in the basilar membrane,
but these hair cells are responsible
for sensing the physical vibration,
and converting it into a neural impulse
that travels up the auditory nerve to the brain.
Without properly functioning or present outer hair cells
there is not enough vibration along the basilar membrane
to trigger a neural impulse from the inner hair cells.
Without properly functioning, or present inner hair cells
it doesn't even matter how much vibration
you have along the basilar membrane
because there's nothing to create
a neural impulse to send up to the brain.
Basically, the vast majority of hearing losses are caused
by improperly functioning inner and outer hair cells.
And, on top of that, one of the main causes of tinnitus
is lack of auditory information
from the ears up to the brain, which would
also be caused by the same thing.
So it stands to reason that if you could regenerate,
regrow, or replace these damaged,
or missing inner and outer hair cells
you could potentially cure hearing loss and tinnitus.
But before I dig deeper into some of the potential cures
for hearing loss and tinnitus,
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Now, let's go ahead and take a look
at some of these potential cures for these conditions.
Currently, there are three different methods
that scientists are researching
in order to find a cure for hearing loss and tinnitus.
We have gene therapy, we have molecular therapy,
and we have stem cell therapy.
Scientists have identified over 100 different genes
that can cause genetic hearing loss,
and gene therapy could be used
as a way to prevent these hearing losses
before they even occur, or as a treatment option
for these hearing losses after they've occurred.
As of right now, there are only animal models
that suggest that gene therapy could be
an effective treatment option for hearing loss
and tinnitus at some point in the distant future.
Molecular therapy is even more promising,
at this point, where they use different molecular compounds
that can permeate the round window of the cochlea
to stimulate dormant progenitor cells to regrow hair cells.
You may have seen one of my several videos
about FX 322 and FX 345 that use this molecular therapy
in order to awaken these dormant progenitor cells.
And if you wanna see those videos
I will have them linked in the description.
However, the main topic of this video
is exploring whether or not stem cells
could be the key to curing hearing loss and tinnitus.
In general, you have four main types of stem cells
that are used in therapeutics.
These include adult stem cells, embryonic stem cells,
spiral ganglion derived neural stem cells,
and inducible pluripotent stem cells.
And each of these stem cells could be
either administered endogenously, or exogenously.
By endogenously I just mean stimulating resident stem cells
that are already inside of the cochlea.
Very similar to how molecular therapy would work
by awakening dormant progenitor cells.
However, due to the lack of resident stem cells
inside of the cochlea, it is much more likely
that exogenous methods like transplantation of stem cells
into the cochlea would be a better bet.
If stem cells could be used to grow hair cells
inside of a lab, which is already being done,
and then transplanted into your cochlea it could be possible
to restore your natural hearing ability.
Just imagine going into a surgical procedure.
And then, in the weeks and months following that procedure
your hearing just started gradually coming back.
While this would probably be a very expensive way
to get your hearing back, if effective, people
who could afford it could actually cure their hearing loss.
However, while the use of stem cells
does sound very exciting there are some major hurdles
that would have to be overcome
before this could be a viable option to cure hearing loss.
First, while researchers have been effective
at growing stem cells into hair cells structures
inside of a lab, it is a much different story,
actually getting those stem cells into a cochlea
without causing more damage than
what you would recover from a hearing perspective.
It's kind of like taking 10 steps backwards
just to take one step forward.
Second, even if they are successful
at transplanting stem cells into the cochlea
the endolymph fluid inside of the cochlea
would be a very harsh environment
for a foreign stem cell to survive.
So they would actually have to go in
and change the chemical composition of this endolymph fluid
before they actually do the procedure.
Third would be correctly targeting the exact areas
that you want to regrow inner and outer hair cells,
and have them grow in the right location
rather than having them just grow anywhere.
Fourth, you would need them to establish
a neural connection with the auditory nerve.
It would do you absolutely no good
to grow hair cell-like structures,
and not have them innervate with the nerve
because they would be there, they just wouldn't do anything.
And fifth, these stem cells would have
to be programmed properly for them to turn
into the appropriate type of hair cell,
whether it's an inner hair cell or an outer hair cell,
and they could not just continuously reproduce
because then you could be left with a situation
where you have a tumor growing inside of your ear.
And that is a much bigger problem
than just having a hearing loss.
Despite all of these limitations with recent successes
that scientists have had with animal models
they do believe that stem cell therapies
will be a viable treatment option
to potentially cure hearing loss and tinnitus.
It might just be a really long time before we get there.
In the meantime, if you do have hearing loss
the most logical thing for you to do
is to treat your hearing loss
with whatever treatment options are currently available.
Because even if they do come out with a stem cell cure
within the next 10 years, the long-term auditory deprivation
that you would go through between now and then
may significantly reduce your benefit from treatment.
So if you think you have a hearing loss,
I highly recommend that you see an audiologist
to identify exactly what type of hearing loss that you have.
And so you can identify what
the most appropriate treatment options are
so you are much better prepared
if a stem cell cure comes out in the future.
That's it for this video, if you have any questions
leave them in the Comments section below.
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Also feel free to check out my website, DrCliffAud.com.
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