>> Commentator: Here at Johns Hopkins Medicine.
Known for groundbreaking research,
teaching and medical care.
>> Welcome to Facebook live from Johns Hopkins medicine.
I'm Elizabeth Tracey.
>> And I'm Sami Tuffaha.
I'm a plastic surgeon here at Johns Hopkins
specializing in hand, and upper extremity surgery.
And I have a particular interest in treating disorders
affecting the peripheral nervous system.
>> And you've already, thank you first of all,
so much for joining me today.
And you've already introduced a term
that might be a little bit confusing.
So I'm hoping that you'll define it.
When you talk about the peripheral nervous system,
what does that mean?
>> Yeah absolutely.
So we break the nervous system down into the central,
and the peripheral nervous system.
The central nervous system involves
the brain and the spinal cord.
And the peripheral nervous system you can think of
as a circuitry that connects the central nervous system
to the muscle and the skin,
and everything else in our body really.
>> And talk to me about the function
of the peripheral nervous system.
>> Yeah, that's a great question.
So the peripheral nervous system is a relay system,
and it basically relay signals
from the central nervous system to our body and back.
So when we want to move a body part
a signal is sent from the brain and spinal cord
through the peripheral nervous system
to our muscle, and that activates motion.
And likewise, it also relays signals back
from the sensory organs in our skin
and other tissues through the peripheral nervous system
back to the brain so that we can perceive,
and sense, and interact with our environment.
>> What are the range of things that can happen
to the peripheral nervous systems such that repairs needed?
>> So there are a number of different pathologies
that can affect the peripheral nervous system.
The main reason why you would need
to have a peripheral nerve repaired is trauma.
You know, when these peripheral nerves
travel all through our body.
And so when we have trauma to a body part
it's not uncommon for a peripheral nerve to be involved.
And depending on the distribution of that peripheral nerve
you'll have some amount of paralysis and numbness.
And that's really the issue that we try to address.
And we try to restore those functions through our surgeries.
>> Of course I have to ask how does a plastic surgeon
get involved in repair of peripheral nerves?
>> You know, that's a fantastic question.
Peripheral nerves are kind of this orphan.
Peripheral nerve surgeon's orphan subspecialty
that floats around amongst a number
of different surgical specialties, including neurosurgery
orthopedic surgery, plastic surgery, and ENT surgery.
And really all of the surgical subspecialties
have some involvement in peripheral nerves.
But, you know, there are some of us who, for whatever reason
take a special interest in it, and really dive deep into it.
And it's actually, I would say plastic surgery
is one of the few specialties that really has a,
plays a prominent role in peripheral nerve surgery.
>> Well, it sounds like then you said deep dive
that it's great to have your expertise
for people who have the unfortunate experience
of having those kinds of injuries.
How often does this happen?
>> You know, the specific numbers I don't have off
at the top of my head, but like I said, it's not uncommon
because these peripheral nerves travel through the body.
And so when you have injury to a tissue, it's not uncommon
to also have involvement of a peripheral nerve.
>> How will somebody know it's important
to come and see someone like you?
>> Well, you know, obviously if you cut yourself,
you have a laceration or some sort of wound,
and you notice that you have some numbness
or some weakness that would be highly suggestive
that you may have a peripheral nerve injury.
In which case I would recommend seeking treatment
both for the wound, and for those specific symptoms.
>> Would there be a certain time period
that somebody should wait,
and see whether things get better, and then come to see you?
Or would it be a good idea to come see you right away?
>> That's a fantastic question.
The timing of intervention is really critical,
and that's where we, you know, kind of think a lot,
and debate amongst each other, actually, as a sub-specialty.
You know, there's often this period of watchful waiting
where some peripheral nerve injuries
will spontaneously recover.
For instance, if it just happens to be a stretch injury,
and not a complete laceration.
And so we usually, if we're not sure
if the nerve is in continuity or not,
we'll have a period of watchful waiting.
But you don't want to wait too long because when a muscle
or an end organ is not receiving nerve supply,
and input from the peripheral nervous system
it will actually atrophy.
And that atrophy is irreversible.
So we're trying to find that sweet spot
where we've given the nerve enough time to recover
but not too much time that it's too late to intervene.
>> And is there an average period of time
that that would actually entail?
>> Most people would intervene somewhere
between three months and nine months.
Now, obviously if you know that the nerve
is completely severed, then you're going to go in,
and not intervene in an acute fashion.
So I'm really discussing more specifically stretch injuries
or injuries where you're not really sure
the extent of the injury.
And that's very common with brachial plexus injuries
which is kind of a subtype within the spectrum
of peripheral nerve injuries.
>> So the brachial plexus of course is that bunch of nerves
that sort of run underneath our armpit,
and then go out to our hands,
and our arms and all that, right?
>> Exactly.
So if you think about the peripheral nervous system
as a tree, those are really the big tree trunks
that are coming out of the spinal cord,
and then they keep branching,
and branching and branching further.
But you know, one of the issues with the peripheral,
with the brachial plexus in specific
is that each of those tree trunks
will eventually branch out to supply a very large area.
So if you were to injure one or two,
or, you know, God forbid all five of those tree trunks,
those main divisions coming out of your spinal cord
that make up the brachial plexus,
it can really have devastating consequences.
And it's not uncommon for patients to show up
with complete paralysis and numbness
of their upper extremity.
>> Let's talk about the repair.
>> Yeah, so, you know, there's been a lot of development
over the past decades, and one of the most exciting
developments, and that I think is really facilitating
better outcomes is the use of nerve transfers.
And what a nerve transfer involves
is essentially borrowing redundant nerve supply
from a place that you have it,
and rerouting it to the place that you're missing it.
And it's pretty amazing that when you do that,
the brain can actually reprogram itself
such that these inputs that were once going somewhere else
will actually be integrated into this new distribution.
And over time with training and practice
these patients can learn to use,
to basically incorporate this new wiring that we give them
to have pretty natural motion and sensation.
>> So I'm hoping that you can help me
to understand this just a little bit better.
Are you saying that the nerve supply to let's say one part
of my arm could be transplanted to another part of my arm
and that I could train my brain to make it function there?
Yes, yes exactly.
Let me give you a more specific example.
So, you know, there are two nerves, two main nerves
that go to supply the muscles that flex the elbow
going to the biceps and the brachialis,
and they come off of the musculocutaneous nerve.
And you really only need one of those two muscles
to be able to flex your elbow.
And so let's say now you're missing function in your hand
that you really need, you can borrow
one of those two nerves and send that down towards the hand.
And then those axons will slowly regenerate
at about a millimeter a day, and then they'll go,
and re-enervate or find a new muscle to supply in the hand.
And then the brain will reprogram itself to use that nerve
that was once flexing the elbow to now use the hand.
>> This sounds pretty complicated.
Is this a long surgery to accomplish this?
>> You know, the surgeries are often long,
often because we're doing multiple
nerve transfers at a time.
You know, I guess this would be a good chance
to highlight the fact that I work
with a neurosurgeon named Allan Belzberg.
And he is a expert in peripheral nerve surgery as well.
He's dedicated his long career to peripheral nerve surgery,
and he shares my passion in peripheral nerve surgery.
And so we team up on these cases,
which makes them go faster.
And I think it allows us to get better outcomes
because, you know, while there's a lot of overlap
in terms of our specific areas of expertise,
we also bring different things to the table
since we come from different training backgrounds.
And I think that ultimately benefits the patient.
And I think that's one of the strengths
of our program here at Johns Hopkins,
is that we have a true multidisciplinary approach
to treating these problems.
>> Talk to me about outcomes since you brought that up.
What can people expect
once they've had this kind of surgery?
>> Yeah, that's a great question.
So, you know, kind of trying to frame
the expectations for patients
before we go into surgery is incredibly important.
You know, you can imagine a patient, like I mentioned
who has complete paralysis of their upper extremity.
And, you know, unfortunately we're not able to restore
normal function to all the different muscle groups.
And what we're trying to do is just restore
some extent of meaningful recovery.
And so we talk to the patient about their goals,
and we tell them about in our experience
these are the most important functions to try to restore.
And, you know, we're not trying to go for full strength,
and concert pianist abilities.
We're just trying to give them some meaningful
restoration of function so that they can perform
their activities of daily living.
And we, you know, one of the expressions we like to use
is that a little bit goes a long way
for these types of scenarios.
>> You mentioned before that you're interested
not only in peripheral nerves
but also in injuries to the spinal cord.
Can you tell me a little more about that?
>> Yes, I'm glad you asked.
That's actually a very exciting cutting edge field
that we at Johns Hopkins are part of the leading edge on.
And, you know, I discussed with you the use
of nerve transfers for peripheral nerve injuries.
We can actually repurpose those
for the treatment of specific types of spinal cord injuries.
So when you have a spinal cord injury,
typically the function below that level of injury is lost,
but you have restoration of function
above that level of injury.
So if you have a spinal cord injury at the level of
let's say the mid brachial plexus,
then you can almost treat that
like a brachial plexus injury.
Where you can reroute those nerves
from above the level of injury,
where they're still functioning
to below the level of injury where they're needed.
And the spinal cord will not regenerate
whereas peripheral nerve system will regenerate.
And so we're basically taking advantage of the ability
of the peripheral nerve system to regenerate
to address these spinal cord injuries.
>> How often would that kind of thing be called for,
and are there anatomic limits to that?
If let's say I have a spinal cord injury
so that my legs aren't working well, could I use nerves
that are in my upper part of my body for that?
>> That's a great question.
You know, we haven't really been able
to address such specific scenario.
I would say the ideal scenario would be a patient
who has some upper extremity function,
and loss of other parts of their upper extremity function.
And those are the best patients in terms of our ability
to use these nerve transfers to restore function.
>> And would these actually work if the spinal cord
was completely severed at a certain level?
>> Yeah, absolutely.
Because above that level of injury
the spinal cord is still intact,
and it's still sending signals
to the peripheral nervous system.
And so again, you're going to have redundant nerves
with multiple nerve supplying functioning muscles
that you can reroute towards areas
that were now not functioning
because they were supplied by the spinal cord level
and peripheral nerves below the level of injury.
>> Talk to me a little bit, if you would
about your speculations for the future,
because it sounds to me like there's a lot going on
in the repair of these nerves, and it sounds
like you're very optimistic about what's possible.
>> Yeah, so, you know, I think we can already
provide patients with some really great outcomes
but there's still a lot of room for improvement.
And at present, we're really relying
on the patient's innate capacity to regenerate.
And, you know, we don't really have any therapies
at this point that we can give patients to improve
the process of nerve regeneration to make it happen
more quickly and more robustly.
But there are some promising candidates
that are coming out of the lab.
The lab that I lead in particular is looking
at a number of very promising candidates
one of which is currently in clinical trials.
And so the clinical trial
that we're running right now is blinded.
So I can't tell you what the outcomes are as of yet
but we are optimistic that this could eventually lead
to the first therapy that's clinically indicated
for peripheral nerve injuries.
And then it could also be given to patients
with spinal cord injuries where we do nerve transfers,
and then we can give them this therapy
to make our nerve transfers work better.
Is there anything else you'd like to add?
>> You know, Elizabeth I just to really highlight
how much I enjoy working with this patient population.
You know, they come in with such devastating injuries,
and it's really a longitudinal relationship
where we first start to talk
about their injury and expectations.
And then we go through the surgery process,
and we spend a lot of time together afterwards
kind of through the whole recovery process and rehab.
And it's just so incredible to see these patients
recover their function, their ability to move
their extremities, and interact with their environment.
And I think that's really what makes
it all worthwhile for me.
And, you know, I just wanted to highlight
how much I enjoy working with this patient population
and how that's really kind of
what we focus on with these scenarios.
>> Well, thank you so very much for that.
And thanks for joining me today.
>> Thanks so much, Elizabeth.
I really enjoyed the conversation, and it was a pleasure.