I'm a pediatrician and an anesthesiologist, so I put children to sleep
for a living. (Laughter) And I'm an academic, so I put audiences to
sleep for free. (Laughter) But what I actually mostly do is I manage
the pain management service at the Packard Children's Hospital up
at Stanford in Palo Alto. And it's from the experience from about 20
or 25 years of doing that that I want to bring to you the message
this morning, that pain is a disease.
Now most of the time, you think of pain as a symptom of a disease,
and that's true most of the time. It's the symptom of a tumor or an
infection or an inflammation or an operation. But about 10 percent
of the time, after the patient has recovered from one of those
events, pain persists. It persists for months and oftentimes for
years, and when that happens, it is its own disease. And before I tell
you about how it is that we think that happens and what we can do
about it, I want to show you how it feels for my patients. So
imagine, if you will, that I'm stroking your arm with this feather, as
I'm stroking my arm right now. Now, I want you to imagine that I'm
stroking it with this. Please keep your seat. (Laughter) A very
different feeling. Now what does it have to do with chronic pain?
Imagine, if you will, these two ideas together. Imagine what your life
would be like if I were to stroke it with this feather, but your brain
was telling you that this is what you are feeling -- and that is the
experience of my patients with chronic pain. In fact, imagine
something even worse. Imagine I were to stroke your child's arm
with this feather, and their brain [was] telling them that they were
feeling this hot torch.
That was the experience of my patient, Chandler, whom you see in
the photograph. As you can see, she's a beautiful, young woman.
She was 16 years old last year when I met her, and she aspired to
be a professional dancer. And during the course of one of her dance
rehearsals, she fell on her outstretched arm and sprained her wrist.
Now you would probably imagine, as she did, that a wrist sprain is a
trivial event in a person's life. Wrap it in an ACE bandage, take some
ibuprofen for a week or two, and that's the end of the story. But in
Chandler's case, that was the beginning of the story. This is what
her arm looked like when she came to my clinic about three months
after her sprain. You can see that the arm is discolored, purplish in
color. It was cadaverically cold to the touch. The muscles were
frozen, paralyzed -- dystonic is how we refer to that. The pain had
spread from her wrist to her hands, to her fingertips, from her wrist
up to her elbow, almost all the way to her shoulder.
But the worst part was, not the spontaneous pain that was there 24
hours a day. The worst part was that she had allodynia, the medical
term for the phenomenon that I just illustrated with the feather and
with the torch. The lightest touch of her arm -- the touch of a hand,
the touch even of a sleeve, of a garment, as she put it on -- caused
excruciating, burning pain.
How can the nervous system get this so wrong? How can the
nervous system misinterpret an innocent sensation like the touch of
a hand and turn it into the malevolent sensation of the touch of the
flame? Well you probably imagine that the nervous system in the
body is hardwired like your house. In your house, wires run in the
wall, from the light switch to a junction box in the ceiling and from
the junction box to the light bulb. And when you turn the switch on,
the light goes on. And when you turn the switch off, the light goes
off. So people imagine the nervous system is just like that. If you hit
your thumb with a hammer, these wires in your arm -- that, of
course, we call nerves -- transmit the information into the junction
box in the spinal cord where new wires, new nerves, take the
information up to the brain where you become consciously aware
that your thumb is now hurt.
But the situation, of course, in the human body is far more
complicated than that. Instead of it being the case that that junction
box in the spinal cord is just simple where one nerve connects with
the next nerve by releasing these little brown packets of chemical
information called neurotransmitters in a linear one-on-one
fashion, in fact, what happens is the neurotransmitters spill out in
three dimensions -- laterally, vertically, up and down in the spinal
cord -- and they start interacting with other adjacent cells. These
cells, called glial cells, were once thought to be unimportant
structural elements of the spinal cord that did nothing more than
hold all the important things together, like the nerves. But it turns
out the glial cells have a vital role in the modulation, amplification
and, in the case of pain, the distortion of sensory experiences.
These glial cells become activated. Their DNA starts to synthesize
new proteins, which spill out and interact with adjacent nerves, and
they start releasing their neurotransmitters, and those
neurotransmitters spill out and activate adjacent glial cells, and so
on and so forth, until what we have is a positive feedback loop.
It's almost as if somebody came into your home and rewired your
walls so that the next time you turned on the light switch, the toilet
flushed three doors down, or your dishwasher went on, or your
computer monitor turned off. That's crazy, but that's, in fact, what
happens with chronic pain. And that's why pain becomes its own
disease. The nervous system has plasticity. It changes, and it
morphs in response to stimuli.
Well, what do we do about that? What can we do in a case like
Chandler's? We treat these patients in a rather crude fashion at this
point in time. We treat them with symptom-modifying drugs --
painkillers -- which are, frankly, not very effective for this kind of
pain. We take nerves that are noisy and active that should be quiet,
and we put them to sleep with local anesthetics. And most
importantly, what we do is we use a rigorous, and often
uncomfortable, process of physical therapy and occupational
therapy to retrain the nerves in the nervous system to respond
normally to the activities and sensory experiences that are part of
everyday life. And we support all of that with an intensive
psychotherapy program to address the despondency, despair and
depression that always accompanies severe, chronic pain.
It's successful, as you can see from this video of Chandler, who, two
months after we first met her, is now doings a back flip. And I had
lunch with her yesterday because she's a college student studying
dance at Long Beach here, and she's doing absolutely fantastic.
But the future is actually even brighter. The future holds the
promise that new drugs will be developed that are not symptom-
modifying drugs that simply mask the problem, as we have now,
but that will be disease-modifying drugs that will actually go right
to the root of the problem and attack those glial cells, or those
pernicious proteins that the glial cells elaborate, that spill over and
cause this central nervous system wind-up, or plasticity, that so is
capable of distorting and amplifying the sensory experience that we
call pain. So I have hope
that in the future, the prophetic words of George Carlin will be
realized, who said, "My philosophy: No pain, no pain."
Thank you very much.
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