The mystery of chronic pain Elliot Krane
[Music]
I’m a pediatrician and an
anesthesiologist so I put children to
sleep for a living and I’m an academic
so I put audiences to sleep for free
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 of 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 is 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 then 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
us please keep UC
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 his feather but
your brain was telling you that this is
what you were 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 were 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
sixteen 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 rapid in an ace
bandage takes 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
categorically 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 a 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
up to 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 simply where one
nerve communicates 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 where
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
wall so 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
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 a 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 doing a backflip and I had lunch
with her yesterday because she’s a
college student studying dance at Long
Beach chair 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 the central nervous
system wind-up
or plasticity that so is capable of
distorting and amplifying the sensory
experience that we call pain so that 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
[Applause]
you