Elliot Krane: The mystery of chronic pain

Translator: Noelia Samartin Veiga Reviewer: Serv. de Norm. Lingüística U. de Santiago de Compostela

Son pediatra e anestesista,

polo que gaño a vida durmindo nenos.

I'm a pediatrician and an anesthesiologist,

(Risas)

so I put children to sleep for a living.

Tamén son académico, polo que durmo ao público de balde.

(Laughter)

And I'm an academic, so I put audiences to sleep for free.

(Risas)

(Laughter)

Pero en realidade dedícome

a levar a Unidade de Dor

But what I actually mostly do

is I manage the pain management service

no Hospital Infantil Packard en Stanford, Palo Alto.

at the Packard Children's Hospital up at Stanford in Palo Alto.

E coa experiencia

de 20 ou 25 anos traballando nisto

And it's from the experience

tráiovos unha mensaxe esta mañá:

from about 20 or 25 years of doing that

a dor é unha enfermidade.

that I want to bring to you the message this morning,

that pain is a disease.

Xeralmente,

pénsase na dor coma no síntoma dunha patoloxía

Now most of the time,

e isto é certo a maioría das veces.

you think of pain as a symptom of a disease,

É o síntoma dun tumor, dunha infección,

and that's true most of the time.

It's the symptom of a tumor or an infection

dunha inflamación ou dunha cirurxía.

Pero en arredor do 10% dos casos,

or an inflammation or an operation.

os pacientes seguirán padecendo dor

But about 10 percent of the time,

despois de recuperarse da enfermidade.

after the patient has recovered from one of those events,

Pode persistir meses,

pain persists.

e, ás veces, anos.

It persists for months

Cando sucede isto,

and oftentimes for years,

a dor é unha enfermidade por si mesma.

and when that happens,

Antes de que vos conte como cremos que sucede isto,

it is its own disease.

And before I tell you about how it is that we think that happens

e qué podemos facer ó respecto,

quixera mostrarvos como senten a dor os meus pacientes.

and what we can do about it,

I want to show you how it feels for my patients.

Imaxinade, se podedes,

que vos acaricio o brazo con esta pluma,

So imagine, if you will,

como estou acariciando o meu neste intre.

that I'm stroking your arm with this feather,

as I'm stroking my arm right now.

Agora quero que imaxinedes

que o estou acariciando con isto.

Now, I want you to imagine

Por favor, ficade nos asentos.

that I'm stroking it with this.

(Risas)

Please keep your seat.

(Laughter)

Unha sensación moi diferente.

Pero, que ten que ver isto coa dor crónica?

A very different feeling.

Now what does it have to do with chronic pain?

Imaxinade, se queredes, as dúas ideas xuntas.

Imagine, if you will, these two ideas together.

Imaxinade como sería a vosa vida

se vos acariciasen con esta pluma,

Imagine what your life would be like

pero os vosos cerebros vos din

if I were to stroke it with this feather,

que o que están sentindo é isto:

but your brain was telling you

esta é a experiencia dos meus pacientes con dor crónica.

that this is what you are feeling --

and that is the experience of my patients with chronic pain.

De feito, imaxinade algo aínda peor.

Imaxinade que estou acariciando o brazo dun fillo voso con esta pluma

In fact, imagine something even worse.

Imagine I were to stroke your child's arm with this feather,

e o seu cerebro dille

que o que sente é esta chama.

and their brain [was] telling them

that they were feeling this hot torch.

Esta era a vivencia de Chandler, unha paciente miña

That was the experience of my patient, Chandler,

á que vedes na foto.

Como podedes ver, é unha rapaza fermosa.

whom you see in the photograph.

Tiña 16 anos cando a coñecín o ano pasado,

As you can see, she's a beautiful, young woman.

E quería ser bailarina profesional.

She was 16 years old last year when I met her,

and she aspired to be a professional dancer.

Durante un dos seus ensaios de baile,

caeu co brazo estendido e torceu o pulso.

And during the course of one of her dance rehearsals,

she fell on her outstretched arm and sprained her wrist.

Probablemente pensedes, igual ca fixo ela,

que una torcedura de pulso é trivial

Now you would probably imagine, as she did,

na vida dunha persoa.

that a wrist sprain is a trivial event

Envólvese cunha venda elástica,

in a person's life.

Tómase ibuprofeno 1 ou 2 semanas

Wrap it in an ACE bandage,

e fin da historia.

take some ibuprofen for a week or two,

Pero no caso de Chandler, este foi o inicio da historia.

and that's the end of the story.

But in Chandler's case, that was the beginning of the story.

Esta era a pinta do seu brazo

cando veu á clínica tres meses despois da torcedura.

This is what her arm looked like

when she came to my clinic about three months after her sprain.

Fixádevos que o brazo ten a cor alterada,

como denegrida.

You can see that the arm is discolored,

Estaba frío coma o dun cadáver.

purplish in color.

Os músculos estaban xeados, paralizados

It was cadaverically cold to the touch.

--como nós dicimos, distónicos.

The muscles were frozen, paralyzed --

dystonic is how we refer to that.

A dor estendérase dende o pulso cara á man

The pain had spread from her wrist to her hands,

e as puntas dos dedos, e cara ó cóbado.

chegando case ó ombreiro.

to her fingertips, from her wrist up to her elbow,

Pero o peor non era

almost all the way to her shoulder.

a dor espontánea que sentía as 24 horas do día.

But the worst part was,

not the spontaneous pain that was there 24 hours a day.

O peor era a alodinia,

un termo médico usado para o fenómeno que antes expliquei

The worst part was that she had allodynia,

coa pluma e a chama.

the medical term for the phenomenon that I just illustrated

O máis leve contacto no brazo

with the feather and with the torch.

--o rozamento dunha man,

The lightest touch of her arm --

mesmo o contacto dunha manga, dunha prenda ao poñela--

the touch of a hand,

causáballe unha dor insoportable, moi ardente.

the touch even of a sleeve, of a garment, as she put it on --

caused excruciating, burning pain.

Como pode o sistema nervioso equivocarse dese xeito?

How can the nervous system get this so wrong?

Como pode o sistema nervioso

confundir una sensación inocente

How can the nervous system

como o tacto dunha man

misinterpret an innocent sensation

e convertela nunha sensación tan maligna

like the touch of a hand

and turn it into the malevolent sensation

como o contacto cunha chama?

Ben, se cadra pensades que o sistema nervioso

of the touch of the flame?

Well you probably imagine that the nervous system in the body

é como a cablaxe da vosa casa.

Nela os cables pasan polas paredes

is hardwired like your house.

dende o interruptor da luz, a unha caixa de conexións no teito

In your house, wires run in the wall,

from the light switch to a junction box in the ceiling

e dende aí ata a lámpada.

and from the junction box to the light bulb.

Cando se calca no interruptor, acéndese a luz.

And when you turn the switch on, the light goes on.

E cando se pecha, a luz apágase.

And when you turn the switch off, the light goes off.

A xente imaxina que o sistema nervioso funciona así.

So people imagine the nervous system is just like that.

Se pegas cun martelo no polgar,

estes cables do brazo --chamados nervios--

If you hit your thumb with a hammer,

transmiten a información á caixa de conexións na medula espiñal

these wires in your arm -- that, of course, we call nerves --

onde novos cables, novos nervios,

transmit the information into the junction box in the spinal cord

levan a información ata o cerebro,

where new wires, new nerves,

que é cando te das conta de que magoaches o polgar.

take the information up to the brain

where you become consciously aware that your thumb is now hurt.

Por suposto, a situación no corpo humano

But the situation, of course, in the human body

é moito máis complexa.

Poderíase pensar

is far more complicated than that.

que a caixa de conexións na medula espiñal

Instead of it being the case

é só onde un nervio conecta co seguinte

that that junction box in the spinal cord

liberando paquetiños marróns

is just simple where one nerve connects with the next nerve

de información química que chamamos neurotransmisores

by releasing these little brown packets

de forma linear un a un;

of chemical information called neurotransmitters

pero en realidade o que sucede

in a linear one-on-one fashion,

é que se esparexen en tres dimensións

in fact, what happens

--lateralmente, verticalmente, arriba e abaixo na medula espiñal--

is the neurotransmitters spill out in three dimensions --

laterally, vertically, up and down in the spinal cord --

e comezan a interactuar

con outras células adxacentes.

and they start interacting

Estas células, chamadas gliais,

with other adjacent cells.

antes pensábase que eran

These cells, called glial cells,

elementos estruturais pouco importantes da medula espiñal

were once thought to be

que non tiñan máis función ca a de unir os elementos importantes,

unimportant structural elements of the spinal cord

that did nothing more than hold all the important things together,

como os nervios.

Pero a verdade é que

like the nerves.

a glía xoga un papel vital

But it turns out

na modulación, amplificación

the glial cells have a vital role

e, no caso da dor, na distorsión

in the modulation, amplification

and, in the case of pain, the distortion

das experiencias sensoriais.

Estas células gliais actívanse.

of sensory experiences.

O seu ADN sintetiza novas proteínas

These glial cells become activated.

que se liberan

Their DNA starts to synthesize new proteins,

e interactúan cos nervios adxacentes,

which spill out

e comezan a liberar os seus neurotransmisores.

and interact with adjacent nerves,

E estes esparéxense,

and they start releasing their neurotransmitters,

activan células gliais adxacentes, e así sucesivamente,

and those neurotransmitters spill out

ata que se produza

and activate adjacent glial cells, and so on and so forth,

unha retroalimentación positiva.

until what we have

É case como se alguén fora á vosa casa

is a positive feedback loop.

e cambiara a cablaxe das paredes,

It's almost as if somebody came into your home

de modo que a seguinte vez que acendedes a luz

and rewired your walls

funcionara a cadea do WC tres portas máis alá,

so that the next time you turned on the light switch,

ou o lavalouza acendera só

the toilet flushed three doors down,

ou se apagara o monitor do ordenador.

or your dishwasher went on,

É unha loucura,

or your computer monitor turned off.

pero de feito, iso é o que sucede

That's crazy,

coa dor crónica.

but that's, in fact, what happens

E por iso a dor convértese nunha enfermidade por si mesma.

with chronic pain.

O sistema nervioso ten plasticidade.

And that's why pain becomes its own disease.

Cambia e transfórmase

The nervous system has plasticity.

en resposta ós estímulos.

It changes, and it morphs

E que facemos ó respecto?

in response to stimuli.

Que podemos facer nun caso como o de Chandler?

Well, what do we do about that?

Hoxe en día tratamos eses pacientes

What can we do in a case like Chandler's?

de forma bastante rudimentaria.

We treat these patients in a rather crude fashion

Tratámolos con fármacos modificadores dos síntomas

at this point in time.

We treat them with symptom-modifying drugs --

--analxésicos--

que verdadeiramente non son moi eficaces

painkillers --

para este tipo de dor.

which are, frankly, not very effective

Collemos nervios que son ruidosos e activos

for this kind of pain.

que deberían estar en silencio,

We take nerves that are noisy and active

e adormecémolos con analxésicos locais.

that should be quiet,

E o máis importante que facemos

and we put them to sleep with local anesthetics.

é usar un rigoroso, e a miúdo incómodo proceso

And most importantly, what we do

is we use a rigorous, and often uncomfortable, process

de terapia física e terapia ocupacional

co fin de reeducar os nervios no sistema nervioso

of physical therapy and occupational therapy

para que teñan unha resposta normal

to retrain the nerves in the nervous system

ás actividades e experiencias sensoriais

to respond normally

que forman parte da vida cotiá.

to the activities and sensory experiences

E apoiamos todo isto

that are part of everyday life.

cun programa de psicoterapia intensiva

And we support all of that

para enfrontar o desánimo, a desesperación e a depresión

with an intensive psychotherapy program

to address the despondency, despair and depression

que acompañan sempre

á dor crónica severa.

that always accompanies

É exitoso,

severe, chronic pain.

como se pode ver neste vídeo de Chandler

It's successful,

quen, dous meses despois de coñecela,

as you can see from this video of Chandler,

está facendo unha viravolta para atrás.

who, two months after we first met her,

Onte comín con ela,

is now doings a back flip.

porque é unha estudante universitaria de danza en Long Beach,

And I had lunch with her yesterday

todo lle está indo moi ben.

because she's a college student studying dance at Long Beach here,

Pero o futuro é incluso máis brillante.

and she's doing absolutely fantastic.

But the future is actually even brighter.

O futuro promete

que os novos medicamentos que se desenvolverán

The future holds the promise

non serán fármacos modificadores da sintomatoloxía

that new drugs will be developed

que simplemente agachan o problema,

that are not symptom-modifying drugs

como facemos agora,

that simply mask the problem,

senón que serán fármacos modificadores da enfermidade

as we have now,

but that will be disease-modifying drugs

que realmente actuarán na raíz do problema

e atacarán ás células gliais

that will actually go right to the root of the problem

ou a esas proteínas prexudiciais

and attack those glial cells,

que as células gliais elaboran,

or those pernicious proteins

esparexéndose e provocando no sistema nervioso a sensibilización

that the glial cells elaborate,

that spill over and cause this central nervous system wind-up,

ou plasticidade,

que é capaz

or plasticity,

de distorsionar e amplificar

that so is capable

a experiencia sensorial coñecida como dor.

of distorting and amplifying

Así, esperamos

the sensory experience that we call pain.

que no futuro

So I have hope

se cumpran as palabras proféticas de George Carlin

that in the future,

the prophetic words of George Carlin will be realized,

que dicía: "A miña filosofía:

non hai dor, non hai dor"

who said, "My philosophy:

No pain, no pain."

(Risas)

Moitas grazas.

(Aplausos)

Thank you very much.

(Applause)