The mysterious science of pain - Joshua W. Pate

Prevoditelj: Mirela Ivoš Recezent: Sanda L

In 1995, the British Medical Journal

1995. godine British Medical Journal

published an astonishing report about a 29-year-old builder.

objavio je zapanjujuće izvješće o 29-godišnjem graditelju.

He accidentally jumped onto a 15-centimeter nail,

On je slušajno skočio na čavao dug 15 centimetara

which pierced straight through his steel-toed boot.

koji je probio njegovu čizmu s čeličnom kapicom.

He was in such agonizing pain that even the smallest movement was unbearable.

Osjećao je tako očajničku bol da je i najmanji pokret bio nepodnošljiv.

But when the doctors took off his boot, they faced a surprising sight:

Ali kada su mu liječnici skinuli čizmu, dočekao ih je iznenađujuć prizor:

the nail had never touched his foot at all.

čavao nije ni dotaknuo njegovo stopalo.

For hundreds of years,

Stotinama godina

scientists thought that pain was a direct response to damage.

znanstvenici su mislili da je bol izravan odgovor na ozljedu.

By that logic, the more severe an injury is, the more pain it should cause.

Po toj logici, što je ozljeda ozbiljnija, uzrokovat će veću bol.

But as we’ve learned more about the science of pain,

Ali kako smo učili sve više o znanosti boli,

we’ve discovered that pain and tissue damage don’t always go hand in hand,

otkrili smo da bol i oštećenje tkiva ne idu uvijek ruku pod ruku,

even when the body’s threat signaling mechanisms are fully functioning.

čak i kada mehanizmi koji tijelu signaliziraju opasnost odlično rade.

We’re capable of experiencing severe pain out of proportion to an actual injury,

U stanju smo iskusiti opaku bol uzrokovanu stvarnom ozljedom,

and even pain without any injury,

ali također i bol bez ikakve ozljede,

like the builder, or the well-documented cases of male partners

poput graditelja, ili dobro dokumentirani slučajevi kada muški partneri

of pregnant women experiencing pain during the pregnancy or labor.

trudnih žena iskuse bol tijekom trudnoće ili poroda.

What’s going on here?

Što se ovdje događa?

There are actually two phenomena at play:

Zapravo postoje dva fenomena na snazi:

the experience of pain, and a biological process called nociception.

iskustvo boli i biološki proces pod nazivom nocicepcija.

Nociception is part of the nervous system’s protective response

Nocicepcija je dio zaštitnog odgovora živčanog sustava

to harmful or potentially harmful stimuli.

na štetni ili potencijalno štetni podražaj.

Sensors in specialized nerve endings

Senzori u specijaliziranim završecima živaca

detect mechanical, thermal, and chemical threats.

otkrivaju mehaničke, termalne i kemijske prijetnje.

If enough sensors are activated,

Ako se dovoljno senzora aktivira,

electrical signals shoot up the nerve to the spine and on to the brain.

električni signali odlaze živcima do kralježnične moždine te potom do mozga.

The brain weighs the importance of these signals

Mozak procjenjuje važnost tih signala

and produces pain if it decides the body needs protection.

i stvara bol ako dođe do zaključka da je tijelu potrebna zaštita.

Typically, pain helps the body avoid further injury or damage.

Obično bol pomaže tijelu da izbjegne daljnje ozljede ili oštećenje,

But there are a whole set of factors besides nociception

ali postoje različiti skupovi faktora uz nocicepciju

that can influence the experience of pain— and make pain less useful.

koji utječu na iskustvo boli i čine bol manje korisnom.

First, there are biological factors that amplify nociceptive signals to the brain.

Prvo, tu su biološki faktori koji pojačavaju nociceptivne signale prema mozgu.

If nerve fibers are activated repeatedly,

Ako se živčana vlakna opetovano aktiviraju,

the brain may decide they need to be more sensitive

mozak može odlučiti da trebaju biti osjetljivija

to adequately protect the body from threats.

kako bi na prikladan način zaštitila tijelo od opasnosti.

More stress sensors can be added to nerve fibers

Više senzora stresa može biti dodano živčanim vlaknima

until they become so sensitive that even light touches to the skin

dok ne postanu toliko osjetljiva da čak i lagani dodir kože

spark intense electrical signals.

potiče snažne električne signale.

In other cases,

U ostalim slučajevima,

nerves adapt to send signals more efficiently, amplifying the message.

živci se prilagode kako bi djelotvornije slali signale pojačavajući poruku.

These forms of amplification

Ovi oblici pojačavanja

are most common in people experiencing chronic pain,

najčešći su kod ljudi koji doživljavaju kroničnu bol,

which is defined as pain lasting more than 3 months.

koja se definira kao bol u trajanju duljem od 3 mjeseca.

When the nervous system is nudged into an ongoing state of high alert,

Kad je živčani sustav ponukan u stanje stalne visoke uzbune,

pain can outlast physical injury.

bol može trajati dulje od fizičke ozljede.

This creates a vicious cycle in which the longer pain persists,

Ovo stvara začarani krug u kojemu što dulje bol traje,

the more difficult it becomes to reverse.

to ju je teže suzbiti.

Psychological factors clearly play a role in pain too,

Psihološki faktori očito također igraju ulogu u boli,

potentially by influencing nociception and by influencing the brain directly.

potencijalno utječući na nocicepciju i utječući izravno na mozak.

A person’s emotional state, memories,

Osobno emocionalno stanje, uspomene,

beliefs about pain and expectations about treatment

uvjerenja o boli i očekivanja u vezi liječenja

can all influence how much pain they experience.

mogu također utjecati na to koliko boli osoba doživljava.

In one study,

U jednom istraživanju

children who reported believing they had no control over pain

djeca koja su iznijela uvjerenja kako ona nemaju kontrolu nad boli

actually experienced more intense pain

zapravo su doživljavala intenzivniju bol

than those who believed they had some control.

od djece čija su uvjerenja bila kako imaju nešto kontrole.

Features of the environment matter too:

Značajke okoline također su važne.

In one experiment,

U jednom ekperimentu

volunteers with a cold rod placed on the back of their hand

volonterima kojima je prislonjen ledeni štap na stražnju stranu ruke

reported feeling more pain when they were shown a red light than a blue one,

izjavili su kako osjećaju jaču bol kada im je pokazano crveno svjetlo nego plavo,

even though the rod was the same temperature each time.

iako je štap svaki puta bio iste temperature.

Finally, social factors like the availability of family support

Konačno, društveni faktori poput dostupnosti obiteljske podrške

can affect perception of pain.

mogu utjecati na percepciju boli.

All of this means that a multi-pronged approach to pain treatment

Sve ovo znači da višestruki pristup liječenju boli koji

that includes pain specialists, physical therapists, clinical psychologists, nurses

uključuje specijaliste za bol, terapeute, kliničke psihologe, medicinske sestre

and other healthcare professionals is often most effective.

i ostale zdravstvene radnike često je najučinkovitiji.

We’re only beginning to uncover the mechanisms behind the experience of pain,

Tek počinjemo otkrivati mehanizme koji stoje u podlozi doživljavanja boli,

but there are some promising areas of research.

ali postoje obećavajuća područja istraživanja.

Until recently,

Donedavno se mislilo

we thought the glial cells surrounding neurons were just support structures,

kako glija stanice koje okružuju živce samo podupiru strukture,

but now we know they have a huge role in influencing nociception.

ali sada znamo da one imaju ogromnu ulogu u utjecanju na nocicepciju.

Studies have shown that disabling certain brain circuits in the amygdala

Istraživanja su pokazala kako onespo- sobljavanje određenih moždanih krugova

can eliminate pain in rats.

u amigdali može ukloniti bol kod štakora.

And genetic testing in people with rare disorders

I genetska testiranja ljudi s rijetkim poremećajima

that prevent them from feeling pain

zbog kojih ne osjećaju bol

have pinpointed several other possible targets for drugs

ukazala su na nekoliko mogućih opcija lijekova

and perhaps eventually gene therapy.

i s vremenom možda gensku terapiju.