Let's say that it would take you ten minutes to solve this puzzle. How long would it take if you received constant electric shocks to your hands? Longer, right? Because the pain would distract you from the task. Well, maybe not; it depends on how you handle pain. Some people are distracted by pain. It takes them longer to complete a task, and they do it less well. Other people use tasks to distract themselves from pain, and those people actually do the task faster and better when they're in pain than when they're not. Some people can just send their mind wandering to distract themselves from pain. How can different people be subjected to the exact same painful stimulus and yet experience the pain so differently? And why does this matter? First of all, what is pain? Pain is an unpleasant sensory and emotional experience, associated with actual or potential tissue damage. Pain is something we experience, so it's best measured by what you say it is. Pain has an intensity; you can describe it on a scale from zero, no pain, to ten, the most pain imaginable. But pain also has a character, like sharp, dull, burning, or aching. What exactly creates these perceptions of pain? Well, when you get hurt, special tissue damage-sensing nerve cells, called nociceptors, fire and send signals to the spinal cord and then up to the brain. Processing work gets done by cells called neurons and glia. This is your Grey matter. And brain superhighways carry information as electrical impulses from one area to another. This is your white matter. The superhighway that carries pain information from the spinal cord to the brain is our sensing pathway that ends in the cortex, a part of the brain that decides what to do with the pain signal. Another system of interconnected brain cells called the salience network decides what to pay attention to. Since pain can have serious consequences, the pain signal immediately activates the salience network. Now, you're paying attention. The brain also responds to the pain and has to cope with these pain signals. So, motor pathways are activated to take your hand off a hot stove, for example. But modulation networks are also activated that deliver endorphins and enkephalins, chemicals released when you're in pain or during extreme exercise, creating the runner's high. These chemical systems help regulate and reduce pain. All these networks and pathways work together to create your pain experience, to prevent further tissue damage, and help you to cope with pain. This system is similar for everyone, but the sensitivity and efficacy of these brain circuits determines how much you feel and cope with pain. This is why some people have greater pain than others and why some develop chronic pain that does not respond to treatment, while others respond well. Variability in pain sensitivities is not so different than all kinds of variability in responses to other stimuli. Like how some people love roller coasters, but other people suffer from terrible motion sickness. Why does it matter that there is variability in our pain brain circuits? Well, there are many treatments for pain, targeting different systems. For mild pain, non-prescription medications can act on cells where the pain signals start. Other stronger pain medicines and anesthetics work by reducing the activity in pain-sensing circuits or boosting our coping system, or endorphins. Some people can cope with pain using methods that involve distraction, relaxation, meditation, yoga, or strategies that can be taught, like cognitive behavioral therapy. For some people who suffer from severe chronic pain, that is pain that doesn't go away months after their injury should have healed, none of the regular treatments work. Traditionally, medical science has been about testing treatments on large groups to determine what would help a majority of patients. But this has usually left out some who didn't benefit from the treatment or experienced side effects. Now, new treatments that directly stimulate or block certain pain-sensing attention or modulation networks are being developed, along with ways to tailor them to individual patients, using tools like magnetic resonance imaging to map brain pathways. Figuring out how your brain responds to pain is the key to finding the best treatment for you. That's true personalized medicine.
Imaxina que che levase dez minutos resolver este quebracabezas. Canto che levaría se recibises descargas eléctricas constantes nas mans? Máis, verdade? Porque a dor distraeríate da tarefa. Ou ao mellor non; depende de como xestiones a dor. Algunhas persoas distráense coa dor. Lévalles máis completar unha tarefa, e fana peor. Outras usan as tarefas para distraerse da dor, e esa xente fai a tarefa máis rápido e mellor cando sinte dor que cando non. Algúns poden deixar a súa mente vagando para distraerse da dor. Como pode algunha xente someterse exactamente aos mesmos estímulos dolorosos pero experimentar a dor de xeito tan distinto? E por que importa isto? Primeiro de todo, que é a dor? A dor é unha experiencia sensorial e emocional desagradable, asociada cun dano real ou potencial aos tecidos. A dor é algo que experimentamos, así que a mellor maneira de medila é polo que dis que é. A dor ten unha intensidade, pódela describir nunha escala de cero, sen dor, a dez, a maior dor imaxinable. Pero a dor tamén ten un carácter, como punxente, xordo, ardente ou agudo. Que é exactamente o que crea estas percepcións da dor? Cando te fas dano, as células nerviosas detectoras do dano nos tecidos, chamadas nociceptores, acéndense e mandan sinais á medula espiñal e logo arriba, ao cerebro. O traballo de procesamento fano unhas células chamadas neuronas e gliais. Esta é a túa materia gris. E as superestradas do cerebro levan información como impulsos eléctricos de unha área a outra. Esta é a túa materia branca. A superestrada que leva a información da dor da medula espiñal ao cerebro é a nosa vía de detección que acaba no córtex, a parte do cerebro que decide que facer co sinal da dor. Outro sistema de células cerebrais interconectadas, chamada a rede de saliencia, decide a que prestar atención. Como a dor pode ter consecuencias serias, o sinal da dor activa a rede de saliencia inmediatamente. Ben, agora estás prestando atención. O cerebro tamén responde á dor e ten que xestionar estes sinais de dor. Entón, actívanse as vías motoras para quitar a man dun fogón quente, por exemplo. Pero as redes de modulación tamén se activan e levan endorfinas e encefalinas, substancias químicas que se liberan cando sentes dor ou fas exercicio intenso e que crean a euforia do corredor. Estes sistemas químicos axudan a regular e reducir a dor. Todas estas redes e vías traballan xuntas para crear a túa experiencia de dor, para previr máis dano no tecido e axudarche a xestionar a dor. Este sistema é similar para todos, pero a sensibilidade e eficacia destes circuítos cerebrais determina canto sentes e como te enfrontas á dor. Por isto, algunha xente sente máis dor que outra e por que algúns desenvolven dores crónicas que non responden a tratamentos, mentres que outros responden ben. A variabilidade na sensibilidade á dor non é tan diferente a todos os tipos de variabilidade en resposta a outros estímulos. Ao igual que algúns adoran as montañas rusas pero outros sofren mareos espantosos. Por que importa que haxa variabilidade nos nosos circuítos cerebrais da dor? Ben, hai moitos tratamentos para a dor, dirixidos a diferentes sistemas. Para a dor media, os medicamentos sen prescrición poden actuar nas células onde comezan os sinais de dor. Outros medicamentos e anestésicos máis fortes actúan reducindo a actividade dos circuítos que detectan a dor ou estimulando o noso mecanismo de xestión de problemas, ou endorfinas. Algunhas persoas poden lidar coa dor con métodos que supoñen distracción, relaxación, meditación, ioga ou estratexias que poden ensinarse, como a terapia de conduta cognitiva. Para algunhas persoas que sofren dores crónicas graves, é dicir, dores que non desaparecen meses despois da lesión, os tratamentos habituais non funcionan. Tradicionalmente, a ciencia médica consistía en probar tratamentos en grupos grandes para determinar que ía axudar á maioría dos pacientes. Pero iso adoitaba deixar fóra a quen non melloraba co tratamento ou experimentaba efectos secundarios. Agora estanse a crear tratamentos novos que estimulan ou bloquean directamente algúns detectores da dor ou redes de modulación, así como maneiras de adaptalos a cada paciente usando ferramentas como a resonancia magnética para facer mapas das vías cerebrais. Descubrir como responde á dor o teu cerebro é fundamental para atopar o mellor tratamento para ti. Esa é a verdadeira medicina personalizada.