Chapter 8. General Principles of Sensory Processing, Touch, and Pain

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Jayne O'Donnell and Ken Alltucker, Doctors are misusing 2016 opioid pain medication guidelines, federal officials said Wednesday, a clear response to increasing complaints from chronic pain patients who say they are the victims of an overreaction to the opioid crisis. The Centers for Disease Control and Prevention, in new guidance for opioid prescribing, said many physicians were guilty of a "misapplication" of 2016 guidelines that clamped down on the use of opioids. The new guidelines, published in the New England Journal of Medicine, was the latest federal acknowledgement that many physicians' responses to the opioid crisis went too far. Former Food and Drug Administration commissioner Scott Gottlieb, a physician, spoke out last July about the impact the opioid crisis response had on pain patients when he called for development of more options. Until then, people in the middle of cancer treatments, having "acute sickle cell crises" or with pain after surgery shouldn't be affected by the earlier recommendations, CDC said. These patients were outside the scope of the guidelines, which were intended for primary care doctors treating chronic pain patients, CDC said. Doctors that set hard limits or cut off opioids are also misapplying the government's guidance, CDC said. Doctors should prescribe the lowest effective dosage and avoid increasing it to 90 "morphine milligram equivalents" a day or "carefully justify" any decision to raise the dose to that level.

Keyword: Pain & Touch; Drug Abuse
Link ID: 26173 - Posted: 04.25.2019

Yao-Hua Law When it comes to migration science, birds rule. Although many mammals — antelopes, whales, bats — migrate, too, scientists know far less about how those animals do it. But a new device, invented by animal navigation researcher Oliver Lindecke, could open a new way to test how far-ranging bats find their way. Lindecke, of Leibniz Institute for Zoo and Wildlife Research in Germany, has been studying bat migration since 2011. He started with analyzing different forms of hydrogen atoms in wild bats to infer where they had flown from. But figuring out how the bats knew where to go was trickier. Lindecke needed a field setup that let him test what possible cues from nature helped bats navigate across vast distances. The first step was studying in which direction the bats first take flight. Such experiments on birds typically involve confining the animals in small, enclosed spaces. But that doesn’t work for bats, which tend to fall asleep in such spaces. So he invented what he calls the circular release box: a flat-bottom, funnel-shaped container topped by a wider lid. To escape, the bat crawls up the wall and takes off from the edge. Bat tracks in a layer of chalk (Lindecke says he was inspired by a snow-covered Berlin street) indicate where the bat took off. In August 2017, Lindecke captured 54 soprano pipistrelle bats (Pipistrellus pygmaeus) in a large, 50-meter-wide trap at the Pape Ornithological Research Station in Latvia as the animals were migrating along the coast of the Baltic Sea toward Central Europe. Experiments with the new device showed that the adult bats flew straight in the direction in which they took off, Lindecke and colleagues report online March 1 in the Journal of Zoology. |© Society for Science & the Public 2000 - 2019

Keyword: Animal Migration
Link ID: 26159 - Posted: 04.20.2019

By Jamie Lauren Keiles When Jennifer Allen watched videos of space, she sometimes felt this peculiar sensation: a tingling that spread through her scalp as the camera pulled back to show the marble of the earth. It came in a wave, like a warm effervescence, making its way down the length of her spine and leaving behind a sense of gratitude and wholeness. Allen loved this feeling, but she didn’t know what caused it. It was totally distinct from anything she’d experienced before. Every two years or so she’d take to Google. She tried searching things like “tingling head and spine” or “brain orgasm.” For nine years, the search didn’t turn up anything. Then, around 2009, it did. As always, Allen typed her phrases into Google, but this time she got a result on a message board called SteadyHealth. The post was titled WEIRD SENSATION FEELS GOOD: i get this sensation sometimes. theres no real trigger for it. it just happens randomly. its been happening since i was a kid and i’m 21 now. some examples of what it seems has caused it to happen before are as a child while watching a puppet show and when i was being read a story to. as a teenager when a classmate did me a favor and when a friend drew on the palm of my hand with markers. sometimes it happens for no reason at all The poster went on to demand an explanation. In the discussion, nobody had one, but many described a similar feeling — a “silvery sparkle” inside the head, a euphoric “brain-gasm” or a feeling like goose bumps in the scalp that faded “in and out in waves of heightened intensity.” Many people agreed that the sensation was euphoric. (“Aside from an actual orgasm, it’s probably the most enjoyable sensation possible,” one user wrote.) Its triggers were as varied as watching someone fill out a form, listening to whispering sounds or seeing Bob Ross paint landscapes on TV. Allen scrolled through pages and pages of discussion. Oh my gosh, she remembers thinking. These people are talking about exactly what I experience. © 2019 The New York Times Company

Keyword: Pain & Touch; Hearing
Link ID: 26114 - Posted: 04.04.2019

By C. Claiborne Ray Q. How do bees find the flowers in the container garden on the fourth-floor deck of my city apartment? A. Foraging bees use the same methods to find nectar and pollen four floors up that they use at ground level. Honeybees routinely fly two miles from their hives in their search for raw material for honey; it doesn’t require much extra energy to fly several stories up. It takes only one scout to report a promising garden to the rest of the hive with a famous waggle dance. The scout relies on its sophisticated eyes, which are tuned to a variety of wavelengths, including ultraviolet color patterns in flowers that are invisible to people. We’re taking you on a journey to help you understand how bees, while hunting for pollen, use all of their senses — taste, touch, smell and more — to decide what to pick up and bring home. When the bees get closer to flowers, smell receptors begin transmitting information. And it has recently been discovered that both bumblebees and honeybees can detect and discriminate among weak electrostatic fields emanating from flowers. The bees accumulate a positive charge, while the flowers have a negative charge. The interaction between the fields is detected by antennae or sensitive hairs on the body. The electrical field helps bees to recognize pollen-rich blooms and perhaps even to transfer the pollen. © 2019 The New York Times Company

Keyword: Animal Migration; Animal Communication
Link ID: 26102 - Posted: 04.02.2019

By Heather Murphy An article this week about Jo Cameron, who has lived for 71 years without experiencing pain or anxiety because she has a rare genetic mutation, prompted questions from New York Times readers. The notion that the same gene could be responsible for the way a person processes physical and psychological pain left many perplexed: Aren’t they totally different? Or does her story hint that sensitivity to one type of pain might be intertwined with sensitivity to another? Childbirth, Ms. Cameron said, felt like “a tickle.” She often relies on her husband to alert her when she is bleeding, bruised or burned because nothing hurts. When someone close to her has died, she said, she has felt sad but “I don’t go to pieces.” She cannot recall ever having been riled by anything — even a recent car crash. On an anxiety disorder questionnaire, she scored zero out of 21. “I drive people mad by being cheerful,” she said. Here’s a bit about what’s known: Do those who live without pain also live without anxiety? No. Before encountering Ms. Cameron, the scientists who studied her case worked with other patients who did not experience pain. “Reduced anxiety has not really been noted before in the other pain insensitivity disorders we work on,” said Dr. James Cox, a senior lecturer from the Molecular Nociception Group at University College London. He also said that given Ms. Cameron had gone more than six decades without realizing just how unusual she was, there could be others like her. A number of such individuals contacted The Times after the article was published. © 2019 The New York Times Company

Keyword: Pain & Touch; Emotions
Link ID: 26100 - Posted: 04.01.2019

Ian Sample Science editor Doctors have identified a new mutation in a woman who is barely able to feel pain or stress after a surgeon who was baffled by her recovery from an operation referred her for genetic testing. Jo Cameron, 71, has a mutation in a previously unknown gene which scientists believe must play a major role in pain signalling, mood and memory. The discovery has boosted hopes of new treatments for chronic pain which affects millions of people globally. Cameron, a former teacher who lives in Inverness, has experienced broken limbs, cuts and burns, childbirth and numerous surgical operations with little or no need for pain relief. She sometimes leans on the Aga and knows about it not from the pain, but the smell. “I’m vegan, so the smell is pretty obvious,” she says. “There’s no other burning flesh going on in the house.” But it is not only an inability to sense pain that makes Cameron stand out: she also never panics. When a van driver ran her off the road two years ago, she climbed out of her car, which was on its roof in a ditch, and went to comfort the shaking young driver who cut across her. She only noticed her bruises later. She is relentlessly upbeat, and in stress and depression tests she scored zero. “I knew that I was happy-go-lucky, but it didn’t dawn on me that I was different,” she says. “I thought it was just me. I didn’t know anything strange was going on until I was 65.” © 2019 Guardian News & Media Limited

Keyword: Pain & Touch; Genes & Behavior
Link ID: 26090 - Posted: 03.28.2019

Amber Dance Robert Sorge was studying pain in mice in 2009, but he was the one who ended up with a headache. At McGill University in Montreal, Canada, Sorge was investigating how animals develop an extreme sensitivity to touch. To test for this response, Sorge poked the paws of mice using fine hairs, ones that wouldn’t ordinarily bother them. The males behaved as the scientific literature said they would: they yanked their paws back from even the finest of threads. But females remained stoic to Sorge’s gentle pokes and prods1. “It just didn’t work in the females,” recalls Sorge, now a behaviourist at the University of Alabama at Birmingham. “We couldn’t figure out why.” Sorge and his adviser at McGill University, pain researcher Jeffrey Mogil, would go on to determine that this kind of pain hypersensitivity results from remarkably different pathways in male and female mice, with distinct immune-cell types contributing to discomfort2. Sorge and Mogil would never have made their discovery if they had followed the conventions of most pain researchers. By including male and female mice, they were going against the crowd. At the time, many pain scientists worried that females’ hormone cycles would complicate results. Others stuck with males because, well, that’s how things were done. Today, inspired in part by Sorge and Mogil’s work and spurred on by funders, pain researchers are opening their eyes to the spectrum of responses across sexes. Results are starting to trickle out, and it’s clear that certain pain pathways vary considerably, with immune cells and hormones having key roles in differing responses. © 2019 Springer Nature Publishing AG

Keyword: Pain & Touch; Hormones & Behavior
Link ID: 26089 - Posted: 03.28.2019

Maria Temming A new analysis of people’s brain waves when surrounded by different magnetic fields suggests that people have a “sixth sense” for magnetism. Birds, fish and some other creatures can sense Earth’s magnetic field and use it for navigation (SN: 6/14/14, p. 10). Scientists have long wondered whether humans, too, boast this kind of magnetoreception. Now, by exposing people to an Earth-strength magnetic field pointed in different directions in the lab, researchers from the United States and Japan have discovered distinct brain wave patterns that occur in response to rotating the field in a certain way. These findings, reported in a study published online March 18 in eNeuro, offer evidence that people do subconsciously respond to Earth’s magnetic field — although it’s not yet clear exactly why or how our brains use this information. “The first impression when I read the [study] was like, ‘Wow, I cannot believe it!’” says Can Xie, a biophysicist at Peking University in Beijing. Previous tests of human magnetoreception have yielded inconclusive results. This new evidence “is one step forward for the magnetoreception field and probably a big step for the human magnetic sense,” he says. “I do hope we can see replications and further investigations in the near future.” During the experiment, 26 participants each sat with their eyes closed in a dark, quiet chamber lined with electrical coils. These coils manipulated the magnetic field inside the chamber such that it remained the same strength as Earth’s natural field but could be pointed in any direction. Participants wore an EEG cap that recorded the electrical activity of their brains while the surrounding magnetic field rotated in various directions. |© Society for Science & the Public 2000 - 2019

Keyword: Pain & Touch
Link ID: 26052 - Posted: 03.19.2019

By Haider Warraich The United States uses a third of the world’s opioids but a fifth of Americans still say they suffer from chronic pain. The only demonstrable effect of two decades of widespread prescription of opioids has been catastrophic harm. With more than 47,000 Americans dying of opioid overdoses in 2017 and hundreds of thousands more addicted to them, it was recently reported that, for the first time, Americans were more likely to die of opioids than of car accidents. This has forced many to take a step back and ponder the very nature of pain, to understand how best to alleviate it. The ancient Greeks considered pain a passion — an emotion rather than a sensation like touch or smell. During the Dark Ages in Europe, pain was seen as a punishment for sins, a spiritual and emotional experience alleviated through prayers rather than prescriptions. In the 19th century, the secularization of Western society led to the secularization of pain. It was no longer a passion to be endured but a sensation to be quashed. The concept of pain as a purely physical phenomenon reached its zenith in the 1990s, when medical organizations such as the American Pain Society and the Department of Veterans Affairs succeeded in having pain designated a “fifth vital sign,” alongside blood pressure, temperature and breathing and heart rate. This coincided with the release of long-acting opioids like OxyContin. Doctors believed they now had an effective remedy for their patients’ suffering. While opioids do help many patients with acute pain from injuries, surgeries or conditions like cancer, looking back it’s clear that using opioids to treat chronic pain — backaches, bum knees and the like — might well be considered the worst medical mistake of our era. © 2019 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 26047 - Posted: 03.18.2019

Alix Spiegel There's a before, and there's an after. In the before, it was a relatively normal night. The kind of night any 14-year-old girl might have. Devyn ate dinner, watched TV and had small, unremarkable interactions with her family. Then, around 10 o'clock, she decided to turn in. "I went to bed as I normally would, and then all of a sudden ... my hips... they just hurt unimaginably!" Devyn says. "I started crying, and I started shaking." It was around midnight, but the pain was so intense she couldn't stop herself — she cried out so loudly she woke her mother, Sheila. Together, they did everything they could to neutralize the pain — stand up, lie down, hot bath, pain medication. But there was no escape, not for Devyn, and so not for Sheila. "You go to cancer first, right? It's like, 'OK, maybe you have cancer, maybe it's a tumor?' " Sheila says. When she was calm enough to reason with herself, Sheila decided cancer was improbable but wondered what was going on? The only thing they could think of was that the hip pain was somehow related to the minor knee surgery Devyn had gotten a few months before — she had broken the tip of her distal femur one day during dance practice. So as usual, Sheila snapped to attention to solve the problem. It was 2016 — surely modern medicine could fix this. (NPR is not using Devyn's or Sheila's last name to protect Devyn's privacy as a minor discussing her medical treatment.) They started by calling Devyn's surgeon, but the surgeon had no explanation for the pain. He renewed Devyn's prescription for Percocet and wrote a new prescription for tramadol. But the pain only got worse, so they lined up more appointments: their pediatrician, a naturopath, a pain specialist, a sports medicine doctor. © 2019 npr

Keyword: Pain & Touch
Link ID: 26024 - Posted: 03.11.2019

By Jan Hoffman and Abby Goodnough Three years ago this month, as alarms about the over-prescription of opioid painkillers were sounding across the country, the federal government issued course-correcting guidelines for primary care doctors. Prescriptions have fallen notably since then, and the Trump administration is pushing for them to drop by another third by 2021. But in a letter to be sent to the Centers for Disease Control and Prevention on Wednesday, more than 300 medical experts, including three former White House drug czars, contend that the guidelines are harming one group of vulnerable patients: those with severe chronic pain, who may have been taking high doses of opioids for years without becoming addicted. They say the guidelines are being used as cover by insurers to deny reimbursement and by doctors to turn patients away. As a result, they say, patients who could benefit from the medications are being thrown into withdrawal and suffering renewed pain and a diminished quality of life, even to the point of suicide. The letter writers form an uneasy alliance spanning differing positions on opioids — professors of addiction medicine as well as pain specialists, some patient representatives who have taken money from the pharmaceutical industry, and the former drug czars, from the Obama, Clinton and Nixon administrations. Michael Botticelli, who served as the drug czar under President Obama and now leads the Grayken Center for Addiction at Boston Medical Center, said he signed the letter because “there has been enough anecdotal evidence to raise the alarm bells” about the misuse of the guidelines leading to pain patients losing effective treatment. “The C.D.C. really does need a rigorous evaluation of this because we don’t know how big the problem is,” he said. “Minimally, we need some level of clarification on appropriate use of the guidelines.” © 2019 The New York Times Company

Keyword: Pain & Touch; Drug Abuse
Link ID: 26016 - Posted: 03.07.2019

Sarah DeWeerdt An analysis of four mouse models negates certain assumptions underlying the “signaling imbalance theory,” a popular hypothesis about autism’s origins in the brain. The findings suggest that the imbalance is a compensatory response to other problems in the brain, rather than the underlying cause of autism. The signaling imbalance theory holds that the brains of autistic people have too much excitatory brain activity and not enough inhibitory signals to counteract it. This imbalance then causes neurons to fire too often, the theory goes, and contributes to motor problems, sensory hypersensitivity and other autism traits. This hypothesis, first suggested in 2003, is so popular that it is often cited as fact. The new study questions its underlying assumptions, however. The researchers did find a skewed signaling balance but not the unusually high rate of neuronal firing, or “spikes.” “It’s not as straightforward as the classic hypothesis is worded,” says study leader Dan Feldman, professor of neurobiology at the University of California, Berkeley. “The [signals] are changing in a way that stabilizes brain function rather than creates excess spikes.” Feldman’s team found this pattern in four popular models of autism: mice lacking the genes CNTNAP2 or FMR1, or missing one copy of TSC2 or a region of chromosome 16 called 16p11.2. © 1986 - 2019 The Scientist

Keyword: Autism
Link ID: 25992 - Posted: 02.28.2019

By Perri Klass, M.D. I believe my mother thought that needing to medicate her own discomfort would be a kind of moral and physical weakness. This applied only to herself; if I told her that I was hurting, or that one of her grandchildren was in pain, she would have been anxious for something to help. She felt our pain, you might say, but she denied her own. I’ve spent the past couple of weeks thinking about pain in children and writing about pain in children — acute pain and chronic pain, pain with shots and pain after surgery, pain medicines and pain specialists. I asked the pain experts I interviewed about the different ways that different people experience pain from the same stimulus: Why does one child cry inconsolably after a needle stick while another, same age, same size needle, watches with curiosity as the shot is administered and doesn’t even flinch? There is a great deal of variation in how much pain people experience, I was told, and by and large we should take people at their word. Some people are more prone to soreness, some are relatively less sensitive, some hypersensitive, and there are differences in the ways that different people process pain, and in the ways they respond to drugs. And “hypersensitive” is not a code word for “complains more” — it’s a neurological category. And then of course there are psychological factors. That is not to say that pain is psychogenic, said Dr. Charles Berde, the founder of the division of pain medicine at Boston Children’s Hospital, and one of my teachers when I did my training there. People who are anxious or terrified of pain, people who have post-traumatic stress disorder, may actually experience more pain, he said, because the pain circuits in their brains are revved up. © 2019 The New York Times Company

Keyword: Pain & Touch
Link ID: 25931 - Posted: 02.04.2019

By Benedict Carey Veteran insomniacs know in their bones what science has to say about sleep deprivation and pain: that the two travel together, one fueling the other. For instance, people who develop chronic pain often lose the ability to sleep well, and quickly point to a bad back, sciatica or arthritis as the reason. The loss of sleep, in turn, can make a bad back feel worse, and the next night’s slumber even more difficult. Why sleep deprivation amplifies pain is not fully worked out, but it has to do with how the body responds to an injury such as a cut or turned ankle. First, it hurts, as nerves send a blast up the spinal cord and into the brain. There, a network of neural regions flares in reaction to the injury and works to manage, or blunt, the sensation. Think of the experience as a kind of physiological dialogue between the ground unit that took the hit and the command-control center trying to contain the damage. In a new study, a team of neuroscientists has clarified the nature of the top-down portion of that exchange, and how it is affected by sleep. In a sleep-lab experiment, the researchers found that a single night of sleep deprivation reduced a person’s pain threshold by more than 15 percent and left a clear signature in the brain’s pain-management centers. In a separate experiment, the team determined that small deviations in the average amount of sleep from one day to another predicted the level of overall pain felt the next day. “What’s exciting about these findings is that they will stimulate, and justify, doing more research to figure this system out,” said Michael J. Twery, director of the sleep disorders branch of the National Heart, Lung and Blood Institute, who was not involved in the new study. “Once we understand how sleep deprivation changes how these pathways function, we should be able to manage pain more effectively — all types of pain.” © 2019 The New York Times Company

Keyword: Sleep; Pain & Touch
Link ID: 25909 - Posted: 01.29.2019

By Perri Klass, M.D. Acute pain that calls out to warn you — “Hey, don’t walk on this broken leg!” — may be unpleasant, but it’s also protective. That acute pain is letting you know that a part of your body needs to heal, or in some other way needs extra attention, said Dr. Neil Schechter, the director of the chronic pain clinic at Boston Children’s Hospital. That’s very different, he said, from chronic pain that goes on over the course of months, whether abdominal pain or headache or musculoskeletal — it may persist and be incapacitating, because “the pain has become the disease.” That doesn’t mean the pain is any less painful for the person experiencing it. “There is really strong evidence supporting the psychological treatment for chronic pain, and that doesn’t imply that the pain itself is a psychological problem,” said Rachael Coakley, a psychologist who is the director of clinical innovation and outreach in pain medicine at Boston Children’s Hospital. Her book, “When Your Child Hurts,” is an excellent resource for parents. “When you’re a kid and you’ve had pain for a really long time, a lot of that is an experience of not having control over what’s happening in your body,” said Anna C. Wilson, a pediatric pain psychologist at Oregon Health and Science University. “Relaxation and other biobehavioral techniques help kids gain a sense of control.” She tells patients, “Your pain is absolutely real, and chronic pain in particular is a neurologic problem.” She recommended TED Talks by Dr. Elliot Krane, an anesthesiologist, and Lorimer Moseley, a neuroscience professor, to help explain chronic pain. Chronic pain develops, Dr. Schechter said, when there is an underlying biological vulnerability, either inherited or resulting from stressors like infections or procedures or traumas, and then a triggering event, such as a gastrointestinal infection or an injury. © 2019 The New York Times Company

Keyword: Pain & Touch; Development of the Brain
Link ID: 25887 - Posted: 01.21.2019

Jonathan Lambert Pain is a complicated experience. Our skin and muscles sense it, just like they sense softness or warmth. But unlike other sensations, the experience of pain is distinctly unpleasant. Pain has to hurt for us to pay attention to it, and avoid hurting ourselves further. But for people in chronic pain, the pain has largely lost its purpose. It just hurts. While it has long been understood how nerves signal pain to the brain, scientists haven't known how the brain adds a layer of unpleasantness. Findings of a study published Thursday in Science offer an answer. A research team from Stanford University pinpointed the neurons in mouse brains that make pain hurt and were able to alter these neurons in a way that reduced the unpleasantness of pain without eliminating the sensation. The study lays the groundwork for future research into more targeted pain treatments. "This study is a major advance," says Irene Tracey, a pain neuroscientist at Oxford University who wasn't involved in the study. "It was a tour de force and a welcome addition to understanding this complex and major problem." Stanford neuroscientist Grégory Scherrer, who co-led the study, started the search for pain neurons in the amygdala — the slim, almond-shaped region scientists know regulates many emotions. The challenge for Scherrer was to sift through the tangle of neurons there and identify the ones associated with pain. © 2019 npr

Keyword: Pain & Touch
Link ID: 25884 - Posted: 01.19.2019

Emily Chung · CBC News · Could the pain you feel in your body be all in your head? At least some of it might be — if you're a man (or a male mouse), a new study has found. Male humans and male mice — but not females of either species — both became hypersensitive to pain when put in an environment where they had previous had a painful experience, reports a new Canadian-led study published last week in the journal Current Biology. "The sex difference was completely unexpected," said Loren Martin, the University of Toronto Mississauga assistant professor of psychology who led the study. While there was no reason to believe males and females would respond differently, if they did, he would have expected females, not males, to develop pain hypersensitivity, since they're generally more sensitive to pain and more prone to chronic pain. Martin originally ran an experiment on mice while he was a postdoctoral researcher in the lab of McGill University professor Jeffrey Mogil, who holds two research chairs related to pain. They wanted to to see how the mice would react if brought back to a place where they had had a painful experience — a 30-minute tummy ache cause by dilute vinegar in their stomachs — and whether they could be conditioned to be hypersensitive to pain. The reason they were interested is because there is growing evidence that chronic pain is linked to biochemical "rewiring" in nerves similar to what happens with the formation of memories in the brain, and may itself be akin to or linked to memory, Martin said. If that's the case, chronic pain could potentially be treated by de-rewiring the nerves back to their normal state. ©2018 CBC/Radio-Canada

Keyword: Pain & Touch; Sexual Behavior
Link ID: 25864 - Posted: 01.15.2019

By Perri Klass, M.D. Pain control in infants and children has come a long way over the past few decades. Experts know how to provide appropriate anesthesia when children need surgery and understand the ways that even very young children express distress when they’re hurting afterward. There is a lot of evidence about reducing the pain and anxiety that can accompany immunizations and blood draws, and there is increasing expertise about helping children who struggle with chronic pain. But today’s parents may be shocked to learn that was not always the case. As recently as the early 1980s, the pain of children and infants was thought to be different from that of adults and was sometimes treated differently, or sometimes not treated at all. Change doesn’t always come easily in medicine, so there’s a certain onus on parents to make sure that their children get state-of-the-art pain management around procedures, large and small. That means preparation before any planned surgery, ideally with a child life specialist, and it means careful attention to the child’s pain afterward, with parents well backed up by medical specialists. Let me start in the bad old days: About 30 years ago, when I was doing my residency, my 4-year-old son fractured his femur. After surgery, he found himself on the orthopedic ward of my very own hospital, and in a fair amount of pain (the femur is the biggest bone in the body, and there was a lot of tissue damage). As his busybody on-call pediatric resident mother, I discovered that the pain control ordered by the surgeons was “IM MSO4 PRN.” That meant he could have an intramuscular dose of morphine whenever the pain from the fracture was so bad that it overcame a 4-year-old’s fear of shots. To get pain relief, he would have to request the needle. © 2019 The New York Times Company

Keyword: Pain & Touch; Development of the Brain
Link ID: 25854 - Posted: 01.10.2019

Gently stroking a baby reduces activity in their brain associated with painful experiences, a study has found. The study, by University of Oxford and Liverpool John Moores University, monitored the brain activity of 32 babies while they had blood tests. Half were stroked with a soft brush beforehand and they showed 40% less pain activity in their brain. Author Rebeccah Slater said: "Touch seems to have analgesic potential without the risk of side-effects." The study found that the optimal pain-reducing stroking speed was about 3cm (1in) per second. "Parents intuitively stroke their babies at this optimal velocity," said Prof Slater. "If we can better understand the neurobiological underpinnings of techniques like infant massage, we can improve the advice we give to parents on how to comfort their babies." That speed of stroking activates a class of sensory neurons in the skin called C-tactile afferents, which have been previously been shown to reduce pain in adults. But it had been unclear whether babies had the same response or whether it developed over time. "There was evidence to suggest that C-tactile afferents can be activated in babies and that slow, gentle touch can evoke changes in brain activity in infants," said Prof Slater. Prof Slater said the study, published in Current Biology, could explain anecdotal evidence of the soothing power of touch-based practices such as infant massage and kangaroo care, where premature babies are held against the skin to encourage parent-infant bonding and possibly reduce pain. © 2018 BBC.

Keyword: Pain & Touch
Link ID: 25795 - Posted: 12.18.2018

By Kelly Servick If you’ve ever unwittingly grabbed a hot pan, you know our bodies have exquisite reflexes for avoiding or minimizing injuries. But once the damage is done, we also have a spontaneous urge to sooth the pain—to blow on a burned hand, cradle a broken toe, or suck on a cut finger. A new study reveals a neural circuit behind this soothing response in mice. Many common animal tests of pain don’t involve this circuit, the authors contend, which could explain why some painkillers that seem to work in mice prove ineffective in people. “We know there is not just one ‘pain pathway’ or a single brain site involved in processing pain,” says Kathleen Sluka, a neuroscientist at the University of Iowa in Iowa City, who was not involved in the new work. “Understanding the different pathways that underlie unique behaviors could one day help us to individualize treatments” for patients based on how they respond to pain. Harvard University neurobiologist Qiufu Ma and his team wanted to tease apart different aspects of pain, not just in the brain but in the neurons throughout our bodies that relay signals up the spinal cord. Ma and his collaborators previously proposed two general groups of sensory neurons: ones that project to the outermost layer of skin and ones that branch to deeper tissue throughout the body—the underlying skin layers, bones, joints, and muscles. Ma suggests the first group is a first-line defense that monitors our surroundings for danger and prompts us to pull away from a hot pan or a sharp prick. The deeper nerves, he suggests, are attuned to the lasting pain of an injury or illness—and may drive the experience of unpleasantness and distress that comes with pain. Our reflexes avoid potential harm, Ma explains; “the suffering of pain is very different.” © 2018 American Association for the Advancement of Science

Keyword: Pain & Touch
Link ID: 25774 - Posted: 12.11.2018