Chapter 8. General Principles of Sensory Processing, Touch, and Pain
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Ruth Williams Throughout the animal kingdom, there are numerous examples of neurons that respond to multiple stimuli and faithfully transmit information about those various inputs. In the mouse, for example, there are certain neurons that respond to both temperature and potentially damaging touch. In the fruit fly, there are neurons that sense light, temperature, pain, and proprioceptive stimuli—those arising as a result of body position and movement. And in C. elegans, two sensory neurons, known as PVD neurons, that run the length of the body on either side are thought to regulate proprioception as well as responses to harsh touch and cold temperature. Scientists have now figured out how a single PVD neuron can relay two different stimuli: while harsh touch results in typical firing of the neuron—an impulse that travels the length of the cell—proprioception causes a localized response in one part of the cell with no apparent involvement of the rest. The findings are reported today (November 14) in Developmental Cell. “[The] paper illustrates that different parts of the neuron do different things,” says neuroscientist Scott Emmons of Albert Einstein College of Medicine who did not participate in the research, “and that just makes the whole system much more complex to interpret,” he says. To examine how a single neuron interprets distinct inputs and drives corresponding behaviors, neuroscientist Kang Shen of Stanford University and colleagues focused on PVD neuron–regulated escape behavior when a worm is poked with a wire and the worm’s normal wiggling motion as it responds to proprioceptive stimuli. © 1986–2019 The Scientist
Keyword: Pain & Touch; Development of the Brain
Link ID: 26823 - Posted: 11.16.2019
Darian Woods Recently, Purdue Pharma filed for bankruptcy as part of a tentative multi-billion dollar settlement with state and local governments over lawsuits alleging that the company misled doctors and the public about the addictive nature of their well-known painkiller, Oxycontin. But Purdue Pharma's story is part of a pattern that has repeated itself throughout the history of the opium trade. It's a pattern documented by the book Opium: How An Ancient Flower Shaped And Poisoned Our World by Dr. John H. Halpern and David Blistein. The cycle begins when an opium product proves devastating to users. Innovators come along, promising a safer alternative, and virtually every time, they downplay the risks of addiction. Addiction ensues. Then come new innovators, promising something better and less addictive, and the cycle continues. This cycle, Halpern and Blistein recount, goes all the way back to Ancient Greece. Aulus Cornelius Celsus was a doctor famous for writing one of the world's first medical encyclopedias, which included a recipe for opium pills. He recommended it for insomnia, bad headaches, and joint pain. It didn't turn out so well. Opium addiction spread, and its victims included Roman emperor Marcus Aurelius. Around 1000 AD, Persian physician Avicenna developed standard opium doses the size of chickpeas. Dose standardization helped prevent overdoses but opium addiction rose in Persia over the following centuries. Avicenna himself died of an opium overdose. © 2019 npr
Keyword: Drug Abuse; Pain & Touch
Link ID: 26791 - Posted: 11.05.2019
Kas Roussy · CBC News · At the Toronto Rehabilitation Institute, Dr. Andrea Furlan, a pain specialist, is holding a regular meeting with some of her colleagues. Sitting around the table are physiotherapists, pharmacists, doctors and nurses. Other health-care professionals have joined in via teleconferencing. The discussion focuses on chronic pain and the role opioids have in treating the condition at a time when current prescribing guidelines in Canada advises doctors to put the prescription pad down. On a monitor, someone asks Furlan how she should start tapering her patient who is prescribed opioids. "Each patient is different," Furlan said. "I don't have a recipe for everyone. The patients are afraid of the pain getting worse. They are afraid of the withdrawal symptoms. You need to provide a lot of education." She also suggests exercise and physiotherapy — even diet and sleep can have an impact on chronic pain. One in five Canadians suffers from chronic pain (i.e., pain that is ongoing and lasts longer than six months like low back pain, nerve damage or arthritis). For these pain sufferers, opioids are a lifesaver. But access to the pain medication is getting harder because of doctors' concerns about addiction and abuse. More than 12,800 apparent opioid-related deaths occurred from January 2016 to March 2019, according to the Public Health Agency of Canada, the vast majority from illicit fentanyl use. "I have had patients referred to us because their doctors cut them from opioids," said Furlan. "That's ridiculous because they were not addicted. They were not having any complications. They were not on a high dose." ©2019 CBC/Radio-Canada
Keyword: Pain & Touch; Drug Abuse
Link ID: 26786 - Posted: 11.04.2019
By Aimee Cunningham At age 37, Hope Hartman developed a painful, burning rash in her right ear, in the part “you would clean with a Q-tip,” the Denver resident says. The pain got so bad she went to a local emergency room, where the staff was flummoxed. Hartman was admitted to the hospital, where she started to lose sensation on the right side of her face. During that 2013 health crisis, Hartman’s husband, Mike, sent a picture of the ear to his mom, a nurse. She said it looked like zoster, better known as shingles, which is caused by the varicella zoster virus. She “diagnosed it from an iPhone photo,” Hartman recalls. Antiviral treatment didn’t fully clear the infection. For about two weeks after her release from the hospital, Hartman coped with severe pain, hearing loss and difficulty eating. Her right eye wouldn’t fully open or close. Following an appointment with neurologist Maria Nagel of the University of Colorado School of Medicine in Aurora, Hartman was admitted to the university’s hospital to get another antiviral drug intravenously. The pain subsided, and Hartman regained her hearing and the feeling in her face. To spare others the same trauma of a delayed diagnosis, Hartman arranged for Nagel to give a talk on the virus at the local hospital where staff missed the signs of the illness, known as Ramsay Hunt syndrome. That’s the name for a shingles infection that strikes the facial nerve important to facial movement. As Hartman experienced, varicella zoster virus can cause a grab bag of symptoms that go beyond the typical torso rash. Hartman’s young age didn’t help with the diagnosis. Shingles is more common in people 50 and older. But no one is risk-free. Varicella zoster virus lives in about 95 percent of the U.S. adult population, thanks to the virus’s first line of attack: chicken pox. The body eventually clears the itchy, red pox from the skin, but the virus remains, dormant in nerve cells. The rash kept scores of U.S. children home from school until about 1995 (when a vaccine became available). © Society for Science & the Public 2000–2019.
Keyword: Pain & Touch
Link ID: 26773 - Posted: 10.31.2019
People with long-term health problems such as arthritis are more likely to feel pain on humid days, a study has suggested. Folklore suggests the cold makes pain worse - but there is actually little research into the weather's effects. And this University of Manchester study of 2,500 people, which collected data via smartphones, found symptoms were actually worse on warmer, damper days. Researchers hope the findings will steer future research into why that is. Hearing someone say their knee is playing up because of the weather is pretty common - usually because of the cold, Some say they can even predict the weather based on how their joints feel. But carrying out scientific research into how different types of weather affect pain has been difficult. Previous studies have been small, or short-term. In this research, called Cloudy with a Chance of Pain, scientists recruited 2,500 people with arthritis, fibromyalgia, migraine and neuropathic pain from across the UK. They recorded pain symptoms each day, for between one and 15 months, while their phones recorded the weather where they were. Damp and windy days with low pressure increased the chances of experiencing more pain than normal by about 20%. So if someone's chances of a painful day with average weather were five in 100, they would increase to six in 100 on a damp and windy day. Cold, damp days also made pain worse. But there was no association with temperature alone, or rainfall. 'Pain forecast' Prof Will Dixon, of the Centre for Epidemiology Versus Arthritis, at the University of Manchester, who led the study said: "Weather has been thought to affect symptoms in patients with arthritis since [ancient Greek physician] Hippocrates. © 2019 BBC
Keyword: Pain & Touch
Link ID: 26746 - Posted: 10.24.2019
Will Stone & Allison Aubrey There's no doubt that opioids have been massively overprescribed in U.S. In the haste to address the epidemic, there's been pressure on doctors to reduce prescriptions of these drugs — and in fact prescriptions are declining. But along the way, some chronic pain patients have been forced to rapidly taper or discontinue the drugs altogether. Now, the U.S. Department of Health and Human Services has a new message for doctors: Abrupt changes to a patient's opioid prescription could harm them. On Thursday, the agency issued new guidelines for physicians on how best to manage opioid prescriptions. They recommend a deliberate approach to lowering doses for chronic pain patients who have been on long-term opioid therapy. "It must be done slowly and carefully," says Adm. Brett P. Giroir, MD, assistant secretary for health for HHS. "If opioids are going to be reduced in a chronic patient it really needs to be done in a patient-centered, compassionate, guided way." This is a course correction of sorts. In 2016, the Centers for Disease Control and Prevention issued prescribing guidelines. Those highlighted the risks of addiction and overdose and encouraged providers to lower doses when possible. In response, many doctors began to limit their pain pill prescriptions, and in some cases cut patients off. These guidelines led to rigid rules in some cases. Giroir says it's concerning that some clinicians, policymakers, and health systems are "interpreting guidelines as mandates." © 2019 npr
Keyword: Pain & Touch; Drug Abuse
Link ID: 26691 - Posted: 10.11.2019
By Jane E. Brody My grandson Stefan was about 8 years old when he began to get migraine headaches. As soon as he could after getting home from school, he would lie down and go to sleep, awakening an hour or two later, usually with the headache gone. But before the pain abated, he sometimes vomited, prompting him and his relatives to keep barf bags handy at all times. Then as Stefan approached puberty, these debilitating headaches stopped as mysteriously as they had begun. Though Stefan’s headaches were disruptive and disabling, he was luckier than his grandma. My migraine attacks (misdiagnosed as sinus headaches) began around puberty, usually occurred three times a month, each lasting for three days, and didn’t end until menopause. Even though sleep can often terminate a migraine attack, nothing I tried brought relief, and there were no prescription medications at the time to treat or prevent them. Attention parents, teachers, coaches, doctors and anyone else who interacts with children and teens: Too often, adults tell them to “suck it up, it’s just a headache.” A migraine is not “just a headache,” nor is it something they can ignore. A migraine makes you feel sick all over, often acutely sensitive to light and noise, nauseated and unable to concentrate on anything but the desire for relief. Very young children with migraine may be spared the head pain and instead get only gastrointestinal symptoms like vomiting and stomach pain. Migraine is a disease with a genetic component and often runs in families. The pounding, nauseating headache is a symptom of that disease. Before puberty, the disorder affects boys and girls equally, but after puberty, when testosterone kicks in to suppress migraine attacks in boys, the incidence among girls becomes very much higher. © 2019 The New York Times Company
Keyword: Pain & Touch
Link ID: 26674 - Posted: 10.07.2019
Katarina Zimmer Several recent studies in high-profile journals reported to have genetically engineered neurons to become responsive to magnetic fields. In doing so, the authors could remotely control the activity of particular neurons in the brain, and even animal behavior—promising huge advances in neuroscientific research and speculation for applications even in medicine. “We envision a new age of magnetogenetics is coming,” one 2015 study read. But now, two independent teams of scientists bring those results into question. In studies recently posted as preprints to bioRxiv, the researchers couldn’t replicate those earlier findings. “Both studies . . . appear quite meticulously executed from a biological standpoint—multiple tests were performed across multiple biological testbeds,” writes Polina Anikeeva, a materials and cognitive scientist at MIT, to The Scientist in an email. “I applaud the authors for investing their valuable time and resources into trying to reproduce the results of their colleagues.” The promise of magnetogenetics Being able to use small-scale magnetic fields to control cells or entire organisms would have enormous potential for research and medical therapies. It would be a less invasive method than optogenetics, which requires the insertion of optical fibers to transmit light pulses to specific groups of neurons, and would provide a more rapid means of inducing neural activity than chemogenetics, which sparks biochemical reactions that can take several seconds to stimulate neurons. © 1986–2019 The Scientist
Keyword: Pain & Touch; Brain imaging
Link ID: 26642 - Posted: 09.24.2019
Alex Smith Lori Pinkley, a 50-year-old from Kansas City, Mo., has struggled with puzzling chronic pain since she was 15. She's had endless disappointing visits with doctors. Some said they couldn't help her. Others diagnosed her with everything from fibromyalgia to lipedema to the rare Ehlers-Danlos syndrome. Pinkley has taken opioids a few times after surgeries but says they never helped her underlying pain. "I hate opioids with a passion," Pinkley says. "An absolute passion." Recently, she joined a growing group of patients using an outside-the-box remedy: naltrexone. It is usually used to treat addiction, in a pill form for alcohol and as a pill or a monthly shot for opioids. As the medical establishment tries to do a huge U-turn after two disastrous decades of pushing long-term opioid use for chronic pain, scientists have been struggling to develop safe, effective alternatives. When naltrexone is used to treat addiction in pill form, it's prescribed at 50 mg, but chronic-pain patients say it helps their pain at doses of less than a tenth of that. Low-dose naltrexone has lurked for years on the fringes of medicine, but its zealous advocates worry that it may be stuck there. Naltrexone, which can be produced generically, is not even manufactured at the low doses that seem to be best for pain patients. Instead, patients go to compounding pharmacies or resort to DIY methods — YouTube videos and online support groups show people how to turn 50 mg pills into a low liquid dose. Some doctors prescribe it off-label even though it's not FDA-approved for pain. © 2019 npr
Keyword: Pain & Touch; Drug Abuse
Link ID: 26641 - Posted: 09.24.2019
Patti Neighmond For people who live with chronic pain, getting up, out and moving can seem daunting. Some fear that physical activity will make their pain worse. But in fact, researchers find the opposite is true: The right kind of exercise can help reduce pain. Today, Emma Dehne agrees. Dehne is 44, lives in Chapel Hill, N.C., and works as a business officer in the office of the executive vice chancellor at the University of North Carolina. She says her commitment to exercise is relatively recent. Just a year and a half ago, Dehne pretty much avoided any physical movement she didn't have to make. Just climbing stairs was painful — "sometimes to the point where I would have to hold on to the banister to help myself up," she says, "and I couldn't even extend my leg." At times, it felt as though the ligaments in her knees "were tearing." Dehne was diagnosed around age 40 with osteoarthritis in both knees, a painful swelling and deterioration of the cushioning cartilage in those joints that reduces their range of motion. Luckily for her, she says, she worked at the Thurston Arthritis Research Center at the University of North Carolina. The woman working in the cubicle next to hers ran a program that encouraged people with osteoarthritis to start walking to help reduce their pain. Dehne was skeptical but felt she was just too young to be burdened by this disease; she agreed to give brisk walks a try. In the beginning she felt stiff, tired and out of breath. That changed quickly. © 2019 npr
Keyword: Pain & Touch
Link ID: 26635 - Posted: 09.23.2019
Shawna Williams Pain, unpleasant though it may be, is essential to most mammals’ survival, a warning to back off before we lose a limb or worsen a wound. So it was curious when, in a 2008 study, molecular physiologist Gary Lewin and his colleagues found that, unlike most mammals, naked mole rats (Heterocephalus glaber) didn’t lick or flick a limb that had been injected with a small amount of capsaicin—the hot in hot chili pepper. The mole rats turned out to be similarly nonchalant when exposed to dilute hydrochloric acid. “We wondered, first of all, how they became insensitive to these things,” says Lewin, who heads up a lab at Berlin’s Max Delbrück Center for Molecular Medicine. The team took an evolutionary approach to finding the answer. Several group members traveled to the naked mole rat’s native territory of East Africa to try out three common pain-causing substances on seven other mole rat species, plus the more distantly related East African root rat. They found that, in addition to the naked mole rat, the Natal mole rat was insensitive to capsaicin, while the Cape mole rat and the root rat didn’t seem to feel a burn from the hydrochloric acid. Most startlingly, one species, the highveld mole rat (Cryptomys hottentotus pretoriae), didn’t flinch when injected with a few milliliters of a highly diluted solution of an irritant present in mustard and wasabi known as AITC—an agent that even the naked mole rat reacted to. When team member Karlien Debus donned a gas mask to inject a similar amount of 100 percent AITC under the skin of a highveld mole rat, there was still no response. “Probably the AITC was the most interesting because AITC is a substance that actually every [other] animal in the entire animal kingdom avoids,” Lewin says. An electrophilic compound, AITC can crosslink an animal’s proteins and damage its cells. © 1986–2019 The Scientist.
Keyword: Pain & Touch; Evolution
Link ID: 26623 - Posted: 09.19.2019
By Laura Sanders Two artists who paint with their toes have unusual neural footprints in their brains. Individual toes each take over discrete territory, creating a well-organized “toe map,” researchers report September 10 in Cell Reports. Similar brain organization isn’t thought to exist in people with typical toe dexterity. So finding these specialized maps brings scientists closer to understanding how the human brain senses the body, even when body designs differ (SN: 6/12/19). “Sometimes, having the unusual case — even the very rare one — might give you important insight into how things work,” says neuroscientist Denis Schluppeck of the University of Nottingham in England, who was not involved in the study. The skills of the two artists included in the study are certainly rare. Both were born without arms due to the drug thalidomide, formerly used to treat morning sickness in pregnant women. As a result, both men rely heavily on their feet, which possess the dexterity to eat with cutlery, write and use computers. The brain carries a map of areas that handle sensations from different body parts; sensitive fingers and lips, for example, have big corresponding areas. But so far, scientists haven’t had much luck in pinpointing areas of the human brain that respond to individual toes (although toe regions have been found in the brains of nonhuman primates). But because these men use their feet in unusually skilled ways, researchers wondered if their brains might represent toes a bit differently. The two artists, along with nine other people with no special foot abilities, underwent functional MRI scans while an experimenter gently touched each toe. For many people, the brain areas that correspond to individual toes aren’t discrete, says neuroscientist Daan Wesselink of University College London. But in the foot artists’ brains, “we found very distinct locations for each of their toes.” When each toe was touched, a patch of brain became active, linking neighboring toes to similarly neighboring areas of the brain. © Society for Science & the Public 2000–2019
Keyword: Pain & Touch; Brain imaging
Link ID: 26601 - Posted: 09.11.2019
Giorgia Guglielmi People who have low-risk surgery in Canada and the United States fill prescriptions for opioid painkillers at nearly seven times the rate seen in Sweden, according to recent research1. Studying these differences could help nations such as the United States to develop prescribing guidelines to counteract the surge in opioid use that is devastating some communities, say the study authors. The findings, which are published on 4 September in JAMA Network Open, are the first to quantify the differences in opioid use for people who had similar types of surgery across countries. There’s anecdotal evidence that clinicians tend to prescribe more opioids after surgery in some countries than in others, says Mark Neuman, an anaesthesiologist at the University of Pennsylvania in Philadelphia, who led the study. And over-prescription of opioids is associated with an increased risk of developing long-term dependence and addiction, he says. To investigate further, Neuman and his team gathered prescription data from between 2013 and 2016 from Canada, the United States and Sweden. The countries all have similar levels of surgical care as well as detailed data on opioid prescriptions. The team found that nearly 79% of people in Canada and about 76% of those in the United States who had one of 4 operations — and who filled their opioid prescriptions — did so within 7 days of leaving hospital, compared with 11% of people in Sweden (see ‘Painkiller prescriptions’). “That’s a striking difference,” says Gabriel Brat, a surgeon at Beth Israel Deaconess Medical Center in Boston, Massachusetts. The procedures were removals of the gallbladder, appendix, breast lumps or meniscus cartilage in the knee. © 2019 Springer Nature Publishing AG
Keyword: Drug Abuse; Pain & Touch
Link ID: 26590 - Posted: 09.09.2019
Patti Neighmond The pathway to opioid abuse for women often starts with a prescription from the doctor's office. One reason is that women are more likely than men to seek help for pain. Pain researchers say that not only do women suffer more painful conditions, they actually perceive pain more intensely than men do. "The burden of pain is substantially greater for women than men," says researcher and psychologist Roger Fillingim, "and that led pain researchers like myself to wonder if the pain perception system is different in women than in men." For more than two decades, Fillingim has been studying gender differences and pain, most recently at the University of Florida's Pain Research and Intervention Center of Excellence, where he is director. He recruits healthy male and female volunteers to take part in experimental pain sessions using various painful stimuli, including pressure, heat, cold and electrical stimulation. Probes are typically applied to the hand or arm. As intensity of the stimuli is increased, volunteers are asked to rate their pain on a scale of zero to 10, where zero is no pain and 10 is the most intense pain one can imagine. If volunteers report pain levels at 10, Fillingim stops the experiment immediately. "On average, women report the same stimuli to be more painful than men," Fillingim says, emphasizing that the same stimulus is applied to everybody, so if there are differences in how painful the experience is, it can't be because of the stimulus because it's calibrated to be the same for all. © 2019 npr
Keyword: Pain & Touch; Sexual Behavior
Link ID: 26546 - Posted: 08.27.2019
/ By Lola Butcher Like all primary care physicians, Danielle Ofri sees a lot of aching backs. Low back pain is one of the top five reasons people visit the doctor, and based on extensive experience, Ofri knows how the conversations will go. Patients want relief from miserable pain, so they want an imaging study. “I want to see what’s going on — that’s what they say,” says Ofri, who treats patients at Bellevue Hospital in Manhattan. The easy thing to do is order a scan and send them home to wait for the results. The right thing to do, in the vast majority of cases, is to deliver the bad news: They need to wait for the pain to subside on its own, which may mean a few weeks of agony. In the meantime, if possible, it’s best to stay active and limit bed rest. An over-the-counter pain reliever might help. Unless certain symptoms point to a more serious problem, the physician shouldn’t order any imaging within the first six weeks of pain. On this last point, medical guidelines are remarkably clear and backed by studies demonstrating that routine imaging for low back pain does not improve one’s pain, function, or quality of life. The exams are not just a waste of time and money, physician groups say; unnecessary imaging may lead to problems that are much more serious than back pain. And yet, between 1995 and 2015, magnetic resonance imaging (MRI) and other high-tech scans for low back pain increased by 50 percent, according to a new systematic review published in the British Journal of Sports Medicine. According to a related analysis, up to 35 percent of the scans were inappropriate. Medical societies have launched campaigns to convince physicians and patients to forgo the unnecessary images, but to little avail. Copyright 2019 Undark
Keyword: Pain & Touch; Brain imaging
Link ID: 26540 - Posted: 08.26.2019
Scott Hensley At some point nearly everyone has to deal with pain. How do Americans experience and cope with pain that makes everyday life harder? We asked in the latest NPR-IBM Watson Health Poll. First, we wanted to know how often pain interferes with people's ability to work, go to school or engage in other activities. Overall, 18% of Americans say that's often a problem for them. Almost a quarter – 24% — say it's sometimes the case. The degree to which pain is a problem varies by age, with 22% of people 65 and older saying pain interferes often with their daily lives compared with only about 9% of people 35 and younger. Once pain strikes, how do people deal with it? The poll found that 63% of people had sought care for their pain and 37% hadn't. Younger people were less likely to have pursued care. The most common approach is an over-the-counter pain reliever. Sixty percent of people said that is something they do. Another popular choice, particularly among younger people, is exercise, including stretching and yoga. Forty percent of those under 35 say exercise is a way they seek relief. Only 11% of people 65 and older say exercise is something they try for pain. Overall, 26% of people see exercise as helpful for their pain. That level of exercise is "really exciting to see," says Brett Snodgrass, a nurse practitioner and clinical coordinator of palliative medicine at Baptist Health Systems in Memphis, Tenn. In her experience, not nearly as many people were doing that, even a few years ago. © 2019 npr
Keyword: Pain & Touch; Drug Abuse
Link ID: 26532 - Posted: 08.23.2019
Nicola Davis A new organ involved in the sensation of pain has been discovered by scientists, raising hopes that it could lead to the development of new painkilling drugs. Researchers say they have discovered that the special cells that surround the pain-sensing nerve cells that extend into the outer layer of skin appear to be involved in sensing pain – a discovery that points to a new organ behind the feeling of “ouch!”. The scientists say the finding offers new insight into pain and could help answer longstanding conundrums. “The major question for us now is whether these cells are actually the cause for certain kinds of chronic pain disorders,” Prof Patrik Ernfors, a co-author of the research from the Karolinska Institute in Sweden, told the Guardian. Writing in the journal Science, the researchers reveal how they examined the nature of cells in the skin that, they say, have largely been overlooked. These are a type of Schwann cell, which wrap around and engulf nerve cells and help to keep them alive. The study has revealed these Schwann cells have an octopus-like shape. After examining tissues, the team found the body of the cells sits below the outer layer of the skin, but that the cells have long extensions that wrap around the ends of pain-sensing nerve cells that extend up into the epidermis, the outer layer of the skin. The scientists were surprised at the findings because it has long been believed that the endings of nerve cells in the epidermis were bare or unwrapped. “In the pain field, we talk about free nerve endings that are responsible for pain sensation. But actually they are not free,” Ernfors said. © 2019 Guardian News & Media Limited
Keyword: Pain & Touch; Glia
Link ID: 26507 - Posted: 08.16.2019
By Sandra G. Boodman Galen Warden was lying in a hot bath after a punishing week at her demanding marketing job. Her neck and shoulders were, as usual, in knots, so Warden thought she’d expedite the relaxation that a restorative soak usually delivered by sliding under the water. When she sat up about 30 seconds later, Warden recalled, “it felt like my entire scalp was on fire.” Her face, neck and shoulders were unaffected, but her scalp felt as though it had been doused with acid. It would take nearly three months before the cause of Warden’s unusual symptom, which was repeatedly attributed to a tension headache, was revealed. During that time, the emergence of other symptoms failed to prompt the specialist treating her to reconsider her initial diagnosis. If anything, the new problems seemed to harden the doctor’s conviction that Warden’s problem was stress-related. Looking back, Warden said she is struck by what she characterizes as her medical naivete. "It's been a cautionary tale for my friends," she said. "I can't believe I kept going back to a well that was dry." Shocked by the fiery sensation engulfing her scalp, Warden turned on the shower and ran cool water over her head, frantically trying to think about what might have triggered it. She hadn’t rubbed her scalp hard or used a different shampoo or bath product. © 1996-2019 The Washington Post
Keyword: Pain & Touch
Link ID: 26485 - Posted: 08.12.2019
Anna Ploszajski A man who lost his hand 17 years ago has been given the sense of touch through a brain-controlled robotic prosthetic. Keven Walgamott, whose arm was amputated below the elbow after an accident, can now feel 119 different touch sensations through the prosthetic as if it were his own limb. He is able to distinguish between large, small, soft and hard objects when blindfolded, and handle delicate objects such as grapes and eggs. Everyday tasks such as putting on his wedding ring, peeling a banana or holding a mobile phone are now possible. “The most amazing thing for me is what the team was able to do,” said Walgamott. “[They] take a bunch of mechanical pieces and provide, through a computer, not only the ability to move all fingers and grasp things but be able to feel again.” The prosthetic hand and wrist has been in development for 15 years. Electrodes were implanted in the remaining part of his arm, allowing communication between the prosthetic hand and his brain. The hand can move in six directions and is equipped with 19 sensors that detect touch and positioning. The arrays interpret the signals Walgamott’s brain sends to his arm nerves, and a computer outside the body translates these into digital information, which then instructs the prosthetic to move as the wearer intends. They also provide Walgamott’s nerves with computer-generated touch signals from the prosthesis, which are then interpreted by his brain. © 2019 Guardian News & Media Limited
Keyword: Pain & Touch; Robotics
Link ID: 26449 - Posted: 07.25.2019
Shuai Xu, Arun Jayaraman and John A. Rogers. Thin, soft electronic systems that stick onto skin are beginning to transform health care. Millions of early versions1 of sensors, computers and transmitters woven into flexible films, patches, bandages or tattoos are being deployed in dozens of trials in neurology applications alone2; and their numbers growing rapidly. Within a decade, many people will wear such sensors all the time. The data they collect will be fed into machine-learning algorithms to monitor vital signs, spot abnormalities and track treatments. Medical problems will be revealed earlier. Doctors will monitor their patients’ recovery remotely while the patient is at home, and intervene if their condition deteriorates. Epidemic spikes will be flagged quickly, allowing authorities to mobilize resources, identify vulnerable populations and monitor the safety and efficacy of drugs issued. All of this will make health care more predictive, safe and efficient. Where are we now? The first generation of biointegrated sensors can track biophysical signals, such as cardiac rhythms, breathing, temperature and motion3. More advanced systems are emerging that can track certain biomarkers (such as glucose) as well as actions such as swallowing and speech. Small companies are commercializing soft biosensor systems that measure clinical data continuously. These include Vital Connect in San Jose, California; iRhythm in San Francisco, California; MC10 in Lexington, Massachusetts; and Sibel Health in Evanston, Illinois. For example, iRhythm’s single-use Zio patch monitors electrical pulses from the heart for 14 days, and is more effective than intermittent hospital check-ups at detecting abnormal rhythms4. But it is bulky and temporary, and the data must be downloaded after use, rather than transmitted in real time.
Keyword: Pain & Touch; Robotics
Link ID: 26425 - Posted: 07.18.2019