Wednesday, December 26, 2012
"Our results suggest the importance of adequate sleep in various chronic pain conditions or in preparation for elective surgical procedures," said lead author Timothy Roehrs, PhD, of the Sleep Disorders and Research Center at Henry Ford Hospital in Detroit.
The small study by researchers at Henry Ford and Wayne State University involved 18 healthy, pain-free, and tired volunteers. They were randomly assigned to either four nights of their usual amount of sleep or an extended sleep period of 10 hours in bed per night.
The extended sleep group slept an average of 1.8 hours more per night. The added sleep not only increased their daytime alertness, it also reduced their sensitivity to pain in a heat test.
The well-rested group kept their finger on a radiant heat source 25 percent longer than the control group; even though the control group was given a 60 mg dose of codeine to dull their pain.
"We were surprised by the magnitude of the reduction in pain sensitivity, when compared to the reduction produced by taking codeine," said Roehers.
In the 1960s, average sleep duration was estimated to be about 8 hours a day; whereas by 2005 it was 7 hours or less. A recent national survey reported that 21% of the population slept 6 hours or less a day.
Researchers say a number of factors are contributing to this trend, including 24 hour access to entertainment, social and family responsibilities, time spent commuting, and around-the-clock demand for commercial services that require working overnight. By some estimates, up to 25 percent of the population suffers from sleep deprivation.
While some sleep disorders, such as obstructive sleep apnea and narcolepsy, stem from physiological conditions, for most people sleepiness is due to insufficient time in bed and reduced sleep time.
What's important, according to Roehrs, is that many of the medical problems caused by lack of sleep are reversible, and can be accomplished in a short period of time.
"The results of the current study indicate that a relatively short bedtime extension, four nights, is sufficient to provide benefit for alertness and pain sensitivity for individuals with this level of excessive sleepiness," he said.
Roehrs says this is the first study to show that extended sleep in mildly sleep deprived volunteers reduces their pain sensitivity. He adds that the results, combined with data from previous research, indicate that increased pain sensitivity in sleepy individuals is the result of their underlying sleepiness.
The study appears in the December issue of the peer-review, scientific journal SLEEP, which is published online by the Associated Professional Sleep Societies LLC, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.
Monday, December 24, 2012
TWO WEEKS INTO Ted Kaptchuk's first randomized clinical drug trial, nearly a third of his 270 subjects complained of awful side effects. All the patients had joined the study hoping to alleviate severe arm pain: carpal tunnel, tendinitis, chronic pain in the elbow, shoulder, wrist. In one part of the study, half the subjects received pain-reducing pills; the others were offered acupuncture treatments. And in both cases, people began to call in, saying they couldn't get out of bed. The pills were making them sluggish, the needles caused swelling and redness; some patients' pain ballooned to nightmarish levels. "The side effects were simply amazing," Kaptchuk explains; curiously, they were exactly what patients had been warned their treatment might produce. But even more astounding, most of the other patients reported real relief, and those who received acupuncture felt even better than those on the anti-pain pill. These were exceptional findings: no one had ever proven that acupuncture worked better than painkillers. But Kaptchuk's study didn't prove it, either. The pills his team had given patients were actually made of cornstarch; the "acupuncture" needles were retractable shams that never pierced the skin. The study wasn't aimed at comparing two treatments. It was designed to compare two fakes.
Although Kaptchuk, an associate professor of medicine, has spent his career studying these mysterious human reactions, he doesn't argue that you can simply "think yourself better." "Sham treatment won't shrink tumors or cure viruses," he says.
But researchers have found that placebo treatments—interventions with no active drug ingredients—can stimulate real physiological responses, from changes in heart rate and blood pressure to chemical activity in the brain, in cases involving pain, depression, anxiety, fatigue, and even some symptoms of Parkinson's.
The challenge now, says Kaptchuk, is to uncover the mechanisms behind these physiological responses—what is happening in our bodies, in our brains, in the method of placebo delivery (pill or needle, for example), even in the room where placebo treatments are administered (are the physical surroundings calming? is the doctor caring or curt?). The placebo effect is actually many effects woven together—some stronger than others—and that's what Kaptchuk hopes his "pill versus needle" study shows. The experiment, among the first to tease apart the components of placebo response, shows that the methods of placebo administration are as important as the administration itself, he explains. It's valuable insight for any caregiver: patients' perceptions matter, and the ways physicians frame perceptions can have significant effects on their patients' health.
For the last 15 years, Kaptchuk and fellow researchers have been dissecting placebo interventions—treatments that, prior to the 1990s, had been studied largely as foils to "real" drugs. To prove amedicine is effective, pharmaceutical companies must show not only that their drug has the desired effects, but that the effects are significantly greater than those of a placebo control group. Both groups often show healing results, Kaptchuk explains, yet for years, "We were struggling to increase drug effects while no one was trying to increase the placebo effect."
Last year, he and colleagues from several Harvard-affiliated hospitals created the Program in Placebo Studies and the Therapeutic Encounter (PiPS), headquartered at Beth Israel Deaconess Medical Center—the only multidisciplinary institute dedicated solely to placebo study. It's a nod to changing attitudes in Western medicine, and a direct result of the small but growing group of researchers like Kaptchuk who study not if, but how, placebo effects work. Explanations for the phenomenon come from fields across the scientific map—clinical science, psychology, anthropology, biology, social economics, neuroscience. Disregarding the knowledge that placebo treatments can affect certain ailments, Kaptchuk says, "is like ignoring a huge chunk of healthcare." As caregivers, "we should be using every tool in the box."
WESTERN MEDICINE, however, has been slow to agree with him—partly because of his message, and in his case, often because of the messenger. An acupuncturist by training, he is an unlikely leader in the halls of academia. With a degree in Chinese medicine from an institute in Macao, Kaptchuk is one of the few faculty members at Harvard Medical School (HMS) with neither a Ph.D. nor M.D.—"a debit, not a credit at most medical schools," says Finland professor of clinical pharmacology emeritus Peter Goldman, one of his early Harvard advisers. (Kaptchuk's diploma is recognized as a doctorate in many states, but not in Massachusetts.) When Kaptchuk came to Harvard in 1995, "he knew about Chinese herbs and healing needles, and he'd written a very fine book on Chinese medicine [The Web That Has No Weaver (1983)]," says Goldman, "but he didn't know the first thing about how to conduct clinical studies."
Kaptchuk joined the faculty as an instructor in medicine and apprenticed himself to several seasoned clinicians and investigators. Within a few years, he was winning National Institutes of Health grants and publishing in medicine's top journals. "What his colleagues saw was a fierce intellect and curiosity," said Goldman. "He was asking questions no one was asking."
Ironically, says Kaptchuk, it was his success as an acupuncturist that made him leave the profession for academia. "Patients who came to me got better," he says, but sometimes their relief began even before he'd started his treatments. He didn't doubt the value of acupuncture, but he suspected something else was at work. His hunch was that it was his engagement with patients—and perhaps even the act of caring itself.
For his ideas to gain traction with Western doctors, however, Kaptchuk knew he needed scientific proof. His chance would come in the early 2000s in a collaboration with gastroenterologists studying irritable bowel syndrome (IBS), a chronic gastrointestinal disorder accompanied by pain and constipation. The experiment split 262 adults with IBS into three groups: a no-treatment control group, told they were on a waiting list for treatment; a second group who received sham acupuncture without much interaction with the practitioner; and a third group who received sham acupuncture with great attention lavished upon them—at least 20 minutes of what Kaptchuk describes as "very schmaltzy" care ("I'm so glad to meet you"; "I know how difficult this is for you"; "This treatment has excellent results"). Practitioners were also required to touch the hands or shoulders of members of the third group and spend at least 20 seconds lost in thoughtful silence.
The results were not surprising: the patients who experienced the greatest relief were those who received the most care. But in an age of rushed doctor's visits and packed waiting rooms, it was the first study to show a "dose-dependent response" for a placebo: the more care people got—even if it was fake—the better they tended to fare.
Kaptchuk's innovative studies were among the first to separate components of the placebo effect, explains Applebaum professor of medicine Russell Phillips, director of the Center for Primary Care at HMS. For years, doctor-patient interactions were lumped into a generic "placebo response": a sum of such variables as patients' reporting bias (a conscious or unconscious desire to please the researchers); patients simply responding to doctors' attention; the different methods of placebo delivery; and symptoms subsiding without treatment—the inevitable trajectory of most chronic ailments. "There was simply no way to quantify the ritual of medicine," says Phillips of the doctor-patient interaction. And the ritual, he adds, is the one finding from placebo research that doctors can apply to their practice immediately.
But other placebo treatments (sham acupuncture, pills, or other fake interventions) are nowhere near ready for clinical application—and Kaptchuk is not recommending that they should be. Such treatments all require deception on the part of doctors, an aspect of placebo medicine that raises serious ethical questions for practitioners.
This was disturbing for Kaptchuk, too; deception played no role in his own success as a healer. But years of considering the question led him to his next clinical experiment: What if he simply told people they were taking placebos? The question ultimately inspired a pilot study, published by the peer-reviewed science and medicine journal PLOS ONE in 2010, that yielded his most famous findings to date. His team again compared two groups of IBS sufferers. One group received no treatment. The other patients were told they'd be taking fake, inert drugs (delivered in bottles labeled "placebo pills") and told also that placebos often have healing effects.
The study's results shocked the investigators themselves: even patients who knewthey were taking placebos described real improvement, reporting twice as much symptom relief as the no-treatment group. That's a difference so significant, says Kaptchuk, it's comparable to the improvement seen in trials for the best real IBS drugs.
ALTHOUGH this IBS "open-label" study was small and has yet to be replicated, fellow placebo researcher Frank Miller of the department of bioethics at the National Institutes of Health considers it a significant step toward legitimizing placebo studies. But to really change minds in mainstream medicine, Miller says, researchers have to show biological evidence that minds actually change—a feat achieved only in the last decade through imaging technology such as positron emission tomography (PET) scans and functional magnetic resonance imaging (fMRI).
The first evidence of a physiological basis for the placebo effect appeared in the late 1970s, when researchers studying dental patients found that by chemically blocking the release of endorphins—the brain's natural pain relievers—scientists could also block the placebo effect. This suggested that placebo treatments spurred chemical responses in the brain that are similar to those of active drugs, a theory borne out two decades later by brain-scan technology. Researchers like neuroscientist Fabrizio Benedetti at the University of Turin have since shown that many neurotransmitters are at work—including chemicals that use the same pathways as opium and marijuana. Studies by other researchers have shown that placebos increase dopamine (a chemical that affects emotions and sensations of pleasure and reward) in the brains of Parkinson's patients, and patients suffering from depression who've been given placebos reveal changes in electrical and metabolic activity in several different regions of the brain.
Kaptchuk's team has investigated the neural mechanisms of placebos in collaboration with the Martinos Center for Biomedical Imaging at Massachusetts General Hospital. In two fMRI studies published in the Journal of Neuroscience in 2006 and 2008, they showed that placebo treatments affect the areas of the brain that modulate pain reception, as do negative side effects from placebo treatment—"nocebo effects." (Nocebo is Latin for "I shall harm"; placebo means "I shall please.") But nocebo effects also activate the hippocampus, a different area associated with memory and anxiety. As happened with Kaptchuk's patients in the "pill versus needle" study, the headaches, nausea, insomnia, and fatigue that result from fake treatments can be painfully real, afflicting about a quarter of those assigned to placebo treatment in drug trials(see "The Nocebo Effect," May-June 2005). "What we 'placebo neuroscientists'…have learned [is] that therapeutic rituals move a lot of molecules in the patients' brain, and these molecules are the very same as those activated by the drugs we give in routine clinical practice," Benedetti wrote in an e-mail. "In other words, rituals and drugs use the very same biochemical pathways to influence the patient's brain." It's those advances in "hard science," he added, that have given placebo research a legitimacy it never enjoyed before.
This new visibility has encouraged not only research funds but also interest from healthcare organizations and pharmaceutical companies. As healthcare companies increasingly reward doctors for maintaining patients' health (rather than for the number of procedures they perform), "research like Ted's becomes increasingly relevant," says Minot professor of medicine and HMS dean for graduate education David Golan, a professor of biological chemistry and molecular pharmacology.
This year, the Robert Wood Johnson Foundation, the nation's largest philanthropy focused on health and healthcare, awarded Kaptchuk's PiPS program a $250,000 grant to support a series of seminars at Harvard designed to connect placebo experts with researchers in related fields. And the latest findings to emerge from PiPS—a 2012 study showing that genetic variations may explain why only certain people respond to placebo effects—has caught the attention of the Food and Drug Administration.
That study, published last October in PLOS ONE, showed that patients with a certain variation of a gene linked to the release of dopamine were more likely to respond to sham acupuncture than patients with a different variation—findings that could change the way pharmaceutical companies conduct drug trials, says Gunther Winkler, principal of ASPB Consulting, LLC, which advises biotech and pharmaceutical firms. Companies spend millions of dollars and often decades testing drugs; every drug must outperform placebos if it is to be marketed. "If we can identify people who have a low predisposition for placebo response, drug companies can preselect for them," says Winkler. "This could seriously reduce the size, cost, and duration of clinical trials…bringing cheaper drugs to the market years earlier than before."
NOT ALL OF Kaptchuk's studies have been so warmly received. Though few academics quarrel with the quality of his research, he's remained a prime target for such watchdog groups as Quackwatch and The Skeptics' Society, organizations that question nonconventional medical approaches. (Other well-known targets include Deepak Chopra, Andrew Weil '63, M.D. '68, and the late Nobel Prize winner Linus Pauling.) In 2011, he and a team of researchers published a paper in The New England Journal of Medicine (NEJM) that raised the hackles of some of his fiercest critics.
That paper (praised by scholars as one of the most carefully controlled and definitive placebo studies ever done) described a study of 40 asthma patients given four different interventions: active treatments with real albuterol inhalers; placebo treatments with fake inhalers that delivered no medication; sham acupuncture treatments; and intervals with no treatment at all. The patients returned for 12 sequential visits, receiving each type of treatment three times—a novel approach in placebo study that created a large amount of data (480 treatments in total) and turned subjects into their own controls (if patients are compared to themselves from one treatment to the next, researchers can eliminate subjects' individual differences as a variable). The researchers had hoped to find improved lung function with both the real and sham treatments; what they found instead was that only the real treatment yielded results—the others showed no significant improvement. Yet when Kaptchuk's team measured patients' own assessments of improvement, the researchers found no difference reported between the real and sham treatments: the patients'subjective responses directly contradicted their own objective physical measures.
To Dr. Harriet Hall, a retired family physician who writes critically about alternative and complementary medicine for such publications as Skeptic Magazineand Skeptical Inquirer, this discrepancy between objective and subjective results is precisely where the danger lies. As she told a reporter for The Atlantic in December 2011, following the publication of Kaptchuk's NEJM study, "Asthma can be fatal. If the patient's lung function is getting worse but a placebo makes them feel better, they might delay treatment until it is too late."
To Kaptchuk's team, on the other hand, the conflicting results not only reveal important lessons for researchers and clinicians, but illuminate a gap that is central to placebo research. "Placebos have limitations, and we need to know what they are," Kaptchuk says. "We'd hoped for measurable objective changes in breathing; what we got instead was a more precise diagram of placebo effects and how clearly the ritual of medicine makes people more comfortable." That in itself is important information, he says. "Our job is to make people feel better," and though this study was small, "what we've really done here is open up a new set of questions." No one has yet studied how long-term experience with the ritual of medicine might ultimately affect the course of chronic afflictions, he says. "We hope we've opened up that path."
Kaptchuk and his team have begun to take steps in that direction, continuing to ask new questions and push the boundaries of placebo research. A study published online this past year in the Proceedings of the National Academy of Sciencesdemonstrated that the placebo response can occur even at the unconscious level. The team showed that images flashed on a screen for a fraction of a second—too quickly for conscious recognition—could trigger the response,but only if patients had learned earlier to associate those specific images with healing. Thus, when patients enter a room containing medical equipment they associate with the possibility of feeling better, "the mind may automatically make associations that lead to actual positive health outcomes," says psychiatry research fellow Karin Jensen, the study's lead author.
Those findings led to the team's most recent work: imaging the brains of physicians whilethey treat patients—a side of the treatment equation that no one had previously examined. (The researchers constructed an elaborate set-up in which the doctors lay in fMRI machines specially equipped to enable them both to see their patients outside the machine and administer what they thought was a nerve-stimulating treatment.) "Doctors give subtle cues to their patients that neither may be aware of," Kaptchuk explains. "They are a key ingredient in the ritual of medicine." The hope is that the new brain scans will reveal how doctors' unconscious thought figures into the treatment recipe.
WITHIN ACADEMIA, Kaptchuk and his fellow researchers have not escaped criticism, but the voices have been few and far between. The most notable appeared in 2001 in the NEJM—the same publication that included Kaptchuk's asthma study a decade later. In a paper titled, "Is the Placebo Powerless?" two Danish researchers reviewed 114 published studies involving 7,500 patients and questioned both the research methods and the short duration of most placebo studies. Many of the trials reviewed lacked "no-treatment" groups—an important control group missing even in Kaptchuk's first "pill versus needle" study.
But Kaptchuk's response to such criticism is perhaps as rare in academia as his pedigree. "If I remember correctly," said Asbjorn Hrobjartsson, the lead author of that 2001 paper during a recent phone conversation, "Ted was already thinking along the same lines as we were and realized [our paper] pointed out real methodological problems." When Hrobjartsson came to speak at Harvard a year later, he stayed at Kaptchuk's home, and in 2011, the two coauthored a paper (with the NIH's Frank Miller) on biases and best practices in placebo study.
When Kaptchuk talks about Hrobjartsson's 2001 paper now, he winces, then nods with acceptance. "At first when I read it, I worried I'd be out of a job," he says. "But frankly, [Hrobjartsson] was absolutely right." In order to legitimize his findings to mainstream practitioners, the results must be expertly quantified, he acknowledges. "We have to transform the art of medicine into the science of care."
Sunday, December 23, 2012
Men are famous for ignoring aches and pains. It's macho. Men get physical exams less often than women. They tend to remain silent if worried about their health. When hurt, their impulse is to shun doctors and rely on home remedies, like avoiding heavy lifting to ease backaches. Male athletes play through injuries. It's all about virility and manliness.
The stereotype has exceptions, of course. But denial of injury and ill health — from the relatively inconsequential to the grave — is common enough that physicians seek ways to encourage men to be more forthcoming.
So it pays to listen carefully when guys start talking about intolerable pain and upended lives. Doing so led me to an unexpected finding that I have confirmed in a trove of federal data. It suggests thatyoga can be remarkably dangerous — for men.
Guys who bend, stretch and contort their bodies are relatively few in number, perhaps one in five out of an estimated 20 million practitioners in the United States and 250 million around the globe. But proportionally, they are reporting damage more frequently than women, and their doctors are diagnosing more serious injuries — strokes and fractures, dead nerves and shattered backs. In comparison, women tell mainly of minor upsets.
Men who are breaking the code of silence are doing so with physicians in hospital emergency rooms, who in turn report their findings to the federal government.
Their outspokenness reveals much about modern yoga and suggests ways it can be made safer. As a practitioner since 1970, I know some of the guy hazards personally and have learned through painful experience how to live with my inflexible body.
The male disclosures help explain one of the central mysteries of modern yoga — why it is largely a feminine pursuit. As Yoga Journal, the field's top magazine, put the question: "Where Are All the Men?"
Science has long viewed the female body as relatively elastic. Now the new disclosures suggest that women who tie themselves in knots also enjoy a lower risk of damage. It seems like common sense.
Surprisingly, evidence of the male danger has, to my knowledge, never before been made public. Nor has its flip side — that women seem less vulnerable. The subject of male risk merits discussion if only because the booming yoga industry has long targeted men as a smart way to expand its franchise.
Informal observations hint at possible explanations. Yoga experts say women tend to see classes as refuges while men see challenges — their goal at times to impress the opposite sex.
Women say men push themselves too far, too fast. Men admit to liking the intensity but say the problem is pushy teachers who force them into advanced poses while urging them to ignore pain.
I stumbled on the issue after my book, published in February, laid out a century and a half of science and, in its chapter on injuries, contradicted the usual image of yoga as completely safe. The yoga establishment makes billions of dollars by selling itself as a path to healthy perfection. Predictably, it responded with sharp denials.
I also received a surprising number of moving replies from injured yogis — male and female — including stroke victims.
A letter initiated my inquiry. In April, a man told how an agonizing back injury had turned his life into "a living hell." Too many instructors, he wrote, are "pushing us too hard and having us do dangerous poses."
The "us" resonated.
Suddenly, I realized his cry sounded familiar.
I raced through a correspondence file and saw that many of the letters about serious damage had come from men.
Tara Stiles, a yoga teacher who runs a popular studio in Manhattan, told me that guys have more muscle (one reason for their relative inflexibility) and can thus force themselves into challenging poses they might otherwise find impossible. It seemed a plausible explanation for blinding pain.
Other teachers echoed her analysis and cited supporting anecdotes.
Yoga poses are unisex. But in my research, I found a world of poorly known information on gender disparity.
"Science of Flexibility," by Michael J. Alter, explained how the pelvic regions of women are shaped in a way that permits an unusually large range of motion and joint play. In yoga, the pelvis is the central pivot for extreme bending of the legs, spine and torso.
In June, I turned to the Consumer Product Safety Commission and its National Electronic Injury Surveillance System, which monitors hospital emergency rooms. In July, officials sent me 18 years of annual survey data that summarized the admission records for yoga practitioners hurt between 1994 and 2011, the maximum available span.
First, I needed a baseline that would let me compare the guy admissions to males doing yoga in the United States. Figures in the yoga literature described men as making up some 10 percent of practitioners at the beginning of the period and 23 percent at the end. So the middle ground seemed to be roughly 16 percent.
Then I dug into the medical data. The analysis took weeks, but the results spoke volumes.
If men were getting hurt in proportion to their numbers, the rate of injury would have been about 16 percent — my estimate for the fraction of practitioners who were male. But the rate was higher. Over all, I found that men accounted for slightly more than 24 percent of the admissions to hospital emergency rooms.
To deepen my analysis, I focused on specific injuries, especially ones inside the body. Guys, it turned out, accounted for 20 percent of the torn muscles and damaged ligaments, which result in swollen joints. Dislocations of the knee, shoulder and other joints came in at 24 percent.
The figure for broken bones and fractures was 30 percent. The injury sites ranged from the toe to the tibia, the bigger of the two bones in the lower leg.
For nerve damage, which can result in pain and lost muscle control, the male figure jumped to more than 70 percent. The cases included sciatica, where compression of a spinal nerve in the lower back can result in pains that race down the back, hip and leg.
I found the trend in women's admissions to be just the opposite. The major injuries were few proportionately, and the minor traumas quite abundant. Women, for instance, accounted for a vast majority of the fainting episodes.
None of this means that women go unharmed, as my letter files and the admission records show. But men seem to get it worse.
In August, I shared my analysis with Loren M. Fishman, a doctor in Manhattan who uses yoga in his rehabilitation practice and whom I profile in my book. "It's men's strength turning against them," he remarked.
Some yoga practitioners will surely see my analysis as unconvincing. That's O.K. It's the kind of topic that can only benefit from thorough discussion — as well as rigorous new studies that can rule out the possibility of false clues.
Skeptics may argue that the injured guys are simply wimps who are inflating the male-injury figures.
That seems unlikely. A new book, "Hell-Bent," by Benjamin Lorr, evokes the contrary ethos in its subtitle: "Obsession, Pain, and the Search for Something Like Transcendence in Competitive Yoga."
Happily, the field is evolving in ways that may enhance safety.
All-male classes, by definition, avoid the flexibility gap between women and men and instead play to masculine strengths. The classes tend to emphasize muscle building and fitness moves like squats, as well as poses. Their developers tend to avoid talk of injuries, a marketing no-no.
The styles include YoGuy ("be comfortable") and Broga (as in bro yoga, "where it's O.K. if you can't touch your toes"). A number of studios offer what they call yoga for dudes.
I'm a yoga enthusiast, not a basher. I do my routine every day and want the practice to thrive — but to do so honestly, with public candor about its real strengths and weaknesses.
From reader mail, I know that many yogis are working hard to make the practice safer. The male risk factor seems an important consideration in the redesign of poses and routines. And I'm sure instructors of mixed classes will find many ways of reducing any danger. A first step would be frank discussions with students.
In time, it seems likely that the myth of perfection will give way to the reality of better yoga — for everyone, including guys.
Saturday, December 22, 2012
Cannabis makes pain more bearable rather than actually reducing it, a study from the University of Oxford suggests.
Using brain imaging, researchers found that the psychoactive ingredient in cannabis reduced activity in a part of the brain linked to emotional aspects of pain.
But the effect on the pain experienced varied greatly, they said.
The researchers' findings are published in the journal Pain.
The Oxford researchers recruited 12 healthy men to take part in their small study.
Participants were given either a 15mg tablet of THC (delta-9-tetrahydrocannabinol) - the ingredient that is responsible for the high - or a placebo.
The volunteers then had a cream rubbed into the skin of one leg to induce pain, which was either a dummy cream or a cream that contained chilli - which caused a burning and painful sensation.
Each participant had four MRI scans which revealed how their brain activity changed when their perception of the pain reduced.
Dr Michael LeeOxford University
Cannabis appears to mainly affect the emotional reaction to pain in a highly variable way."
Dr Michael Lee, lead study author from Oxford University's Centre for Functional Magnetic Resonance Imaging of the Brain, said: "We found that with THC, on average people didn't report any change in the burn, but the pain bothered them less."
MRI brain imaging showed reduced activity in key areas of the brain that explained the pain relief which the study participants experienced.
Dr Lee suggested that the findings could help predict who would benefit from taking cannabis for pain relief - because not everyone does.
"We may in future be able to predict who will respond to cannabis, but we would need to do studies in patients with chronic pain over longer time periods."
He added: "Cannabis does not seem to act like a conventional pain medicine. Some people respond really well, others not at all, or even poorly.
"Brain imaging shows little reduction in the brain regions that code for the sensation of pain, which is what we tend to see with drugs like opiates.
"Instead cannabis appears to mainly affect the emotional reaction to pain in a highly variable way."
Mick Serpell, a senior lecturer in pain medicine at Glasgow University, said the study confirmed what was already known.
"It highlights the fact that cannabis may be a means of disengagement for the patient, rather than a pain reliever - but we can see that happen with opioids too."
Thursday, December 20, 2012
Another Good Reason to Quit Smoking in New Year: Less Back Pain - University of Rochester Medical Center
A University of Rochester Medical Center analysis of more than 5,300 patients followed for eight months during treatment of spinal disorders showed that cigarette smokers reported far more pain than never-smokers or those who had quit.
Smoking cessation either prior to treatment or during the course of care was related to significant improvements in pain – a result that underlines the need for structured stop-smoking programs among the legions of patients who experience back pain due to degenerative disease, deformity, or musculoskeletal problems, said Caleb Behrend, M.D., chief resident in the Department of Orthopaedics and Rehabilitation at URMC.
Glenn R. Rechtine, M.D., a nationally recognized spinal surgeon and adjunct faculty at URMC, led the study, which was published in the Journal of Bone and Joint Surgery.
"We found that people who stopped smoking had meaningful benefit by reduction of their pain," said Behrend. "The pain improvement is in addition to all the other benefits you gain from quitting."
The relationship between pain and smoking is complex and full of contradictions. Nicotine has analgesic properties, for example, and yet clinical evidence shows that smokers are at higher risk for developing back pain and other chronic pain disorders, according to the American Society of Anesthesiologists.
Scientists already know that nicotine interacts with a family of proteins (nAChR), which have a key role in the central, and peripheral nervous system, and control anxiety and pain. Prolonged exposure to cigarettes upsets the function of these cells and eventually changes the way pain is processed, as well as impairing oxygen delivery to tissues, predisposing a person to bone and joint disorders such as osteoporosis, and inducing inflammation and depression. Smokers with spinal conditions also tend to have persistently more intense pain and more long-term disability.
The URMC study noted a daunting fact: Nearly all people will experience back pain at some point in their lives and many will seek medical care. And because the socioeconomic impact of spinal disorders (cost of care and lost productivity for patients) is so great, researchers wanted to find out if improvements in pain could be achieved with a cost-effective intervention such as smoking cessation.
Researchers reviewed a prospectively maintained database of 5,333 patients, who completed questionnaires about pain at the initial doctors' visit and at the time of discharge from care. Patients were treated with surgery, or with physical therapy, injections, over-the-counter medications, and home exercise programs. Physicians counseled all smokers to quit, and patients were referred to a smoking cessation hotline.
Of the 5,333 people, those who had never smoked or had quit some time ago reported less pain than smokers or those who had just quit. By the end of the follow-up period, the people who had recently quit or who quit during treatment showed significant improvements in pain. People who continued to smoke during treatment had no improvement in pain on all scales.
Behrend noted that younger people tended to comprise the group of current smokers and those who only decided to quit during treatment; this is consistent with other studies showing that smoking is associated with degenerative spine disease at a younger age. Older patients tended to comprise the group who had never smoked or quit long ago.
The rate of smoking cessation was 22 percent, and research shows that up to 36 percent of patients with painful spinal disorders are able to quit with help from a structured program. A grant from the Southwestern Medical Foundation was used to create and maintain the patient database.
Wednesday, December 19, 2012
These symptoms were truly unbearable for Gretchen Molannen, a 39-year-old Florida woman who committed suicide earlier this month. Roughly 16 years ago, Molannen developed a rare and little-known condition called persistent genital arousal disorder (PGAD). Like many women who suffer from the debilitating disorder, Molannen was forced to quit her job and had difficulty maintaining relationships with family and friends, let alone boyfriends. She underwent diagnostic procedures and sought treatment for her symptoms from a variety of doctors, none of whom could provide her with any answers or long-term relief. Molannen divulged every detail of her battle with PGAD to The Tampa Bay Times—from her masturbation habits to previous suicide attempts—for an exposé that was printed the day before she put an end to her suffering.
There may have been other triggers that led to Molannen's suicide, but doctors who specialize in PGAD and other pelvic pain disorders say severe depression is not uncommon among their patients. Dr. Robert Echenberg, a gynecologist and founder of Pennsylvania's Institute for Women in Pain, said he's seen at least seven suicide attempts among his 125 patients in the last year, one as recently as last week. Just five months ago, a Dutch woman with PGAD took her own life.
"Depression and pain and hopelessness are a bad combination," Echenberg told The Daily Beast. Even with Molannen's suicide spotlighting the condition in the media, PGAD remains largely ignored or misunderstood in the medical world. "So many patients feel hopeless because they have been treated over and over again without success, and have frequently been told the pain is 'in their heads,'" he said. "Others tell me they'd rather have cancer just so doctors would listen to their plight and they could develop a plan for health care."
Still widely misconceived as a "sexual disorder," PGAD is one of many conditions that falls under the umbrella of vulvodynia, or chronic pelvic pain—an issue that affects 20 percent of reproductive-age women, according to Dr. Echenberg. PGAD was introduced to the medical world in a 2001 study by the late Sandra Leiblum, a pioneer in modern sex therapy.
A small group of researchers scattered around the world have since connected the phenomenon to the pudendal nerve, the sensory neuron that triggers arousal. Dr. Michael Hibner, a gynecological surgeon in Arizona, says PGAD develops when the pudendal nerve is compressed or irritated, causing the clitoral dorsal nerve to fire off at random. As a result, women afflicted with the disorder feel constantly on the brink of the big O.
The concept of multiple, occasionally spontaneous orgasms titillates many women and men, even those in the medical profession. Kim Ramsey, 44, was working as a nurse in an emergency room when she first learned she had PGAD. "My colleagues would be like, 'Wow, you're so lucky,'" she said. "But I genuinely thought I was having some sort of nervous breakdown. I felt flushed. My vagina and breasts were engorged. I kept thinking, 'How do I keep a grip on reality and function in a patient-nurse setting without people knowing?'"
Uninformed doctors have left other patients at their wit's end, some of whom feel they have no choice but to take matters into their own hands.
"Some women have pierced their own genitalia to drain the blood that pools in their genital region," said Anna Reid, 26, who lives in Australia and was diagnosed with PGAD last March. She has since worked with Dr. Hibner and found comfort in online support groups, which were originally launched by Jeannie Allen, 51, in 2006. Allen's PGAD Support was the first such network to be established and remains the most well-known worldwide, with roughly 400 active members.
But that number reflects only a small portion of women around the world with PGAD, which doctors like Hibner estimate to be in the thousands. Other authorities on chronic pelvic pain say causes and treatments are too complex for most gynecologists to comprehend.