Here are 10 recent research findings on the causes and treatment of pain as well as physician education on pain.
1. Researchers find molecular clue to understanding neuropathic pain. Scientists from The Scripps Research Institute found dimethylsphingosine, a small-molecule byproduct of cellular membranes in the nervous system, is produced at abnormally high levels in the spinal cords of rats with neuropathic pain and appears to cause pain when injected. Using a new approach called metabolomics, which looks at differences in the levels of small-molecule metabolites that serve as the foundation of basic cellular processes, researchers determined the levels of metabolites in tissue from previously injured tibial leg nerves in rats. They found that all the major abnormalities in metabolite levels were present in the dorsal horn region of the spinal cord, not the injured leg nerve fiber or in blood plasma as expected. The dorsal horn region receives signals from the tibial nerve and sends them to the brain. The molecule DMS, a byproduct of cellular reactions involving sphingomyelin, a molecule in the insulating sheaths of nerve fibers, stood out to researchers. They also determined DMS causes pain by stimulating the release of pro-inflammatory molecules from astrocytes, neuron-supporting cells.
2. Women report more intense pain than men. A study published in The Journal of Pain found women report more intense pain than men with the same medical conditions. Atul Butte, MD, associate professor at the Stanford University School of Medicine, studied 160,000 pain reports from more than 72,000 patients and found women consistently report higher pain scores than men for the same conditions. In some cases, the difference was one whole point on the 0-10 pain scale — an improvement physicians use to judge whether pain medication is working or not.
3. Older patients more likely to be given only painkillers for lower back pain. A new study published in Pain found older patients with lower back pain are more likely to be given only painkillers after consultation. Researchers studied more than 15,000 patients over the age of 25 and found the prevalence of lower pain back was 28.5 percent. Prevalence peaked from age 41-50, but one in four patients over the age of 80 reported lower pain back. Researchers also found patients aged 70 and older were 1.74 times more likely to only be prescribed painkillers than 40-year-old patients and 1.45 times more likely to be prescribed painkillers with other medications. Patients over 70 were less likely to be prescribed physical therapy or exercise.
4. One-sixth of head and neck cancer survivors suffer from chronic pain. A study published in Archives of Otolaryngology Head & Neck Surgery found nearly one-sixth of head and neck cancer survivors suffer from chronic pain after five years of survival. Researchers conducted a quality of life study on five-year survivors of head and neck cancer. They found survivors shared many health-related quality of life issues with the general population, but more than half reported problems eating, 28.5 percent reported depression symptoms and 17.3 percent reported substantial pain. In multivariate analyses, researchers determined pain and dietary problems at one year were the strongest independent predictors of quality of life at five years. The researchers concluded that early inventions addressing eating issues and pain management could improve long-term quality of life for these patients.
5. Benefits of muscle relaxants and neuromodulators for rheumatoid arthritis pain don't outweigh side effects. Australian researchers found the benefits of muscle relaxants and neuromodulators for treating rheumatoid arthritis pain don't outweigh the side effects. Researchers looked at muscle relaxants — including benzodiazepine agents diazepam and triazolam and non-benzodiazepine agent zopiclone — and found they did not reduce pain when taken for up to two weeks, but use was associated with drowsiness and dizziness. They also looked at neuromodulators — including oral nefopam, topical capsaicin and oromucosal cannabis — and found weak evidence to support pain reduction. Use was associated with nausea, sweating, dizziness, dry mouth, light headedness, local burning and irritation.
6. High dose opioid might reset nerve signals and end chronic pain. A new study published in Science found a high dose of the opiate remifentanil essentially reset nerve signals that caused chronic pain in rats. A research team from the Center for Brain Research of the Medical University of Vienna induced long-term potentiation, where nerves fire pain signals repeatedly, in rats by exposing nerve fibers known to carry pain signals to low-frequency electrical stimulation, exposing them to high-frequency electrical stimulation or injecting capsaicin, the pain-causing ingredient in chili peppers. Researchers gave the rats a high intravenous dose of remifentanil — up to four times the dose usually given to control pain. The drug reduced the pain within 10 minutes, but even after the drug's effects had worn off, the chronic pain was significantly reduced in the rats treated with low-frequency stimulation. A second dose given an hour later returned the pain levels to normal. Although the dose is high, it's well below the fatal threshold, the authors said. In pre-clinical trials, patients tolerated the dosage well.
7. Listening to music effective for pain relief. A study published in The Journal of Pain found listening to music can be effective for reducing pain in high-anxiety patients who are easily absorbed in cognitive activities. Researchers from the University of Utah Pain Research Center evaluated the responses of 143 individuals to pain shocks while listening to music, following melodies and identifying deviant tones. They found arousal from the pain stimuli decreased with the increasing difficulty of the music-related task. They also found individuals with high levels of anxiety about pain had the greatest engagement in the task and experienced greater reductions in pain responses.
Another study published in Urology found noise-cancelling headphones playing classical music reduced pain and anxiety during a prostate biopsy. A research team at Duke University randomly assigned 88 patients to three groups: The first had no headphones, the second wore noise-cancelling headphones with no music and the third wore noise-cancelling headphones and listened to Bach concertos. Blood pressure was taken before and after a trans-rectal biopsy. Both groups with no music reported an elevated diastolic blood pressure, which often rises with stress and anxiety, after the procedure. The group listening to music reported no blood pressure increase and less self-reported pain.
8. Spinal manipulation is more effective for neck pain than medication. A study published in the Annals of Internal Medicine found spinal manipulation therapy was more effective in reducing neck pain than medication. Almost 300 patients at a university research center and one pain clinic in Minnesota received spinal manipulation therapy, home exercise with advice or medication for 12 weeks. Outcomes were measured at two, four, eight, 12, 26 and 52 weeks. Researchers found spinal manipulation therapy had a statistically significant advantage over medication after eight, 12, 26 and 52 weeks. Home exercise with advice had an advantage over medication only at 26 weeks and was similar at other points.
9. Pain education in medical schools needs improvement. A study published in Pain found education is "limited, variable and often fragmentary." Researchers at Johns Hopkins University examined curriculum of more than 100 U.S. and Canadian medical schools and found 80 percent of U.S. schools require one or more pain sessions, while 92 percent Canadian schools require one or more sessions. Median hour of instruction on pain topics in Canadian schools was double that in U.S. schools. Researchers also found many topics included in the International Association for the Study of Pain core curriculum were minimally covered or not covered at all.
10. Opioid abuse linked to mood and anxiety disorders. A study published in the Journal of Psychological Medicine found people with mood and anxiety disorders, such as bipolar and panic disorders, might be more likely to abuse opioids. Researchers at the Johns Hopkins Bloomberg School of Public Health used data from the National Epidemiologic Study on Alcohol and Related Conditions, which included interviews with individuals over age 18 in 2001-2002 and 2004-2005, researchers examined the link between mood and anxiety disorders and non-medical prescription opioid use.
Related Articles on Pain Management:
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1. Researchers find molecular clue to understanding neuropathic pain. Scientists from The Scripps Research Institute found dimethylsphingosine, a small-molecule byproduct of cellular membranes in the nervous system, is produced at abnormally high levels in the spinal cords of rats with neuropathic pain and appears to cause pain when injected. Using a new approach called metabolomics, which looks at differences in the levels of small-molecule metabolites that serve as the foundation of basic cellular processes, researchers determined the levels of metabolites in tissue from previously injured tibial leg nerves in rats. They found that all the major abnormalities in metabolite levels were present in the dorsal horn region of the spinal cord, not the injured leg nerve fiber or in blood plasma as expected. The dorsal horn region receives signals from the tibial nerve and sends them to the brain. The molecule DMS, a byproduct of cellular reactions involving sphingomyelin, a molecule in the insulating sheaths of nerve fibers, stood out to researchers. They also determined DMS causes pain by stimulating the release of pro-inflammatory molecules from astrocytes, neuron-supporting cells.
2. Women report more intense pain than men. A study published in The Journal of Pain found women report more intense pain than men with the same medical conditions. Atul Butte, MD, associate professor at the Stanford University School of Medicine, studied 160,000 pain reports from more than 72,000 patients and found women consistently report higher pain scores than men for the same conditions. In some cases, the difference was one whole point on the 0-10 pain scale — an improvement physicians use to judge whether pain medication is working or not.
3. Older patients more likely to be given only painkillers for lower back pain. A new study published in Pain found older patients with lower back pain are more likely to be given only painkillers after consultation. Researchers studied more than 15,000 patients over the age of 25 and found the prevalence of lower pain back was 28.5 percent. Prevalence peaked from age 41-50, but one in four patients over the age of 80 reported lower pain back. Researchers also found patients aged 70 and older were 1.74 times more likely to only be prescribed painkillers than 40-year-old patients and 1.45 times more likely to be prescribed painkillers with other medications. Patients over 70 were less likely to be prescribed physical therapy or exercise.
4. One-sixth of head and neck cancer survivors suffer from chronic pain. A study published in Archives of Otolaryngology Head & Neck Surgery found nearly one-sixth of head and neck cancer survivors suffer from chronic pain after five years of survival. Researchers conducted a quality of life study on five-year survivors of head and neck cancer. They found survivors shared many health-related quality of life issues with the general population, but more than half reported problems eating, 28.5 percent reported depression symptoms and 17.3 percent reported substantial pain. In multivariate analyses, researchers determined pain and dietary problems at one year were the strongest independent predictors of quality of life at five years. The researchers concluded that early inventions addressing eating issues and pain management could improve long-term quality of life for these patients.
5. Benefits of muscle relaxants and neuromodulators for rheumatoid arthritis pain don't outweigh side effects. Australian researchers found the benefits of muscle relaxants and neuromodulators for treating rheumatoid arthritis pain don't outweigh the side effects. Researchers looked at muscle relaxants — including benzodiazepine agents diazepam and triazolam and non-benzodiazepine agent zopiclone — and found they did not reduce pain when taken for up to two weeks, but use was associated with drowsiness and dizziness. They also looked at neuromodulators — including oral nefopam, topical capsaicin and oromucosal cannabis — and found weak evidence to support pain reduction. Use was associated with nausea, sweating, dizziness, dry mouth, light headedness, local burning and irritation.
6. High dose opioid might reset nerve signals and end chronic pain. A new study published in Science found a high dose of the opiate remifentanil essentially reset nerve signals that caused chronic pain in rats. A research team from the Center for Brain Research of the Medical University of Vienna induced long-term potentiation, where nerves fire pain signals repeatedly, in rats by exposing nerve fibers known to carry pain signals to low-frequency electrical stimulation, exposing them to high-frequency electrical stimulation or injecting capsaicin, the pain-causing ingredient in chili peppers. Researchers gave the rats a high intravenous dose of remifentanil — up to four times the dose usually given to control pain. The drug reduced the pain within 10 minutes, but even after the drug's effects had worn off, the chronic pain was significantly reduced in the rats treated with low-frequency stimulation. A second dose given an hour later returned the pain levels to normal. Although the dose is high, it's well below the fatal threshold, the authors said. In pre-clinical trials, patients tolerated the dosage well.
7. Listening to music effective for pain relief. A study published in The Journal of Pain found listening to music can be effective for reducing pain in high-anxiety patients who are easily absorbed in cognitive activities. Researchers from the University of Utah Pain Research Center evaluated the responses of 143 individuals to pain shocks while listening to music, following melodies and identifying deviant tones. They found arousal from the pain stimuli decreased with the increasing difficulty of the music-related task. They also found individuals with high levels of anxiety about pain had the greatest engagement in the task and experienced greater reductions in pain responses.
Another study published in Urology found noise-cancelling headphones playing classical music reduced pain and anxiety during a prostate biopsy. A research team at Duke University randomly assigned 88 patients to three groups: The first had no headphones, the second wore noise-cancelling headphones with no music and the third wore noise-cancelling headphones and listened to Bach concertos. Blood pressure was taken before and after a trans-rectal biopsy. Both groups with no music reported an elevated diastolic blood pressure, which often rises with stress and anxiety, after the procedure. The group listening to music reported no blood pressure increase and less self-reported pain.
8. Spinal manipulation is more effective for neck pain than medication. A study published in the Annals of Internal Medicine found spinal manipulation therapy was more effective in reducing neck pain than medication. Almost 300 patients at a university research center and one pain clinic in Minnesota received spinal manipulation therapy, home exercise with advice or medication for 12 weeks. Outcomes were measured at two, four, eight, 12, 26 and 52 weeks. Researchers found spinal manipulation therapy had a statistically significant advantage over medication after eight, 12, 26 and 52 weeks. Home exercise with advice had an advantage over medication only at 26 weeks and was similar at other points.
9. Pain education in medical schools needs improvement. A study published in Pain found education is "limited, variable and often fragmentary." Researchers at Johns Hopkins University examined curriculum of more than 100 U.S. and Canadian medical schools and found 80 percent of U.S. schools require one or more pain sessions, while 92 percent Canadian schools require one or more sessions. Median hour of instruction on pain topics in Canadian schools was double that in U.S. schools. Researchers also found many topics included in the International Association for the Study of Pain core curriculum were minimally covered or not covered at all.
10. Opioid abuse linked to mood and anxiety disorders. A study published in the Journal of Psychological Medicine found people with mood and anxiety disorders, such as bipolar and panic disorders, might be more likely to abuse opioids. Researchers at the Johns Hopkins Bloomberg School of Public Health used data from the National Epidemiologic Study on Alcohol and Related Conditions, which included interviews with individuals over age 18 in 2001-2002 and 2004-2005, researchers examined the link between mood and anxiety disorders and non-medical prescription opioid use.
Related Articles on Pain Management:
Medtronic RestoreSensor Gaining Popularity
Stanford's Dr. Philip Pizzo Urges Public Health Campaign, More Pain Specialists
12 Statistics on ASC Pain Management Case Volume