Posted tagged ‘pain’

New imaging study investigates role of dopamine in migraine attacks

April 7, 2017

Many people suffer from migraines —throbbing, painful headaches that last up to 72 hours and are often accompanied by nausea, vomiting and sensitivity to light and sound.

Although not fully understood, an imbalance in a brain neurotransmitter is thought to contribute to migraines. The neurotransmitter, dopamine, is a chemical in your brain that affects your movements, emotions, motivations and sensory perceptions, including the ability to modulate pain.

Now, researchers at the University of Michigan have shown that dopamine levels in the brain fall during a migraine attack relative to their baseline level between attacks, as reported in a recent news release.

The research team performed two PET scans on different days to study eight migraine sufferers during a spontaneous migraine and in between attacks, comparing their brain activity and dopamine levels with and without a headache. On average, these patients were 27 years old and experienced migraines about six times per month. The scientists also imaged eight healthy adults, comparing migraine sufferers to controls.

They found that dopamine levels in the brain fluctuated, temporarily reducing during migraine attacks. They also found that the study participants were more sensitive to non-painful stimuli, such as warmth applied to the forehead, during a migraine.

“With this study, we better understand how dopamine is related to the suffering during a migraine attack,” said Alex DaSilva, DDS, DMedSc, assistant professor of dentistry and of the Center for Human Growth and Development at the University of Michigan, in the video above. “Lower dopamine levels mean you are more sensitive to pain and stimulation. Second, lower dopamine levels also inhibit your behavior. You want a dark room. You want to avoid social interactions.”

In their paper, the researchers call for additional studies to confirm the results and evaluate how they can be used to develop more effective migraine therapies.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Targeting protein may help researchers improve pain medication

January 24, 2017

headache-1910649_1280For many people, living with chronic pain is a way of life. Unfortunately, existing pain medications are not always effective and can be addictive, which has led to an opioid epidemic in the United States.

In their search for better therapies to manage pain, researchers are investigating the underlying mechanisms that signal and control pain in the body. A central component of this pain pathway is a protein called Nav1.7, which is present at the endings of pain-sensing nerves. Nav1.7 is known to help alert your brain when your body encounters potentially harmful stimuli, like when your hand touches a hot pan.

Past research demonstrated that people with non-functioning Nav1.7 don’t feel pain. This discovery led to the development of drugs that block Nav1.7 activity. Unfortunately, these drugs didn’t really work. It turns out that the role of Nav1.7 is more complicated than first thought.

“It seemed so obvious and simple, but it was not so simple,” said Tim Hucho, PhD, a neuroscientist at the University Hospital Cologne in Germany, in a recent Science News story.

Researchers have now found that Nav1.7 plays a second role — triggering the production and release of natural opioid compounds, like endorphins, that suppress the transmission of pain signals to the brain. People with non-functioning Nav1.7 do not feel pain and have increased expression of the genes in charge of making natural opioids.

The news story explains:

“An investigation of rat and mice nerve cells reveals the tug-of-war between Nav1.7’s pain-promoting and pain-relieving powers. Cells with nonfunctioning Nav1.7 have amped up activity in the cellular machinery that kicks off pain relief, Hucho and colleagues report. They suggest that Nav1.7 acts like the axis point in a playground seesaw. When the pain-promoting side is dialed down, the pain-relieving side becomes more dialed up than usual, and cells make more of their in-house opioids.”

This research suggests a new approach to pain management: using opiates in combination with a Nav1.7 blocker to make opiates more effective and reduce their associated side effects. However, a lot more research is needed before this work can be translated into treating people with chronic pain.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Researchers discover “brain signature” for fibromyalgia using brain scans

October 27, 2016

portrait-1006703_1280Millions of patients suffering from fibromyalgia often experience widespread musculoskeletal pain, sleep disturbances, fatigue, headaches and mood disorders. Many also struggle to even get diagnosed, since there are currently no laboratory tests for fibromyalgia and the main symptoms overlap with many other conditions. However, new research may help.

Scientists from the University of Colorado, Boulder may have found a pattern of brain activity that identifies the disease. They used functional MRI (fMRI) scans to study the brain activity of 37 fibromyalgia patients and 35 matched healthy controls, while the participants were exposed to a series of painful and non-painful sensations.

As reported recently in the journal PAIN, the research team identified three specific neurological patterns correlated with fibromyalgia patients’ hypersensitivity to pain.

Using the combination of all three patterns, they were able to correctly classify the fibromyalgia patients and the controls with 92 percent sensitivity and 94 percent specificity — meaning that their test accurately identified 92 percent of those with and 94 percent of those without the disease.

Tor Wager, PhD, senior author and director of the school’s Cognitive and Affective Control Laboratory, explained the significance of the work in a recent news release:

“Though many pain specialists have established clinical procedures for diagnosing fibromyalgia, the clinical label does not explain what is happening neurologically and it does not reflect the full individuality of patients’ suffering. The potential for brain measures like the ones we developed here is that they can tell us something about the particular brain abnormalities that drive an individual’s suffering. That can help us both recognize fibromyalgia for what it is – a disorder of the central nervous system – and treat it more effectively.”

More research is needed, but this study sheds a bit of light on this “invisible” disease.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

The Opioid Crisis: Medicine X panelists explore the complexity of managing chronic pain

September 19, 2016
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Photograph courtesy of Medicine X

Saturday’s Medicine X session on the opioid crisis focused on how best to manage the chronic pain felt by millions of Americans every day. The session engaged panelists with different perspectives, including a patient in chronic pain and physicians struggling to decide when to prescribe opioids. All the panelists recognized that opioid addiction is a serious and pervasive problem, but they also warned that proper pain management is a complex issue.

Jeanmarie Perrone, MD, professor of emergency medicine at the Hospital of University of Pennsylvania, told the audience, “I need good pain management to work in the emergency room. We need these drugs, we just need to be conscientious about it.”

ePatient Britt Johnson, a Medicine X board member and owner of The Hurt Blogger, understands this all too well. She shared her story of needing opioids to function due to severe pain from spondyloarthropathy and rheumatoid arthritis, which she’s had for most of her life.

Johnson addressed the media’s oversimplification of the issue. “Pain is not politically correct,” she said. “The media tells me that all opioids are all bad. The media makes everyone believe that I, too, am struggling with addiction. And the media lumps me in with statistics on heroin usage and overdose deaths.” She went on to say that she winds up “feeling guilt and shame for constantly experiencing pain. And I’m reminded constantly how heart breaking overdose stories are, which they are. But my story is not connected to those stories.”

Pain expert Frank Lee, MD, agreed that “we’re starting to stereotype chronic opioid patients as heroin addicts and physicians as pill pushers.” Lee described the impact of this on his practice and how it increases his risk if he prescribes a large or moderate dose of opioids to a patient. “If I just follow the CDC guidelines and tell the patient that I can’t prescribe this medication, it makes my life easier,” he said.

Lee shared a story about one of his patients who recently died. In her 70s, Mary had severe rheumatoid arthritis and three back surgeries. When he “inherited” Mary from a different pain doctor, she was on massive doses of opioids — close to 300 mg morphine daily equivalents, several times the recommended dose. “Maybe I was naïve, but I went through all the dangers of opioids. I told her, ‘We need to come down on your dose.’ She was hesitant, but she said ‘if you really need to do this, okay.’ During the next three months, we went down from almost 300 mg to about 70 mg. She ended up in the emergency room twice, because she just couldn’t take it. It hurt too much,” he said. “She cared enough to try what I recommended and I felt like I owed her the chance. We went back to the insane amount of her opioids and she did well.” However, Lee expressed his concern over what the high opioid doses did to her body.

Lee and others discussed the need to distinguish between patients like Johnson and Mary from those who are prone to opioid addiction. Sean Mackey, MD, PhD, chief of the division of pain medicine at Stanford, declared the need for more quality data on pain — through programs like the National Pain Strategy — to help identify the risk factors of the people that are more vulnerable. Cynthia Reilly, director of the prescription drug abuse project at The Pew Charitable Trusts, professed that prescription drug monitoring programs are part of the solution.

The panel agreed that another solution is to make integrated medicine options more affordable. “At the pharmacy I get a bottle of 60 Percocet for ten dollars, yet I have to pay out of pocket for massage, acupuncture, heat therapy, ice packs, cognitive behavioral therapy, pain psychologists and anything else,” said Johnson. “Opioids have the cheapest barrier to access, yet raising the price of opioids is not the answer; putting complimentarily pain therapies on an even playing field is.”

Although mostly harmonious, the panel discussion became heated near the end when a member of the audience interrupted, asking to hear more from Johnson. Feeling that she was being left out of the conversation, she said, “I’m sitting here and the discussion about the pain crisis is happening around me, when I’m right here and it could be happening with me. We could be having a real discussion here.” The panel concluded that we need to do a better job bringing everyone together with different perspectives.

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.

Chronic pain is correlated with major depression — for sufferer and spouse, study finds

August 25, 2016
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Image by Stefano Vitale via Stanford Medicine magazine

Chronic pain — pain that lasts longer than three months — debilitates over 100 million Americans and costs the United States over half a trillion dollars annually, but we still don’t really understand its underlying risk factors.

According to a new study recently published in PLOS Medicine, genetics and your home environment substantially contribute to your risk of chronic pain. The study also found that chronic pain is correlated with major depressive disorder (MDD), and both conditions are in part caused by a variety of genes.

The study was conducted by Andrew McIntosh, MD, chair of biological psychiatry at the University of Edinburgh, and his colleagues using data from two large United Kingdom population studies — including 23,960 individuals from the Generation Scotland: Scottish Family Health Study and 112,151 individuals with genotyping and phenotypic data from the United Kingdom Biobank.

It makes sense that someone with chronic pain has a higher risk of being severely depressed. But the study found that you also have increased risk for major depression if you’re living with a spouse or partner with chronic pain.

The authors discuss possible reasons for this spousal effect, which were summarized in a recent news story:

  • “You may choose a spouse similar to yourself, with similar existing predispositions to the conditions (assortative mating).
  • It’s possible that caring for a spouse with chronic illness makes you more likely to develop depression.
  • The environment you share with your spouse may contribute to both your risks of chronic pain and MDD; shared environmental factors could include diet, infectious disease, and hobbies.”

Determining the extent of these environmental factors was beyond the scope of the current study, but the authors recommend future research to identify the causal mechanisms that link chronic pain and major depressive disorder. They concluded in the paper:

“The answers to these questions are likely to signpost new directions for therapeutic interventions and highlight the symptoms that are most amenable to treatment, as well as prevention.”

This is a reposting of my Scope blog story, courtesy of Stanford School of Medicine.


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