Why do some people seem to feel pain more intensely than others? How do pain syndromes develop and sometimes linger long after the original stimulus is gone?
The role of early life events in creating a susceptibility to pain problems in later years was a major theme of recent findings discussed at the 2012 Pain Research Symposium. Co-hosted by UAB Medicine’s Comprehensive Neuroscience Center and Department of Anesthesiology, the symposium was organized by the Alliance for the Development and Advancement of Pain Treatment (ADAPT), a pain research working group of the CDC.
The symposium matched pain researchers from England and across the US with their UAB counterparts in sessions exploring new findings on key topics and their implications for patient care.
“Pain systems are evolving and changing rapidly in childhood. There are critical periods when the nervous system is forming. Insults then—injuries, illnesses or even psychological stresses—can cause changes that seem to prime the body for more sensation if there is a second insult later,” panelist Timothy Ness, MD, PhD and UAB Professor of Anesthesiology, said.
“Pain is more hard wired than other sensory experiences and more complex, triggering a response not only in sensory areas of the brain, but also those governing emotions such as fear or rage and behaviors such as escape,” he said. “Differences in pain perception aren’t simply a matter of genetics. We’re finding that epigenitics are also involved.”
In the first session, Pediatric Pain and Its Effects, Maria Fitzgerald, PhD of University College London discussed her seminal work on neonatal pain. She was joined by UAB researchers Alan Randich, PhD, who spoke about the links between early-in-life bladder inflammation and adult bladder pain, and Tom Vetter, MD, MPH, who talked about community-based participatory research in pediatric chronic pain.
Ness said, “There is a myth that babies don’t feel pain, but they do. They may feel it more since pain suppressing systems don’t fully develop in humans until age five. What we’re learning now is how important pain management is throughout life.”
Deep Tissue Pain was the topic of the next session. Kathleen Sluka, PhD, PT of the University of Iowa is researching peripheral and central mechanisms of musculoskeletal pain, and neurotransmitters and receptors that mediate hyperalgesia. She spoke on models of muscle pain and its transmission. UAB’s Ursula Wesselman, MD, PhD outlined her work on chronic pelvic pain and translational research insights. Mason Frazier, MD discussed pain management and the role of musculoskeletal radiology at UAB.
The afternoon began with a session on Visceral Pain and Its Modulation. Emeran Mayer, MD of UCLA is working in translational studies of visceral pain and stress. He is also investigating alterations in stress-induced pain modulation, and cellular and molecular level neuron response to visceral stimulation. Mayer spoke on translational approaches to chronic visceral pain. UAB researcher Meredith Robbins, PhD discussed the role of spinal corticotropin releasing factor-2 receptors in stress-induced bladder hypersensitivity. Georg Deutsch, PhD of UAB shared his expertise on arterial spin labeling imaging of quantitative changes in regional cerebral blood flow in pain conditions.
Headache pain was the topic of a session with Andy Ahn, MD, PhD of the University of Florida and UAB’s John Rothrock, MD, a nationally noted expert in migraines. Ahn has been researching severe headaches described as “throbbing.” In the past it was generally assumed that the throbbing sensation was a vascular phenomenon. Ahn’s work has found that the throbbing does not match the beat of the pulse. It does, however, coincide with alpha waves.
The symposium concluded with three UAB investigators discussing Neuropathic Pain and Processing. Candace Floyd, MD talked about spinal cord injury, neuropathic pain and NF-kB. Timothy Ness, MD, PhD presented studies of spinal cord injury-related pain in humans. Michael Froelich, MD, MS outlined the latest developments in functional imaging in pain research.
“We’re beginning to understand the mechanisms of pain, but we’re still some distance from translating that into better pain relief for patients,” Ness said. “Physicians typically receive little formal training in pain unless they are in a specialty that requires more than a few basic lectures.
‘There is a tendency to under treat pain. This may be from a fear of dependency or addiction. Another problem is that we aren’t always able to track how well efforts to relieve pain actually work in a specific patient. After one or two changes in medication, if patients don’t come back, we may assume the last thing we prescribed worked when they may have gone on to seek other remedies elsewhere or perhaps just gave up.
“Ultimately, our goal is to use what we learn about pain to help people,” Ness said. “Now that we’re getting better insights into how pain works, we need to find better ways to deal with it. Then we need to get that information to physicians to help them help their patients find relief.”