Brain changes that cause pain sensitivity may affect older women more

A new study has found that the brain system that allows us to inhibit our own pain changes with age, and that gender differences in these changes may lead women to be more sensitive to moderate pain than men in as older adults.

Researchers used fMRI to examine the brain responses of men and women who rated the intensity and unpleasantness of pain during exposure to increasing levels of heat. The results suggest that established sex differences in pain perception could likely be attributed at least in part to this brain network, and offer new evidence that these sex differences may become more disparate with age.

“The most innovative part of this study is looking at gender by age,” said the study’s lead author, Michelle Failla, an assistant professor in the College of Nursing at Ohio State University. “Most of the work characterizing the regions of the brain that respond to pain has been done in people aged 18 to 40. We want to understand what happens between the ages of 30 and 90, because that’s when that people start to experience chronic pain.”

The study was recently published in The pain diary.

Much previous research has shown that women are more sensitive to pain than men, but the brain regions and functions behind sex differences in pain perception remain largely a mystery. And later in adulthood, when the risk of chronic pain is higher and our pain tolerance decreases, even less is known about the brain’s role in pain perception.

In this study, the researchers clarified that they looked comprehensively at sex-based differences, which may be related not only to biological sex, but also to social factors that influence how people respond to pain.

The imaging component of the study focused on the descending pain modulation system (DPMS), a hub of brain regions that communicate with each other to engage signal transmission, including activation of opioid receptors. , which allows us to reduce our own pain.

The study sample included 27 women and 32 men aged 30 to 86 years, who were asked to report when the applied heat reached levels of barely noticeable, mild and moderate pain and d ‘rate how unpleasant each level was. The researchers used fMRI imaging to observe DPMS activity that corresponded to each participant’s individual pain response.

“Different brain regions are involved in these distinctions between perception of pain intensity and unpleasantness. So we thought it was important to look at both and see how these brain regions are recruited during pain,” said Failla, also a researcher at the Research Center. Healthy Aging, Self-Management, and Complex Care at Ohio State’s College of Nursing.

The results showed that a few regions of the brain’s pain modulation system indicated a difference by sex and age: at the moderate pain level, men showed an increased DPMS response with age, while with increasing As women aged, the DPMS response decreased. A diminished brain response would likely result in a lesser ability to exploit our own physiological functions to reduce our pain.

Presumed is a key word: although DPMS is thought to play an important role in pain sensitivity and tolerance, researchers are still working to describe exactly how it works and how an intact or dysfunctional system shows up in scans.

“We don’t know exactly what the optimal response of DPMS is,” Failla said. “Are we seeing it activated to make up for your pain, or is it already working, meaning the pain could have been worse?”

Researchers are continuing this work, which includes studying the brain activity of people who may have difficulty expressing the pain they feel, such as people with dementia or autism.

The more scientists learn about the brain’s role in pain perception, the better chance there will be of achieving more effective pain management, Failla said.

“Pain is such an individual experience. In science, we look at individual factors that can specifically influence pain and what makes it different for each person,” she said. “This could then identify a mechanism that we can target, or even just allow us to better understand that there are different levels of innate abilities to modulate pain.”

This study was conducted at Vanderbilt University Medical Center and was funded by a grant from the National Institute on Aging awarded to co-authors Todd Monroe of Ohio State and Ronald Cowan of the Health Sciences Center from the University of Tennessee.

Other co-authors include Paul Beach of Emory University, Sebastian Atalla of the University of North Carolina, and Mary Dietrich and Stephen Bruehl of Vanderbilt University.