Back pain can cause greater irritation to noise

People with chronic back pain process everyday sounds differently and more intense than people without pain, according to new research from the University of Colorado Anschutz (United States), which has shown that there is an effective treatment that can help.

The study, published in the journal Annals of Neurology and collected by Europa Press, is one of the first to link this hypersensitivity sound with specific, measurable changes in the brain, indicating that chronic back pain affects far beyond the back.

“Our findings confirm what many patients have been saying for years: that everyday sounds actually feel harsher and more intense. Their brains respond differently, in the regions that process both the intensity of the sound and its emotional impact,” explains the lead author of the article, the Dr. Yoni Asharassistant professor of internal medicine and co-director of the Pain Sciences Program at the University of Colorado Anschutz School of Medicine.

He adds that this indicates that chronic back pain is not limited to the back. “There is a broader sensory amplification in the brain, which opens the door to treatments that can help reduce that volume,” he points out.

This is how the study was carried out

The researchers compared the neural and self-reported responses of 142 adults with chronic back pain to those of 51 pain-free controls. All participants, including controls, underwent brain imaging.

During the MRI session, the researchers asked participants to perform various tasks, such as listening to sounds, while asking them how unpleasant they found them and measuring the intensity of the response of key brain regions.

The differences between chronic pain patients and healthy controls were considerable. The researchers found that, on average, they reacted more intensely than the 84% of people without pain.

The scans also revealed that the changes were not occurring in the initial auditory processing areas, but in higher areas of the brain. In particular, the scans showed responses more intense in the regions that process sound (the auditory cortex) and the emotional sensations (the insula). At the same time, they observed less activity in brain regions that normally help calm or regulate reactions, such as the medial prefrontal cortex.

The researchers also looked at treatment options and assigned participants with chronic back pain to one of three groups. On the one hand, pain reprocessing therapy (PRT), with therapy sessions designed to help people reinterpret pain as a result of brain amplification rather than just back problems.

On the other hand, placebo treatmentwith a saline injection administered in a supportive clinical environment, and third, usual care, in which participants continued with the treatments they were already using.

They found that, of all the treatments, the Pain Reprocessing Therapy was the more effective. Not only did it reduce the heightened brain response to sound, it also increased activity in brain regions involved in regulating unpleasant experiences.

“This shows that the brain’s exaggerated sensory response can be improved with psychological treatment, so rather than being something patients get stuck with, this sensitivity is treatable,” Ashar says.

“These findings reinforce the growing evidence that chronic back pain is not just a back problem, but that the brain plays a fundamental role in its development, amplifying various sensations: sensory signals from the back, sounds and probably other sensations as well,” he explains.

Ashar’s previous research found that pain reprocessing therapy led to two-thirds of participants with chronic back pain becoming pain free or almost pain free after treatment, far exceeding the approximately 20% improvement seen in the placebo group.

The research also raises several important questionsas if this increased sensitivity is a cause of chronic back pain or a pre-existing vulnerability to developing chronic pain.

Preliminary evidence from other groups suggests that people with greater natural sensitivity to sensory information might be more likely to develop chronic pain after an injury. It is also unclear whether this amplification extends to other senses, such as light, smell, or taste, or whether this occurs with other chronic pain conditions.

They claim that their next study will assess sensitivity in other senses to determine the true extent of this amplification and whether a central region of the brain could be responsible for this amplification in all senses.