The chronic back pain makes hypersensitive the nerves and causes them to overreact to sounds: this is what was revealed by a new study published in Annals of Neurology, signed by an international team of researchers from the universities of Hamburg, Dartmouth and Colorado. In simple words: if you have had back pain for some time, your brain may have turned up the “volume” of everything that comes from the outside, making even stimuli that for others are just background noise unpleasant.
Hypersensitivity to noise and chronic pain: research data
The question of the researchers of this study was: but if the brain becomes hypersensitive to pain from back pain, isn’t it perhaps also hypersensitive to other things? How does it sound?
To answer this question, the researchers recruited 142 people with chronic back pain and 51 healthy people as a control group. All participants underwent two types of stimulation while inside a functional magnetic resonance imaging (fMRI) scanner, a tool that allows real-time observation which areas of the brain are activated: a physical pressure on the thumb, at two different intensities (low and high), and a sharply annoying sound — the classic sound of a knife scraping glass — also at two volume levels.
After each stimulation, participants had to indicate how unpleasant they found the sensation, on a scale of 0 to 100.
The results revealed a surprising reality: patients with back pain reported much higher levels of unpleasantness to sounds compared to the control group. We are talking about a statistically very significant effect, even more marked than the sensitivity to physical pressure on the body. In practice, chronic back pain appears to be accompanied bygeneralized sensory amplification.
Neuroscience of pain: why the brain “turns up the volume” of sounds
But what exactly happens in the “control unit” of our body? Thanks to functional magnetic resonance imaging (fMRI), scientists have observed that the brain of those suffering from chronic pain undergoes a real neural reprogramming:
- Hyper-activity in the Insula and Auditory Cortex: These areas, dedicated to processing the senses and emotions, overreact to sounds. The insula, in particular, seems to “scream” to the rest of the brain that noise is an imminent danger.
- Hypo-activity in the control system (mPFC): On the contrary, areas such as the medial prefrontal cortex, which should help us regulate emotions and give the right weight to stimuli, are less active in patients.
Researchers have found that these brain patterns in back pain are strikingly similar to those seen in fibromyalgia. This suggests that many chronic conditions share the same “system error”: the central sensitization.
Back pain and fibromyalgia: shared brain mechanisms
Until recently, it was thought that chronic back pain was almost exclusively linked to physical problems of the spine. This study changes everything, showing that chronic pain is often a condition nociplastywhere the main problem is the way the nervous system processes signals.
Research has shown that sensitivity to sounds is directly linked to the intensity of back pain experienced over the past week. The stronger the pain, the more “electric” and intolerant the brain seems to become to any other external stimulus, confirming that chronic pain is not an isolated event in a muscle, but a change in state of the entire individual.
Pain Reprocessing Therapy (PRT): how to recalibrate the nervous system
The real turning point in the research concerns treatment. Scientists have tested the Pain Reprocessing Therapy (PRT)an innovative psychological therapy that aims at “central desensitization”. The goal of PRT is not just to reduce pain, but to teach the brain to interpret sensory signals as “safe” rather than dangerous.
The results were encouraging: PRT significantly reduced the perceived unpleasantness of sounds. At the cerebral level, the therapy led to a increased activity in the medial prefrontal cortex.
This means that the brain can actually “heal” and resume regulating stimuli correctly, demonstrating that hypersensitivity is not an immutable trait, but a reversible process.
