Chronic Back Pain Linked to Heightened Sound Sensitivity

A new study by the University of Colorado Anschutz has established a connection between chronic back pain and altered processing of everyday sounds. Individuals with chronic back pain reportedly process sounds more intensely compared to those without pain.

The research, published in Annals of Neurology, identified specific, measurable brain changes linked to this sound hypersensitivity.

The study suggests that chronic back pain impacts more than just the back, indicating a broader sensory amplification within the brain.

Unpacking the Study: Brain Changes Revealed

The study compared self-reported and neural responses in 142 adults experiencing chronic back pain against 51 pain-free control participants. All participants underwent brain imaging.

During MRI sessions, participants listened to various sounds, reported how unpleasant they felt, and researchers measured the responses in key brain regions. Differences between the groups were significant, with chronic pain patients reacting more strongly than 84% of pain-free individuals on average.

Brain scans showed stronger responses in regions that process sound (auditory cortex) and emotional sensations (insula), indicating that the changes were occurring higher up in the brain. Simultaneously, lower activity was observed in brain regions typically involved in regulating reactions, such as the medial prefrontal cortex.

Promising Treatment: Pain Reprocessing Therapy

The researchers also investigated treatment options by assigning participants with chronic back pain to one of three groups:

• Pain Reprocessing Therapy (PRT): This therapy is designed to help individuals reframe pain as an amplification by the brain rather than solely a physical issue in the back.
• Placebo treatment: A saline injection administered within a supportive clinical environment.
• Usual care: Participants continued with their existing treatments.

Pain Reprocessing Therapy proved to be the most effective intervention. It not only reduced the heightened brain response to sound but also increased activity in brain regions associated with regulating unpleasant experiences.

Previous research by the study's senior author, Yoni Ashar, PhD, indicated that PRT led two-thirds of participants with chronic back pain to become pain-free or nearly pain-free following treatment.

Implications and Future Directions

The findings suggest that the brain's exaggerated sensory response is treatable with psychological intervention.

The study also raises questions regarding whether this heightened sensitivity causes chronic back pain or represents a pre-existing vulnerability. Future research will explore if this amplification extends to other senses like light, smell, or taste, and whether a central brain region is responsible for such widespread sensory amplification.