Chronic back pain may activate an unexpected brain network, study finds

Chronic lower back pain, which persists for at least three months, is a major cause of disability globally. Researchers have discovered that movements triggering flare-ups of this type of pain may activate a brain network associated with self-awareness. In a study published in the British Journal of Anaesthesia, scientists found that chronic back pain was linked to increased activity in the brain's default mode network, a group of connected regions typically more active during self-reflection and mind wandering.

This was surprising because the default mode network usually becomes less active during acute pain. The study, involving 114 adults with chronic lower back pain, used functional magnetic resonance imaging (fMRI) to measure brain activity during a leg movement that induced pain. The results showed that the pain flare-ups increased blood flow in pain-processing and movement-regulating brain regions, but also in key default mode network areas.

Participants reporting more severe chronic back pain exhibited stronger connections between the default mode network and regions processing sensations from the back. This suggests that chronic pain may become intertwined with how individuals perceive themselves and their bodies. The researchers noted that while the observed brain activity could reflect lingering pain or anxiety, future treatments for chronic pain might target how people relate to their pain, rather than just the pain sensations themselves.