Researchers at UC San Diego found that movement-triggered chronic back pain activates the brain's default mode network, suggesting the condition is deeply tied to a patient's sense of self.

Researchers at the UC San Diego School of Medicine have discovered that the brain's default mode network (DMN) activates during movement-induced chronic low back pain flares. Published in the British Journal of Anaesthesia, the study indicates that this network, often called the 'self network,' becomes engaged when patients experience pain triggered by movement. This finding suggests that chronic pain is not just a physical sensation but is integrated into a patient's identity.

Brain Activity During Pain Flares

The study involved 114 patients with chronic low back pain who performed a 'leg raise test' to trigger pain flares while undergoing functional MRI brain scans. Researchers observed that, unlike acute pain which typically causes the DMN to deactivate, movement-evoked chronic pain caused the DMN to turn on. Patients with more severe pain displayed stronger connections between the DMN and the primary somatosensory cortex, the region responsible for processing sensations from the back.

Implications for Pain Treatment

The findings suggest that standard symptom-based treatments, such as opiates, may be ineffective for chronic low back pain because they do not address the brain's maladaptive coupling of physical pain with the sense of self. Corresponding author Fadel Zeidan noted that current medicine often focuses on symptom removal rather than the source of chronic pain. The research team is now investigating mind-body approaches, including mindfulness meditation and psilocybin, to help patients separate the physical experience of pain from their identity.