NEW DELHI: A study has found that targeting the brain's default mode network, which becomes active when one is thinking about themselves and their identity or reflecting on internal thoughts and feelings, may be a better approach to managing chronic low back pain.
Findings published in the British Journal of Anaesthesia showed pain that patients of chronic low back pain experience due to a movement could be turning on the brain region, or 'self-network', possibly explaining why typical symptom-based treatments are often ineffective.
Researchers from the US' University of California San Diego had 114 patients perform a 'leg raise test' -- a standard way to trigger a back pain flare -- while measuring blood flow in the brain using a specialised functional MRI technique.
The team also tested how the patients' brains responded to a harmless but painful heat stimulus on the calf, comparable to accidentally touching a hot stove.
They found that the brain region's default mode network is turned on when patients of chronic low back pain experience sudden pain brought on by a movement, providing the first evidence that the experience of chronic pain is not merely a sensation, but is deeply embedded in the sense of self.
In contrast, when the participants were subjected to the painful heat, their default mode network shut down, which is the brain's usual response to acute pain, allowing the brain to focus entirely on the external threat rather than on the self, according to author Fadel Zeidan, professor in the department of anesthesiology.
"In every pain study, when you're experiencing pain, the DMN (default mode network) deactivates," said Zeidan.
"What we show for the first time ever is that when you have a pain flare, it turns on instead. You start to identify the experience with who you are," the author said.
About 619 million people across the world were affected by low back pain in 2020, the World Health Organization says.
In essence, the brain in chronic low back pain is maladaptively coupling the physical pain with a deep, internal sense of self, the researchers said.
"The moment-to-moment experience is contaminated not only by the feeling of pain, but by the anticipation of it and recovery from it. It's contaminated by past experiences like embarrassment about not being able to participate in normal activities and fear of movement when trying to avoid the pain," Zeidan said.
Standard treatments including opiates often fail because pain flares evoked by movement in chronic low back pain patients activate different brain networks than typical acute pain, the researchers said.
"Current pain medicine is fixated on ridding patients of their pain symptoms, but that's not the source of chronic pain. These data suggest that a chronic pain flare also encompasses one's identity," Zeidan said.
Mind-body and psychedelic medicine approaches target the whole person, Zeidan said.
"Mindfulness is a meditation technique that's about cultivating non-judgmental awareness of the present moment that dramatically reduces pain in a very unique way. Psilocybin seemingly resets the pain system that integrates trauma, past experiences and future worries to facilitate a restart, if you will," the author explained.
"They're not a silver bullet -- you're not necessarily getting rid of the pain, but you're changing the relationship you have with that pain so it doesn't contaminate your everyday life," Zeidan said.