Introduction: The transition from acute to chronic low back pain (cLBP) is associated with reduced neural density in the insular cortex, a neural hub for interoception and the salience network. People commonly cope with cLBP by ignoring it and distracting themselves from the experience of pain. This coping style appears to be beneficial for acute pain but has been shown to be of questionable benefit for chronic pain. Can an opposite coping style of mindful interoceptive exposure to the pain experience itself and its phenomenological sensory components be an alternative approach?
Methods: We performed a single-arm feasibility study in patients with cLBP using a 2-minute attention exercise guided by a smartphone app several times per day over 8 weeks. We assessed feasibility, standard pre-post pain outcomes, function and key psychological parameters by standard questionnaires and EMA. We compared pre to post intervention quantitative sensory testing and task-based fMRI. We used reflexive thematic qualitative analysis for exit interviews that included an innovative micro-phenomenology technique.
Results: Pre-screened 301 patients, 38 eligible/consented, 31 enrolled, 29 completed, mostly female, mean age 48, majority pain for >5 years. Mean pain intensity [0-10] improved from 4.8 ±1.7 to 3.1 ±1.9 (p <.001); mean PEG score (intensity and interference with daily life; range 0-30) 13.7 ±6.2 to 8.4 ±6.6 (p <.001); pain impact (9 items incl physical function) 22.3 ±8.7 to 19.7 ±8.1 (p =.004). 21 of 29 improved PEG score ³30%. There were significant improvements in PCS Rumination and MAIA Not-Worrying. Mid-posterior insula (interoceptive sensory cortex) pain-related fMRI activation recovered with high responders showing significantly greater recovery compared to low responders. Exit interviews demonstrated that participants became aware of their usual habit of avoidance and the challenge of and resistance to focusing on pain. They were surprised how pain sensations varied over time and described a variety of three-dimensional pain shapes with a variety of colors, transparency, temperature, and density that for some changed dramatically with a mindful attention focus. They reported on using regulation of breathing and found that the threat value of their pain diminished.
Discussion: This single-arm study assessed a phone-based mindful interoceptive attention task for patients with chronic low back pain by mixed methods including questionnaires, QST, fMRI and interviews. The findings appear to support the notion that mindful interoceptive exposure to the sensations of their cLBP using a simple 2-minute attention exercise with a phone app—rather than ignoring and distracting from it—may be beneficial for cLBP. If confirmed by further research, this would be an innovative paradigm for pain management.