Background & Aims

Chronic low back pain(cLBP) is a major public health concern and medication treatment is of limited value. Mind-body interventions like Mindfulness-Based Stress Reduction show modest benefits, while the Mindfulness-based Interoceptive Exposure Task (MIET) from mindfulness-integrated cognitive behavioral therapy displayed promising results in a pilot study[1]. MIET focuses on interoception, the perception of body stimuli including pain[1]. The insula cortex (IC), the core interoceptive region, is crucial for acute pain processing, pain chronicity, maintenance and recovery, with dysfunctional insula function and structure often observed in cLBP[2;3]. This study explores an 8-week, smartphone-based interoceptive attention training for cLBP, and assesses its impact on pain-related brain response with functional MRI. We argue that changes in neural circuitry underlying interoception may serve as biomarker for the study of mind-body approaches for cLBP.

Methods

This mixed methods study involved 29 participants who met criteria for cLBP and also rated low on interoceptive awareness[4]. Subjects completed self-report battery, quantitative sensory testing (QST) and functional MRI (intervention details and qualitative data are reported in the accompanying abstract#AMYWZ5DLMY). The Pain, Enjoyment of Life, and General Activity Scale(PEG) was the primary outcome measure. Data were analyzed for treatment response, defined as at least 50% reduction in PEG scores over treatment. This resulted in two groups: MyP+(n=15) and MyP-(n=14). Subjects completed a validated thermal pain-anticipation paradigm[5] in the scanner at baseline and at 8-weeks following treatment completion. The fMRI data was preprocessed and modeled with AFNI. Group level analysis was conducted with linear mixed effects models using 3dLMEr and examined for Group (MyP+, MyP-) x Time (Pre, Post) effects.

Results

On average, MyP+ showed 65% decrease in PEG scores, while MyP- showed a 9.3% increase. Whole-brain linear mixed effects models showed pain anticipation related activations within right prefrontal cortex and several visual areas. During pain stimulation, significant group-by-time interaction was observed within the bilateral ventral anterior insulas, right posterior insula, left ventral striatum, ventral anterior cingulate, the right prefrontal cortex, posterior cingulate and several visual areas. Furthermore, although groups did not differ in behavioral and QST measures, and did not show many neural differences in experimental pain-related activation at baseline, baseline differences related to the endogenous back pain processing were observed within anterior insula during thermal pain anticipation and in posterior insula/parietal operculum during thermal pain stimulation.

Conclusions

This work suggests that an 8-week, smartphone-based interoceptive attention training can effectively reduce chronic pain and modify pain-related brain response suggesting that changes in neural circuitry underlying interoception may serve as biomarker for the study of mind-body approaches for cLBP. Our findings add valuable information to the mechanisms underlying the effects of non-opioid, interoception-based therapies in cLBP sufferers. Our new mobile intervention–if shown effective in RCTs–implies a potential paradigm shift in the management of chronic pain. Further work is warranted.

References

[1] Craig AD. How do you feel? Interoception: the sense of the physiological condition of the body. NatRevNeurosci 2002;3(8):655-666.
[2] Craig AD. How do you feel [mdash] now? The anterior insula and human awareness. Nat Rev Neurosci 2009;10(1):59-70.
[3] Ferraro S, Klugah-Brown B, Tench CR, Yao S, Nigri A, Demichelis G, Pinardi C, Bruzzone MG, Becker B. Dysregulated anterior insula reactivity as robust functional biomarker for chronic pain-Meta-analytic evidence from neuroimaging studies. Hum Brain Mapp 2022;43(3):998-1010.
[4] Mehling WE, Acree M, Stewart A, Silas J, Jones A. The Multidimensional Assessment of Interoceptive Awareness, Version 2 (MAIA-2). PLoS One 2018;13(12):e0208034.

Presenting Author

Irina Strigo

Poster Authors

Sergio Garcia Guerra

BSc

NCIRE

Lead Author

Salvatore Torrisi

University of California, San Francisco

Lead Author

Emily Murphy MA

Emotion and Pain Laboratory, San Francisco Veterans Affairs Health Care Center

Lead Author

Tiffany Toor BS

Emotion and Pain Laboratory, San Francisco Veterans Affairs Health Care Center

Lead Author

Veronica Goldman BS

Osher Center for Integrative Health, University of California San Francisco

Lead Author

Benedict Alter

University of Pittsburgh

Lead Author

Joseph Vu PhD

VA Advanced Imaging Research Center, San Francisco Veterans Affairs Health Care Center

Lead Author

Rick Hecht

Osher Center for Integrative Health, University of California San Francisco

Lead Author

Jeff Lotz PhD

Department of Orthopedic Surgery, University of California San Francisco

Lead Author

Alan Simmons PhD

Department of Psychiatry, University of California San Diego

Lead Author

Wolf Mehling

UCSF

Lead Author

Irina Strigo

Emotion and Pain Laboratory, San Francisco Veterans Affairs Health Care Center

Lead Author

Topics

  • Treatment/Management: Pharmacology: Psychological and Rehabilitative Therapies