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The following is a summary of “Chronic pain-induced functional and structural alterations in the brain: a multi-modal meta-analysis,” published in the November 2024 issue of Pain by Zeng et al. 

Chronic pain is a debilitating condition associated with brain alterations, but the variability in neuroimaging results across modalities necessitates a comprehensive multi-modal meta-analysis.  

Researchers conducted a retrospective study to examine brain alterations in individuals with chronic pain using a multi-modal meta-analysis approach, including structural, resting-state functional connectivity, and pain processing paradigms in functional magnetic resonance imaging.  

They performed a systematic literature search across PubMed, OVID Embase, OVID Medline, and Web of Science, including studies published until May 30th, 2022, to identify research on chronic pain and MRI techniques in 3 modalities. Studies meeting the inclusion criteria reported brain alterations in individuals with chronic pain across the 3 modalities, with sufficient statistical thresholds and adequate sample sizes. Voxel-wise meta-analyses were conducted using seed-based d-mapping to detect significant alterations in each modality and shared alterations across the modalities were identified by conjunction analyses.  

The results showed 47 structural, 37 resting-state functional connectivity, and 41 pain-processing studies were included in the formal analysis. Individuals with chronic pain exhibited significant structural and functional changes in the insular cortex, with reduced gray matter, disrupted functional connectivity with the frontoparietal network, and increased activation during painful stimuli processing. Distinct activation patterns were found in the left and right insular cortex when processing pain stimuli vs anticipation. Also, alterations in the superior temporal gyrus and superior frontal gyrus were monitored across all modalities.  

Investigators concluded the multi-modal meta-analysis identified consistent brain alterations in patients with chronic pain, highlighting the complex interplay between structural and functional change.   

Source: jpain.org/article/S1526-5900(24)00718-1/abstract