403: Brain Changes in Chronic Low Back Pain comapred to healthy controls: An fMRI Study

Topic: Clinical Science
Subtopic: Pain category (ICD-11), Chronic primary musculoskeletal pain, Physiotherapy, Treatment/management , Imaging (e.g. fMRI, PET, MRS)

Background and Aims: Chronic low back pain (CLBP) is associated with persistent pain, disability, and altered central pain processing. Neuroimaging evidence suggests that long-standing pain is linked with structural and functional brain changes, particularly in regions involved in pain modulation, emotion, and motor control. However, the pattern of baseline brain alterations in CLBP compared with healthy individuals requires further clarification. Understanding these changes is important for identifying central mechanisms contributing to pain persistence. This study aimed to compare baseline structural brain measures, functional connectivity, and effective connectivity between individuals with CLBP and healthy controls using functional magnetic resonance imaging.

Methods: This cross-sectional study included 30 individuals with chronic low back painand 10 age- and sex-matched healthy controls. All participants underwent resting-state and task based functional magnetic resonance imaging using a 1.5T scanner. Structural analysis was performed to assess grey matter volume using voxel-based morphometry. Functional connectivity was examined within key networks including the default mode network and sensorimotor network. Effective connectivity was analysed using directional modelling approaches to study influence between brain regions. Clinical measures including pain intensity and disability were recorded in the CLBP group. Between-group comparisons were performed to identify structural and connectivity differences at baseline.

Results: Compared to healthy controls, individuals with CLBP showed significant reduction in grey matter volume in the dorsolateral prefrontal cortex, anterior cingulate cortex, insula, and thalamus. Functional connectivity analysis revealed decreased connectivity within the default mode network and disrupted connectivity between sensorimotor and prefrontal regions. Increased connectivity was observed in limbic areas associated with emotional processing. Effective connectivity analysis demonstrated altered directional influence from the prefrontal cortex to the thalamus and amygdala, suggesting impaired top-down pain modulation. These structural and network-level alterations were consistent across participants with moderate to severe disability scores in the CLBP group.

Conclusions: The findings demonstrate that chronic low back pain is associated with measurable structural and connectivity changes in brain regions involved in pain processing, emotional regulation, and motor control. Reduced grey matter volume and disrupted functional and effective connectivity indicate maladaptive neuroplastic changes in persistent pain. Altered top-down modulation pathways may contribute to pain chronification and disability. These baseline differences highlight the central nervous system involvement in chronic musculoskeletal pain. Understanding these alterations may help in developing targeted rehabilitation strategies aimed at restoring normal brain connectivity and improving long-term clinical outcomes in individuals with chronic low back pain.

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Presenting Author: Muhammed Rashid
Submitting Author: Muhammed Rashid

Senior Author: Muhammed Rashid

IASP 2026 Global Year theme of Neuropathic Pain: No