Objective: Chronic low back pain has been observed to decrease movement coordination. However, it is unclear whether the existing alteration of inter-hemispheric synchrony of intrinsic activity in patients with chronic low back-related leg pain (cLBLP). The present study aims to investigate the alteration of homotopic connectivity and its clinical association with the cLBLP patients.
Participants and methods: A cohort of cLBLP patients (n=25) and well-matched healthy controls (HCs) (n=27) were recruited and underwent MRI scanning and a battery of clinical tests. The voxel-mirrored homotopic connectivity (VMHC) was used to analyze the interhemispheric coordination in the typical (0.01–0.1 Hz) as well as five specific (slow-6 to slow-2) frequency bands and associated with clinical index in cLBLP patients.
Results: We observed that cLBLP patients with lower homotopic connectivity than HCs in the inferior temporal gyrus, the superior temporal gyrus, the basal ganglia, the middle frontal gyrus, and the medial prefrontal cortex in the typical and five specific frequency bands, respectively. In the typical and five specific frequency bands, significant positive correlations were observed between the VMHC values of medial prefrontal cortex and the visual analogue scale scores, while the VMHC values of basal ganglia negative correlated with the values of two-point tactile discrimination (2PD) test for the right hand in cLBLP patients, etc. Further receiver operating characteristic curve analysis revealed that VMHC in the above regions with decreased could be used to differentiate the cerebral functional plasticity of cLBLP from healthy individuals with high sensitivity and specificity.
Conclusion: Our results imply that multiscale frequency-related interhemispheric disconnectivity may underlie the central pathogenesis of functional coordination in patients with cLBLP.
Keywords: interhemispheric integration, voxel-mirrored homotopic connectivity, chronic low back-related leg pain, chronic pain, resting-state fMRI