Alterations in functional connectivity in patients with non-specific chronic low back pain after motor control exercise: a randomized trial

Abstract

BACKGROUND Motor control exercise (MCE) is effective in alleviating non-specific chronic low back pain (NCLBP). Neuro-imaging research is warranted to explore the underlying neural mechanisms of MCE. AIM We used resting-state functional magnetic resonance imaging (rs-fMRI) to explore the central mechanism underpinning the effects of MCE in patients with NCLBP. DESIGN A randomized, single-blinded, controlled trial. SETTING The setting was out-patient and community. POPULATION Fifty-eight patients with NCLBP. METHODS Patients were randomized into the MCE or manual therapy (MT) group. All the participants completed pain-related clinical assessments and rs-fMRI scans before and after intervention. We performed exploratory whole-brain analyses in regional homogeneity (ReHo) and resting-state functional connectivity (rsFC) with significant post-pre differences in ReHo before and after intervention, and investigated associations between imaging and pain-related clinical assessments. RESULTS Compared with the MT group, a greater alleviation in pain intensity and disability was observed in the MCE group after intervention, and was sustained at the 6-month follow-up (P<0.001). Only the MCE group showed increased ReHo values in the right pre-central gyrus and decreased ReHo values in the bilateral posterior cerebellum (voxel level P<0.001, cluster-level FWE corrected P<0.05). Decreased rsFC of the right posterior cerebellum-left superior parietal gyrus and left insula were significantly positively associated with pain-related disability (voxel level P<0.001, cluster-level FWE corrected P<0.05). CONCLUSIONS These findings demonstrated that MCE had superior effects in relieving pain and pain-related disability, which might be associated with its modulation of rsFC between the cerebellum and areas involved in sensory-discriminative processing of noxious and somato-sensory stimuli, affection, and cognition. CLINICAL REHABILITATION IMPACT This study provided preliminary evidence that MCE might alleviate NCLBP through its modulation of the function of brain areas related to chronic pain and postural control. Those results support MCE’s clinical application and help physiotherapists to provide better multidisciplinary interventions with the combination of MCE and other first-line treatments.

Disrupted Resting-State Functional Connectivity and Effective Connectivity of the Nucleus Accumbens in Chronic Low Back Pain: A Cross-Sectional Study

“… 32 Another study reported significantly altered EC in the cerebellum-neocortex and cerebellum-basal ganglia circuits in patients with major depressive disorder, 31 and decreased rsFC between bilateral cerebellar and cortical brain regions in patients with cLBP after motor control exercise. 62 Both the brainstem and the cerebellum have important roles in the regulation of pain and emotion; therefore, the abnormalities of the rsFC and EC between them and NAC may be an important reason for the persistence of pain and negative emotions in cLBP.…”