Chronic back pain is associated with parts of the brain not communicating normally. This study finds that spinal manipulation helps the brain to re-organize itself, and may be another mechanism as to how chiropractic treatment helps back problems. ~ Dr. Broussard
Increased Salience Network Connectivity following Spinal Manipulative Therapy is Associated with Reduced Pain in Chronic Low Back Pain Patients
The Journal of Pain
K. Isenburg, M. Loggia
April 2019 Volume 20, Issue 4, Supplement, Page S42
Abstract
Chronic low back pain (cLBP) has been associated with maladaptive brain plasticity, and non-pharmacological therapies such as Spinal Manipulative Therapy (SMT) have shown promise in reducing pain and modifying intrinsic brain physiology. However, more translational research is needed using clinical models. We investigated functional salience network (SLN) connectivity response to SMT, and linked response to cLBP pain reduction. Fifteen cLBP patients (8 female, 37.7 ± 9.7 (M± SD) years old), and 16 healthy controls (HC, 8 female, 38.2 ± 10.4 years old) were scanned with resting state fMRI before and after a single session of spinal manipulation and spinal mobilization (grades V and III of the Maitland Joint Mobilization Grading Scale) at separate visits. Patients rated clinical pain (0-100) pre- and post-therapy. Intrinsic SLN connectivity was assessed using dual regression probabilistic independent component analysis. Voxelwise analyses were cluster corrected for multiple comparison (z>2.3, p<0.05), followed by Region of Interest (ROI) analyses (α<0.05). Both manipulation (t=3.3, p=0.005) and mobilization (t=2.56, p=0.02) reduced clinical back pain following SMT. However, manipulation (but not mobilization) significantly increased SLN connectivity to thalamus (F=18.18, p<0.001) and M1 (F=4.89, p=0.04). Additionally, this increase for cLBP was greater than for HC following manipulation (Thal: F=12.75, p<0.001; M1: F=12.16, p<0.002). Furthermore, a voxelwise regression analysis indicated that greater SMT-induced increase in SLN connectivity to lateral prefrontal cortex (LPFC) was associated with with greater clinical back pain reduction. Interestingly, for spinal mobilization, a ROI-based regression analysis using this LPFC cluster found a similar non-significant trend between pain reduction and LPFC connectivity post-mobilization (R=-0.44, p=0.1). Our data suggest that while manipulation increases SLN connectivity to sensorimotor processing regions (i.e. thalamus, M1), increased SLN connectivity to cognitive processing regions (i.e. LPFC) supports SMT analgesia, with more robust recruitment of this brain-based mechanism by spinal manipulation compared to mobilization.