Disrupted functional connectivity of the periaqueductal gray in chronic low back pain.
Chronic low back pain is a common neurological disorder. The periaqueductal gray (PAG) plays a key role in the descending modulation of pain. In this study, we investigated brain resting state PAG functional connectivity (FC) differences between patients with chronic low back pain (cLBP) in low pain or high pain condition and matched healthy controls (HCs). PAG seed based functional connectivity (FC) analysis of the functional MR imaging data was performed to investigate the difference among the connectivity maps in the cLBP in the low or high pain condition and HC groups as well as within the cLBP at differing endogenous back pain intensities. Results showed that FC between the PAG and the ventral medial prefrontal cortex (vmPFC)/rostral anterior cingulate cortex (rACC) increased in cLBP patients compared to matched controls. In addition, we also found significant negative correlations between pain ratings and PAG-vmPFC/rACC FC in cLBP patients after pain-inducing maneuver. The duration of cLBP was negatively correlated with PAG-insula and PAG-amygdala FC before pain-inducing maneuver in the patient group. These findings are in line with the impairments of the descending pain modulation reported in patients with cLBP. Our results provide evidence showing that cLBP patients have abnormal FC in PAG centered pain modulation network during rest.
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA ; Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA ; Department of Psychology, National University of Singapore, Singapore, Singapore.
Rongjun
R
Yu
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA ; Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
Randy L
RL
Gollub
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA ; Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
Rosa
R
Spaeth
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA ; Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
Vitaly
V
Napadow
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA ; Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA ; Perioperative and Pain Medicine, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School (HMS), Boston, MA, USA.
Ajay
A
Wasan
Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA ; Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, USA.
Jian
J
Kong
D000328:Adult; D059350:Chronic Pain / Q000175:diagnosis / Q000378:metabolism*; D005260:Female; D006801:Humans; D017116:Low Back Pain / Q000175:diagnosis / Q000378:metabolism*; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008875:Middle Aged; D009434:Neural Pathways / Q000378:metabolism / Q000473:pathology; D010147:Pain Measurement / Q000379:methods*; D010487:Periaqueductal Gray / Q000378:metabolism* / Q000473:pathology; D017397:Prefrontal Cortex / Q000378:metabolism* / Q000473:pathology; D055815:Young Adult
Chronic low back pain; Functional connectivity; Periaqueductal gray; fMRI