title: White matter involvement in chronic musculoskeletal pain.
abstract: There is emerging evidence that chronic musculoskeletal pain is associated with anatomic and functional abnormalities in gray matter. However, little research has investigated the relationship between chronic musculoskeletal pain and white matter. In this study, we used whole-brain tract-based spatial statistics and region-of-interest analyses of diffusion tensor imaging data to demonstrate that patients with chronic musculoskeletal pain exhibit several abnormal metrics of white matter integrity compared with healthy controls. Chronic musculoskeletal pain was associated with lower fractional anisotropy in the splenium of the corpus callosum and the left cingulum adjacent to the hippocampus. Patients also had higher radial diffusivity in the splenium, right anterior and posterior limbs of the internal capsule, external capsule, superior longitudinal fasciculus, and cerebral peduncle. Patterns of axial diffusivity (AD) varied: patients exhibited lower AD in the left cingulum adjacent to the hippocampus and higher AD in the anterior limbs of the internal capsule and in the right cerebral peduncle. Several correlations between diffusion metrics and clinical variables were also significant at a P < .01 level: fractional anisotropy in the left uncinate fasciculus correlated positively with total pain experience and typical levels of pain severity. AD in the left anterior limb of the internal capsule and left uncinate fasciculus was correlated with total pain experience and typical pain level. Positive correlations were also found between AD in the right uncinate and both total pain experience and pain catastrophizing. These results demonstrate that white matter abnormalities play a role in chronic musculoskeletal pain as a cause, a predisposing factor, a consequence, or a compensatory adaptation.
  
  
  CONCLUSIONS
  Patients with chronic musculoskeletal pain exhibit altered metrics of diffusion in the brain's white matter compared with healthy volunteers, and some of these differences are directly related to symptom severity.
authors.affiliation: MindBody Medicine Clinic at Fletcher Allen Healthcare and Clinical Neuroscience Research Unit, University of Vermont, Burlington, Vermont.
authors.forename: Gregory
authors.initials: G
authors.lastname: Lieberman
authors.affiliation: MindBody Medicine Clinic at Fletcher Allen Healthcare and Clinical Neuroscience Research Unit, University of Vermont, Burlington, Vermont.
authors.forename: Marina
authors.initials: M
authors.lastname: Shpaner
authors.affiliation: Department of Radiology and MRI Center for Biomedical Imaging, University of Vermont, Burlington, Vermont.
authors.forename: Richard
authors.initials: R
authors.lastname: Watts
authors.affiliation: Department of Radiology and MRI Center for Biomedical Imaging, University of Vermont, Burlington, Vermont; Philips Healthcare, Best, The Netherlands.
authors.forename: Trevor
authors.initials: T
authors.lastname: Andrews
authors.affiliation: Department of Radiology, Columbia University, New York, New York.
authors.forename: Christopher G
authors.initials: CG
authors.lastname: Filippi
authors.affiliation: MindBody Medicine Clinic at Fletcher Allen Healthcare and Clinical Neuroscience Research Unit, University of Vermont, Burlington, Vermont.
authors.forename: Marcia
authors.initials: M
authors.lastname: Davis
authors.affiliation: MindBody Medicine Clinic at Fletcher Allen Healthcare and Clinical Neuroscience Research Unit, University of Vermont, Burlington, Vermont. Electronic address: Magdalena.Naylor@uvm.edu.
authors.forename: Magdalena R
authors.initials: MR
authors.lastname: Naylor
mesh_terms: D000328:Adult; D059350:Chronic Pain / Q000473:pathology*; D038524:Diffusion Magnetic Resonance Imaging; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008297:Male; D008875:Middle Aged; D059352:Musculoskeletal Pain / Q000473:pathology*; D066127:White Matter / Q000473:pathology*
keywords: Diffusion tensor imaging (DTI); chronic pain; neuroimaging; white matter