title: Patients with pain disorder show gray-matter loss in pain-processing structures: a voxel-based morphometric study.
abstract: OBJECTIVE
  To investigate whether the functional changes in pain disorder might be reflected by structural brain changes. Pain disorder assessed with the Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (DSM-IV) criteria is characterized by persistent and distressing chronic pain at one or more body sites which cannot be fully explained by a physiological process or somatic disorder. Psychological factors are thought to play a major role. Recent neuroimaging studies evidenced altered pain processing in patients suffering from this disorder.
  
  
  METHODS
  Fourteen right-handed women fulfilling the DSM-IV criteria for pain disorder and 25 healthy age-matched women were investigated with magnetic resonance imaging. In the voxel-based morphometry analysis, we compared both groups for changes of gray-matter density. We included age and Beck Depression Inventory scores as nuisance variables to minimize possible confounding effects of age or depressive comorbidity.
  
  
  RESULTS
  In the patient group, we found significant gray-matter decreases in the prefrontal, cingulate, and insular cortex. These regions are known to be critically involved in the modulation of subjective pain experiences.
  
  
  CONCLUSIONS
  In the context of similar results in patients with other functional pain syndromes, such as fibromyalgia and chronic back pain, we suggest that structural changes in fronto-limbic brain circuits represent not only an objective marker of these pain syndromes but also constitute a critical pathophysiological element. These findings represent a further proof of the important role of central changes in pain disorder.
authors.affiliation: Neurologische Klinik, Klinikum rechts der Isar, Technische Universität München, München, Germany. valet@lrz.tum.de
authors.forename: Michael
authors.initials: M
authors.lastname: Valet
authors.forename: Harald
authors.initials: H
authors.lastname: Gündel
authors.forename: Till
authors.initials: T
authors.lastname: Sprenger
authors.forename: Christian
authors.initials: C
authors.lastname: Sorg
authors.forename: Mark
authors.initials: M
authors.lastname: Mühlau
authors.forename: Claus
authors.initials: C
authors.lastname: Zimmer
authors.forename: Peter
authors.initials: P
authors.lastname: Henningsen
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Tölle
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000886:Anthropometry; D002540:Cerebral Cortex / Q000473:pathology*; D015986:Confounding Factors, Epidemiologic; D003863:Depression / Q000150:complications / Q000473:pathology; D003865:Major Depressive Disorder / Q000150:complications / Q000473:pathology; D005260:Female; D005858:Germany / Q000453:epidemiology; D006179:Gyrus Cinguli / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D010146:Pain / Q000453:epidemiology / Q000473:pathology* / Q000523:psychology; D017397:Prefrontal Cortex / Q000473:pathology; D013001:Somatoform Disorders / Q000453:epidemiology / Q000473:pathology* / Q000523:psychology