title: Alterations in resting-state regional cerebral blood flow demonstrate ongoing pain in osteoarthritis: An arterial spin-labeled magnetic resonance imaging study.
abstract: OBJECTIVE
  Increasing evidence suggests a central nervous system (CNS) component underpinning persistent pain disease states. This study was undertaken to determine regional cerebral blood flow (rCBF) changes representing ongoing pain experienced by patients with painful osteoarthritis (OA) of the carpometacarpal (CMC) joint and to examine rCBF variability across sessions. We used pulsed continuous arterial spin labeling (pCASL), a perfusion magnetic resonance imaging (MRI) technique.
  
  
  METHODS
  The study included 16 patients with CMC OA and 17 matched controls. Two pCASL scans and numerical rating scale (NRS) estimates of ongoing pain were acquired in each of two identical sessions. Voxelwise general linear model analyses were performed to determine rCBF differences between OA and control groups, rCBF differences between sessions within each group, and whether sessionwise rCBF differences were related to variability in perceived ongoing pain.
  
  
  RESULTS
  In the OA group, rCBF increases representing ongoing pain were identified in the primary and secondary somatosensory, insula, and cingulate cortices; thalamus; amygdala; hippocampus; and dorsal midbrain/pontine tegmentum, including the periaqueductal gray/nucleus cuneiformis. Sessionwise rCBF differences in the OA group in the postcentral, rostral/subgenual cingulate, mid/anterior insula, prefrontal, and premotor cortices were related to changes in perceived ongoing pain. No significant sessionwise rCBF differences were observed in controls.
  
  
  CONCLUSIONS
  This is the first quantitative endogenous perfusion MRI study of the cerebral representation of ongoing, persistent pain due to OA. Observed rCBF changes potentially indicate dysregulated CNS appraisal and modulation of pain, most likely the maladaptive neuroplastic sequelae of living with painful OA. Understanding the neural basis of ongoing pain is likely to be important in developing novel treatment strategies.
authors.affiliation: King's College London, London, UK. Matthew.Howard@kcl.ac.uk
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Howard
authors.forename: Duncan
authors.initials: D
authors.lastname: Sanders
authors.forename: Kristina
authors.initials: K
authors.lastname: Krause
authors.forename: Jonathan
authors.initials: J
authors.lastname: O'Muircheartaigh
authors.forename: Aikaterini
authors.initials: A
authors.lastname: Fotopoulou
authors.forename: Fernando
authors.initials: F
authors.lastname: Zelaya
authors.forename: Michael
authors.initials: M
authors.lastname: Thacker
authors.forename: Nathalie
authors.initials: N
authors.lastname: Massat
authors.forename: John P
authors.initials: JP
authors.lastname: Huggins
authors.forename: William
authors.initials: W
authors.lastname: Vennart
authors.forename: Ernest
authors.initials: E
authors.lastname: Choy
authors.forename: Maxine
authors.initials: M
authors.lastname: Daniels
authors.forename: Steven C R
authors.initials: SC
authors.lastname: Williams
mesh_terms: D018771:Arthralgia / Q000503:physiopathology*; D001931:Brain Mapping; D052737:Carpometacarpal Joints; D016022:Case-Control Studies; D002490:Central Nervous System / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D054022:Cerebrum / Q000098:blood supply*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008875:Middle Aged; D009473:Neuronal Plasticity / Q000502:physiology; D010003:Osteoarthritis / Q000503:physiopathology*; D012039:Regional Blood Flow / Q000502:physiology*; D012146:Rest / Q000502:physiology*; D013113:Spin Labels
chemical_list: D013113:Spin Labels