title: Cerebral Cortical Thickness in Chronic Pain Due to Knee Osteoarthritis: The Effect of Pain Duration and Pain Sensitization.
abstract: OBJECTIVE
  This study investigates associations between cortical thickness and pain duration, and central sensitization as markers of pain progression in painful knee osteoarthritis.
  
  
  METHODS
  Whole brain cortical thickness and pressure pain thresholds were assessed in 70 participants; 40 patients with chronic painful knee osteoarthritis (age = 66.1± 8.5 years, 21 females, mean duration of pain = 8.5 years), and 30 healthy controls (age = 62.7± 7.4, 17 females).
  
  
  RESULTS
  Cortical thickness negatively correlated with pain duration mainly in fronto-temporal areas outside of classical pain processing areas (p<0.05, age-controlled, FDR corrected). Pain sensitivity was unrelated to cortical thickness. Patients showed lower cortical thickness in the right anterior insula (p<0.001, uncorrected) with no changes surviving multiple test correction.
  
  
  CONCLUSIONS
  With increasing number of years of suffering from chronic arthritis pain we found increasing cortical thinning in extended cerebral cortical regions beyond recognised pain-processing areas. While the mechanisms of cortical thinning remain to be elucidated, we show that pain progression indexed by central sensitization does not play a major role.
authors.affiliation: Arthritis Research UK Pain Centre, University of Nottingham, Nottingham, United Kingdom.|Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom.|Arthritis Research UK Pain Centre, Radiological Sciences, Queen's Medical Centre, Nottingham, United Kingdom.
authors.forename: Hamza M
authors.initials: HM
authors.lastname: Alshuft
authors.affiliation: Arthritis Research UK Pain Centre, University of Nottingham, Nottingham, United Kingdom.|Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom.|Division of Rehabilitation and Aging, the University of Nottingham, Nottingham, United Kingdom.
authors.forename: Laura A
authors.initials: LA
authors.lastname: Condon
authors.affiliation: Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom.|Arthritis Research UK Pain Centre, Radiological Sciences, Queen's Medical Centre, Nottingham, United Kingdom.
authors.forename: Robert A
authors.initials: RA
authors.lastname: Dineen
authors.affiliation: Arthritis Research UK Pain Centre, University of Nottingham, Nottingham, United Kingdom.|Radiological Sciences, Division of Clinical Neuroscience, University of Nottingham, Nottingham, United Kingdom.|Arthritis Research UK Pain Centre, Radiological Sciences, Queen's Medical Centre, Nottingham, United Kingdom.
authors.forename: Dorothee P
authors.initials: DP
authors.lastname: Auer