title: Effects of chondroitin sulfate on brain response to painful stimulation in knee osteoarthritis patients. A randomized, double-blind, placebo-controlled functional magnetic resonance imaging study.
abstract: BACKGROUND
  Knee osteoarthritis is causing pain and functional disability. One of the inherent problems with efficacy assessment of pain medication was the lack of objective pain measurements, but functional magnetic resonance imaging (fMRI) has emerged as a useful means to objectify brain response to painful stimulation. We have investigated the effect of chondroitin sulfate (CS) on brain response to knee painful stimulation in patients with knee osteoarthritis using fMRI.
  
  
  METHODS
  Twenty-two patients received CS (800mg/day) and 27 patients placebo, and were assessed at baseline and after 4 months of treatment. Two fMRI tests were conducted in each session by applying painful pressure on the knee interline and on the patella surface. The outcome measurement was attenuation of the response evoked by knee painful stimulation in the brain.
  
  
  RESULTS
  fMRI of patella pain showed significantly greater activation reduction under CS compared with placebo in the region of the mesencephalic periaquecductal gray. The CS group, additionally showed pre/post-treatment activation reduction in the cortical representation of the leg. No effects of CS were detected using the interline pressure test.
  
  
  CONCLUSIONS
  fMRI was sensitive to objectify CS effects on brain response to painful pressure on patellofemoral cartilage, which is consistent with the known CS action on chondrocyte regeneration. The current work yields further support to the utility of fMRI to objectify treatment effects on osteoarthritis pain.
authors.affiliation: Departamento de Reumatología, Hospital del Mar, Barcelona, España.
authors.forename: Jordi
authors.initials: J
authors.lastname: Monfort
authors.affiliation: Unidad de Investigación en RM, Hospital del Mar, Cibersam G21, Barcelona, España. Electronic address: 21404jpn@comb.cat.
authors.forename: Jesús
authors.initials: J
authors.lastname: Pujol
authors.affiliation: Unidad de Investigación en RM, Hospital del Mar, Cibersam G21, Barcelona, España.
authors.forename: Oren
authors.initials: O
authors.lastname: Contreras-Rodríguez
authors.affiliation: Departamento de Reumatología, Hospital del Mar, Barcelona, España.
authors.forename: Jone
authors.initials: J
authors.lastname: Llorente-Onaindia
authors.affiliation: Unidad de Investigación en RM, Hospital del Mar, Cibersam G21, Barcelona, España; Department of Psychology and Neuroscience. University of Colorado Boulder, Colorado, Estados Unidos.
authors.forename: Marina
authors.initials: M
authors.lastname: López-Solà
authors.affiliation: Unidad de Investigación en RM, Hospital del Mar, Cibersam G21, Barcelona, España.
authors.forename: Laura
authors.initials: L
authors.lastname: Blanco-Hinojo
authors.affiliation: Área de Investigación y Desarrollo Clínico, División de Farma-Ciencia, Bioibérica, Barcelona, España.
authors.forename: Josep
authors.initials: J
authors.lastname: Vergés
authors.affiliation: Área de Investigación y Desarrollo Clínico, División de Farma-Ciencia, Bioibérica, Barcelona, España.
authors.forename: Marta
authors.initials: M
authors.lastname: Herrero
authors.affiliation: Área de Investigación y Desarrollo Clínico, División de Farma-Ciencia, Bioibérica, Barcelona, España.
authors.forename: Laura
authors.initials: L
authors.lastname: Sánchez
authors.affiliation: Unidad de Investigación en RM, Hospital del Mar, Cibersam G21, Barcelona, España.
authors.forename: Hector
authors.initials: H
authors.lastname: Ortiz
authors.affiliation: Centro de Atención Sanitaria Primaria Vila Olímpica (PAMEM), Barcelona, España.
authors.forename: Francisco
authors.initials: F
authors.lastname: Montañés
authors.affiliation: Unidad de Investigación en RM, Hospital del Mar, Cibersam G21, Barcelona, España; Departamento de Psicología Clínica y Sanitaria, Universidad Autónoma de Barcelona, Barcelona, España.
authors.forename: Joan
authors.initials: J
authors.lastname: Deus
authors.affiliation: Departamento de Reumatología, Hospital del Mar, Barcelona, España.
authors.forename: Pere
authors.initials: P
authors.lastname: Benito
mesh_terms: D000368:Aged; D000700:Analgesics / Q000494:pharmacology* / Q000627:therapeutic use; D002809:Chondroitin Sulfates / Q000494:pharmacology* / Q000627:therapeutic use; D004311:Double-Blind Method; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D059906:Neuroimaging; D020370:Osteoarthritis, Knee / Q000188:drug therapy*; D010147:Pain Measurement / Q000379:methods*; D058748:Pain Perception / Q000187:drug effects*; D010487:Periaqueductal Gray / Q000000981:diagnostic imaging / Q000187:drug effects; D016896:Treatment Outcome
chemical_list: D000700:Analgesics; D002809:Chondroitin Sulfates
keywords: Artrosis de rodilla; Chondroitin sulfate; Condroitín sulfato; Dolor; Functional magnetic resonance image; Knee osteoarthritis; Pain; Resonancia magnética funcional