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  • Poster presentation
  • Open Access

Pain threshold in adolescents with juvenile idiopathic arthritis and fibromyalgia

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Pediatric Rheumatology201412 (Suppl 1) :P295

  • Published:


  • Juvenile Idiopathic Arthritis
  • Fibromyalgia
  • Pain Threshold
  • Functional Magnetic Resonance Imaging
  • Juvenile Idiopathic Arthritis Patient


Pain is a frequent complaint in pediatric practice and is present in several chronic organic diseases, such as juvenile idiopathic arthritis (JIA). While JIA patients show symptoms such as inflammation of the joints and other structures, such as the heart and eyes, patients with idiopathic musculoskeletal pain (IMP) experience a painful condition that is not associated with presence of tissue injuries. Juvenile fibromyalgia (JFM), disorder characterized by recurrence of disabling pain, is a classic example IMP. This study shows preliminary data of a protocol for evaluation of brain activation using functional magnetic resonance imaging (fMRI) after a painful stimulus produced by pressure.


To evaluate and compare the pain threshold in adolescents with JIA and JFM that will be examined by fMRI scan.


Twenty nine adolescents were divided into 3 groups: 10 adolescents with JFM, 9 adolescents with JIA and 10 healthy adolescents without complaints of pain.

Using a mechanical system, designed for experiments with fMRI, a series of discrete pressure stimulus were performed, with duration of 5 seconds, applied on the left thumb by a stiff rubber tube connected to a hydraulic piston, enabling a controlled and reproducible stimulation. Participants were asked to graduate the intensity of pain sensation evoked by an ascending series of pressure stimulus, until the subjective rating of pain reported was graded as 4 (four).


The amount of pressure used in the pressure stimulus was significantly different between groups (p = 0.0003). The pain threshold was lower in JFM group (mean pressure used = 3.70 kg/cm2), followed by the group of healthy adolescents (4.45 kg/cm2) and the JIA group (4.88 kg/cm2). All participants reported the same subjective pain rating 4 (four).


Adolescents with JFM presentes a decrease in the threshold for pain, which was significantly lower when compared with adolescents with JIA with long history of organic pain.

Disclosure of interest

None declared.

Authors’ Affiliations

Pediatrics, UNIFESP, Brazil
Brain Institute, Hospital Albert Einstein, São Paulo, Brazil


© Molina et al; licensee BioMed Central Ltd. 2014

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated.