Pain Processing and Pain Neuroscience Education in Children With Chronic Abdominal Pain
Condition: Abdominal Pain; Irritable Bowel Syndrome
MeSH terms: Irritable Bowel Syndrome; Syndrome; Abdominal Pain
Study type: Interventional

Summary: 
      The primary scientific objective of the study entails examining whether altered endogenous
      pain inhibition is present in children with functional abdominal pain (FAP) and irritable
      bowel syndrome (IBS) compared with healthy controls (Part 1). A secondary objective implies
      examining whether pediatric pain neuroscience education (PNE) is able to improve pain
      catastrophizing, pain-related fear, pain intensity (including symptoms and indices of central
      sensitization) and pain-related functional disability in children with FAP or IBS (Part 2).
    

Detailed description: 
      Abdominal pain-related functional gastrointestinal disorders (AP-FGIDs) are common in
      children, showing a prevalence of 13.5% in Western populations and developing countries.
      Gastrointestinal disorders are categorised within the Rome criteria III, with irritable bowel
      syndrome (IBS) (65%) and functional abdominal pain (FAP) (35%) as most commonly occurring
      subtypes, followed by FAP syndrome, functional dyspepsia and abdominal migraine. These
      numbers call for action, knowing that persistent pain periods associated with AP-FGIDs
      significantly interferes with a child's daily functioning. Children suffering from AP-FGIDs
      participate less during recreational activities, show difficulties in maintaining social
      contacts, are more absent at school and express academic impairments. Additionally, they
      report decreased health related quality of life and need more health care utilization.

      To date, the pathogenesis underlying AP-FGIDs in children remains unclear. Previous studies
      suggested abnormal brain-gut interaction, altered gut motility, visceral hypersensitivity,
      psychosocial disturbance and immune activation as possible explanations for the symptoms. In
      accordance to research in adults with FGIDs evidence is even growing for the contribution of
      central sensitization (CS) in the development or persistence of AP-FGIDs in children. CS is
      defined as "an amplification of neural signalling within the central nervous system that
      elicits pain hypersensitivity" or "increased responsiveness of nociceptive neurons in the
      central nervous system to their normal or subthreshold afferent input". This process
      encompasses malfunctioning of descending inhibitory nociceptive pathways which result in
      dysfunctional endogenous analgesic control and increased activity of descending nociceptive
      facilitation and overactivity of the pain neuromatrix in the brain. A systematic review
      addressing the contribution of CS in pediatric chronic pain conditions concluded that
      manifestations such as somatic hyperalgesia and altered central pain processing in children
      with recurrent abdominal pain disorders (RAP) and deficient descending inhibitory nociceptive
      processing in girls with irritable bowel syndrome (IBS) are indicative of CS in some subtypes
      of AP-FGIDs (review in progress). However, given the heterogeneous study populations,
      different protocols and methods used to objectify the presence of CS in this review, no clear
      statement could be made. In addition, no study examining descending inhibitory nociceptive
      processing in children with FAP was found.

      Descending inhibitory nociceptive processing might be dysfunctional in children with FAP and
      IBS. Anyhow, research demonstrated that this manifestation of CS can be further influenced by
      the child's characteristics. Behavioural responses, emotional and cognitive aspects are
      involved in the facilitation of sensitization through an increased cerebral activation of
      limbic structures, the insula and large areas of the frontal, temporal and parietal cortices,
      resulting in a diminished inhibition of the descending pathways.

      Parental behaviours may also play an important role in the child's adjustment to pain.
      Parents are considered essential participants in the management of their child's pain, as
      parental attitudes, responses, and beliefs can influence the child's pain and adherence to
      treatment. Indeed, both parental solicitous behaviours (e.g., according special privileges to
      the child) and parental discouraging behaviours (e.g., criticizing the child) have been found
      to be associated with increased functional disability. Further, evidence suggests that
      children's own pain beliefs and pain coping skills may be modelled after their parents'
      (maladaptive) pain beliefs and pain coping skills. Additionally, increased levels of parent
      emotional distress have been linked to higher levels of child functional disability and
      self-reported pain. This underscores the importance of including parents in the assessment
      and treatment of pediatric chronic pain for optimal outcomes.

      Negative cognitions of both the parents and the child can develop when they do not understand
      the origin of the FAP or IBS. Based on the premise that a better understanding of the nature
      of the illness results in improved patient outcomes, both child and parents should be
      addressed by education. Given the possible contribution of CS in children with FAP or IBS,
      education should include explanation and reassurance about the cause of pain, a brief summary
      of relevant pain mechanisms and the integral role of psychosocial and physical factors in
      precipitating and maintaining pain. This main content can be given by pain neuroscience
      education (PNE). PNE has been studied in various adult chronic pain populations and has shown
      to be effective in changing pain beliefs and improving health status as well as pain coping
      strategies.

      In contrast to a traditional model of tissue injury or nociception and pain, PNE aims to
      describe how the nervous system interprets information from tissues through peripheral nerve
      sensitization, central sensitization, synaptic activity and brain processing. It also
      explains how neural activation, as either upregulation or downregulation, has the ability to
      modulate the pain experience in response to (or in absence of) nociceptive input. Patients
      are thus educated that the nervous system's processing of their injury, in conjunction with
      various psychosocial aspects, determines their pain experience and that pain is not always a
      true representation of the status of the tissues. Up to recently, no studies have examined
      the benefits of PNE in the context of pediatric chronic pain. Drawing upon available evidence
      in adult samples, it is expected that PNE provided to children will lead to beneficial child
      pain-related outcomes. Involving parents in PNE sessions will facilitate increased parental
      understanding of biopsychosocial factors that influence their child's pain, as well as learn
      how they can support their child to manage symptoms.

      Concrete, the present study will examine (1) the function of descending inhibitory
      nociceptive processing in children with FAP or IBS compared to healthy children (Part 1) and
      whether (2) reconceptualization of pain, by PNE, is able to influence pain catastrophizing,
      pain-related fear, pain intensity (including symptoms and indices of central sensitization)
      and pain-related functional disability (Part 2).
    

Intervention name(s): Usual care; Pain Neuroscience education; Extra care
Intervention type(s): Other; Other; Other
Intervention description(s): During usual care therapy, children and their parents will receive a +/- 1 h session containing bio-medical directed education and information about the gastro-intestinal system and its function. This knowledge will be brought to bear with a hypnotic journey through their body, guided by a nurse with specific expertise in pediatric abdominal pain. Furthermore, the influence of stress on the gastro-intestinal system will be explained, combined with exercises to practise abdominal respiration.; This therapy will consist out of a +/- 1 h one-on-one educational session about neurophysiology of pain, adjusted to the child's comprehension status. The content of the education sessions and pictures will be based on the book "Explain Pain" by Butler and Moseley and will include explanation and reassurance about the cause of pain, a brief summary of relevant pain mechanisms and the integral role of psychosocial and physical factors in precipitating and maintaining pain. Metaphors, leaflets, books and audio-visual media will be used in a supportive function to consolidate verbally transmitted information. Parents will participate in the PNE session as well.; During this therapy session, all the patient's/ parents questions that arose from the previous session (Usual care) will be answered. Afterwards, the educated content from this previous session will be revised. Nothing new will be taught. At the end of the session, the participant will be asked to demonstrate the previously learned exercises on abdominal respiration. If the exercises are not well performed, the therapist will correct them.
Other intervention name(s): PNE
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Double (Investigator, Outcomes Assessor)
Primary purpose: Treatment
Keywords: Chronic pain; Endogenous Pain Processing; Central sensitization; Pain neuroscience education