title: In the mind or in the brain? Scientific evidence for central sensitisation in chronic fatigue syndrome.
abstract: BACKGROUND
  Central sensitisation entails several top-down and bottom-up mechanisms, all contributing to the hyperresponsiveness of the central nervous system to a variety of inputs. In the late nineties, it was first hypothesised that chronic fatigue syndrome (CFS) is characterised by hypersensitivity of the central nervous system (i.e. central sensitisation). Since then, several studies have examined central sensitisation in patients with CFS. This study provides an overview of such studies.
  
  
  METHODS
  Narrative review.
  
  
  RESULTS
  Various studies showed generalised hyperalgesia in CFS for a variety of sensory stimuli, including electrical stimulation, mechanical pressure, heat and histamine. Various tissues are affected by generalised hyperalgesia: the skin, muscle tissue and the lungs. Generalised hyperalgesia in CFS is augmented, rather than decreased, following various types of stressors like exercise and noxious heat pain. Endogenous inhibition is not activated in response to exercise and activation of diffuse noxious inhibitory controls following noxious heat application to the skin is delayed.
  
  
  CONCLUSIONS
  The observation of central sensitisation in CFS is in line with our current understanding of CFS. The presence of central sensitisation in CFS corroborates with the presence of several psychological influences on the illness, the presence of infectious agents and immune dysfunctions and the dysfunctional hypothalamus-pituitary-adrenal axis as seen in these severely debilitated patients.
authors.affiliation: Department of Human Physiology, Vrije Universiteit Brussel (VUB), Brussels, Belgium. Jo.Nijs@vub.ac.be
authors.forename: Jo
authors.initials: J
authors.lastname: Nijs
authors.forename: Mira
authors.initials: M
authors.lastname: Meeus
authors.forename: Jessica
authors.initials: J
authors.lastname: Van Oosterwijck
authors.forename: Kelly
authors.initials: K
authors.lastname: Ickmans
authors.forename: Greta
authors.initials: G
authors.lastname: Moorkens
authors.forename: Guy
authors.initials: G
authors.lastname: Hans
authors.forename: Luc S
authors.initials: LS
authors.lastname: De Clerck
mesh_terms: D002490:Central Nervous System / Q000378:metabolism* / Q000502:physiology; D015673:Fatigue Syndrome, Chronic / Q000503:physiopathology* / Q000523:psychology; D005356:Fibromyalgia / Q000503:physiopathology* / Q000523:psychology; D006801:Humans; D006930:Hyperalgesia / Q000503:physiopathology* / Q000523:psychology; D010146:Pain / Q000523:psychology*; D010147:Pain Measurement; D017288:Pain Threshold / Q000502:physiology / Q000523:psychology*