title: Contribution of central sensitisation to the development of non-cardiac chest pain.
abstract: BACKGROUND
  Non-cardiac chest pain mimics angina pectoris but generally originates from the oesophagus. Visceral hypersensitivity may contribute, but its neurophysiological basis is unclear. We investigated whether central sensitisation, an activity-dependent amplification of sensory transfer in the central nervous system, underlies visceral pain hypersensitivity and non-cardiac chest pain.
  
  
  METHODS
  We studied 19 healthy volunteers and seven patients with non-cardiac chest pain. Acid was infused into the lower oesophagus. Sensory responses to electrical stimulation were monitored within the acid-exposed lower oesophagus, the non-exposed upper oesophagus, and the cutaneous area of pain referral, before and after the infusion.
  
  
  RESULTS
  In healthy volunteers, acid infusion into the lower oesophagus lowered the pain threshold in the upper oesophagus (mean decrease 18.2% [95% CI 10.4 to 26.0]; p=0.01) and on the chest wall (24.5% [10.2 to 38.7]; p=0.01). Patients with non-cardiac chest pain had a lower resting oesophageal pain threshold than healthy controls (45 [30 to 58] vs 64 [49 to 81] mA; p=0.04). In response to acid infusion, their pain threshold in the upper oesophagus fell further and for longer (mean fall in area under threshold/time curve 26.7 [11.0 to 42.3] vs 5.8 [2.8 to 8.8] units; p=0.04).
  
  
  CONCLUSIONS
  The finding of secondary viscerovisceral and viscerosomatic pain hypersensitivity suggests that central sensitisation may contribute to visceral pain disorders. The prolonged visceral pain hypersensitivity in patients with non-cardiac chest pain suggests a central enhancement of sensory transfer. New therapeutic opportunities are therefore possible.
authors.affiliation: Section of Gastroenterology, University of Manchester, Hope Hospital, Salford, UK.
authors.forename: S
authors.initials: S
authors.lastname: Sarkar
authors.forename: Q
authors.initials: Q
authors.lastname: Aziz
authors.forename: C J
authors.initials: CJ
authors.lastname: Woolf
authors.forename: A R
authors.initials: AR
authors.lastname: Hobson
authors.forename: D G
authors.initials: DG
authors.lastname: Thompson
mesh_terms: D000328:Adult; D002637:Chest Pain / Q000209:etiology*; D004558:Electric Stimulation; D004947:Esophagus / Q000187:drug effects*; D005260:Female; D006801:Humans; D006851:Hydrochloric Acid / Q000009:adverse effects*; D006930:Hyperalgesia / Q000209:etiology*; D008297:Male; D008875:Middle Aged; D017288:Pain Threshold / Q000187:drug effects*; D011984:Sensory Receptor Cells / Q000187:drug effects*
chemical_list: D006851:Hydrochloric Acid