title: Is the pain in chronic pancreatitis of neuropathic origin? Support from EEG studies during experimental pain.
abstract: OBJECTIVE
  To prove the hypothesis that patients with chronic pancreatitis would show increased theta activity during painful visceral stimulation.
  
  
  METHODS
  Eight patients and 12 healthy controls underwent an experiment where the esophagus was electrically stimulated at the pain threshold using a nasal endoscope. The electroencephalogram (EEG) was recorded from 64 surface electrodes and "topographic matching pursuit" was used to extract the EEG information in the early brain activation after stimulation.
  
  
  RESULTS
  A major difference between controls and patients were seen in delta and theta bands, whereas there were only minor differences in other frequency bands. In the theta band, the patients showed higher activity than controls persisting throughout the 450 ms of analysis with synchronous brain activation between the channels. The main theta components oscillated with 4.4 Hz in the patients and 5.5 Hz in the controls. The energy in the delta (0.5-3.5 Hz) band was higher in the controls, whereas the patients only showed scattered activity in this band.
  
  
  CONCLUSIONS
  The differences in the theta band indicate that neuropathic pain mechanisms are involved in chronic pancreatitis. This has important implications for the understanding and treatment of pain in these patients, which should be directed against drugs with effects on neuropathic pain disorders.
authors.affiliation: Department of Medical Gastroenterology, Aalborg University Hospital, Aalborg DK-9000, Denmark. drewes@smi.auc.dk
authors.forename: Asbjørn M
authors.initials: AM
authors.lastname: Drewes
authors.forename: Maciej
authors.initials: M
authors.lastname: Gratkowski
authors.forename: Saber A K
authors.initials: SA
authors.lastname: Sami
authors.forename: Georg
authors.initials: G
authors.lastname: Dimcevski
authors.forename: Peter
authors.initials: P
authors.lastname: Funch-Jensen
authors.forename: Lars
authors.initials: L
authors.lastname: Arendt-Nielsen
mesh_terms: D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003700:Delta Rhythm; D004558:Electric Stimulation; D004947:Esophagus / Q000294:innervation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000209:etiology* / Q000503:physiopathology; D010146:Pain / Q000209:etiology* / Q000503:physiopathology; D010147:Pain Measurement; D017288:Pain Threshold; D050500:Pancreatitis, Chronic / Q000150:complications* / Q000503:physiopathology; D013826:Theta Rhythm