Assessment of experimental pain from skin, muscle, and esophagus in patients with chronic pancreatitis.
OBJECTIVE
Comprehensive experimental methods are of major relevance assessing pain mechanisms in patients with chronic pain. Chronic pancreatitis is thought to involve the sensory response in other visceral organs and somatic tissue. We, therefore, aimed at exploring the pain mechanisms in chronic pancreatitis (CP) using a multimodal and multitissue stimulation approach.


METHODS
Ten patients (mean age, 50 years) with CP and 13 healthy controls (mean age, 35 years) participated. None of the patients took analgesics regularly. All were exposed to multimodal (mechanical, thermal, and electrical) experimental pain in the skin, muscles, and esophagus.


RESULTS
The patients were hyposensitive to mechanical stimulations of the skin (P = 0.001), but there were no differences in the pain to thermal and electrical stimulations. In the muscle and esophagus, no differences in pain thresholds were found. The difference between single and repeated stimulations reflecting the degree of central sensitization was 17% in controls and 36% in patients (P = 0.001). The referred pain area to electrical stimulation was 30.1 cm2 in the patients and 7.7 cm2 for the controls (P = 0.02).


CONCLUSIONS
The findings suggest that the balance among central hyperexcitability, neuroplastic changes, and descending pain-modulating pathways may explain the pain response to experimental multimodal stimulations in CP. This will likely also reflect the clinical pain mechanisms and may have important impact in selection of treatment, where drugs with potential effects on these mechanisms should be used.
Dimcevski
Georg
G
Department of Medical Gastroenterology, Haukeland University Hospital, Bergen, Norway.
Staahl
Camilla
C
Andersen
Søren Due
SD
Thorsgaard
Niels
N
Funch-Jensen
Peter
P
Arendt-Nielsen
Lars
L
Drewes
Asbjørn Mohr
AM
D000328:Adult; D000344:Afferent Pathways / Q000502:physiology*; D004558:Electric Stimulation; D004947:Esophagus / Q000294:innervation; D005260:Female; D006358:Hot Temperature; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000294:innervation; D010146:Pain / Q000209:etiology* / Q000503:physiopathology; D017288:Pain Threshold / Q000502:physiology*; D050500:Pancreatitis, Chronic / Q000150:complications* / Q000503:physiopathology*; D010812:Physical Stimulation; D012867:Skin / Q000294:innervation