Cerebral excitability is abnormal in patients with painful chronic pancreatitis. (16th April 2012)

• Record Type: Journal Article
• Authors: Olesen, S.S.; Hansen, T.M.; Graversen, C.; Valeriani, M.; Drewes, A.M.
• Is Part Of: European journal of pain. Volume 17:Number 1(2013)
• Page Start: 46
• Page End: 54
• Publication Date: 2012-04-16
• Subjects: Pain -- Periodicals; Pain -- Treatment -- Periodicals; Pain -- Physiological aspects -- Periodicals; 616.0472
• DOI: 10.1002/j.1532-2149.2012.00155.x
• Languages: English
• ISSNs: 1090-3801

Abstract

<abstract abstract-type="main"> <title>Abstract</title> <sec id="ejp155-sec-0003" sec-type="section"> <title>Background</title> <p>We investigated whether patients with painful chronic pancreatitis (CP) present abnormalities in the cerebral response to experimental pain stimuli.</p> </sec> <sec id="ejp155-sec-0004" sec-type="section"> <title>Methods</title> <p>Contact heat‐evoked potentials (CHEPS) were recorded in 15 patients with CP and in 15 healthy volunteers during repetitive stimulation of the upper abdominal region (pancreatic 'viscerotome') and the right forearm (heterologous area). Three sequences of painful stimuli were applied at each site. Subjective pain scores were assessed by a visual analogue scale. Habituation was calculated as the relative change in CHEPS amplitudes between the first and the third stimulation sequence.</p> </sec> <sec id="ejp155-sec-0005" sec-type="section"> <title>Results</title> <p>As expected pain scores decreased in healthy volunteers during successive stimulations at both sites (i.e., habituation), while in the CP group, they remained unchanged. The cerebral response consisted of an early‐latency, low‐amplitude response (N1, contralateral temporal region) followed by a late, high‐amplitude, negative–positive complex (N2/P2, vertex). During successive stimulation of the pancreatic area, N2/P2 amplitude increased 25% in CP patients, while they decreased 20% in healthy volunteers (<italic>p</italic> = 0.006). After stimulation of the forearm, N2/P2 amplitudes increased 3% in CP patients compared to a decrease of 20% in healthy volunteers (<italic>p</italic> = 0.06).</p> </sec> <sec id="ejp155-sec-0006" sec-type="section"> <title>Conclusions</title> <p>Taken together, CP patients had an abnormal cerebral response to repetitive thermal stimuli. This was most prominent after stimulation of the upper abdominal area. As this area share spinal innervation with the pancreatic gland, these findings likely mirror distinctive abnormalities in cerebral pain processing.</p> </sec> </abstract>