Temporal Summation in Patients With Irritable Bowel Syndrome (IBS) Compared to Healthy Controls (HC)

Abstract

INTRODUCTION: A recent study demonstrated a significant correlation between somatic hyperalgesia and increased permeability in patients with irritable bowel syndrome (Pain 2009;146:41-46). In order to determine the importance of this association, we performed quantitative sensory testing in patients with moderately active inflammatory bowel disease (IBD) as a model disease with increased permeability. METHODS: Healthy controls and patients with confirmed Crohn's disease or ulcerative colitis were invited. Patients completed the SIBDQ as a validated health status measure for IBD patients. Pain thresholds were determined over the dominant hand and the four abdominal quadrants for pressure and heat application. Threshold and tolerance for ischemic and cold pain were assessed and rated during regular hand exercises with a blood pressure tourniquet inflated to 200 mmHg and during ice water immersion of the dominant hand, respectively. RESULTS: Fifty controls (37±2 years) and 10 IBD patients (36±4 years; SIBD score: 39.9±1.9) were recruited. Pain thresholds for pressure (5.8±0.2 vs. 5.7±0.4 kg/cm2) or heat (44.3±0.4 vs. 43.4±0.4o C; controls vs. IBD) over the dominant did not differ. Pressure thresholds were significantly lower over the abdomen, but did not differ between the groups (figure). In contrast, heat pain thresholds were similar between forearm and abdominal wall and did not differ between the groups. The results for ischemic pain (threshold: 60.0±7.5 vs. 65.2±14.3 s; tolerance: 117.3±8.6 vs. 134.6±14.0 s) or cold pain (threshold: 15.2±4.2 vs. 13.6±4.8 s; tolerance: 51.8±8.3 vs, 68.4±23.3 s) were comparable for both groups. CONCLUSION: We did not find differences in experimental pain in response to several different stimulus modalities between controls and IBD patients, arguing against an importance of increased intestinal permeability in the development of hyperalgesia.