P379 Inflammatory bowel disease-induced chronic abdominal pain can be ameliorated by transcranial direct current stimulation
M. S. Prüß*, A. Farmer, B. Siegmund
Charité - University Hospital Berlin, Campus Benjamin Franklin, Department of Gastroenterology, Berlin, Germany
Inflammatory bowel disease (IBD) is accompanied by chronic abdominal pain in up to 38%. Transcranial direct current stimulation (tDCS) has been shown to be a powerful method to decrease chronic pain in different pain conditions such as spinal cord injury, pelvic pain and neuropathic pain. This study tested whether anodal tDCS ameliorates chronic abdominal pain in IBD compared with placebo.
The trial conducted used a randomised, placebo-controlled, double-blind, parallel design (ClinicalTrials.gov Identifier: NCT02048137). Twenty patients with either Crohn’s disease or ulcerative colitis were enrolled. Eligibility criteria included abdominal pain (≥ 3/10 on the visual analogy scale for at least 3 months in the past 6 months). Participants were randomly assigned to 2 groups: i) anodal (n = 10), or ii) placebo tDCS (n = 10). tDCS was applied over the primary motor cortex contralateral to the most painful abdominal side for 5 consecutive days (2mA; (i) 20min or (ii) 30sec). Assessments at baseline and after the intervention taken by a blinded evaluator included pressure pain threshold (primary outcome), visual analogy scale, inflammatory markers (C-reactive protein, calprotectin, erythrocyte sedimentation rate), and questionnaires on quality of life, functional symptoms (Irritable Bowel Syndrome-Severity Scoring System (IBS-SSS)), disease activity, and pain catastrophising. Follow-up assessment was performed 1 week after the end of the intervention. Data were analysed using ANOVA and t-tests.
Abdominal pain significantly decreased in the anodal tDCS group compared with placebo. This effect was present for the primary outcome of pressure pain threshold in both sides of the abdomen as well as for the visual analogy scale. Moreover, 1 week after finishing the intervention pain was still significantly decreased in the right abdominal side of the intervention group. Comparing both groups after the 5-day intervention, there was also a significant reduction on the pain catastrophising scale and on the IBS-SSS. Inflammatory markers and disease activity remained unchanged throughout the experiment in both groups. Besides mild adverse effects such as tingling, itching and skin redness, no severe side effect was observed.
For chronic abdominal pain in IBD tDCS seems to be an effective and clinical relevant adjunct therapy. The analgesic effects seen were independent from inflammation and disease activity. This emphasises that central pain mechanisms are involved in chronic abdominal pain. This is in line with clinical observations that pain can persist even if mucosal inflammation is healed. Therefore our next study aims to investigate structural and functional changes in the brain due to chronic abdominal pain in IBD by MRI.