Diminished conditioned pain modulation observed in patients with IBS
Patients with irritable bowel syndrome experienced significantly diminished conditioned pain modulation, a physiological phenomenon where a painful stimulus can inhibit another existing pain, according to research published in Alimentary Pharmacology and Therapeutics.
Qasim Aziz, PhD, FRCP, of the Centre for Neuroscience and Trauma Wingate Institute of Neurogastroenterology, Barts and the London School of Medicine & Dentistry, Queen Mary University of London, and colleagues wrote that abnormal descending pathways could have an important association with IBS and serve as a target for future trials and potential therapies.
“Heightened sensitivity of the viscera to experimental stimulation, referred to as ‘visceral hypersensitivity,’ is an important independent contributor to the gastrointestinal symptom burden of IBS,” they wrote. “The pathogenesis of abdominal pain and visceral hypersensitivity in IBS is complex, multidimensional, and incompletely understood. However, dysregulation within the ‘brain-gut axis,’ a bidirectional interface between the brain and the viscera, has been implicated.”
Aziz and colleagues searched the literature for studies that examined conditioned pain modulation in adults with IBS compared with healthy participants. They performed a meta-analysis to determine the odds ratio and effect size of abnormal conditioned pain modulation in IBS.
In 12 studies that met their inclusion criteria, Aziz and colleagues found that conditioned pain modulation was significantly reduced in patients with IBS compared with healthy controls (OR = 4.84; 95% CI, 2.19–10.71; Hedges’ g effect size = 0.85; 95% CI, 0.42–1.28).
Aziz and colleagues wrote that this difference could be caused by dysregulated pain modulation, as well as central sensitization. They wrote that their findings show a potential for personalized neuromodulatory therapy for patients with IBS.
“Conditioned pain modulation paradigms could be used to improve homogeneity in clinical trials, although international consensus is needed on the specific parameters of such paradigms such as the use of rectal distention vs. somatic pain, the type of conditioning stimulus, and controlling for possible confounding factors,” they wrote. – by Alex Young
Disclosures: The authors report no relevant financial disclosures.