Aliment Pharmacol Ther. 2013 Jun;37(12):1184-97. doi: 10.1111/apt.12319. Epub 2013 Apr 25.
Effect of hypnotherapy and educational intervention on brain response to visceral stimulus in the irritable bowel syndrome.
The purpose of this study was to examine how the brains of IBS patients respond differently to sensations from their bowels after a course of either hypnotherapy or (for comparison) an educational intervention also designed to treat IBS. Signals indicating the amount of brain activity in different parts of the brain were measured by using functional Magnetic Resonance Imaging (fMRI) while a balloon was inflated in the bowel (rectum) of the subjects. A total of thirty-one female patients completed treatment and testing. IBS symptoms improved similarly and significantly in both treatment groups. Participants whose symptoms improved from either type of treatment showed lessened brain response to intense balloon distension afterwards, and their brains reacted more like normal individuals to the gut sensations produced by those balloon distensions. However, patients in the hypnosis group showed reduction in activity in somewhat different brain centers after treatment (posterior insula) compared to the education group, suggesting that hypnosis treatment may perhaps have some specific or unique therapeautic effects on brain activity in IBS patients.
Gut-directed hypnotherapy can reduce IBS symptoms, but the mechanisms underlying this therapeutic effect remain unknown.
To determine the effect of hypnotherapy and educational intervention on brain responses to cued rectal distensions in IBS patients.
Forty-four women with moderate-to-severe IBS and 20 healthy controls (HCs) were included. Blood oxygen level dependent (BOLD) signals were measured by functional Magnetic Resonance Imaging (fMRI) during expectation and delivery of high- (45 mmHg) and low-intensity (15 mmHg) rectal distensions. Twenty-five patients were assigned to hypnotherapy (HYP) and 16 to educational intervention (EDU). Thirty-one patients completed treatments and posttreatment fMRI.
Similar symptom reduction was achieved in both groups. Clinically successful treatment (all responders) was associated with significant BOLD attenuation during high-intensity distension in the dorsal and ventral anterior insula (cluster size 142, P = 0.006, and cluster size 101, P = 0.005 respectively). Moreover HYP responders demonstrated a pre-post treatment BOLD attenuation in posterior insula (cluster sizes 59, P = 0.05) while EDU responders had a BOLD attenuation in prefrontal cortex (cluster size 60, P = 0.05). Pre-post differences for expectation conditions were almost exclusively seen in the HYP group. Following treatment, the brain response to distension was similar to that observed in HCs, suggesting that the treatment had a normalising effect on the central processing abnormality of visceral signals in IBS.
The abnormal processing and enhanced perception of visceral stimuli in IBS can be normalised by psychological interventions. Symptom improvement in the treatment groups may be mediated by different brain mechanisms.
Link to full paper with PMID: 23617618