Effect of hypnotherapy and educational intervention on brain response to visceral stimulus in the irritable bowel syndrome

Abstract

Background: Gut-directed hypnotherapy can reduce IBS symptoms, but the mechanisms underlying this therapeutic effect remain unknown.

Aim: To determine the effect of hypnotherapy and educational intervention on brain responses to cued rectal distensions in IBS patients.

Methods: 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.

Results: 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.

Conclusions: 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.

Clinical trial number: NCT01815164.

© 2013 John Wiley & Sons Ltd.

Figures

Figure 1

Flow chart overviewing the progress of patients and healthy controls during the course of the study.

Figure 2. fMRI session protocol

After 5 min rest and collection of resting state data (reported elsewhere) rectal sensitivity thresholds during rectal distension were determined using ascending method of limits: 0=no sensation, 1=sensation, 2=urgency and 3=maximum tolerable pressure. Twenty visually cued high and 18 low intensity rectal distensions were pseudorandomly delivered with 18 rest periods. Rating of last low and high rectal intensity distension indicated by +. Ratings of current gastrointestinal symptoms and unpleasantness indicated by *.

Figure 3. Frequency and intensity of abdominal pain (hours per 14 days) before and after hypnotherapy. Median and interquartile range are shown in the graph. After hypnotherapy the total numbers of pain hours decreased significantly from median 45.5 hours (range 5.5-225) to 25 hours (range 0-223 hours), paired sign test

Figure 4 a-b

Correlations between pre-post treatment improvement in symptoms versus reduction in blood oxygen level dependent response (increasing blood oxygen level dependent activity on the y-axis of the figure is interpreted as a pre-post treatment blood oxygen level dependent response reduction) during high intensity distension in all treatment responders.

Figure 5a

Blood oxygen level dependent response during high intensity rectal distension before (top panel), after (middle panel) a course of successful hypnotherapy in IBS patients. Blood oxygen level dependent response to the same stimuli in healthy controls is shown in the bottom panel. Images thresholded at p

Figure 5b

Blood oxygen level dependent response during expectation of high intensity rectal distension before (top panel), after (middle panel) a course of successful hypnotherapy in IBS patients. Blood oxygen level dependent response to the same stimuli in healthy controls is shown in the bottom panel. Images thresholded at p