Table 3.
Between-group Differences in Brain Activation During Rectal Balloon Distension
| Anatomical description | Hemisphere | No. of voxels | Peak intensity | Z-score | MNI co-ordinates | ||
|---|---|---|---|---|---|---|---|
|
| |||||||
| x | y | z | |||||
| (A) IBS > Control | |||||||
| Insula | L | 193 | 4.71 | 3.95 | −42 | 14 | 4 |
| Middle temporal gyrus | L | 72 | 4.31 | 3.69 | −57 | −27 | −8 |
| Cerebellum_6 | L | 32 | 3.91 | 3.43 | −24 | −61 | 23 |
| Inferior orbitofrontal cortex | L | 10 | 4.04 | 3.52 | −33 | 32 | −5 |
| (B) Control > IBS | |||||||
| Precuneus | R | 23 | 2.94 | 2.72 | 6 | −52 | 61 |
| Precuneus/superior parietal lobule | L | 34 | 3.31 | 3.02 | −18 | −61 | 58 |
| (C) IBS-D > IBS-C | |||||||
| Calcarine | L | 16 | 2.97 | 2.65 | −15 | −58 | 7 |
| Fusiform gyrus | L | 26 | 3.14 | 2.85 | −39 | −49 | −23 |
| Middle temporal gyrus | R | 25 | 2.86 | 2.66 | 60 | −16 | −11 |
| (D) IBS-C > IBS-D | |||||||
| Supplementary motor area | R | 61 | 3.11 | 2.84 | 12 | −16 | 52 |
| Mid cingulate cortex | R | 35 | 2.60 | 2.33 | 6 | −28 | 52 |
IBS, irritable bowel syndrome; MNI, Montreal Neurological Institute; L, left; R, right; IBS-D, diarrhea-predominant IBS; IBS-C, constipation-predominant IBS.
Significantly higher activation for distension > rest condition (A) in IBS patients when compared with controls, (B) in controls when compared with IBS patients, (C) in IBS-D patients when compared with IBS-C patients, and (D) in IBS-C patients when compared with IBS-D patients.