Table 2:
Clusters and regions defined by their MNI coordinates that showed significant differences between IBS patients and HC in the combined sample.
| MNI Coordinates | |||||||
|---|---|---|---|---|---|---|---|
| Region | Voxels | Hemisphere | t | p(FWE) | X | Y | Z |
| Cluster 1 (IBS < HC) | |||||||
| Caudate Nucleus | 5100 | Left | 3.33 | 0.027 | −6 | 14 | 6 |
| Caudate Nucleus | Right | 4.04 | 0.014 | 8 | 2 | 12 | |
| Nucleus Accumbens (Nacc) | Left | 3.16 | 0.031 | −6 | 14 | −2 | |
| Nucleus Accumbens (Nacc) | Right | 2.89 | 0.041 | 6 | 12 | −4 | |
| Thalamus | Left | 3.57 | 0.022 | −2 | −4 | 8 | |
| Thalamus | Right | 3.87 | 0.017 | 4 | −2 | 8 | |
| Anterior Mid-Cingulate Cortex (aMCC) | Left | 3.54 | 0.029 | 0 | 36 | 12 | |
| Anterior Mid-Cingulate Cortex (aMCC) | Right | 3.54 | 0.029 | 4 | 36 | 12 | |
| Dorsolateral Prefrontal Cortex (dlPFC) | Left | 3.76 | 0.026 | −30 | 40 | 38 | |
| Cluster 2 (IBS < HC) | |||||||
| Dorsolateral Prefrontal Cortex (dlPFC) | 1714 | Right | 4.28 | 0032 | 42 | 38 | 10 |
| Dorsolateral Prefrontal Cortex (dlPFC) | Right | 3.51 | 0.040 | 24 | 14 | 50 | |
| Cluster 3 (IBS < HC) | |||||||
| Superior Temporal Gyrus, Anterior Division | 139 | Right | 4.19 | 0.042 | 54 | 0 | −20 |
Combined sample VBM results show patients with IBS exhibit lower gray matter volume throughout the brain including the dorsolateral prefrontal cortex (dlPFC), anterior cingulate cortex (ACC), thalamus, basal ganglia regions, and superior temporal gyrus.