Page 74 - Bladder Dysfunction in the Context of the Bladder-Brain Connection - Ilse Groenendijk.pdf

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Chapter 3
Technical insights
This study analysed both single subject results and group data. In the group results, during PFMC, activation in superiomedial M1 is split into two separate clusters with less activation compared to the single subject results. The smoothing is indispensable when performing group analysis in view of the large inter-subject variability of the brain anatomy. Consequently, this might cause disappearance of the less significant findings in individuals, like the present clusters in M1. The high folding of the superior end of M1 further complicates group analysis done in a 3D space. The increased BOLD signal at 7T-fMRI makes high resolution single subject activation maps available, and allows for a more accurate understanding of the central organization in humans.12 Cortical single subject results during PFMC have been visualized previously at 3T (see figure 3 in Yani et al.21). The direct comparison between 3T and 7T results within individuals is left for future work.
Conclusion
We have demonstrated that 7T-fMRI can visualize the neural representations in the whole brain involved in voluntary control of the pelvic floor in healthy male subjects. This has been done for the first time with whole brain coverage and high-field imaging, creating a high spatial resolution and a more accurate understanding of the involved brain areas. Our study shows that voluntary PFMC is represented in M1, SMA, MCG, insula, putamen, thalamus and the cerebellum. Our connectivity analysis showed distinct differences between brain mechanisms controlling PFMC and tongue movement. The present high field fMRI study may help to design future 7T studies in individual patients. These stud- ies should provide new insides on the pathological circuits in order to improve clinical practice.