Page 64 - Bladder Dysfunction in the Context of the Bladder-Brain Connection - Ilse Groenendijk.pdf

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Chapter 3
MATERIALS AND METHODS
Subjects Approval for this study was given by the Medical Ethics Committee of the Erasmus Medical Center Rotterdam (METC 2015-451). All included subjects provided writ- ten informed consent. Seventeen healthy right-handed male volunteers (mean age 29.6 SD ±7.8 years) participated in this study. We limited our study to a single sex, since the male and female pelvic floor motor control should be anatomically distinguished and differences in the central control have not been fully identified.16 Furthermore, our study is the first to use 7T-fMRI to study pelvic floor representations in single subjects. Given the exploratory design a homogeneous study population was desired. Subject exclusion criteria were any known impairment of urogenital or tongue motor innervation; current or known neurological, psychiatric or urological disorder(s) and contra-indications for MRI.
Stimuli and functional paradigm All subjects completed the same scanning protocol, consisting of two functional runs followed by a T1-weighted anatomical scan. Functional runs consisted of two motor tasks (pelvic floor contraction and tongue movement), per- formed using a block paradigm. Prior to the scanning session, all subjects underwent a training session in a mock scanner to ensure correct task execution. During this training session motor tasks were performed as described below. For the task ‘pelvic floor muscle contraction’, subjects were visually cued to strain their pelvic floor by contracting their anal sphincter or perineum. To prevent patients from contracting the gluteal muscles, they were instructed to lay still on the MRI bed. The motor task ‘tongue movement’ required subjects to perform horizontal tongue movements. During this condition, subjects were instructed to keep their mouths closed by passively resting the lips and jaws together. Cues were generated in MATLAB using Psychtoolbox (Brainard, 1997) and presented on a 32-inch BOLD screen (Cambridge Research Systems, Rochester, UK). The active condition was indicated by the text ‘MOVE’ and the rest condition by a fixation cross ‘+’. The PFMC task consisted of an active condition of 21.5 seconds, in which the subject was instructed to repeatedly contract their pelvic floor followed by 19.5 seconds of rest, this cycle was repeated 12 times with an additional rest condition at the start of the run, resulting in a total scan time of 500 seconds. The tongue movement task consisted of an active condition of 10 seconds followed by a rest condition of 10 seconds. This cycle was repeated 24 times with an additional rest condition at the start of the run, resulting in a total scan time of 490 seconds.
Data acquisition All data were acquired on a 7T-MRI scanner (Philips Achieva) using a volume transmit coil and a 32-channel receive coil (Nova Medical). Functional data was acquired using a multiband echo planar imaging (mb-EPI) sequence with multiband