Functional MRI in patients with detrusor sphincter dyssynergia: Is the neural circuit affected?

In recent years, the human brain-bladder control network has been visualized in different functional magnetic resonance imaging (fMRI) studies. The role of the brainstem and suprapontine regions has been elucidated. Especially the pontine region and the periaqueductal gray, as the central structures of the micturition circuit, were demonstrated. Detrusor sphincter dyssynergia (DSD) is a common problem in patients with neurological diseases. Residual urine and consecutive urinary tract infections with the risk of kidney damage remain a problem. In the present study, we used fMRI of the brain to compare the activation sites of patients with DSD with those of our previously published healthy controls with special emphasis on the brainstem region.

fMRI was performed in 11 patients with DSD who had an urge to void due to a filled bladder. In a nonvoiding model, they were instructed to contract or to relax the pelvic floor muscles repetitively.

In patients with DSD, we could reproduce the activation sites found in healthy subjects, showing the regions in the brainstem as well as the other micturition-related areas. The activation of the pontine region was more rostral/dorsal compared with the healthy volunteers.

Interestingly, we detected the well-known activation in the pontine region in the patients in the dorsal/rostral part compared with the more ventral activation in the healthy volunteers, suggesting that the L-region of the pontine micturition center is more prominent in cases of DSD.