Central Nervous System Changes Following OnabotulinumtoxinA Injection in the Bladder

Multiple Sclerosis is a severe debilitating disease that affects patient's quality of life. Up to 90% of patients with MS will develop lower urinary tract dysfunction within the first 18 years of the disease. Lower urinary tract symptoms (LUTS) can range from urgency to urge urinary incontinence and/or hesitancy and incomplete bladder emptying. Urgency, frequency, and neurogenic detrusor overactivity (NDO) are the most common urologic findings (34-99%) during diagnostic evaluations of patients with MS. Even though anticholinergic or beta agonist drugs have limited effectiveness and adverse side effects, they are the first line pharmacotherapy for patients with NDO if behavioral modifications and pelvic floor physical therapy are unsuccessful. Onabotulinumtoxin-A (BTX-A) intra-detrusor injection is a highly effective treatment option for patients with NDO who are refractory to more conservative management. BTX-A blocks the release of acetylcholine at the neuromuscular junction and leads to a temporary chemodenervation of the bladder (paralysis of the muscle). Motor effects of BTX-A on the bladder have been extensively studied and widely reported in the literature, and the US Food and Drug Administration has approved BTX-A for the treatment of detrusor overactivity in neurogenic and non-neurogenic patients. However, the sensory effects of BTX-A injection correlating to central nervous system regional perception/localization of urgency, frequency, and urge incontinence in humans are not well known. Over the past decades, functional MRI (fMRI) has been used to study the activation of supraspinal lower urinary tract control centers in healthy subjects during the storage and voiding phases. Given these facts, the investigators are interested in evaluating the role of intra-detrusor injection of BTX-A in afferent response in patients with MS and NDO. High-resolution neuroimaging techniques will help investigators to further understand how MS affects the bladder-brain controls. This study will use fMRI and task-related blood oxygen level dependent (BOLD) signal to evaluate patients with MS and NDO prior to, and 6-10 weeks after intra-detrusor injection of BTX-A with simultaneous urodynamic evaluation. Clinical correlation between women with these chronic urologic problems and new discoveries at level of central nervous system activity will give a better understanding of this disorder, leading to the development of more effective diagnostic and treatment modalities.