Difficulty in bladder emptying (Voiding dysfunction,VD) is a costly urinary condition that leads to urinary tract infections/stones, sepsis, bladder loss, and permanent kidney damage. VD can be present in patients with or without neurologic/brain disorders. Currently the only available therapies for VD include bladder catheters or intermittent self-catheterization. Catheterization is a burden especially in patients with nerve damage, hand skills may be limited. The cost and morbid side effects of catheterizations in patients (blood in the urine, pain, trauma, strictures, and infections) requires investigators to develop new therapies that are beyond the bladder. Such new therapies could target the brain (where bladder control is located). In this proposal, investigators plan to further characterize the brain regions involved in bladder emptying for each patient and ,perform brain modulation, targeting these regions as a possible therapy for VD. Patients with bladder dysfunction will be divided into two groups: Group 1: patients with VD; and Group 2: patients without VD. Specific Aim 1: To evaluate brain pattern in both groups and compare them to each other at the time of bladder emptying. Specific Aim 2: To evaluate reliability of the nerve fibers in the brain and see whether damage to these fibers is related to difficulty emptying the bladder. Specific Aim 3: To perform non-invasive brain stimulation on specific regions of the brain responsible for bladder control to improve bladder emptying. This study is an interventional Study: The investigators have completed a well-powered study on twenty-seven female MS patients during their bladder storage phase. Aims 1 and 2 use the data from previously completed trial and investigators will perform additional imaging analysis on it. Aim 3 is a new and small trial in which investigators planned to modulate the regions of the brain that are related to bladder control.