There is a lot of information about neurogenic bladder and overflow incontinence. See the following:
http://www.urologychannel.com/incontinence/overflow/index.shtml
http://www.healthcentral.com/incontinence/introduction-2566-108.html
http://forums.healthcentral.com/discussion/incontinence/forums/a/tpc/f/1451031/m/9331051
Hope this helps. ~Pete