Neurogenic Bladder

Hi, I have had many problems for many years, many problems with legs, very painful thighs, unable to walk far at all, dexterity with hand problems, tingling, electric shocks, terrible fatigue etc. I am due to go into a neurological hospital as an inpatient shortly for intensive neurophysiotherapy to help my mobility and I am on 900 mg of gabapentin a day for pain.

I have been self catherising for a year now, have had many tests for MS, MRI of brain and Spine - Normal, Evoked potentials - Normal, LP - Normal. Neurologist was convinced I had MS, but apart from urodynamics everything come back fine.

Since then I had urodynamics done, and have a neurogenic bladder, basically I do not feel the need to wee so have to self catherise, what I do not understand is how can I have a neurogenic bladder, when i do not have lesions on the spine.

I am confused, and any advice would be appreciated.