Currently taking Gabapentin

Hi,

I'm waiting MRI results and have no DX except told that i have a muscle problem at this time. Given Gabapentin for the nerve pain and sensory discomfort. I have left side thigh muscle tightness/stiffness. The same leg I suffer with the sensory discomfort( burning/sensitive to touch sensation) and suffer with cold feet at times as well. It's June and it's very warm and i'm wearing woollen socks to keep my feet warm. My legs get easily tired and ache, my left thigh muscle feels stiff after walking alot. When i walk too much my left leg starts twisting so i'm seen by others as limping. (its painless)? and i often don't notice it! Having to use a walkaing stick now as my walking has become slow and i tend to stagger.
I sometimes appear to feel jumpy and off balance when i carry out jobs at home, like hanging out the washing. Since January this year the walking problem has been on and off depending on what i do and for how long. I have other symptoms that appear ok one day then worse the next. incontinence, tinnitus (ringing in the ears) and fatigue and an sensitive left foot etc. Early on when the symptoms appeared (JAN 09) i suffered with slight numb/tingling/pain in feet/palms/buttocks/neck and in the back and under the arm left rib area, these have now gone. My left arm appears less co-ordinated than my right and my finger tips feels sensitive( Left side only). I have suffered with walking/sensory problems etc some years ago, (the symptoms went away). The only thing that is different is that i appear to be suffering for much longer as the symptoms do not apear to be easing like last time.
Are Neurological problems unpredictable as i never know how i'm going to feel on the day as my symptoms are vague to others and annoying for me. I do feel that my problem may be permanant. I take 300mg of Gabapentin 3 times daily, no other medication. Will the medication help with my present symptoms (walking/stiffness) my gp does not know? What causes muscle stiffness/limping/leg to twist when i walk/exercise to much? My GP appears relunctant to give me a answer to my question..