1) you could have a bad ear or ears-- vestibular function in the inner ear can be damaged. (my left ear has been this way all my life--had tests on it in my 20's). This can be from damage from measles, or head injury.

2) you could have a celebellar ataxia. (this can be genetic or from gluten intolerance).
more:
http://www.healthsystem.virginia.edu...uro/ataxia.cfm

causes here:
http://en.wikipedia.org/wiki/Ataxia

3) damage to the deep nerves in the legs, knees, ankles that communicate position..called proprioception.

Some ataxia improves with physical therapy. Some does not.

I am glad the Lidoderm patches are working for you.