Karen,
I just read you 8 years old thread about your neurological symptoms and your long struggle. Good to hear you have found a way to keep your B 12 under control.
David, thanks for all the instructions regarding exercise.
Exercise is important, but --Oh-- such a thing to find time. I think one has to be strict, and make a strict schedule.

This is the first time I have heard someone describe some of the same symptoms I have had.
The way I feel the symptoms are: Especially during stress, exhaustion and tiredness, I feel as if the ground I am standing on is vibrating as if there was an earthquake.
Sometimes when I am sitting on a furniture, it feels like the furniture is vibrating and shaking.
When I get out of a car after having been driving, when I step down, I feel as if I am still "moving" in the same direction as the car was.

Sometimes I have the feeling of dizziness and unsteadiness when I walk in large open spaces.

Often my legs feels really heavy and numb, sometimes I stumble and drag my feet a little.
Sometimes it feels as if there were a rubber band around my knees when my legs feel heavy.
I have explained this feeling to neurologists but have not gotten an answer.
When the doctors are examining my balance and walking, it is not always the same.