I ride a recumbent tricycle. It is wonderful - comfortable and no balance problems - the only downside is the cost. But with a script from your doctor, part or all of the cost of the trike MAY covered by insurance (or as a medical expense on taxes - which was true for me here in Arizona).

The link below shows me on my trike...
http://www.pdplan4life.com/exer-trike.htm

I have found my symptoms are less troublesome after riding my trike for an hour a day.

good luck!