Now I understanad my initial symptoms of PD before Dx. I experienced attacks of "dizzziness" (confusion about which direction was down) without vertigo. I spent a lot of time with audiologists and ENT specialists trying to diagnose an inner ear problem. And all the time the problem was in the proprioception loop involving the basal ganglia.
I still have some degree constantly of the same sensation, and have been given meclazine by my neurologist to treat it. Meclazine does not touch it.
Gait instability was what tipped off the neuro as to my initial Dx.
One thing that doesn't fit is that DOPA greatly alleviated my gait problems within 36-48 hours after I started taking it, whereas it did not seem to affect the PD-associated proprioception problems in the studies ZF cited.
Robert