It was a cheap shot to use a pathetic sick man to make false claim in a political race, and then expect that there can be no criticism of that person.
And besides, if not taking meds makes a parkinson's patient "freeze up", then why did Fox admit to doing such when he testified to Congress?
It depends on how advanced the Parkinson's disease is. People in the early stages of Parkinson's disease will be more shaky than frozen. But the larger, slower movements ("chorea") Mr. Fox displayed are a side effect of his medication, not a sign of under-medication.