One of the countless tricky things about Parkinson’s, we’re learning, is its complete unpredictability. With other diseases, doctors can provide a sense of scale and timing: you are here now; the next step will likely be this; that step will happen most likely in x to y time. With Parkinson’s, the next challenge isn’t always defined. The next step is always in the dark. The time it all takes is always a mystery. And so when a Parkinson’s patient has a bad day, it’s tough to know whether it’s just that or the next step.

“But I thought Parkinson’s was a slow, degenerative disease without sudden declines.”

So did I, but that too is a variable. Mostly, if we’re talking about the termor dominant form, that’s likely the case; if they have the P.I.G.D. (Partial Instability Gait Difficulty) form, there can be, apparently, sudden declines. Papa, sadly, has the P.I.G.D. form. Each change, then, might be a significant change or just a bad day.