It's certainly possible that you have a "pressure rhythm." Time, changes in air pressure, changes in wind direction, and other things can affect hydro, especially if it isn't treated. As far as having NPH in conjunction with, or seconary to, Parkinson's, I don't have an answer for you on that, but it's worth asking the right neurosurgeon. (NOTE: A neurologist will not have answers for you!!) Consider contacting the Hydrocephalus Assn at www.hydroassoc.org or info@hydroassoc.org and telling them what you told us. Be sure to tell them where you are so they can help you find a nsg close to you.

Good luck!

LIZARD