[johnt]

Much of what we discuss in this forum is about what PWP can't do. In this thread I want to focus on what we can do.

18 months ago I started a thread called "Quantifying the short term effect of Stalevo on me".

http://neurotalk.psychcentral.com/thread183360.html

For convenience the graph from Post 1 in that thread is copied here.

Stalevo75.png

In that thread the discussion was mainly about the impact of Stalevo.

The graph shows the number of side to side taps done in 30 seconds by both the left and right hands. Initially the dose has no impact, then as time passes, the number of taps increases as the drug takes effect, approximately doubling at its highest, before trailing off back or, possibly, even below where we started.

In this thread I want to discuss another feature of the graph. It shows something else just as interesting: the score before the drug is taken is not zero, even though I'm at least 14 hours from a previous dose I can still do finger taps, albeit slowly. This must be caused by endogenous production or, possibly, the left-over effect of 16mg per day of controlled release ropinirole last taken 36 hours before this test.

Let's play with the numbers to see where they take us.

The average number of taps per minute before taking the drug is 24.87 (see the other thread for details of these numbers). Over a day that gives roughly 36000 taps. But, in the previous thread it was pointed out that 75mg Stalevo gives an additional 2438 taps. I want a measure that is general and not specific to Stalevo. I note that 75mg of Stalevo is, in its clinical effect, approximately equivalent to 100mg levodopa taken with carbidopa. Therefore, in this case we can estimate the body's production as 100*36000/2438 or, about 1500mg levodopa.

My drug intake has a levodopa equivalent daily dose of approximately 800mg.

Taking the two sources together gives a total for me of 2300mg of levodopa/day with, roughly speaking, two thirds coming from within the body.

It needs validating, across time for an individual and across individuals, but the obvious use of this type of analysis is to objectively measure progression rates.

The online tap test can be found at:

http://www.parkinsonsmeasurement.org...eToSideTap.htm

I would be interested in hearing from people who are happy to carry out this analysis on themselves.

John

[Tupelo3]

John, I give you a lot of credit for taking action in an attempt to expand on knowledge and persistently staying with it.

Gary