Dave My step father (68/9) has a similar non-reaction to sinemet. Has visible effect at a pretty substantial dose (3 Sinemt CR's, 3 Sineme 25/100 a day). His neuro is increasing the dose to see if that makes a difference. He also had us do a MRI to see if he could spot any atypical patterns that may suggest atypical PD. I'll let you know. Bill -- Bill Bell ([log in to unmask])