Brian, David and all, First I'll try once again to disentangle the misunderstanding about two- phase dyskinesia. To say it quite plain: If one has serious two-phase dyskinesia it is not always sure whether the movements at a certain moment are the result of top or of dip of meds. If so, one can't discriminate between +2 en -2 or between +1 or -1 on Brian's chart. Only to discriminate 2 from 1 from 0 is always possible. This is the distance between reality and wish. Brian's charts, if I now understand it well, can only be used if this discrimination can be made, which is for most PWP's no problem at all. In the past this discrimination has given me much puzzling and trouble. Now it is easier, partly by learning and partly because during the years the off dyskinesia has grown more than the on dyskynesia and the difference between them is more outspoken too. So I can try to start with Brian's chart anyway and will do so within a few days. I read this morning that about 10% of PD'suffer from two-phase dyskinesia So it is important enough to give it some further attention. I once wrote about it but can add something. This may be of special interest to some 150 readers of this list. Some of them may be just as confused about this as I was. That's why I will describe the symptoms in detail. The end of med's dyskinesia is accompanied by high tensed muscles. The movement is more in the legs than in the trunk. The tension in the muscles is higher on the most afflicted side. The going together of forced movement with tensed muscles is the most tormenting aspect of PD. In the top of med's phase the movements are more in the trunk and shoul- dres. The muscle tonus is lower and if this tension is still high it is on the least afflicted side. Unfortunately this is schematic representation of a more messed-up reality. But for me it seems the best scheme to rely on. The ends of med. dysk. stops when the new l-dopa arrives or else after some time (about one and a half hour). The dysk. normally gives way to an on phase. The only part of the day it has to stop without help is in the evening. I don't use any med's in the night and have to wait till my "cold turkey" is over. The mechanism behind the end of med's dysk. has yet to be found. A simple overcompensation can't be it. The dysk. becomes worse when the disease is more advanced and more of the dopamine producing cells disappeared. Some other system seems to be activated. Ida Kamphuuis Holland.