Hans, I do not understand why either, however I know it works. I am subject to dyskinesia in my neck and shoulders. When it finally leaves, I have migraine-like headaches. They are from the occipital nerve being pinched during the dyskinesia. My last doctor told me to do ice-massage on the neck muscles involved. It works wonders and the headaches go away. don't forget how to laugh (and do it often) Marling McReynolds 49/3 [log in to unmask] http://members.tripod.com/~marling