This symptoms came on immediately when my PN came on back in the spring, and it was very intense. Being ignorant of what was happening to me, I recall being particularly frightened of the sudden leg or full body jerks when I was trying to fall asleep on my side. It was horrifying. It has calmed down quite a bit since, and I can't recall the last time I jerked suddenly, or more than a little twitch almost, but I do still shake when lying down and before going to sleep.