I get the jerking fingers a lot - I've posted a lot about this over the past few months. Sometimes, my finger movements are triggered by twitches in the forearms but a lot of the time, they just move on their own. I went through about a two-week period where my right pinky just moved on its own like crazy all the time. Then, one day - it just stopped. About a week later, it came back again for a few days and now it's gone again. Sometimes, my thumbs will do this but not as much as the pinky. The pinky will kind of pull inward towards my palm and hang there for a bit and then let go. Sometimes, gripping things or working at something will trigger this as well.
Like 17Wildcat17 says, I also get this at night when just falling asleep or waking - or when having a nap.
I'm positive it is BFS - I had a second EMG test yesterday and pointed this out to the neuro and he totally agreed. I even asked him about PD and not a chance - it's BFS.
Hope this helps,
God Bless, Mark