I had the same symtom for about 2 years. In addition to my pinky finger, I had twitching muscles on my lower arm, upper arm and shoulder. These muscles were always the same ones, that is the same muscle string as opposed to different ones in the same area. Pinky fingers and the area wherre my pinkies attach to my hand are somewhat numb. Also, I had cramps on both hands on my wrist area when I strained them lifting something heavy, etc. I can now create these cramps if I make a motion with my wrist as if to touch my pinky finger to inside of my wrist, while somewhat forcing it. These symptoms were slowly getting worse. Recently I developed pins and needels feeling on my left arm, caused by a particular posture ( whenever I sit haunced while looking slightly upward, in front of a computer screen).
I was recently dionised with herniated discs on my neck, 4 levels, worst being C5C6 and C6C7 (MRI results). I am considering surgery.
I realize your symptoms are not as bad as mine. If you are suffering from the same problem that is in it's early stages, you may not show positive on "Hoffmann's sign", as I did not either, last year. Hoffmann's sign is a measure of your reflexes, search the web for a desciption. Now, I am showing positive on Hoffmann's sign as well as signs of hyper reflexes.
Sorry to ramble on, I thought my experience may enlighten somebody who is suffering from something similar. I am new here, just signed in and started responding to this thread.
Thanks for the reply. You are correct, there has been no progression (or regression)of the symptoms over the last 5 years.
Interesting that you mention a bad disk pushing on a nerve as a possible cause. About 15 years ago I was in an accident that caused a herniated disk at L4/L5 (plainly visible and proniunced in an MRI). It remains herniated to date and I have never had surgery on this. I have learned to live with it and go very "easy" on my back. However, could it take 10 years for the pinky twitch to manifest from such an injury?
It's somewhat reassuring that there has been no progression of the symptoms over the last 5 years, at least not that you mentioned in your post. Could represent a benign fasciculation, (muscle twitching that does not progress to a serious neurological disease). Fasciculations can also be caused by cervical spine disease (such as a bad disc pushing on a nerve coming out from the spinal cord) or peripheral neuropathies as well as ALS (although this is NOT what this sounds like). As you've had it for quite some time, you may consider seeing a neurologist for a formal examination and possibly an EMG just to make sure nothing else is going on. Good luck.