Shaking thumb. Please help me be rational.

[ckelley116]

For the last 3-4 weeks I've noticed that my right thumb, when held in a certain position (such as when I've got it extended over my phone, even though it happens when I'm not holding my phone) shakes back and forth very visibly. My left thumb is completely normal. This doesn't happen when at rest, although my whole hand feels shaky and weak most of the time, very much like when my blood sugar is low. Half the time I look at my hand expecting to see it twitching and jerking like crazy because of the way it feels, but it's not. And I haven't been dropping anything or experiencing any true weakness that I've noticed, so I'm guessing this is just a perception and not a true sensation. But the thumb shaking is definitely real, and although I'm doing my best not to go there, Parkinson's disease has entered my head and I can't get it out.

Here's why I know I'm being irrational:
1) I'm only 39, so I'm young for PD.
2) I'm female, and while females do get PD, it's more common in men.
3) I have no family history of neurological disorders of any kind.
4) I do have a history of carpal tunnel syndrome in that hand. I had a cortisone shot in March 2018 and haven't had any symptoms since, but before the shot I was numb 24/7 for more than 4 months. This could easily have caused dead nerves and some muscle atrophy that means that muscle is just weaker. The fleshy part of my palm, at the base of my thumb, is a bit flatter than on my left hand (where I don't have CTS) and I've also been feeling some twitching in that area. I know twitching is not a sign of PD, at least not in the early stages.
5) PD tremors are supposed to happen when at rest, and mine occur only when my thumb is in a specific position.
6) I'm on a computer literally all day long (customer service rep by day; author and freelance graphic designer by night). Plus I'm right-handed, so I spend 90% of my day with that hand clenching a mouse or my phone.
7) I have anxiety and tremors and twitching are common symptoms of anxiety.

I could go on, but I think that's enough for now. I'm trying so hard to focus on these reasons I don't have Parkinson's disease, and not the very slim possibility that I do have it. But it's so difficult to be rational when the twitching is in just in one hand, and when I can feel it every time I try to use my hand. Has anyone experienced anything like this? I'm trying not to focus on it in hopes that it will go away, but I'm not having much luck.

[travelgirl77]

Well, I have a shaking index finger and bonus, it happens while at rest. I had the same thing last year and it eventually went away. But, I also am concerned about PD. I did just lie in bed for 5 minutes and I can feel the different twitches and pops all over my body, in various places, but the finger is the most prevalent and constant. If I were you, I would completely chalk it up to CTS, since you know you have had that before and you are using your fingers all day long. They are likely tired...that is the most rational explanation, as you have already sussed out above. If you look in the search bar you will see countless posts from people who have one specific area (whether it is a finger, toe, eyelid, lip, etc) that twitches for days, weeks, or months. Like you, I am trying to be rational, in that I had this very issue last year and it eventually went away. I am also somewhat comforted by the fact that my whole body has twitches, even though this one is much more prominent, for whatever reason.