Have you tried anti-inflammatories or ice or anything like that?
I'm actually on the verge of going back to the hand specialist myself - I've noticed that my left hand pinky isn't always doing just what I want it to do. I've noticed it doing scales that are part of my warm up. I'm fine at 8th notes, but 16th give me problems. I did bump up my tempo a bit, but even back at the slower tempo, it's difficult - it's almost like the hand fatigues much faster than it should.
It sucks getting old, don't it?
I'd avoid stuff like cortisones, but recommend warm-ups before with stretching and stretching and ice after practice if you've spent more than 40 minutes practicing. Unless my hands are active each day (computer keyboard, handling kitchen tools, working at my job, guitar practice) they'll weaken from lack of use. The key is strengthening them. Yet, because strengthening is mostly a form of exercise, it's important to treat the exercise like you would to a visit to the gym. You don't begin cold. You warm up with either some targeted warm-up exercises for the areas of the body you plan on exercising.
For hands and wrists, that typically involves some hand manipulation that gets the blood flowing to the hand area. YouTube has some videos you can choose from that outline what you'll need to do. Once the hands are warm, you can do some stretching exercises. Your doctor can provide you with some physical therapy printouts, or prescribe some PT specifically for this purpose. If perhaps you'd prefer to do this solo, be sure to be diligent regards the exercises, otherwise they won't solve your pain issue.
Like
@veinbuster, I used to have sloppy computer workstation posture. After several hours of using the mouse alone, I'd end up slumping to the right side of my computer chair misaligning my spine. What solved that was purchasing a decent office desk chair from a used office furniture outlet for about $40-60. My current ride had plenty of seat cushion, and I've made a conscious effort to stop slumping to the right. Not only did this help solve any hand issues, but it helped relieve right side shoulder and hip pain. (My right deltoid bothered me for quite a few years until the doctor and I reasoned that it was extended computer use and poor posture that was the culprit.)
FTR, my doc suggested strengthening my hands after I had just become acquainted with using a home computer, but had not strengthened my hands enough to the point where pain wasn't an issue anymore. For the wrist pain/numbness associated with sleeping at night, the wrist braces solved that problem.
Today, can usually practice for 45 minutes without feeling much after effects. I still cool down and stretch, though. Prevents any muscle/joint stiffness from occurring.