I get this and it's due to compression of the spinal cord in my spine. I have stenosis a well as a large disc herniation at C5/C6. In the past, I've had both hands cramp up, causing my fingers to close in on my hand, though the cramping in my hands doesn't actually hurt for some reason. I also get cramps in my feet and other areas that DO hurt. Long ago, when I first told a Doctor about it, he described it as tetany, though I didn't have any calcium, magnesium, nor other imbalances. That doctor never sent me for an MRI of my neck, either, even though he knew about similar issues in my lumbar spine, as well the severe neck & shoulder pain that I had. He said it was fibromyalgia and ended up giving me TONS of lidocaine injections up and down my spine that were costly. Those injections did absolutely nothing except caused me a lot of extra pain. My muscles were always in terrible spasm and all those injections made my spasms worse.

Several years later, I did see a different doctor, who sent me for MRIs right away, and that is when my cervical spine issues were confirmed.

Over the years, I have had periods where my neck seemed okay with no hand or fingers symptoms and no nerve pain. It always come back at some point, though. But anyway, when my neck gets worse, that is when my hands cramp up. I have also noticed the cramping cease when taking steroids and even Humira for a short while.