Dibilitating Hand Cramps

For years I have had claw-like hand cramps in my right hand and wrist. I take calcium, b-complex and potassium, and have odne so for years. I have been tested for carpal tunnel and the doctors have said the cramps are unrelated. I saw a neurologist, who shrugged his shoulders. For the last year I've just lived with the pain and avoided activities that depend on my holding any weight in my right hand. However, today I had an hour-long cramping episode that brought me to tears. I had to place my hand on a flat surface and hold it down to ease the pain. Where do I turn? The doctors have told me they don't "really know what causes hand cramps." They've all suggested the above vitimins and I have followed the advice faithfully. Yes, Advil works, but, it also makes me very tired.