I Have Hand Cramps That Twist And Mangle My Fingers

I have hand cramps that twist and mangle my fingers into claws. I need to have my wife pull them open. It affects my wrists as well. My neck does the same and I fight to keep my head straight. I suffer from nagging limiting shoulder and jaw pain. The Dr put me on nitro sublingual tablets but they find no cardiac problems. Could the jaw pain be less cardiac and more Dystonia?