Hi Beth! I've had them. I don't get them that often and they always happen during the night from the jaw/neck down to the toes. Once the rock hard stiffening eases up, it is sore and takes a while for everything to relax enough to go back to sleep. I sometimes will take another Neurontin when this happens and it seems to help.
I hope you are feeling better.

You definitely are not alone on this one.