I get episodes of cramps too and have not found any rhyme or reason. Bad times just seem to come and go. I have started taking my vitamins before bed and that seems in general to help me have a better night. Wish I could help. My only thought is to get checked for peripheral artery disease, intermittent claudication or some other circulatory problem just in case, but likely it is one of the 'other' manifestations of small fiber neuropathy, besides burning. The cramping, aching, gnawing stuff that it seems a lot of people either don't have or don't talk about.