my husband is a multiple myeloma cancer patient and due to a pinched nerve from a tumor made by the cancer he became numb from belly down to his toes ( april 2016) today as laying in his bed, he just started twitching his left foot and feels a burning sensation there (on top of his skin between fifth and the third toe) I tried to locate and I feel a pimple size thing in the nerve, and he told me that s where the pain is coming from, evreytime I touch it, he twitch, what would be the possible reason of his twitching?