I received an epidural steroid injection about 12 hrs ago @ C6/C7. Can this cause EXTREME leg/g cramps every 1/2hr - hr since?? Haven't had this B4!!

Go to ER. No, an uncomplicated injection should NOT do this, but if there was contact with spinal cord or injection chemicals went subarachnoid, this could be a serious issue. Have this addressed NOW.
May B coincidence- -I have not heard of this happening. If they R persistent call Ur treating MD.