What Causes Severe Pain In The Spine?

Doctor I am Sundar(Hosur. TamilNaud). My mother(58) facing heavy spine problem last 40 days. Before 25 days doctors investigated the issue with MRI and said that spine D4,D9,and D11 having a kind of blood clot. biopsy also done and it is -ve(no problem found). after she is following the medicine properly. but daily she is suffering in fever, vomit and heavy spine pain. please advice me doctor what could be the cause and procedure of the treatment..