My father is an 82-year old male, has always been in excellent health and had right head pain a year ago for several months which went away. Several months ago it returned along with shaky hands, wobbly & achy legs, some dizziness, sweating & flushed face, eye redness & burning, sinus pain and tiredness. He went to his G.P. several times who prescribed sinus meds, antibiotics and some neuro testing which found nothing. What could be going on?