Help - my mother has been experiencing loss of horizontal vision from left to right since august after a severe headache -- the headaches respond somewhat to meds but the vision continues to worsen -- she has had numerous optometry exams that show the worsening of visual fields but no apparent problems with the eye - -MRI and CT scans do not show anything -- she recently had spinal fluid drawn for testing but we don't have the results yet -- she is 75 -- i am desperate for some answers