My Aunt 89 Yrs Had A Sudden Onset Of Confusion

my aunt 89 yrs had a sudden onset of confusion , paranoia approx. 1 week after a fall in an assistant living. Had a rotator cuff tear with ac separation but denied hitting her head. At first thought was a UTI , neg , had blood work and a brain CT neg. repeated u/a neg. On lexopril, warfin Celebrex. Don't know where to go from here. 60% confused with periods of lucid remarks. is a stroke always comfirmed with a CT scan? She has no other stroke S/s
Where do we go from here?