Has anyone ever had problems with dizziness after surgery or during stroke recovery? What was the cause and was there anything that helped ?

Short story my wife had 1st stroke Dec 24th, 2nd Feb 28, diagnosed with MM March 28th, 3rd stroke April 2nd, Surgery on right side & 4th stroke April 11, surgery on left April 18.

Left hospital after surgery hardly able to move right side, needing a wheelchair and with difficulty speaking due to aphasia. After 3 weeks in rehab was able to walk short distances with walker. 2 months later is able to walk over 900ft at the mall (we measure the progress), walk up a few steps and speaking nearly normally.

Then about a week and a half ago she woke up feeling dizzy and could only walk short distances (no more than 20-30 feet) with out feeling like she would fall. This continued for a week, at outpatient rehab they said if it got worse to go in and get checked out. It did keep getting worse so we went to the hospital, they did a CT scan and said it all looked good, they saw no change from a surgery follow-up CT scan from last month. They don't know what is causing the dizziness. They had her stop taking the small amount of blood pressure medication she was on but it didn't help either.