Second stroke ?

My grandma who is 87yrs old had a stroke in march affecting her right side of brain causing weekness to left arm leg and hand. She had really done well started walking with a frame etc. She had been out of reabilitation 3wks when we found her collapsed making noises unable to speak and recognise us.they thought it was another stroke that she had had but the scan was clear, so they were then treating her for a urine infection she,s had antibiotics but that test has come back clear.Her memory is really bad she has forgoten names and dosnt know how old she is year she was born and just repeats the same questions and keeps saying that a lot of the hospital staff used to work with her, shes also very lethargic and is sleeping a lot,could it be another stroke that has affected the other side are something else.