I know this is old and I hope the OP might find some use from this. I don't know of anyone who doesn't love their grandmother so I hope my questions aren't unkind. I'm not a doctor but the question I would ask you is whether or not she had any deficits (i.e. forgetfulness, unusual behavior, etc.) before the surgery? The ischemia means that there was a lack of blood flow to cells in the white matter of the cerebrum and some of the cells died since it states that the small vessels (and the cells that get oxygen and nutrients from it) were damaged. Depending on how many cells were lost, there may be a slight loss of associative and executive function or it may be more serious. The cerebrum is a major part of the brain that is associated with high level functioning so depending on where the actual damage occured The fact that it is chronic and not acute means that this is not a sudden thing but something that was already in place. I hope that there is more imaging scheduled (MRI, PET) so a neurologist can help figure out how bad things are.