Vascular Dementia - Constant deterioration

My mother who is 70, has been diagnosed with a Vascular Dementia Condition. This is further complicated by depression. She is on treatment for depression, asprin and a statin.

I always thought Dementia was a slow progressing condition.

But it appears that over the last few months the condition just seems to get that little bit worse week by week.

The Dr said that sometimes there is a run of tine wee strokes and then things may plateou out for a while, however, we are a year down the line and this has not happened.

I am a person that kidn of looks at worst case scenario and best case scenario and work somewhere inbetween, however, I cannot find much on what type of prognosis could occur.

Any advise gratefully received