Is Increased Aggression In An Elderly Lady Suggestive Of Dementia?

Is it possible that an 85 year old female may have dementia if normally and in the past she was basically a nice person, but over the past two years has become more aggressive, demanding and unrealistic in her expectations from her spouse? Example: spouse recently had operation and in the first 24 hours was in the care of his daughter. Female calls and demands that he come to be at her side as she is lonely without him . . .