Although irritability and frustration are common in early dementia, in a person who does not have a lifelong tendency to acting out in a hostile way, this is more often seen in the moderate to severe stages Stages
Course of disease progression defined by levels or periods of severity: early, mild, moderate, moderately severe, severe of Alzheimer's disease Alzheimer's disease
A neurological disease that affects memory and behaviour. It is characterized by beta-amyloid plaques and neurofibrillary tangles in the brain. There is no known cause but genetics and lifestyle are thought to play a role.. By contrast, some people with frontal lobe Frontal lobe
The front part of the brain. It is important for the control of voluntary movement or activity, cognition and feelings. dementia, it is an early sign Sign
In medicine a sign is what a physician finds by examining a patient. For example, a patient with the symptom of pain might have signs of a fast heart rate, a pale face, a clammy touch and tenderness.. It is also seen early in patients with dementia due to certain types of stroke Stroke

Blood supply to the brain is interrupted, usually by a blood clot. As a result, a portion of the brain can die from not receiving enough blood and oxygen.