A change in personality is often noticed as an early signSign 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. of dementia. Important aspects of personality change as dementia progresses, although relative preservation of personality past the mild stage was said to be a sign of vascularVascular Relating to blood vessels that carry blood throughout the body. dementia.