According to the National Institute of Neurological Disorders and Stroke, Alzheimer's disease is a progressive, neurodegenerative disease that occurs when nerve cells in the brain die. The disease often results in the following behaviors: Impaired memory, thinking, and behavior Confusion Restlessness Personality and behavior changes Impaired judgment Impaired communication Inability to follow directions Language deterioration Impaired thought processes that involve visual and spatial awareness Emotional apathy