BAsic information description A brain disorder that involves gradual mental deterioration. The more gradual form, with slow development of symptoms, begins around ages 65 to 70. A rapidly progressive form begins in adults around ages 36 to 45. frequent signs and symptoms Early stages: Forgetful of recent events. Increasing difficulty doing mental tasks, such as usual work, balancing a checkbook, or maintaining a household. Personality changes, including poor impulse control and poor...