Gradual onset:

Impaired memory Language difficulty Impaired judgment Lack of spontaneity Social difficulties Depression, terror

Steady progress:

Wandering Repetitive behavior Disorientation Twitching, seizures Difficulty thinking Agitation

Terminal stage:

Complete dependence Inability to recognize people Severe speech impairment Emaciation Total loss of body control

Course of disease varies greatly, averaging eight to 10 years

Source: Alzheimer's Association, National Institute on Aging, Mayo Clinic