Dementia

Dementia is the general name for a decline in cognitive abilities that impacts a person's ability to perform everyday activities. This typically involves problems with memory, thinking, and behavior. Aside from memory impairment and a disruption in thought patterns, the most common symptoms include emotional problems, difficulties with language, and decreased motivation... Several diseases and injuries to the brain such as a stroke can give rise to dementia. However, the most common cause is Alzheimer's disease, a neurodegenerative disorder. https://en.wikipedia.org/wiki/Dementia