Dementia
Dementia was a broad syndrome that could affect several cognitive functions, including memory, attention, and problem solving abilities.

Some people who suffered from dementia spoke their native language again. ()

The Vidiian phage could also cause hallucinatory dementia. ()

When Jean-Luc Picard discussed returning to space to seek out the twin sister of Dahj Asha, Laris exclaimed: "Have you gone mad!? Is it dementia?" ()

Types of dementia 
Dementia puglistica 
Holo-transference dementia syndrome
Multi-infarct dementia

External link

Medical conditions