It happens unexpectedly: a person long thought lost to the ravages of dementia, unable to recall the events of their lives or even recognize those closest to them, will suddenly wake up and exhibit surprisingly normal behavior, only to pass away shortly thereafter. This phenomenon, which experts refer to as terminal or paradoxical lucidity, has been reported since antiquity, yet there have been very few scientific studies of it. That may be about to change.
Source: Medicine Science Daily