Delirium in a 74-year-old man: correct imaging revealed the truth.

Delirium is a cognitive disorder. DSM-IV criteria for delirium must include both acute onset and fluctuating symptoms; disturbance of consciousness (including inattention); at least one of the following: disorganised thinking, disorientation, memory impairment or perceptual disturbance; and evidence of a putative causal medical condition. Traditionally, the course has been described as transient in which recovery is likely to be complete if the underlying aetiological factor is promptly corrected or is self-limited.