Differences between Delirium and Dementia

Features	Delirium	Dementia
Onset	Usually acute	Usually insidious
Course	Usually recover in 1 week, may take up to 1 month.	Usually protracted, although may be reversible
Consciousness	Clouded	Usually normal
Orientation	Grossly disturbed	Usually normal, disturbed only in late stages
Memory	Immediate retention and recall disturbed	Immediate retention and recall normal Recent memory disturbed, remote memory disturbed only in late stages
Comprehension	Impaired	Impaired only in late stages
Sleep- wake cycle	Grossly disturbed	Usually normal
Attention and concentration	Grossly disturbed	Usually normal
Diurnal  variation	Marked sun downing present	Usually absent
Perception	Visual illusions and hallucinations very common	Usually absent. Hallucinations may occur
Other features	Asterixis, Multifoal myoclonus	Catastrophic reaction,perseveration