<unk>  is a general term referring to many acute and chronic physical disorders that cause impaired mental function. It does not usually include psychiatric disorders. Though<unk>  is a common diagnosis in the elderly, it is related to disease processes and is not an inevitable part of aging.
Acute<unk>  is a temporary state of mental impairment caused by intoxication, overdose or infection.
Organic brain syndrome
Diencephalic syndrome
Acquired brain injury
Traumatic brain injury
Anoxic brain injury
Chiasmal Syndrome
Acute disseminated encephalomyelitis
Brain stem death