title: Delirium (acute confusional states).
abstract: Delirium (acute confusional states), a common and often overlooked psychiatric disorder, can occur at any age, but elderly persons are especially prone to develop it. In later life, it is often a conspicuous feature of systemic or cerebral disease and drug (notably anticholinergic) toxicity, and it may constitute a grave prognostic sign. Its development in a hospitalized patient may interfere with his or her management, disrupt ward routine, and cause medicolegal complications as a result of patient injury. Acute onset of a fluctuating level of awareness, accompanied by sleep-wake cycle disruption, lethargy or agitation, and nocturnal worsening of symptoms, are diagnostic. Early recognition of delirium and treatment of its underlying cause are essential.
mesh_terms: D001288:Attention / Q000502:physiology; D002940:Circadian Rhythm; D003693:Delirium / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology*; D006801:Humans; D011379:Prognosis; D011597:Psychomotor Performance / Q000502:physiology