neurologic disorders
Delirium
Introduction
Delirium is an acute, transient, usually reversible, fluctuating disturbance in attention, cognition, and consciousness level. Causes include almost any disorder or drug. Diagnosis is clinical, with laboratory and usually imaging tests to identify the cause. Treatment is correction of the cause and supportive measures. (See also Overview of Delirium and Dementia .) Delirium may occur at any age but is more common among older people. At least 10% of older patients who are admitted to the hospital have delirium; 15 to 50% experience delirium at some time during hospitalization. Delirium is also common after surgery and among nursing home residents and intensive care unit (ICU) patients. When delirium occurs in younger people, it is usually due to use of a drug (recreational drug or medication) or a life-threatening systemic disorder. Delirium is sometimes called acute confusional state or toxic or metabolic encephalopathy. Delirium and Dementia are separate disorders but are sometimes difficult to distinguish. In both, cognition is disordered; however, the following helps distinguish them: Deliriumaffects mainly attention, is typically caused by acute illness or drug toxicity (sometimes life threatening), and is often reversible. Dementiaaffects mainly memory, is typically caused by anatomic changes in the brain, has slower onset, and is generally irreversible. ). Delirium often develops in patients with dementia; it is called delirium superimposed on dementia (DSD). DSD can occur in up to 49% of patients with dementia during hospitalization. Also, patients with delirium have a higher risk of developing dementia ( General reference ). 