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Delirium

Definition

Delirium is sudden severe confusion and rapid changes in brain function that occur with physical or mental illness.

Alternative Names

Acute confusional state; Acute brain syndrome

Causes, incidence, and risk factors

Delirium is most often caused by physical or mental illness and is usually temporary and reversible. Many disorders cause delirium, including conditions that deprive the brain of oxygen or other substances.

Causes include:

Symptoms

Delirium involves a quick change between mental states (for example, from lethargy to agitation and back to lethargy).

Symptoms include:

  • Changes in alertness (usually more alert in the morning, less alert at night)
  • Changes in feeling (sensation) and perception
  • or awarenessChanges in level of consciousness
  • Changes in movement (for example, may be slow moving or hyperactive)
  • Changes in sleep patterns, drowsiness
  • Confusion (disorientation) about time or place
  • Decrease in short-term memory and recall
  • Disrupted or wandering attention
  • Disorganized thinking
  • Emotional or personality changes
  • Incontinence
  • Movements triggered by changes in the nervous system (psychomotor restlessness )

Signs and tests

The following tests may have abnormal results:

  • An exam of the nervous system (neurologic examination), including tests of feeling (sensation), thinking (cognitive function), and motor function
  • Neuropsychological studies

The following tests may also be done:

Treatment

The goal of treatment is to control or reverse the cause of the symptoms. Treatment depends on the condition causing delirium. The person may need to stay in the hospital for a short time.

Stopping or changing medications that worsen confusion, or that are not necessary, may improve mental function. Substances and medicines that can worsen confusion include:

  • Alcohol
  • , especially narcotics such as codeine, hydrocodone, morphine, or oxycodoneAnalgesics
  • Anticholinergics
  • depressantsCentral nervous system
  • Cimetidine
  • Recreational drugs
  • Lidocaine

Disorders that contribute to confusion should be treated. These may include:

Treating medical and mental disorders often greatly improves mental function.

Medicines may be needed to control aggressive or agitated behaviors. These are usually started at very low dosages and adjusted as needed:

  • Antidepresssants (fluoxetine, citalopram), if depression is present
  • blockers (haloperidol, quetiapine, or risperidone are most commonly used)Dopamine
  • Sedatives (clonazepam or diazepam) in cases of delirium due to alcohol or sedative withdrawal
  • Thiamine

Some people with delirium may benefit from hearing aids, glasses, or cataract surgery .

Other treatments that may be helpful:

Support Groups

Expectations (prognosis)

Acute conditions that cause delirium may occur with chronic disorders that cause dementia . Acute brain syndromes may be reversible by treating the cause.

Delirium often lasts only about 1 week, although it may take several weeks for mental function to return to normal levels. Full recovery is common.

Complications

  • Loss of ability to function or care for self
  • Loss of ability to interact
  • Progression to stupor or coma
  • Side effects of medications used to treat the disorder

Calling your health care provider

Call your health care provider if there is a rapid change in mental status .

Prevention

Treating the conditions that cause delirium can reduce its risk. In hospitalized patients, avoiding sedatives, staying still (immobilization), and bladder catheters, and using reality orientation programs will reduce the risk of delirium in those at high risk.

References

Mendez MF, Kremen SA. Delirium. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. 6th ed. Philadelphia, PA: Elsevier Saunders; 2012:chap 4.

Rudolph JL, Marcantonio ER. Delirium. In: Duthie EH Jr., Katz PR, Malone ML. 4th ed. Philadelphia, PA: Elsevier Saunders; 2007:chap 26.

Encyclopedia content is provided as information only and not intended to replace the advice and instruction from your personal physician.