• Alternative Names

    Acute confusional state; Acute brain syndrome


    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
    • Changes in level of consciousness or awareness
    • 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
      • Unable to remember events since delirium began (anterograde amnesia)
      • Unable to remember events before delirium (retrograde amnesia)
    • Disrupted or wandering attention
      • Inability to think or behave with purpose
      • Problems concentrating
    • Disorganized thinking
      • Speech that doesn't make sense (incoherent)
      • Inability to stop speech patterns or behaviors
    • Emotional or personality changes
      • Anger
      • Agitation
      • Anxiety
      • Apathy
      • Depression
      • Euphoria
      • Irritability
    • 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:

    • Ammonia levels in the blood
    • Blood chemistry (comprehensive metabolic panel)
    • Blood gas analysis
    • Chest x-ray
    • Cerebrospinal fluid (CSF) analysis
    • Creatine kinase level in blood
    • Drug, alcohol levels (toxicology screen)
    • Electroencephalogram (EEG)
    • Head CT scan
    • Head MRI scan
    • Liver function tests
    • Mental status test
    • Serum magnesium
    • Thyroid function tests
    • Urinalysis
    • Vitamin B1 and B12 levels