Delirium

Delirium

Delirium is an often reversible condition when a person experiences sudden mental disturbance with typical features like attention deficit and changes in levels of consciousness. It is actually not a disease but is more properly attributed as a clinical syndrome. Often it is a consequence of an underlying illness or mental problem. ^{[1] [2]}    

Epidemiology

The condition is common in the United States. 40% of patients in the intensive care units are estimated to have it. It is particularly widespread in patients in nursing homes. ^[2]

Causes

Although the exact mechanism is still on its way to be fully comprehended, experts believe that reversible impairment of cerebral oxidative metabolism and aberrations in chemicals called neurotransmitters are the chief mechanism in delirium. The condition is observed to usually set in due to a physical or mental illness or substance abuse. Dehydration and infections like pneumonia are amongst the top causes.

Factors that may increase a person’s chance of developing delirium include old age, dementia, acute febrile illnesses, infections such as urinary tract infection, alcohol or sedative drug withdrawal, impairment with vision or hearing, malnutrition, undergoing surgical procedures, poisoning, electrolyte disturbances and drug abuse.  ^[2][3][4]

Symptoms

The patient usually has a disturbance with consciousness which can manifest as inability to focus or shift attention, cognition problems such as decrease in short term and long term memory and language disturbance, drowsiness, changes in movement, confusion, sensational and perceptual changes, incontinence and personality changes. The transition between mental states is typically immediate. ^{[2] [4]}

Diagnosis

Diagnosis is clinical. After getting the patient’s medical history, the physician conducts a physical examination that includes neurologic and mental status tests. Laboratory tests are useful to exclude other illnesses. Exams include getting ammonia blood level, electroencephalogram (EEG), toxicology screen, thyroid function test, liver function test, CT scan, chest X-ray, lumbar puncture, blood gas analysis and comprehensive metabolic panel. ^[4]  

Treatment

Treatment depends on the cause. If there is a substance that has caused the condition such as alcohol, narcotics or anticholinergics, stopping the patient from taking it or changing the prescription is extremely necessary. When there is an underlying medical problem like thyroid disease or infection, appropriate medical intervention should be instituted. If the patient manifested aggressive behaviors, drugs like antidepressants, dopamine blockers or sedatives may be given on a case to case basis. ^[4]

References:

1.      http://www.news-medical.net/health/Delirium-What-is-Delirium.aspx

2.      http://emedicine.medscape.com/article/288890-overview

3.      http://www.mayoclinic.com/health/delirium/DS01064/DSECTION=causes

4.      http://www.nlm.nih.gov/medlineplus/ency/article/000740.htm

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