Delirium tremens (colloquially, the DTs, "the horrors", "the fear", "the abdabs", "the jimjams", "jazz hands", or "the rats"; afflicted individuals referred to as "jitterbugs" in 1930s Harlem slang; literally, "shaking delirium" or "'trembling madness" in Latin) is an acute episode of delirium that is usually caused by withdrawal from alcohol, first described in 1813.^[1][2] Benzodiazepines are the treatment of choice for delirium tremens.^[3]

Withdrawal from sedative-hypnotics other than alcohol, such as benzodiazepines or barbiturates can also result in seizures, delirium tremens and death if not properly managed. Withdrawal from other drugs which are not sedative-hypnotics such as opiods, marijuana, cocaine etc. do not have major medical complications and withdrawal is therefore not life threatening.^[4] When caused by alcohol, it occurs only in individuals with a history of chronic alcohol consumption. Occurrence of a similar syndrome due to benzodiazepine does not require as long a period of consistent intake of such drugs. Prior use of both benzodiazepines and alcohol can compound the symptoms and is the most dangerous, especially if untreated.^{[clarification needed]}

In the U.S., fewer than fifty percent of alcoholics will develop any significant withdrawal symptoms upon cessation of alcohol intake, and of these, only five percent of cases of acute ethanol withdrawal progress to delirium tremens.^[1] Unlike the withdrawal syndrome associated with opiate dependence, delirium tremens (and alcohol withdrawal in general) can be fatal. Mortality was as high as 35% before the advent of intensive care and advanced pharmacotherapy; in the modern era of medicine, death rates range from 5-15%.^[1]

[edit] Symptoms

The main symptoms are confusion, diarrhea, disorientation and agitation and other signs of severe autonomic instability (fever, tachycardia, hypertension). Other common symptoms include intense perceptual disturbance such as visions of insects, snakes or rats (or stereotypically, pink elephants or tiny figures). These may be hallucinations, or illusions related to the environment, e.g., patterns on the wallpaper that the patient perceives as giant spiders attacking him or her. Unlike hallucinations associated with schizophrenia, delirium tremens hallucinations are primarily visual, but are also associated with tactile hallucinations such as sensations of something crawling on the subject - a phenomenon known as formication.

Delirium tremens can sometimes be associated with severe, uncontrollable tremors of the extremities and secondary symptoms such as anxiety, panic attacks and paranoia. Confusion is often noticeable to onlookers as individuals will have trouble constructing simple sentences or making basic logical calculations. In many cases, people who rarely speak out of turn will have an increased tendency for gaffes even though they are sober.

Delirium tremens (DT) should be distinguished from alcoholic hallucinosis, the latter occurring in approximately 20% of hospitalized alcoholics and not carrying a significant mortality. In contrast, DT occurs in 5-10% of alcohol-dependent people and carries up to 5% mortality with treatment and up to 35% mortality without treatment.^[2] DT is characterized by the presence of altered sensorium; that is, a complete hallucination without any recognition of the real world. DT has extreme autonomic hyperactivity (high pulse, blood pressure, and rate of breathing), and 35-60% of patients have a fever. Some individuals experience seizures.

[edit] Causes

Delirium tremens is caused after a long period of drinking, stopping abruptly and experiencing withdrawal. It may also be triggered by head injury, infection, or illness in people with a history of heavy use of alcohol. It is most common in people who have a history of alcohol withdrawal, especially in those who drink the equivalent of 7 to 8 US pints (3–4 l or 6–7 imp pt) of beer (1 US pint, 400–500 ml or 16–18 imp fl oz of distilled beverage) daily. Delirium tremens also commonly affects those with a history of habitual alcohol use or alcoholism that has existed for more than 10 years.^[5]

The exact pharmacology of ethanol is not fully understood: however, it is theorized that delirium tremens is caused by the effect of alcohol on the benzodiazepine-GABA_A-chloride receptor complex for the inhibitory neurotransmitter GABA. Constant consumption of alcoholic beverages (and the consequent chronic sedation) causes a counterregulatory response in the brain in attempt to regain homeostasis.

This causes downregulation of these receptors, as well as an up-regulation in the production of excitatory neurotransmitters such as norepinephrine, dopamine, epinephrine, and serotonin - all of which further the drinker's tolerance to alcohol and may intensify tonic-clonic seizures.^{[citation needed]} When alcohol is no longer consumed, these down-regulated GABA_A receptor complexes are so insensitive to GABA that the typical amount of GABA produced has little effect; compounded with the fact that GABA normally inhibits action potential formation, there are not as many receptors for GABA to bind to - meaning that sympathetic activation is unopposed. This is also known as an "adrenergic storm"; the effects of which can include (but are not limited to) tachycardia, hypertension, hyperthermia, hyperreflexia, diaphoresis, heart attack, cardiac arrhythmia, stroke, anxiety, panic attacks, paranoia, and agitation.

This is all made worse by excitatory neurotransmitter up-regulation, so not only is sympathetic nervous system over-activity unopposed by GABA, there is also more of the serotonin, norepinephrine, dopamine, epinephrine, and particularly glutamate. Excitory NMDA receptors are also up-regulated, contributing to the delirium and neurotoxicity (by excitotoxicity) of withdrawal. Direct measurements of central norepinephrine and its metabolites is in direct correlation to the severity of the alcohol withdrawal syndrome.^[6] It is possible that psychological (i.e., non-physical) factors also play a role, especially those of infections, malnutrition, or other underlying medical disorders - often related to alcoholism.

[edit] Treatment

Delirium tremens due to alcohol withdrawal can be treated with benzodiazepines. High doses may be necessary to prevent mortality.^[7] Pharmacotherapy is symptomatic and supportive. Typically the patient is kept sedated with benzodiazepines, such as diazepam (Valium), lorazepam (Ativan), chlordiazepoxide (Librium), or oxazepam (Serax) and in extreme cases low-levels of antipsychotics, such as haloperidol or even stronger benzodiazepines like temazepam (Restoril) or midazolam (Versed) until symptoms subside. Older drugs such as paraldehyde and clomethiazole were the traditional treatment but these have now largely been superseded by the benzodiazepines, although they may still be used as an alternative in some circumstances. Acamprosate is often used to augment treatment, and is then carried on into long term use to reduce the risk of relapse. If status epilepticus is present, seizures are treated accordingly. Controlling environmental stimuli can also be helpful, such as a well-lit but relaxing environment to minimise visual misinterpretations such as the visual hallucinations mentioned above. Although used rarely, an alcohol drip may be prescribed to sedate severe patients, who will then need to be "weaned" off of the alcohol.

[edit] See also

• Alcohol detoxification
• Alcohol withdrawal syndrome
• Benzodiazepine withdrawal syndrome
• Delusional parasitosis
• Excited delirium
• Alcohol dementia

[edit] References

[edit] External links

• Medline Encyclopedia: Delirium Tremens
• eMedicine Delirium Tremens