Korsakoff's syndrome

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Korsakoff's syndrome
Classification and external resources
Thiamine
ICD-10 F10.6
ICD-9 291.1, 294.0
DiseasesDB 14107
eMedicine med/2405 
MeSH D020915

Korsakoff's syndrome (Korsakoff's psychosis, amnesic-confabulatory syndrome), is a brain disorder caused by the lack of thiamine (vitamin B1) in the brain. The syndrome is named after Sergei Korsakoff, the neuropsychiatrist who popularized the theory.

Contents

[edit] Symptoms

There are six major symptoms of Korsakoff's syndrome:

  1. anterograde amnesia and
  2. retrograde amnesia, severe memory loss
  3. confabulation, that is, invented memories which are then taken as true due to gaps in memory sometimes associated with blackouts
  4. meager content in conversation
  5. lack of insight
  6. apathy - the patients lose interest in things quickly and generally appear indifferent to change.

These symptoms are caused by a deficiency of thiamine (vitamin B1), which is thought to cause damage to the medial thalamus and possibly to the mammillary bodies of the hypothalamus as well as generalized cerebral atrophy.[1]

When Wernicke's encephalopathy accompanies Korsakoff's syndrome, the combination is called the Wernicke-Korsakoff syndrome. Korsakoff's is a continuum of Wernicke's encephalopathy, though a recognised episode of Wernicke's is not always obvious.

Korsakoff's involves neuronal loss, that is, damage to neurons; gliosis which is a result of damage to supporting cells of the central nervous system; and hemorrhage or bleeding in mammillary bodies. Damage to the dorsomedial nucleus of the thalamus is also associated with this disorder.

[edit] Signs

  • Ataxia
  • Apathy
  • Retrograde and anterograde amnesia
  • Confabulation
  • Tremors
  • Paralysis of muscles controlling the eye
  • Lack of insight to the condition
  • Coma

[edit] Treatment

Treatment involves replacing the thiamine by intravenous (IV) or intramuscular (IM) injection, and providing proper nutrition and hydration. However, the amnesia and brain damage caused by the disease does not respond to thiamine replacement therapy. In some cases, drug therapy is recommended to the patient. If treatment is successful, signs will show within two years though recovery is slow and often incomplete.

[edit] Causes

Conditions resulting in the vitamin deficiency and its effects include chronic alcoholism, and severe malnutrition. Alcoholism is often an indicator of poor nutrition, which in addition to inflammation of the stomach lining, causes thiamine deficiency.[2] As well as alcohol abuse, causes include dietary deficiencies, prolonged vomiting, eating disorders, or the effects of chemotherapy. It can also occur in pregnant women who have a form of extreme morning sickness known as hyperemesis gravidarum.[3] Mercury poisoning can also cause it. It has also been caused by centipede (mukade) bites in Japan[4].

Due to malnutrition and a lack of Thiamine, the hippocampus begins to decay, leaving holes that disallows one's rehearsed information within short term memory to transfer to long term memory (anterograde amnesia)

[edit] Prevention

The most effective method of preventing Korsakoff's syndrome is to avoid B vitamin/thiamine deficiency. In Western nations the most common cause of such deficiency is alcoholism. Thiamine was introduced to alcoholic beverages in the U.S. for a time, but this does not appear to have an effect on Korsakoff's syndrome, as the cause of Korsakoff's syndrome in chronic alcoholics is not a deficiency of thiamine in the diet, but rather a reduction in the body's ability to absorb thiamine in the intestine.[5] In the U.S., government mandates to adding thiamine to alcoholic beverages have been blocked for this reason and also by political groups asserting that such supplementation would encourage alcohol use.[citation needed]

Also, alcohol is, by itself, neurotoxic. It will cause neural damage taken in excess, especially in the hippocampus. The body responds to alcohol ingestion by releasing cortisol as a neuroprotective mechanism (animals that have been adrenalectomized may be killed by a fraction of the dose of alcohol that an unadrenalectomized animal may tolerate). Cortisol, specifically, has been shown to cause irreversible damage to the hippocampus when present in large amounts for extended periods of time.[6] Alcohol in excess may be causal in and of itself in Korsakoff dementia regardless of thiamine addition to spirits. Alcohol toxicity is cumulative; cessation of its use, or never having used it, will reduce risk of korsakoff and other dementias.

[edit] Case studies

A famous case study is recounted by Oliver Sacks in "The Lost Mariner", which can be found in The Man Who Mistook His Wife for a Hat.

Other cases include that of artist Charles Blackman[7] and entertainer Graham Kennedy.[8]

[edit] In popular culture

  • In the fictional show House, episode "Histories", the clinic patient suffers from Korsakoff's as a result of malnutrition.
  • In the novel Mona Lisa Overdrive, the character Slick was incarcerated in a "chemo-penal unit" with "induced Korsakov's" (sic).
  • In the British movie The Wrong Box, Peter Sellers plays a doctor suffering from Korsakoff's syndrome, who is reduced to signing reports of more than questionable medical content, while telling everybody of his former lavish Mayfair office, where only the Lords and Counts used to be his clientèle.

[edit] References

  1. ^ Kolb & Whishaw: Fundamentals of Human Neuropsychology, 2003, pages 473-473
  2. ^ http://www.alzheimers.org.uk/Facts_about_dementia/What_is_dementia/info_korsakoffs.htm
  3. ^ Korsakoff's syndrome
  4. ^ Centipede bites in Japan. [Cutis. 1991] - PubMed Result
  5. ^ http://www.healthatoz.com/healthatoz/Atoz/common/standard/transform.jsp?requestURI=/healthatoz/Atoz/ency/korsakoffs_syndrome.jsp
  6. ^ http://www.tianeptine.com/cortisol-stress.html
  7. ^ Artist's wonderland is back in town - Arts - Entertainment - theage.com.au
  8. ^ [1]

[edit] External links