6. Korsakoff's syndrome
Korsakoff's syndrome is a form of ARBD in which the main cause is a clear lack of thiamine. Korsakoff's syndrome is the most well-known form of ARBD and many people think that it is the most common or even only form. However, Korsakoff's syndrome is much less common than other forms of ARBD such as alcoholic dementia.
Korsakoff's syndrome often develops as part of a condition known as Wernicke-Korsakoff syndrome. This consists of two separate but related stages: Wernicke's encephalopathy followed by Korsakoff's syndrome. Wernicke-Korsakoff syndrome is diagnosed in about one in eight people with alcoholism. However, not everyone has a clear case of Wernicke's encephalopathy before Korsakoff's syndrome develops.
How does Wernicke's encephalopathy develop?
An encephalopathy is a disorder that affects the function of the brain. Wernicke's encephalopathy usually develops suddenly, often after abrupt and untreated withdrawal from alcohol. It has a range of different symptoms, but they may not be obvious and it can be difficult to make a diagnosis.
Symptoms of Wernicke's encephalopathy can include:
- disorientation, confusion or mild memory loss
- undernutrition - for example, the person is very underweight
- involuntary, jerky eye movements or paralysis of the muscles that move the eyes
- poor balance or unsteadiness, or other signs of damage to a part of the brain called the cerebellum (a region involved in co-ordinating movement).
If Wernicke's encephalopathy is suspected, immediate medical treatment is essential. The person will need high doses of thiamine (and other B vitamins) injected slowly into a vein. If treatment is done in time, most symptoms will be reversed in a few days. However, permanent brain damage may result if Wernicke's encephalopathy is left untreated or is not treated properly or in time. In some severe cases the person may die.
How does Korsakoff's syndrome develop?
Where Wernicke's encephalopathy is untreated, or is not treated soon enough, Korsakoff's syndrome usually develops, though often gradually. Damage occurs in several regions of the brain - particularly in important small areas deep within the brain, resulting in severe loss of short-term day-to-day memory. Many other abilities may remain intact, such as working memory (information held in our head for a short time before using it, eg working out how much something costs).