It is a well-known fact that excessive drinking leads to a so-called “blackout”. This form of memory loss is common in normal people and cannot be seen as a major illness. However, there is another disease that can be caused by excessive drinking called Korsakoff’s syndrome. Strictly speaking, this is not caused by alcohol but due to a thiamine (vitamin B1) deficiency and is commonly found in alcoholics and malnourished patients (it has also been reported to be caused by mercury poisoning and after centipede bites in Japan).
The six characteristic symptoms of this syndrome are: anterograde (cannot form new memories) and retrograde (cannot remember old memories) amnesia, confabulation, lack of detail in conversation, lack of insight and apathy.
Korsakoff’s syndrome patients show a very peculiar behaviour. As stated before they suffer from both anterograde and retrograde amnesia so not only can they not remember the past but they cannot make new memories either. Ergo, the brain uses information from its surroundings and attempts to recreate the lost memories, the result being confabulation. Confabulation is essentially what happens when the brain tries to fill in blanks in memories with false information. Confabulation is seen in everyday life too with healthy people but in the case of Korsakoff’s patients the effects are significantly more profound. For example, if you ask a patient what she did yesterday, she may look at your horse-print tie and claim she was horse-riding. If you ask the same question an hour later without your tie and instead holding a book with a photo of a Ferris wheel on the cover, she’ll state that she was at the amusement park. As one of the leading causes of amnesia and confabulation, Korsakoff’s should be suspected in any alcoholic or very underweight patient who keeps changing their stories around.
As previously explained, the disease is caused by thiamine deficiency – therefore, the treatment is administering thiamine. But if the syndrome has persisted for a long time, the brain injury may be permanent. Also, treating the underlying alcoholism and malnutrition is important.
If the thiamine deficiency is prolonged, it may lead to another disease called Wernicke’s encephalopathy. This is known as Wernicke-Korsakoff’s syndrome and in addition to the above symptoms, the patient may also experience confusion, tremors, nystagmus, paralysis of eye muscles, ataxia, coma and can eventually lead to death. All because of a deficiency of a single vitamin.
Who said nutrition is not important?
(NB: Dory from Finding Nemo is one of the most accurate portrayals of amnesia in films)