Korsakoff syndrome (KS)[1] is a disorder of the central nervous system characterized by amnesia, deficits in explicit memory, and confabulation.

This neurological disorder is caused by a deficiency of thiamine (vitamin B1) in the brain, and it is typically associated with and exacerbated by the prolonged, excessive ingestion of alcohol.

[7] Thiamine is essential for the decarboxylation of pyruvate, and deficiency during this metabolic process is thought to cause damage to the medial thalamus and mammillary bodies of the posterior hypothalamus, as well as generalized cerebral atrophy.

[13] Research has also suggested that people with Korsakoff syndrome have impaired executive functions, which can lead to behavioral problems and interfere with daily activities.

[citation needed] Conditions resulting in thiamine deficiency and its effects include chronic alcoholism and severe malnutrition.

[16] Alcoholism may co-occur with poor nutrition, which in addition to inflammation of the stomach lining, causes thiamine deficiency.

[20] PET scans show that there is a decrease of glucose metabolism in the frontal, parietal and cingulated regions of the brain in those with Korsakoff syndrome.

Additionally, autopsies of people who had KS have showed lesions in both the midline and anterior thalamus, and thalamic infarctions.

[22] Treatment involves the replacement or supplementation of thiamine by intravenous or intramuscular injection, together with proper nutrition and hydration.

[citation needed] As an immediate form of treatment, a pairing of intravenous or intramuscular thiamine with a high concentration of B-complex vitamins can be administered three times daily for 2–3 days.

[26] In those who are seriously malnourished, the sudden availability of glucose without proper bodily levels of thiamine to metabolize is thought to cause damage to cells.

[27] Treatment for the memory aspect of KS can also include domain-specific learning, which when used for rehabilitation is called the method of vanishing cues.

[28] People diagnosed with KS are reported to have a normal life expectancy, presuming that they abstain from alcohol and follow a balanced diet.