It is unclear, however, which executive functions are affected most. Nonetheless, IQ is usually not affected by the brain damage associated with Korsakoffs syndrome.At first it was thought that those with KS used confabulation to fill in memory gaps. However, it has been found that confabulation and amnesia do not necessarily co-occur. Studies have shown that there is dissociation between provoked confabulation, spontaneous confabulation (which is unprovoked), and false memories. That is, people affected could be led to believe certain things had happened which actually had not, but so could people without Korsakoff syndrome. Causes
Conditions resulting in thiamine deficiency and its effects include chronic alcoholism and severe malnutrition. Alcoholism may co-occur with poor nutrition, which in addition to inflammation of the stomach lining, causes thiamine deficiency. Other causes include dietary deficiencies, prolonged vomiting, eating disorders, and the effects of chemotherapy. It can also occur in pregnant women who have a form of extreme morning sickness known as hyperemesis gravidarum. Mercury poisoning can also lead to Korsakoff syndrome. Though it does not always co-occur, this disorder can emerge frequently as a consequential result of Wernickes encephalopathy.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. This may contribute to memory loss and amnesia. Structural neuroimaging has also shown the presence of midline diencephalic lesions and cortical atrophy.Structural lesions of the central nervous system, though rare, can also contribute to symptoms of KS.
Korsakoff syndrome (KS) 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. Korsakoff syndrome is often accompanied by Wernicke encephalopathy; this combination is called Wernicke–Korsakoff syndrome.Korsakoff syndrome is named after Sergei Korsakoff, the Russian neuropsychiatrist who described it during the late 19th century. Signs and symptoms
There are seven major symptoms of Korsakoff syndrome, an amnestic-confabulatory syndrome:
anterograde amnesia, memory loss for events after the onset of the syndrome
retrograde amnesia, memory loss extends back for some time before the onset of the syndrome
amnesia of fixation, also known as fixation amnesia (loss of immediate memory, a person being unable to remember events of the past few minutes)
confabulation, that is, invented memories which are then taken as true, due to gaps in memory, with such gaps sometimes associated with blackouts
minimal content in conversation
lack of insight
apathy – interest in things is quickly lost, and there is an indifference to changeBenon R. and LeHuché R. (1920) described the characteristic signs of Korsakoff syndrome with some additional features including: confabulation (false memories), fixation amnesia, paragnosia or false recognition of places, mental excitation, and euphoria.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.