Wernicke-Korsakoff syndrome is a neurological disorder caused by the lack of thiamine (vitamin B1). The disorder includes Wernicke encephalopathy and Korsakoff amnesic syndrome which are not different conditions but different stages of the same disease (Wernicke-Korsakoff syndrome). Wernicke's encephalopathy represents the "acute" phase of the disorder and Korsakoff's amnesic syndrome represents the disorder progressing to a "chronic" or long-lasting stage. The disorder's main features are problems in acquiring new information or establishing new memories, and in retrieving previous memories.

Wernicke's encephalopathy is a degenerative brain disorder caused by the lack of vitamin B1. It may result from:

• Alcohol abuse
• Dietary deficiencies
• Prolonged vomiting
• Eating disorders
• Effects of chemotherapy

B1 deficiency causes damage to the brain's thalamus and hypothalamus. Symptoms include:

• Mental confusion
• Vision problems
• Coma
• Hypothermia
• Low blood pressure
• Lack of muscle coordination (ataxia)

Korsakoff syndrome (also known as Korsakoff's amnesic syndrome) is a memory disorder that results from vitamin B1 deficiency and is associated with alcoholism. Korsakoff's syndrome damages nerve cells and supporting cells in the brain and spinal cord, as well as the part of the brain involved with memory. Symptoms include:

• Amnesia
• Tremor
• Coma
• Disorientation
• Vision problems

Treatment involves replacement of thiamine and providing proper nutrition and hydration. In individuals with Wernicke's encephalopathy, it is very important to start thiamine replacement before beginning nutritional replenishment. In some cases, drug therapy is also recommended. Stopping alcohol use may prevent further nerve and brain damage.

Most symptoms of Wernicke's encephalopathy can be reversed if detected and treated promptly and completely. However, improvement in memory function is slow and, usually, incomplete. Without treatment, these disorders can be disabling and life-threatening.

Wernicke- Korsakoff is caused by thiamine deficiency. Thiamine is a cofactor for several key enzymes important in energy metabolism. Thiamine requirements depend on metabolic rate, with the greatest need during periods of high metabolic demand and high glucose intake.

Because of the role of thiamine in cerebral energy utilization, it has been proposed that its deficiency initiates neuronal injury by inhibiting metabolism in brain regions with high metabolic requirements and high thiamine turnover.

Thiamine deficiency in alcohol abusers results from a combination of inadequate dietary intake, reduced gastrointestinal absorption, decreased hepatic storage, and impaired utilization.

Some studies indicate that there may be a genetic predisposition for the disease. Variants in the high affinity thiamine transporter gene have also been implicated. The SLC19A2 gene provides instructions for making a protein called thiamine transporter 1. This protein is located on the surface of cells, where it works to bring vitamin B1 (thiamine) into cells.

Although these conditions may appear to be two different disorders, they are generally considered to be different stages of Wernicke-Korsakoff syndrome. Wernicke's encephalopathy represents the "acute" phase and Korsakoff's amnesic syndrome represents the "chronic" phase. The symptoms of Wernicke encephalopathy (WE) commonly include:

• Encephalopathy (profound disorientation or mental confusion, inability to think clearly and indifference)
• Vision problems (including double vision, abnormal eye movements (nystagmus) and eyelid drooping)
• Loss of muscle coordination (ataxia).

Other symptoms may include:

• Delirium tremor
• Coma
• Hypothermia
• Hypotension.

Korsakoff syndrome (KS) is seen most frequently in people who abuse alcohol after they experience an episode of WE. Most patients with KS show typical WE lesions in the brain. The main features of Korsakoff's syndrome are impairments in acquiring new information or establishing new memories, and in retrieving previous memories.

The symptoms include:

• Loss of memory and inability to form new memories
• Making of stories (confabulation)
• Seeing or hearing things that are not really there (hallucinations)
• Disorientation
• Vision impairment.

Attention and social behavior are relatively preserved. Affected subjects are able to carry on a socially appropriate conversation that may seem normal to an unsuspecting spectator. Patients with KS are as a rule unaware of their illness. Some patients may have severe cognitive function and global dementia.

In people with memory impairment, lesions in an area of the brain known as the anterior thalamus are commonly found. The shrinking of the mamillary bodies is also specific for WE, so when damaged or very small mamillary bodies are found in a demented patient, it is thought that the dementia may be due to alcohol abuse and malnutrition.