Korsakoff syndrome is a chronic memory disorder caused by severe deficiency of thiamine (vitamin B-1). Korsakoff syndrome is most commonly caused by alcohol misuse, but certain other conditions also can cause the syndrome.

About Korsakoff syndrome

Thiamine helps brain cells produce energy from sugar. When levels fall too low, brain cells cannot generate enough energy to function properly. Korsakoff syndrome is most commonly caused by alcohol misuse, but can also be associated with AIDS, cancers that have spread throughout the body, chronic infections, poor nutrition and certain other conditions. It is also common in people whose bodies do not absorb food properly (malabsorption). This can sometimes occur with a chronic illness or after weight-loss (bariatric) surgery. See causes and risk factors below.

Korsakoff syndrome is often — but not always — preceded by an episode of Wernicke encephalopathy, which is an acute brain reaction to severe lack of thiamine. Wernicke encephalopathy is a medical emergency that causes life-threatening brain disruption, confusion, staggering and stumbling, lack of coordination, and abnormal involuntary eye movements.

Because the chronic memory loss of Korsakoff syndrome often follows an episode of Wernicke encephalopathy, the chronic disorder is sometimes known as Wernicke-Korsakoff syndrome. But Korsakoff syndrome can also develop in individuals who have not had a prior episode of Wernicke encephalopathy.

Prevalence

Scientists don’t know exactly how many people have Korsakoff syndrome. It’s widely considered less common than Alzheimer’s disease, vascular dementia, frontotemporal dementia or dementia with Lewy bodies. Like more common types of dementia, it may be underdiagnosed.

Causes and risk factors

Scientists don't yet know exactly how Korsakoff syndrome damages the brain. Research has shown that severe thiamine deficiency disrupts several biochemicals that play key roles in carrying signals among brain cells and in storing and retrieving memories. These disruptions destroy brain cells and cause widespread microscopic bleeding and scar tissue. Researchers have identified several genetic variations that may increase susceptibility to Korsakoff syndrome. Poor nutrition also may raise risk.

Most cases of Korsakoff syndrome result from alcohol misuse. Scientists don't yet know why heavy drinking causes severe thiamine deficiency in some alcoholics, while others may be affected primarily by alcohol's effects on the liver, stomach, heart, intestines or other body systems. Sign up for our e-news to receive updates about Alzheimer’s and dementia care and research.

Korsakoff syndrome may sometimes be associated with disorders other than alcohol misuse, including anorexia, overly stringent dieting, fasting, starvation or weight-loss surgery; uncontrolled vomiting; AIDS; kidney dialysis; chronic infection; or cancer that has spread throughout the body.

Symptoms

Korsakoff syndrome causes problems learning new information, inability to remember recent events and long-term memory gaps. Memory difficulties may be strikingly severe while other thinking and social skills are relatively unaffected. For example, individuals may seem able to carry on a coherent conversation but moments later are unable to recall that the conversation took place or with whom they spoke.

Those with Korsakoff syndrome may "confabulate," or make up, information they can't remember. They are not "lying" but may actually believe their invented explanations. Scientists don’t yet understand the mechanism by which Korsakoff syndrome may cause confabulation. The person may also see or hear things that are not there (hallucinations).

Diagnosis

Experts recommend that a medical workup for memory loss or other cognitive changes always include questions about an individual's alcohol use. Anyone admitted to the hospital for an alcohol-related condition should be professionally screened for memory loss and cognitive change. The screening should include supplementary questions to assess recent memory. If screening suggests impairment, the person should receive a more detailed cognitive workup.

Outcomes