Wernicke–Korsakoff syndrome (WKS) is the combined presence of Wernicke encephalopathy (WE) and Korsakoff syndrome. Due to the close relationship between these two disorders, people with either are usually diagnosed with WKS as a single syndrome. It mainly causes vision changes, ataxia and impaired memory.The cause of the disorder is thiamine (vitamin B1) deficiency. This can occur due to Wernicke encephalopathy, eating disorders, malnutrition, and alcohol abuse. These disorders may manifest together or separately. WKS is usually secondary to prolonged alcohol abuse. Wernicke encephalopathy and WKS are most commonly seen in people with an alcohol use disorder. Failure in diagnosis of WE and thus treatment of the disease leads to death in approximately 20% of cases, while 75% are left with permanent brain damage associated with WKS. Of those affected, 25% require long-term institutionalization in order to receive effective care. Signs and symptoms
The syndrome is a combined manifestation of two namesake disorders, Wernicke encephalopathy and alcoholic Korsakoff syndrome. It involves an acute Wernicke-encephalopathy phase, followed by the development of a Korsakoff syndrome phase. Wernicke encephalopathy
WE is characterized by the presence of a triad of symptoms:
Ocular disturbances (ophthalmoplegia)
Changes in mental state (confusion)
Unsteady stance and gait (ataxia)This triad of symptoms results from a deficiency in vitamin B1 which is an essential coenzyme. The aforementioned changes in mental state occur in approximately 82% of patients symptoms of which range from confusion, apathy, inability to concentrate, and a decrease in awareness of the immediate situation they are in. If left untreated, WE can lead to coma or death.
In about 29% of patients, ocular disturbances consist of nystagmus and paralysis of the lateral rectus muscles or other muscles in the eye. A smaller percentage of patients experience a decrease in reaction time of the pupils to light stimuli and swelling of the optic disc which may be accompanied by retinal hemorrhage. Finally, the symptoms involving stance and gait occur in about 23% of patients and result from dysfunction in the cerebellum and vestibular system. Other symptoms that have been present in cases of WE are stupor, low blood pressure (hypotension), elevated heart rate (tachycardia), as well as hypothermia, epileptic seizures and a progressive loss of hearing.About 19% of patients have none of the symptoms in the classic triad at first diagnosis of WE; however, usually one or more of the symptoms develops later as the disease progresses. Korsakoff syndrome
The DSM-V classifies Korsakoff syndrome under Substance/Medication-Induced Major or Mild Neurocognitive Disorders, specifically alcohol-induced amnestic confabulatory. The diagnostic criteria defined as necessary for diagnosis includes prominent amnesia, forgetting quickly, and difficulty learning. Presence of thiamine deficient encephalopathy can occur in conjunction with these symptoms.Despite the assertion that alcoholic Korsakoff syndrome must be caused by the use of alcohol, there have been several cases where it has developed from other instances of thiamine deficiency resulting from gross malnutrition due to conditions such as stomach cancer, anorexia nervosa, and gastrectomy. Cognitive effects
Several cases have been documented where Wernicke–Korsakoff syndrome has been seen on a large scale.