Wernicke avföring
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.
Wernicke encephalopathy
The cause of the disorder is thiamine vitamin B 1 deficiency. This can occur due to Wernicke encephalopathy, eating disordersmalnutritionand 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. The syndrome is a combined manifestation of two namesake disorders, Wernicke encephalopathy and Korsakoff syndrome. It involves an acute Wernicke-encephalopathy phase, followed wernicke avföring the development of a Korsakoff syndrome phase. WE is characterized by the presence of a triad of symptoms: [ 7 ].
This triad of symptoms results from a deficiency in vitamin B 1 which is an essential coenzyme. If left untreated, WE can lead to coma or death. A smaller percentage of patients experience a decrease in reaction wernicke avföring of the pupils to light stimuli and swelling of the optic disc which may be accompanied by retinal hemorrhage.
Other symptoms that have been present in cases of WE are stuporlow blood pressure hypotensionelevated heart rate tachycardiaas well as hypothermiaepileptic seizures and a progressive loss of hearing. 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 nervosaand gastrectomy.
Several cases have been documented where Wernicke-Korsakoff syndrome has been seen on a large scale. In52 cases of WKS were documented in a prisoner of war hospital in Singapore where the prisoners' diets included less than 1 mg of thiamine per day. Such cases provide an opportunity to gain an understanding of what effects this syndrome has on cognition.
In this particular case, cognitive symptoms included insomniaanxietydifficulties in concentration, loss of memory for the immediate past, and gradual degeneration of mental state; consisting of confusion, confabulationand hallucinations. In addition to this, it has been noted that some patients displayed an inability to focus, and the inability of others to catch patients' attention.
In a study conducted in by "Wernicke avföring" et al. They found that subjects with WKS showed impairments in wernicke avföring aspects of this test battery but most noticeably, on the cognitive estimation tasks. This task required subjects to estimate a physical quality such as size, weight, quantity or time e. What is the average length of a shower? Patients with WKS performed worse than normal control participants on all of the tasks in this category.
The patients found estimations involving time to be the most difficult, whereas quantity was the easiest estimation to make. Additionally, the study included a category for classifying "bizarre" answers, which included any answer that was far outside of the normal range of expected responses.
Wernicke-Korsakoff syndrom
WKS patients did give answers that could fall into such a category, such as 15 seconds or 1 hour for the estimated length of a shower, or 4 kg or 15 tonnes as the weight of a car. The amnesic symptoms of WKS include both retrograde and anterograde amnesia. The anterograde memory loss is demonstrated through deficits in tasks that involve encoding and then recalling lists of words and faces, as well as semantic learning tasks.
WKS patients have also demonstrated difficulties in perseveration as evidenced by a deficit in wernicke avföring on the Wisconsin Card Sorting Test. This has been demonstrated through measures that assess perceptual priming.
Wernicke-Korsakoff syndrome
Other studies have shown deficits in recognition memory and stimulus-reward associative functions in patients with WKS. WKS patients displayed significant deficits in this task. The patients in this study also showed a significant deficit in their ability to perform this task. People with WKS often show confabulationspontaneous confabulation being seen more frequently than provoked confabulation.
Provoked confabulations can occur when a patient is cued to give a wernicke avföring, this may occur in test settings. The spontaneous confabulations viewed in WKS are thought to be produced by an impairment in source memory, where they are unable to remember the spatial and contextual information for an event, and thus may use irrelevant or old memory traces to fill in wernicke avföring the information that they cannot access.
It has also been suggested that this behaviour may be due to executive dysfunction where they are unable to inhibit incorrect memories or because they are unable to shift their attention away from an incorrect response. It is generally agreed that Wernicke-Korsakoff syndrome results from severe acute deficiency of thiamine vitamin B 1 whilst Korsakoff's psychosis is a chronic neurologic sequela of Wernicke encephalopathy and is usually found in people who have used alcohol chronically.
The metabolically active form of thiamine is thiamine pyrophosphatewhich plays a major role as a cofactor or coenzyme in glucose metabolism. The enzymes that are dependent on thiamine pyrophosphate are associated with the citric acid cycle also known as the Krebs cycleand catalyze the oxidation of pyruvateα-ketoglutarate and branched chain amino acids. Thus, anything that encourages glucose metabolism will exacerbate an existing clinical or sub-clinical thiamine deficiency.