The deficit in stimulus-reward functions was demonstrated by Oscar-Berman and Pulaski who presented patients with reinforcements for certain stimuli but not others, and then required the patients to distinguish the rewarded stimuli from the non-rewarded stimuli. WKS patients displayed significant deficits in this task. The researchers were also successful in displaying a deficit in recognition memory by having patients make a yes/no decision as to whether a stimulus was familiar (previously seen) or novel (not previously seen). The patients in this study also showed a significant deficit in their ability to perform this task. Confabulation
People with WKS often show confabulation, spontaneous confabulation being seen more frequently than provoked confabulation. Spontaneous confabulations refer to incorrect memories that the patient holds to be true, and may act on, arising spontaneously without any provocation. Provoked confabulations can occur when a patient is cued to give a response, 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 for 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. Causes
WKS is usually found in people who have used alcohol chronically. Wernicke–Korsakoff syndrome results from thiamine deficiency.
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.