Wernicke-Korsakoff syndrome is caused by thiamin deficiency. Wernicke-Korsakoff syndrome results from thiamine deficiency. It is generally agreed that Wernicke's encephalopathy results from severe acute deficiency of thiamine(Vitamin B1), whilst Korsakoff's psychosis is a chronic neurologic sequela after Wernicke's encephalopathy.
It is most commonly observed in people with alcoholism since heavy drinkers often eat poorly, and alcoholism interferes with absorption of nutrients from the digestive system. It can also occur in people who are malnourished for other reasons. Thiamin helps produce energy needed to make neurons function properly. Insufficient thiamin can lead to damage or death of neurons.
The metabolically active form of thiamine is thiamine diphosphate which plays a major role as a cofactor or coenzyme in glucose metabolism. The enzymes which are dependent on thiamine diphosphate are associated with the TCA Cycle, and catalyse the oxidation of pyruvate, alphaketoglutarate and branched chain amino acids. Thus, anything that encourages glucose metabolism will exacerbate an existing clinical or sub-clinical thiamine deficiency.
Thiamin deficiency damages regions of the brain, particularly the thalamus and the mammillary bodies. The thalamus is a structure deep within the brain that serves many important functions. It is often called the major relay station of the brain, and many neurons make connections in the thalamus. The mammillary bodies are part of the hypothalamus, located just below the thalamus. The mammillary bodies receive many neural connections from another part of the brain called the hippocampus, which appears to be the primary part of the brain involved in the formation of memories. Neurons in the mammillary bodies make connections with the thalamus, which in turn makes connections with the cortex of the brain, where long-term memories are stored. This may explain why damage to the mammillary bodies and thalamus can lead to anterograde amnesia. Memories formed in the hippocampus are never stored since connections between hippocampus and cortex are disrupted.
Eye movement disorders observed in the acute phase of the condition are probably due to damage to other nearby brain regions that make connections to the nerves controlling eye muscles. These nerves emerge from the brainstem located right below the thalamus and mammillary bodies. Nerves involved in balance also make connections with other nerves in the brainstem, but a separate part of the brain called the cerebellum may also contribute to ataxia. Reasons why some regions of the brain are selectively affected by thiamin deficiency are not yet fully understood, but selective vulnerability of certain neurotransmitters is suspected.
Wernicke-Korsakoff syndrome in alcoholics especially is associated with atrophy of specific regions of the brain, especially the mamillary bodies. Other regions include the anterior region of the thalamus(accounting for amnesic symptoms), the medial dorsal thalamus, the basal forebrain, and median and dorsal raphe nuclei.
One as-yet-unreplicated study has associated susceptibility to this syndrome with a hereditary deficiency of trantsketolase, an enzyme involved in thiamine metabolism.
+%EC%A7%88%EB%B3%91%EC%9D%98+%EC%9B%90%EC%9D%B8.jpg)
