Clinical meaning
Korsakoff syndrome (also called Korsakoff psychosis or Korsakoff amnestic syndrome) is a chronic, typically irreversible neurological condition characterized by profound memory impairment, resulting from permanent brain damage caused by severe thiamine deficiency. It is most often seen as the long-term consequence of untreated or inadequately treated Wernicke encephalopathy, and the combined condition is referred to as Wernicke-Korsakoff syndrome. The underlying pathology involves necrosis and hemorrhagic lesions in the mammillary bodies and medial thalamus, structures that are critical components of the Papez circuit responsible for encoding new memories and retrieving stored memories. When these structures are destroyed by thiamine deficiency, the ability to form new declarative memories (anterograde amnesia) is permanently lost. Retrograde amnesia (loss of memories formed before the illness) is also present but typically follows a temporal gradient, with more recent memories more severely affected than distant memories. The hallmark clinical feature of Korsakoff syndrome, beyond the severe amnesia, is confabulation: the patient spontaneously generates false memories to fill gaps in their memory, without any awareness that these memories are fabricated. This is not deliberate lying but rather the...