This stuff is pretty readily available from common reference books, but here's a start re: Korsakoff Syndrome; which is not a global global brain dysfunction (like an encephalopathy usually is) and generally not acute or reversible, as Wernicke's Encephalopathy often is.
I did a quick search on MD Consult.
From:
Disorders of Memory
Psychiatric Clinics of North America - Volume 28, Issue 3 (September 2005)
"RECENT AND REMOTE MEMORY
Retrograde memory is commonly divided into two temporal components, recent versus remote. Recent memory typically refers to information acquired shortly (ie, days to weeks) before a specified time or event, whereas remote memory refers to information about events or experiences that occurred months to years in the more distant past.
Patients who have retrograde memory impairments often demonstrate a temporal gradient in which memory for more recent events is disrupted more than memory for remote events. Such is the case in amnesic disorders such as alcoholic Korsakoff syndrome. In a classic study of a prominent scientist with this disorder, Butters and Cermak [13] used the patient's own autobiography to test his memory for past life events. His most accurate memories were for events that occurred early in his life, with progressively worse memory for events in subsequent decades and no memory for significant life events that occurred within the decade immediately before his disease onset."
"AMNESIC KORSAKOFF SYNDROME
Amnesic Korsakoff syndrome is caused by damage to medial diencephalic structures, including the dorsomedial nucleus of the thalamus and mammillary bodies, resulting from severe thiamine deficiency, most often related to excessive alcohol consumption. Patients who have amnesic Korsakoff syndrome demonstrate largely normal intelligence and STM ability, but their ability to encode new information into LTM is severely impaired [4]. Patients demonstrate equally poor free recall and recognition [66] and at times recall information that was never presented, a phenomenon known as confabulation [4], [67]. Many patients who have amnesic Korsakoff syndrome also present with a severe, temporally graded retrograde amnesia, as described earlier."
From:
Neurologic Presentations of Nutritional Deficiencies
Neurologic Clinics - Volume 28, Issue 1 (February 2010)
"In KS, memory is disproportionately impaired relative to other aspects of cognitive function. Alertness, attention, social behavior, and other aspects of cognitive functioning are generally preserved. A typical finding is a striking loss of working memory and relative preservation of reference memory. Implicit learning is retained, and these patients can learn new motor skills or develop conditioned reactions to stimuli. Disorientation to time and place may be present. Minor executive dysfunction may also be seen.[321] Confabulation becomes less evident with time.[316] Emotional changes may develop and include apathy or mild euphoria. Structural or neurochemical abnormalities within the limbic and diencephalic circuits likely account for anterograde amnesia. Frontal lobe dysfunction possibly underlies the severe retrograde memory loss and emotional changes found in this syndrome."
A college prof of mine used to tell a story about trying to do memory research on severe Korsakoff patients.
He could never get informed consent.
Prof: Good morning, my name is Dr Smith and I'll be performing the memory tests we're going to do today.
Pt: My name is Tom. What's yours?
Prof: It's good to meet you, Tom. My name is Dr Smith.
Pt: Dr Smith, it's nice to meet you. Why are you here?
Prof: Well, Tom. I'm here to test your memory. Are you ready to begin?
Pt: Sure, but I'm afraid you have me at a disadvantage. You know my name, but what's yours?
Prof: My name is Dr Smith. Shall we begin?
Pt: Yes, let's start. But shouldn't you know my name first? I'm Tom.
Prof: Yes, Tom. And My name is Dr. Smith.
Pt: It's nice to meet you, Dr Smith. Why do I need to see a doctor?
(and so on)
