Which condition involves memory impairment with confabulation and severe short-term memory deficits, commonly linked to chronic alcoholism?

• A. Alzheimer disease
• B. Vascular dementia
• C. Korsakoff syndrome
• D. Lewy body dementia

Answer: (C)

Korsakoff syndrome arises from thiamine (vitamin B1) deficiency, most often linked to chronic alcohol use, and it specifically disrupts memory consolidation. The hallmark is severe short-term (anterograde) memory impairment, with patients having great difficulty forming new memories. To cope with these memory gaps, they frequently confabulate—making up conversations or events to fill in missing pieces—without conscious intent to deceive. This confabulation in the setting of long-standing alcoholism is classic for Korsakoff syndrome and stems from damage to thalamic and mammillary body circuits involved in memory.

In other dementias, memory loss is common but the pattern and accompanying features differ. Alzheimer disease typically shows a gradual, progressive decline across multiple cognitive domains rather than prominent confabulation. Vascular dementia often has a stepwise decline with focal neurologic signs corresponding to cerebrovascular disease. Lewy body dementia features fluctuations in alertness, visual hallucinations, and parkinsonian symptoms rather than the characteristic confabulation-driven memory gaps associated with chronic alcohol–related thiamine deficiency.