Korsakoff syndrome is described as which of the following?

• A. Neuro disorder caused by thiamine deficiency or viral encephalitis
• B. Autoimmune demyelination of the CNS
• C. Degenerative brain disease due to amyloid plaques
• D. Muscular dystrophy due to genetic mutation

Answer: (A)

Korsakoff syndrome is a neuropsychiatric condition arising from a severe thiamine (vitamin B1) deficiency, most often after an episode of Wernicke encephalopathy in people with chronic alcohol use. The defining feature is profound impairment of memory, especially anterograde amnesia with difficulties forming new memories and frequent confabulation, while other cognitive functions can be relatively preserved early on. This memory loss stems from damage to memory-related brain structures, notably the mammillary bodies and thalamic nuclei. The description that fits Korsakoff best is a neuro disorder caused by thiamine deficiency. Other options describe different diseases—autoimmune demyelination of the CNS (such as multiple sclerosis), degenerative brain disease due to amyloid plaques (Alzheimer disease), and muscular dystrophy from a genetic mutation—none of which capture the primary memory-focused neurodegeneration seen in Korsakoff.