This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Organic mental disorders, Subject name: Psychiatry
Not seen in Korsakoff's syndrome 
Select and explain. 
A. Clear consciousness, B. Inability to learn new things, C. Hallucinations, D. Confabulation
C: Hallucinations
Answer: C: Hallucinations 
Explanation: As Korsakoff's psychosis often follows Wernicke's encephalopathy; these are together referred to as Wernicke-Korsakoff syndrome. Clinically, Korsakoff's psychosis presents as an organic amnestic syndrome, characterised by gross memory disturbances, with confabulation. Insight is often impaired. The neuropathological lesion isusually wide-spread, but the most consistent changes are seen in bilateral dorsomedial nuclei of thalamus and mammillary bodies. The changes are also seen in periventricular and periaqueductal grey matter, cerebellum and pas of the brainstem. The underlying cause is believed to be usually severe untreated thiamine deficiency secondary to chronic alcohol use. Ref: A Sho Textbook of Psychiatry, Niraj Ahuja, 7th Edition, pg. no.38