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
[{'content': "Classical triad of global confusion, ataxia and ophthalmoplegia is seen in \nSelect and explain. \nA. Alzheimer's disease, B. Delerium tremors, C. Wernicke's encephalopathy, D. Korsakoff psychosis", 'role': 'user'}, {'content': 'Answer: C \nExplanation: Wernicke&;s encephalopathy is an acute reaction to a severe deficiency of thiamine, the commonest cause being chronic alcohol use. Impoant clinical signs: Ocular signs- coarse nystagmus and ophthalmoplegia with bilateral external rectus paralysis occurring early. Higher mental function disturbances-disorientation, confusion, recent memory disturbances, poor attention span and distractibility are quite common. Other early symptoms are apathy and ataxia (Ref: a sho textbook of psychiatry, Niraj Ahuja, 7th edition, pg no.38)', 'role': 'assistant'}]