NEET PG / USMLE – MCQ 3

A 50-year-old man with a history of alcoholism has difficulty with short-term memory. He is unable to recall the date and cannot remember what he ate for breakfast this morning. He thinks the examiner is a long-lost friend and carries on a conversation with the examiner as if they have known each other for years. His long-term memory appears intact. The patient dies shortly thereafter of a myocardial infarct. Pathologic examination of his brain is most likely to disclose an abnormality involving which of the following?
(A) Amygdala
(B) Caudate nucleus
(C) Hippocampus
(D) Locus caeruleus
(E) Mammillary bodies

Correct answer : (E) Mammillary bodies

The given history is suggestive of Wernicke’s encephalopathy (alcoholism, short term memory loss). The pathological changes seen in Wernicke’s encephalopathy are concentrated in the mammillary bodies, cranial nerve nuclei III, IV, VI and VIII, the thalamus, hypothalamus, periaqueductal grey, cerebellar vermis, and the dorsal nucleus of the vagus nerve.