Question 188

Question:

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 infarction. Athologic examination of his brain is most likely to disclose an abnormality involving which of the following?

Correct Answer: E.  Mammillary bodies

This man suffered from Korsakoff syndrome. His history of alcoholism predisposed him to a thiamine (B1) deficiency, a vitamin that is crucial to cellular energy production. A deficiency of this vitamin causes Wernicke-Korsakoff syndrome. Wernicke encephalopathy is characterized by confusion, ocular disturbance, and ataxia of gait. Korsakoff syndrome manifests as loss of short-term memory and confabulation. The lesion of both of these disorders is found in the mammillary bodies (choice E) of the thalamus.
The amygdala (choice A) is an almond-shaped nuclear mass in the medial part of the anterior temporal lobe. It is involved in processing memory and emotion.
The caudate nucleus (choice B) is a nucleus located in the basal ganglia involved in the control of voluntary movement.
The hippocampus (choice C) is a part of the limbic system found in the medial temporal lobe. It is involved in short term memory and and spatial navigation.
The locus coeruleus (choice D) is a nucleus located in the brain stem. It is involved in the stress response, and secretes norepinephrine.