section 11.2

Question 1

Korsakoff’s syndrome

Answer 1

a disorder of memory common in people who have consumed large amounts of alcohol; the disorder is largely attributable to the brain damage associated with the thiamine deficiency that often accompanies heavy alcohol consumption. In its advanced stages, it is characterized by a variety of sensory and motor problems, extreme confusion, personality changes, and a risk of death from liver, gastrointestinal, or heart disorders.

Question 2

Postmortem examination typically reveals lesions to the

Answer 2

medial diencephalon (the medial thalamus and the medial hypothalamus) and diffuse damage to several other brain structures, most notably the neocortex, hippocampus, and cerebellum.

Question 3

The amnesia of Korsakoff’s syndrome is similar to

Answer 3

medial temporal lobe amnesia in some respects. For example, during the early stages of the disorder, anterograde amnesia for explicit episodic memories is the most prominent symptom. However, as the disorder progresses, retrograde amnesia, which can eventually extend back into childhood, also develops. Deficits in implicit memory depend on the particular test used, but in general they are less severe than those in explicit memory.

Question 4

Hypotheses of what area of the brain is responsible for the amnesia:

Answer 4

• Damage to the mammillary bodies of the hypothalamus was responsible for the memory deficits of Korsakoff patients.
• However, subsequent studies revealed cases of Korsakoff amnesia with no mammillary body damage. But in all of these exceptional cases, there was damage to another pair of medial diencephalic nuclei: the mediodorsal nuclei of the thalamus.

Question 5

However, it is unlikely that the memory deficits of Korsakoff patients are attributable

Answer 5

to the damage of any single structure.

Question 6

Medial diencephalic amnesia

Answer 6

amnesia, such as Korsakoff amnesia, associated with damage to the medial diencephalon.