Alcoholics and other malnourished patients with thiamine deficiency (see 12.01.15) may develop Wernicke's encephalopathy and/or Korsakoff's psychosis. Several neuropathologic findings can be found in the brains of patients with this syndrome.


Sites affected:

(1) mamillary bodies and other portions of the hypothalamus

(2) walls of the third ventricle

(3) periaqueductal gray matter and colliculi (oculomotor nucleus)

(4) floor of the fourth ventricle (locus ceruleus, vestibular nuclei, dorsal vagal nucleus)

(5) thalamus (medial dorsal nuclei)


Degeneration of the mamillary bodies is the classic finding. Involvement of other sites is variable.


Early, acute lesions show petechial hemorrhages with variable neuronal and glial loss.


Long-standing lesions show atrophy and gliosis. They may be brown if there has been hemosiderin and lipofuscin deposition.


Cerebellar degeneration (see previous section) may also be present in some patients.


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