Humpath.com - Human pathology

Home > E. Pathology by systems > Nervous system > Central nervous system > Brain > Wernicke encephalopathy

Wernicke encephalopathy

Tuesday 14 April 2009

Thiamine (vitamin B1) deficiency may result in the slowly evolving clinical disorder beriberi. In certain patients, thiamine deficiency may also lead to the development of psychotic symptoms or ophthalmoplegia that begin abruptly, a syndrome termed Wernicke encephalopathy.

The acute stages, if unrecognized and untreated, may be followed by a prolonged and largely irreversible condition, Korsakoff syndrome, characterized clinically by memory disturbances and confabulation. Because the two syndromes are closely linked, the term Wernicke-Korsakoff syndrome is often applied.

The syndrome is particularly common in the setting of chronic alcoholism, but it may also be encountered in patients with thiamine deficiency resulting from gastric disorders, including carcinoma, chronic gastritis, or persistent vomiting.

Morphology

Wernicke encephalopathy is characterized by foci of hemorrhage and necrosis, particularly in the mammillary bodies but also adjacent to the ventricle, especially the third and fourth ventricles. Early lesions show dilated capillaries with prominent endothelial cells. Subsequently, the capillaries leak red cells into the interstitium, producing hemorrhagic areas that are easily detectable macroscopically.

With time, there is infiltration of macrophages and development of a cystic space with hemosiderin-laden macrophages as a permanent sign of the process. These chronic hemosiderin-laden lesions predominate in patients with Korsakoff syndrome. Lesions in the medial dorsal nucleus of the thalamus appear to be the best correlate of the memory disturbance and confabulation.

Treatment

Treatment with vitamin B1 may reverse manifestations of Wernicke syndrome.