Wernicke's encephalopathy in two patients with acquired immunodeficiency syndrome.

Two non-alcoholic homosexual patients with acquired immunodeficiency syndrome (AIDS) are reported who developed acute Wernicke's encephalopathy in the terminal stage of their illness. The first patient presented with vascular congestion, minute haemorrhages, proliferation of microglia and of the vessel walls at the predilection sites of the Wernicke-Korsakoff process. In the second patient only the mamillary bodies were involved. Besides Wernicke's encephalopathy, a primary cerebral immunoblastoma and cerebral toxoplasmosis were found in the first patient, whereas the second showed severe encephalitis with numerous microglial and multinucleated giant cells reacting positively with anti-HIV antibody. Just as in the development of Wernicke's encephalopathy in malignant diseases, the catabolic trend of the metabolism of the immunodeficient patients with consecutive thiamine deficiency must be considered the principal pathogenetic mechanism.