The effects of induced fever on cerebral functions in neurosyphilis.

Although fever is known to be associated with definite alterations in the circulation and metabolism of the body as a whole and of certain individual organs, there have been few observations on the changes occurring in the brain during fever. An increase in the cerebral arteriovenous oxygen difference was found in 15 patients with dementia paralytica during fever produced by typhoid vaccine and inductotherm (1). It was suggested that the brain in these patients either responded to fever with a rise in metabolism greater than other parts of the body or else the cerebral blood flow is slower during fever, thus accounting for a larger arteriovenous difference. Looney and Borkovic (2), however, found a slight decrease in the cerebral oxygen arteriovenous difference in 12 patients with dementia paralytica undergoing diathermic fever treatment, but they did not believe that these changes were significant. The oxygen consumption of brain tissue in vitro has been found to increase with temperature at levels lower than normal (3). At temperatures greater than normal, however, conflicting results have been obtained by different investigators (3, 4). The present report presents studies on the effects of induced fever on the cerebral circulation and oxygen consumption in 27 patients with neurosyphilis.