Action of Adrenaline and Noradrenaline on the Tremor in Parkinson's Disease

Abstract

Intraven. infusions of epinephrine at the rate of 10 [mu]g./min. caused a marked increase in tremor as judged by both inspection and electromyography, in 9 out of 14 Parkinson patients who were not receiving medication. Infusions of nor-epinephrine at the same rate had no effect on the tremor in 7 patients. The effect of epinephrine was reduced when the patients were receiving medication. The enhancing effect of epinephrine on the tremor was not due to the rise in central blood pressure, nor was it solely due to apprehension. It was probably a central nervous action. The reason why epinephrine, but not nor-epinephrine enhances the tremor, is unknown.