CHRONIC EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS IN MONKEYS

Abstract

Chronic experimental allergic encephalomyelitis was produced in monkeys by the injection of an emulsion of normal monkey brains with falba, paraffin oil and heat-killed tubercle bacilli. In order to produce the chronic stage, it was necessary to reduce the dosage of both brain substance and tubercle bacilli which had been used for the production of acute lesions. Recurrence of clinical symptoms following remissions or the aggravation of symptoms seemed to be related to absorption and rate of absorption of the antigen. The demyelination observed resembled that seen in acute encephalomyelitis and was found in all areas of the white substance. Three types of glia reaction were found. One was a hypertrophy of the astrocytes and other components of the glia series throughout the central nervous system; a 2d was an hypertrophy of the individual glia cells in association with hyperplasia of elements in areas where inflammatory reactions were prominent; the 3d type was related to the process of repair in areas where marked destruction of the nervous parenchyma had taken place. These 3 types of glia reaction can be found in human acute and chronic demye-linating disease.