Abstract
Since 1948, the author has been conducting pathologic anatomic histologic examinations on 29 bodies died of Japanese B encephalitis, and pursued the correlationships among various changes and their genesis of the tissue in the brain. Specifically, the present paper was attempted to observe cerebral changes with special reference to the edematous demyelination, which is very commonly found in the anatomical and histological findings in the bodies died of Japanese B encephalitis.
In every case, as histological finding, injuries caused by the virus to the individual or the defensive repairing mechanisms are demonstrated in combination of various ratio. In most cases, the process to become coarse revealed its close and direct relations to the blood vessel in its establishment, but not so remarkable in certain cases. In the latter cases, it was diffuse, and the basic elements demonstrate a coarse meshed development, or show a congregation of several vacuoles like a honey comb. Occasionally, these are found fused together forming a slithtly large cavity. In both of the cases, it acted destructive to the nervous sheath when they are fused together and enlarged and forms demyelination. Previously, Umeda reported the findings in which the virulence of the virus is expressed by the coarseness as the principal pathological change as seen in the brain of a mouse possessing strong sensitive factor to the Japanese B encephatlitis virus. The findinge in 9 cases dealt with in the present paper are considered related to the findings in the mouse brain stated in the adove. In other words, when the injuries by the virus are recognized, although the reaction formula in the defensive or repairing meachanisms is varying by auch conditions as the virulence of the virus in each epidemic, the individual discrepancy of the animal and the strain factors possessed by the animals, the injuries given to the living subject by the virus are considered to be expressed by the coarseness as the basic common factor. In addition, although the edematous coarseness is a finding due to the circulatory disturbance caused by an inflammation, its nature is considered to be serous inflammation. Therefore, the demyelination is considered to be due to the secondary demyelination without accompanyment of the elementary injnries in the blood vessel.
