Kapronczay Károly szerk.: Orvostörténeti Közlemények 182-185. (Budapest, 2003)

TANULMÁNYOK - ARTICLES - GOSZTONYI, Georg: Stephan Környey's contribution to the study of encephalitides. (Környey István hozzájárulása az. agyhártyagyulladás kutatásához.)

emphasised the significance of axonal damage, as well as the simultaneous presence of foci of different ages. With regard to the histology of neuromyelitis optica he stressed that beside the foci in the spinal cord and the optic region demyelinating lesions could often be seen in the white matter of the occipital lobe. The description of histopathology of the disease was followed by a detailed analysis of the symptomatology and differential diagnosis. In the reviews on encephalitides published in 1939, 1941 and 1943, mentioned above, Környey dealt in long passages with the leukoencephalomyelitides (Környey 1939, 1941, 1943). These review passages reflect the changes in views that took place in the 1930ies and 1940ies concerning these diseases. Neurology abandoned the previously dominating activation theory, which postulated the activation of a common live agent by unknown factors in all demyelinating diseases and progressively the idea of an allergic etiology became dominant. This change of view was rendered possible by the fundamental monkeyexperiments of Rivers and Schwentker (1935) and the firm attitude of Pette (1938c, 1942), based on clinical observations and histopathological studies. In these reviews Környey dealt in detail with the individual demyelinating diseases, their differential diagnosis, and with the small perivenous demyelinating foci, the common histopathological hallmark of the parainfectious and postvaccinal encephalomyelitides. In his reviews, published in 1941 and 1943, he devoted separate passages to the neurological symptomatology of extraneural infectious diseases. In these passages he treated not only the parainfectious demyelinating complications, but also the bacterial complications, and devoted special attention to changes which could be explained by the vasal factor. On the request of Fortschritte der Neurologie und Psychiatrie, a prominent German periodical of continuing education, Környey compiled in 1952 a further review, dealing this time exclusively with the demyelinating encephalomyelitides (Környey, 1952). In the first part of the review he surveyed the experimental studies published after the fundamental experiments of Rivers and Schwentker (1935). He reported on systematic, well structured studies that defined the species in which an allergic encephalitis could be elicited, on studies which developed further the technique to induce the encephalitis and which tried to define the nature of the encephalitogenic antigen. He suggested the use of the expression neuro-allergy also in experimental neuropathology. This term was originally introduced by Pette (1942) to characterize the human demyelinating diseases. While treating the human demyelinating encephalomyelitides, Környey devoted special attention to the parainfectious-postvaccinal and the disseminated encephalomyelitides. As eliciting agents not only virus diseases and viral vaccines, but, exceptionally, anti-typhus and anti-tetanus vaccinations had to be considered (Csermely, 1950, and others). The treatment of disseminated encephalomyelitis together with the parainfectiouspostvaccinal encephalomyelitides and multiple sclerosis deserved special interest. In the literature, cases published as disseminated encephalomyelitides, could be classified in three groups. The first group corresponded to the picture of acute multiple sclerosis. In the second group were ranged cases appearing in the form of the perivenous encephalomyelitis, whose anatomical substrate was identical with that of the parainfectious-postvaccinal encephalomyelitides. The cases of the third group were characterized by the coalescence of small perivenous foci into diffuse demyelinating areas; the separation of these cases from multiple sclerosis raised often problems.