Stephan Környey's contribution to the study of encephalitides.

A considerable part of Környey's work deals with the problem of encephalitides. HIs interest in this topic was roused by Heinrich Pette and in collaboration they studied the histopathology and pathogenesis of experimental and human poliomyelitis. On the basis of their findings they advocated the neural spread of the poliomyelitis virus. THey described the distribution of the poliovirus within the nervous system, its close affinity to the voluntary motor system and analysed the influence of the portal of entry and special neurotropism on the development of the distribution pattern of the process. THe encephalitic process changes as a function of time; the significance of this observation was expressed in the concept of the time factor. Környey designated the affinity of the poliovirus towards the neurons among the cellular components of the nervous tissue as gangliocytotropism. Based on his observation, he characterized the features of neural spread of virsuses and the selective character of this spread within the central nervous system. THe study of two other polioencephalitides with predilectional involvement of the brain stem, Borna disease and tickborne encephalitis, allowed him further pathogenetic assessments. Környey described the first manifestation of subacute panencephalitis in the Carpathian basin. He devoted special attention to the clinical and neuropathological analysis of various forms of leukoencephalomyelitides and closely followed the development of the principle of neuro-allergy (Pette) and the change in the pathogenetic view of these diseases. His excellent synthesising ability enabled him to write comprehensive review articles and textbook chapters on the various aspects of encephalitides.