[Plexus paresis and smallpox vaccination (author's transl)].

Paresis of the left side upper plexus brachialis is diagnosed to a boy of 2;8 years. The trouble appeared after a smallpox vaccination, which had been carried out successfully. There are no symptoms of CNS-disturbance. serumneuritis and virogenic radiculatis are discussed as pathogenic variants. Although postvaccinal peripheral nervous lesions very seldom occur, it does seem possible that the ailment in question could be a consequence of the smallpox vaccination.