APPENDIX G. 



EPIDEMIC POLIOMYELITIS. 



While the occurrence of " infantile paralysis " of sudden onset, 

 and affecting especially one or more limbs, has been known since 

 the earliest times, it is only coincident with the modern develop- 

 ments of neurology that the most prevalent type has been 

 recognised to be associated with inflammatory changes which 

 are specially concentrated in the anterior cornua of the spinal 

 cord. Though the disease chiefly attacks children, older subjects 

 are also affected, and in some epidemics the infection of adults 

 is a prominent feature. The disease is usually sporadic in its 

 incidence, and, as has long been known, in temperate climates 

 it is of most frequent occurrence during the warmer months of 

 the year. It also occurs in an epidemic form. Such outbreaks 

 have been familiar in Norway and Sweden during the last 

 century, but in other countries similar epidemics, limited or 

 extensive, have come under notice. Thus in New York in the 

 summer of 1907 an outbreak of probably over 2000 cases 

 occurred, 762 of which were carefully investigated by a special 

 Commission, and it is from their work that much of our present 

 knowledge of the disease has been derived, and many facts 

 regarding its infective nature have been definitely established. 

 An even more serious epidemic took place in New York in 

 1916. Clinically, the onset of the condition is marked by more 

 or less pronounced fever, often accompanied by sore throat 

 and followed after a few days by signs of paresis and paralysis, 

 and usually in a relatively small proportion of cases resulting 

 in death, though there is great variation in the mortality 

 in different outbreaks. When recovery occurs, many of the 

 paralytic symptoms may pass off, but generally there remains 

 evidence of definite permanent injury to the motor functions 

 of the nervous system. Pathologically, the initial lesions consist 

 in a local or general leptomeningitis with pronounced leucocytic 

 exudation of a polymorpho-nuclear type into the perivascular 



