690 EPIDEMIC POLIOMYELITIS 



Epidemic Encephalitis. — During the spring and summer of 

 1918 a number of cases of encephalitis occurred in Britain, 

 whose nature has not been satisfactorily elucidated. They were 

 characterised clinically by lethargy and drowsiness, often passing 

 into coma, with moderate or no rise of temperature. A great 

 variety of nervous symptoms were recorded, — headache, epileptic 

 fits, spastic phenomena, ascending paralysis, etc., — but the most 

 common and striking feature was the existence of irritative and 

 paralytic affections of the muscles of the. eyelids and eyeballs. 

 The mortality was high. In fatal cases the chief post-mortem 

 changes were, small sub-jiial haemorrhages and haemorrhages 

 into the grey and white matter of the brain, There was some- 

 times marked subdural cedema. Meningitis was not a marked 

 feature, and when it occurred, was patchy ; the cerebro-spinal 

 fluid was usually clear. Microscopically, the haemorrhages 

 appeared to be of venous origin, there was intense capillary 

 congestion and moderate peri-adventitial cellular infiltration; 

 degenerative changes in the oculo-motor centres were recorded. 

 The occurrence of ophthalmoplegia suggested that the condition 

 was botulismus, but the symptoms of the two diseases did not 

 otherwise correspond. No association with the taking of 

 particular articles of food was traceable, and, so far as we are 

 aware, the b. botulinus was never isolated from any of the. cases. 

 It was also suggested that the condition was poliomyelitis of an 

 aberrant type, but the findings differed in certain respects from 

 those of the cerebral cases which have been observed during 

 epidemics of poliomyelitis, and, further, there was no evidence of 

 a concurrent prevalence in Britain of ordinary poliomyelitis. 

 The condition was not confined to Britain, an outbreak having 

 been recorded in Austria during 1917, and in France in 1918; 

 and an obscure disease of a similar nature, which however may 

 have been poliomyelitis, occurred in 1917 in Australia. In the 

 British cases the bacteriological findings were as a rule negative, 

 but in Austria a streptococcus is said to have been isolated 

 which reproduced the disease in monkeys. At present no 

 opinion as to the essential pathology of the condition can be 

 formed, but, on the whole, the evidence rather points to this 

 form of encephalitis not being identifiable with poliomyelitis. 

 It may be said that before poliomyelitis had been recognised as 

 a specific entity, Wernicke (1881) described the above type of 

 disease under the name encephalitis acuta hemorrhagica. 



Methods. — The inoculation of a monkey constitutes the only 

 certain means of diagnosis in a doubtful case of poliomyelitis. 

 A piece of brain removed with all aseptic precaution from a 



