186 PATHOLOGY OF TYPHUS IN MAN 



Ganglion cells in the brain apparently undergo complete 

 destruction only when incorporated in areas involved by pro- 

 liferative lesions. Neuronophagia has been seen by us in all 

 parts of the cerebrum and cerebellum. In addition, in nuclei 

 in the medulla and mid-brain and in the Purkinje cells of the 

 cerebellum we have seen striking changes in the ganglion cells 

 chromolysis and axonal reaction probably exhaustion 

 effects. These observations have been made on tissues re- 

 moved within two hours post mortem and must represent 

 changes which occurred in life. However, we have not under- 

 taken a detailed study of the ganglion cell changes in typhus, 

 as they are not peculiar to this disease. The possibility of the 

 persistence of the proliferative reaction in the central nervous 

 system after subsidence of the temperature or apparent dura- 

 tion of the disease is suggested both by the late deaths of 

 guinea-pigs with paralytic symptoms and by the continuation 

 of severe nervous symptoms in man leading to death long 

 after the fall in temperature. 



Experiments recently begun with guinea-pigs indicates that 

 the virus of typhus does survive in the brain after the tem- 

 perature has become normal. .We have had numerous his- 

 tological indications that this is the case; we have found 

 early cerebral lesions in apparently recovered animals. The 

 following protocol shows that the virus is present in the brain 

 at least on the third day of normal temperature. 



Record of guinea-pig 387, inoculated May 25, 1921 from 

 guinea-pig 376 (see Chart 1, patient 116 strain). 



Temperatures : 



F. F. 



May 25 103.0 June 6 104.2 



26 102.7 " 7 104.1 



" 27 102.9 " 8 104.7 



" 28 104.6 " 9 104.2 



" 29 No record " 10 104.6 



30 102.9 " 11 104.2 



31 No record " 12 No record 



June 1 103.4 13 104.2 



2 103.8 " 14 102.5 



3 102.7 " 15 102.7 



4 103.3 " 16 102.4 



5 ... . No record 



