EDWARD C. ROSENOW 587 



alveolar sockets; the infection caused rarefaction and absorption of bone in the peri- 

 apical region without swelling, pain, or tenderness, and the cellular infiltration and dis- 

 tribution of the bacteria and the well-formed granulomas were also similar. The 

 streptococci isolated from the teeth, often months after inoculation, usually had re- 

 tained respective elective localizing power as measured on intravenous injection into 

 rabbits. 



In 191 6 I reported a series of experiments in which lesions in the spinal cord or 

 brain, characteristic in location, were produced by the intravenous injection of cul- 

 tures containing streptococci from infection atria in cases of multiple sclerosis and 

 transverse myelitis. Similar experiments in cases of neuralgia and multiple neuritis 

 produced, instead, lesions chiefly in the dorsal nerve roots and peripheral nerves, 

 respectively, in a high percentage of animals inoculated.' These experiments suggest- 

 ed strongly that specific or elective localizing power of streptococci, inherent or ac- 

 quired, might be an important factor in the production of diseases of the nervous sys- 

 tem, and led to the isolation of the pleomorphic streptococcus in epidemic poliomye- 

 litis^ and a similar streptococcus in epidemic encephalitis.^ 



Owing to the unusual resistance of the central nervous system to bacterial in- 

 vasion, also well shown in perfusion experiments of Manwaring and Fritschen,^ the 

 incidence of elective localization following intravenous injection was too low for 

 routine work in this field. It was found that intracerebral injection of small amounts 

 of suspensions in sodium chloride solution of material expressed from tonsils, swabbed 

 from nasopharynx, or aspirated from pyorrhea pockets, and of the corresponding 

 primary cultures in broth or of pure cultures after many rapidly made subcultures, was 

 more likely to produce characteristic symptoms than intravenous injection. It often 

 served to separate the causative streptococcus with neurotropic properties, from con- 

 taminating organisms and other streptococci that were without neurotropic power. 

 By this method elective localization of streptococci in different parts of the central 

 nervous system with the production of more or less characteristic symptoms and le- 

 sions has been found to occur in lethargic and other forms of encephalitis, in poli- 

 omyelitis, epidemic hiccup,^ spasmodic torticollis,^ and chorea. In cases of lethargic 

 and myoclonic encephalitis, and of epidemic hiccup and spasmodic torticollis, char- 

 acteristic symptoms followed the injection of sterile filtrates made from cultures and 

 from nasopharyngeal washings during acute attacks, and which were shown to con- 

 tain the specific streptococcus, and in epidemic hiccup, following injection of the 

 corresponding dead bacteria. The observations in encephalitis have recently been 

 corroborated and extended by Evans,^ and Evans and Freeman,** and those in epidem- 

 ic hiccup by Cadham.' 



' Rosenow, E. C: J. A.M. A., 67, 662. 1916. 



^ Rosenow, E. C, and Wheeler, G. W.: /. Infect. Dis., 22, 281. 1918. 



3 Rosenow, E. C: ibid., 34, 329. 1924. 



''Manwaring, W. H., and Fritschen, William: /. Immunol., 8, 83. 1923, 



5 Rosenow, E. C: J.A.M.A., 67, 662. 1916. 



* Rosenow, E. C: J. Nerv. b" Ment. Dis., 59, i. 1924. 

 7 Evans, AHce C: Fiib. Health Rep., 42, 171. 1927. 



* Evans, Alice C, and Freeman, Walter: ibid., 41, 1095. 1926. 

 ' Cadham, F. T.: J. A.M. A., 84, 580. 1925. 



