462 THE TECHNIC OF COMPLEMENT-FIXATION REACTIONS 



(d) The Wassermann reaction has been especially valuable in the 

 study of the so-called parasyphilitic diseases. In general paralysis or 

 paralytic dementia the serum reacts positively in about 100 per cent, of 

 cases, and the cerebrospinal fluid reacts positively in about 92 per cent. 

 The final and conclusive proof of the syphilitic nature of this disease 

 has been furnished by Noguchi and Moore, who found the Treponema 

 pallidum in sections of the brain. In certain cases of general paralysis 

 the blood-serum may react negatively, whereas with the cerebrospinal 

 fluid the reaction is positive. 



The fact that the blood-serum of a patient with a nervous disease 

 reacts positively does not necessarily indicate that the nervous disease 

 is of syphilitic origin, as the reaction may be due to specific infection of 

 some other structure; if, however, the cerebrospinal fluid also reacts 

 positively, then it is almost certain that syphilitic infection of the 

 central nervous system is present. 



In untreated and active cases of tabes dorsalis the blood-serum reacts 

 positively in from 96 to 100 per cent, of cases. In treated cases the 

 number of positive reactions drops to about 40 to 50 per cent; in general, 

 therefore, a positive reaction with the serums of tabetics may be ex- 

 pected in 73 per cent, of cases. With the cerebrospinal fluid the per- 

 centage of positive reactions is somewhat lower, being about 60 per 

 cent. The positive Wassermann reaction is less constant in locomotor 

 ataxia than in general paralysis, due probably to the fact that the former 

 is more chronic and that intercurrent periods of arrest are more prone 

 to occur. 



In cerebral syphilis the blood-serum, and particularly the cerebro- 

 spinal fluid, will react positively less frequently than in general paralysis. 

 In some instances a positive reaction is found with the cerebrospinal 

 fluid and not with the serum, a matter difficult to explain and believed 

 to be due to the confining of the reacting substances in the subarachnoid 

 space. On the other hand, the lesions are probably not brought in 

 direct contact with the spinal fluid. 



There is much evidence to indicate that localization of syphilis in the 

 nervous system is dependent upon a particular strain of Treponema 

 pallidum; other strains appear to possess a special affinity for the 

 visceral organs, bones, etc. 



(e) In tertiary syphilis not accompanied by lesions of the central 

 nervous system the Wassermann reaction with cerebrospinal fluid may 

 be positive in a relatively large percentage of cases. 



4. In Latent Syphilis. In cases of latent syphilis the Wassermann 



