The term "familial neurosyphilis" is usually used to denote involvement of the central nervous system by syphilis in two or more members of the same family. The existence of this situation has been reported repeatedly because it presents the problem of explaining the occurrence of the same type of syphilis in two or more members of the same family. Despite the fact that a great many clinical observations and much experimental work have been carried out, no adequate explanation is as yet forthcoming. The two theoretical explanations to be considered concern, first, the nature of the infective organism with regard to its specificity and virulence and, second, consideration of the person infected with regard to a possible specific familial predisposition to this type of infection.
In this paper it is our purpose to add further clinical observations relative to the occurrence of neurosyphilis in two or more members of the