In a recent extensive review, Menninger1 considered the relation between feeblemindedness and congenital syphilis from two angles: the percentage of congenitally syphilitic persons who are feebleminded and the percentage of feebleminded persons who have congenital syphilis.
With respect to the incidence of feeblemindedness among congenitally syphilitic persons, Menninger collected nine studies. Except for an incidence of 1.8 per cent reported by Hutchinson in 1863, the values for the incidence ranged from 7 per cent of 148 cases (Still) to 57.2 per cent of 42 cases (Breuer), with a median value of 24.5 per cent and a mean value of 28.8 per cent. Menninger stated: "A serious disqualification of these studies is the failure of the authors to establish definite criteria of the concept of feeblemindedness or mental deficiency used by them." Some apparently included all instances of the mildest degree of mental retardation recognized. It must be remembered that
JENKINS RL, BROWN AW, CISLER LE. INFLUENCE OF SYPHILIS ON INTELLIGENCE OF CHILDREN. Am J Dis Child. 1940;60(2):341-351. doi:10.1001/archpedi.1940.02000020095009