| Chancre alone | 23 |
| Chancre followed by secondary symptoms | 16 |
| Total of those with history of chancre | 39 |
| No history of chancre in | 15 |
| Total | 54 |
Of European writers, aside from those already mentioned, Berger claims 43 per cent., and Bernhardt, in commenting on the increasing percentage obtained by accurate investigation, reports an additional series of 7 new cases in private practice, all of which were syphilitic. Fournier, Voigt, Œhnhausen, and George Fisher estimate the syphilitic tabic patients at respectively 93, 81, and 72 per cent. of the whole number. The almost monotonous recurrence of a clear syphilitic history in my more recent records is such that in private practice I have come to regard a non-syphilitic tabic patient as the exception. Among the poorer classes the percentage of discoverable syphilitic antecedents is undoubtedly much less. The direct exciting causes of tabes, exposure and over-exertion, are more common with them and more severe in their operation.
The proof of a relationship between syphilis and tabes dorsalis does not rest on statistical evidence alone. A number of observations show that the syphilitic virus is competent to produce individual symptoms which demonstrate its profound influence on the very centres and tracts which are affected in tabes. Thus, Finger63 showed that obliteration of the knee-jerk is a frequent symptom of the secondary fever of syphilis, and that the relation is so intimate between cause and effect that after the return of the reflex, if there be a relapse of the fever, the obliteration of the knee-jerk is repeated. Both the permanent loss of the knee-jerk (Remak) and the peculiar pupillary symptoms of tabes are sometimes found in syphilitic subjects who have no other sign of nervous disorder; and Rieger and Foster64 regard the syphilitic ocular disturbances, even when they exist independently, as due, like those of tabes, to the spinal, and not to a primarily cerebral, disturbance. Another argument in favor of the syphilitic origin of tabes is derived from the occasional remedial influence of antisyphilitic treatment. The force of this argument is somewhat impaired by the fact that the same measures occasionally appear to be beneficial in tabes where syphilis can be excluded. Still, the results of the mixed treatment in a few cases of undoubted syphilitic origin are sometimes unmistakable and brilliant.65 As some cases, even of long standing, yield to such measures, while others, apparently of lesser gravity and briefer duration, fail to respond to them, the question as to whether syphilis is a direct cause or merely a predisposing factor may be answered in this way: That in the former class it must have been more or less directly instrumental in provoking the disease, while in the latter class it is to be regarded as a remote and predisposing factor, to which other causes, not reached by antisyphilitic treatment, became added. The claim of Erb, that “tabes dorsalis is probably a syphilitic disease whose outbreak is determined by certain accessory provocations,” is not subscribed to unreservedly by a single writer of eminence.
63 “Ueber eine constante nervöse Störung bei florider Syphilis der Secundärperiode,” Vierteljahrschrift für Dermatologie und Syphilis, viii., 1882.
64 “Auge und Rückenmark,” Graefe's Archiv für Ophthalmologie, Bd. xxvii. iii.
65 In one case already referred to a return of both knee-phenomena and complete disappearance of locomotor and static ataxia were effected after a duration of four years. The treatment was neglected and the knee-jerks disappeared, and one has now returned under the resumed treatment, but accompanied by lightning-like pains. At a meeting of the Société médicale des Hôpitaux, held November 10, 1882, Desplats reported a case in which even better results were obtained. Reumont (Syphilis und Tabes nach eigenen Erfahrungen, Aachen, 1881) reports 2 out of 36 carefully observed syphilitic cases cured, and 13 as improved under antisyphilitic treatment.
The question has been raised whether the influence of syphilis is sufficiently great to justify a clinical demarcation between syphilitic and non-syphilitic cases. A number of observers, including Reumont, Leonard Weber, and Fournier, incline to the belief that there are more atypical forms of tabes in the syphilitic group. Others, including Rumpf, Krause, and Berger, are unable to confirm this, but the former admits, what seems to be a general impression among neurologists, that an early preponderance of ptosis, diplopia, and pupillary symptoms is more common with syphilitic than with non-syphilitic tabes. Fournier66 believes that syphilitic patients show more mental involvement in the pre-ataxic period; but it is evident that he has based this belief on a study of impure forms. The advent of tabes in syphilitic cases does not in this respect differ from the rule. The most protracted and severe diplopia I have yet encountered in a tabic patient is one, now under observation, in the initial period of the disease, syphilis being positively excluded as an etiological factor.
66 L'Éncephale, 1884, No. 6.
It seems to be a prevalent opinion that the cases of syphilis in which tabes is developed include a large proportion of instances in which the secondary manifestations were slight and unlike that florid syphilis with well-marked cutaneous and visceral lesions which is more apt to be followed by transitory or severe vascular affections of the cord and brain.
Excesses in alcohol, tobacco, and abuse of the sexual function are among the factors which frequently aggravate the tendency to tabes, and one or more of them will usually be found associated with the constitutional factor in syphilitic tabes. Both alcohol and nicotine have a deleterious effect on nervous nutrition and on the spinal functions, as is illustrated in the effect of the former in producing general neuritis, and of both in provoking optic-nerve atrophy and general paralysis of the insane, not to speak of the pupillary states which often follow their abuse, and the undeniable existence of a true alcoholic ataxia. Sexual excesses were, as stated, at one time regarded as the chief cause: the reaction that set in against this belief went to the extreme of questioning its influence altogether. It is to-day regarded as an important aggravating cause in a large number of cases, and this irrespective of whether it be the result of a satyriacal irritation of the initial period or a precedent factor. In a large number of my patients (18 out of 23 in whom this subject was inquired into) the habit of withdrawing had been indulged in,67 and, as the patients admitted, with distinct deleterious effects, such as fulness and throbbing in the lumbo-sacral region, tremor and rigidity, with tingling or numbness, in the limbs, blurred vision, and sometimes severe occipital headache; in one case lightning-like pains in the region of the anus ensued.68