74 Transactions of the Clinical Society of London, xiii. p. 117, 1880.
75 Archiv für Psychiatrie, xiii. p. 148.
76 Bouchard, “Étude d'Anatomie pathologique sur un Cas de Péllagrie,” Gaz. méd. de Paris, 1864, No. 39.
Among the occasional and exceptional causes of tabes, Leyden and Jolly mention the puerperal state; Bouchut, diphtheria; and several instances are recorded in which psychical shock was responsible for the outbreak of the disease. In a small number of cases I found that mental worry and anxiety coincided with the period of presumable origin of the disease.
Age seems to have no special determining influence. It is true that most sufferers from this disease are men in the prime of life or in the period following it. But it is precisely at these periods that the exposure to the recognized causes of tabes is greatest. It seems as if there were very little liability to the development of tabes after the fiftieth and before the twenty-fifth year; still, some cases of infantile tabes have been recorded.77
77 Excluding the so-called family form of locomotor ataxia: 6 rather imperfectly described cases are cited by Remak (loc. cit.), and 3 additional ones related by himself. Of the latter, 2 had hereditary syphilis, and of 1 the father was both syphilitic and tabic.
In the majority of cases tabes is due to a combination of a number of the above-mentioned factors. The majority of tabic patients in the middle and wealthy classes have had syphilis, and of these, in turn, the majority have been guilty of sexual excesses or perverted sexual acts, while excesses in tobacco and of alcohol are often superadded. Among the poorer patients we find syphilis less frequently a factor, but still present, according to various estimates, in from 20 to 60 per cent. of the cases. Excesses in tobacco play a lesser, and excesses in alcohol a larger, part in the supplemental etiology than in the other class, while exposure to wet and cold and over-exertion are noted in the majority; indeed, in a fair proportion they are the only assignable causes.
DIAGNOSIS.—The recognition of advanced tabes dorsalis is one of the easiest problems of neurological differentiation. The single symptom which has given one of its names to the disease—locomotor ataxia—is so manifest in the gait that even the sufferers from the affection learn to recognize the disease in their fellow-sufferers by the peculiar walk.78
78 At present I have six tabic patients under treatment, who are acquainted with each other, and who have made each other's acquaintance in the singular way of addressing one another on the strength of mutual suffering at Saratoga, at the Hot Springs of Arkansas, and in New York City.
Although there are other chronic affections of the cord which manifest ataxia, such as myelitis predominating in the posterior columns, disseminated sclerosis in a similar distribution, and some partially recovered cases of acute myelitis, the gait is not exactly like that of tabes. The uncertainty may be as great, but the peculiarly stamping and throwing motions are rarely present in these affections. The clinical picture presented by the ataxic patient, aside from his gait, is equally characteristic in advanced cases. Absence of the knee-jerk and other deep reflexes, the bladder paralysis, sensory disturbance, delayed pain-conduction, trophic disturbances, and reflex iridoplegia are found in the same combination in no other chronic disorder of the cord. It is supposable that an imperfect transverse myelitis in the lumbar part of the cord might produce the reflex, ataxic, sensory, sexual, and vesical symptoms of ataxia, but the brachial symptoms found in typical tabes as well as gastric crises would be absent. The pupillary symptoms would also fail to be developed, in all probability. It is to be remembered that only fascicular cord affections can produce a clinical picture exactly like that of tabes in more than one important respect. In analyzing the individual symptoms of the early stage the more important differential features can be most practically surveyed.