Chapter M: M——, was a stout Irish woman about forty years of age. She had (23)

With regard to the involvement of the peripheral nerves proper, aside from the optic, opinion is somewhat divided. The discovery of multiple neuritis, and the recognition of the fact that it had been erroneously confounded with tabes, led Dejerine to claim that tabes might be of peripheral origin. He even proposed to account for the oculo-motor trouble on the basis of an affection of the oculo-motor nerves. This explanation has been repudiated by Westphal and sound authorities generally. That the peripheral nerves are occasionally involved in tabes was already known to Friedreich in 1863,[46] and later Westphal found the cutaneous branches in an advanced tabic patient to present similar changes to those discovered by Friedreich: these findings are confirmed by his Japanese pupil, Sakaky. The nerve-tubes are atrophied, the axis-cylinder being often preserved, and the interneural connective substance is proliferated. But there is no constant relation between these changes and the symptoms of the disease; in one of Sakaky's cases the nerves of an extremity which had been the seat of severe sensory symptoms were entirely normal. The findings in the peripheral nerves of tabic subjects lose much of their value in view of their recent discovery in marantic persons[47] advanced in life, but who had no nervous disease whatever.

[Footnote 46: _Virchow's Archiv_, vol. xxvi. pp. 399-452.]

[Footnote 47: Krause, _Neurologisches Centralblatt_, 1885, p. 53.]

It has been attempted to bring the tabic process in relation to a supposed primary meningitis. Tabes is a rather common nervous affection, and primary spinal meningitis is one of the very rarest. The leptomeninges are found considerably thickened in one out of ten tabic cords, and those who defend the meningitic origin of the disease base their theory on this inconstant finding, and allege that in the cases where it is absent the meningitis has disappeared while the cord lesion progressed. It is a fatal objection to this view that the part of the posterior columns immediately adjoining the pia is often quite free from disease. A meningitic affection, either as an etiological or a complicating factor, can be admitted in those cases only where there is a marginal sclerosis.

The changes in the optic nerve resemble those of the white columns of the cord in their naked-eye and minute character as well as in the controversial nature of the various interpretations made. When affected, the nerve is found to be firmer than normal, and discolored; later it becomes quite gray, and may eventually shrink to two-thirds, and even less, of its normal diameter. It is generally believed that, as in the cord, the myelin undergoes wasting before the axis-cylinder disappears, and that the latter may survive a long time, thus explaining why the patient may retain his visual power for a considerable period after the ophthalmoscope determines the existence of atrophy. No satisfactory explanation {848} has as yet been offered for the optic-nerve affection of tabes. There is no direct continuity of the spinal and optic sclerosis. Two theoretical possibilities suggest themselves. The first is that the lesion of the cord exerts a remote effect upon the physiological, and through this the structural, condition of the optic nerve. That such an influence may be exerted is shown by cases of transverse myelitis low down in the cord, which, according to Erb and Seguin, were complicated by double optic-nerve atrophy. The second theory is that the involved part of the cord and the optic nerve present a similar vulnerability to the same morbid influences. This is illustrated in some cases of chronic alcoholic and nicotine poisoning, in ergotism, and in the spinal affections due to hereditary influences and developmental defects.

To discuss the nature of the disturbing influence which is responsible for the most characteristic evidence of the disease, the ataxia, would be equivalent to reviewing almost every mooted question in spinal physiology. It is to be borne in mind that ataxia is a collective term designating any inco-ordination of movement which is independent of motor paralysis. It may be due to abolition or impairment of tactile perception; it may be due to loss of the muscular sense; it may be due to hampered motor co-ordination; and, finally, it may be due to a disturbance of the space-sense. In my opinion it is only in exceptional cases that any one of these factors can be positively excluded. Occasionally, one has been noted when the ataxia was grave but the tactile sense was unimpaired, or where the muscular sense was perfect but ataxia was well developed. The difficulty with most such records is that no discrimination is made as to the kind of ataxia present. That loss of skill which the patient shows when he shuts his eyes and attempts to perform certain movements without their aid is undoubtedly due to diminished sensation, either tactile or muscular, and usually both. The inability to stand with the eyes closed is probably a cerebellar phenomenon, and in this respect we are on the way to return to Duchenne's opinion. It is true that the cerebellar organ is healthy in most tabic subjects, but its centripetal informer, the direct cerebellar tract, is either itself involved or affected in its origin in the columns of Clarke. But, besides the static ataxia and that motor ataxia which can be neutralized by the use of the eye, there is another disturbance, which, as Erb and his followers hold, cannot be accounted for on the strength of any sensory disturbance. It consists in an interference with the proper succession and rhythm of movement. It seems as if that automatic mechanism by which the individual or grouped muscular contractions engaged in locomotion follow each other with the smoothness of the action of perfectly-fitting cog-wheels were disturbed; the correct after-movement is hesitated over or skipped, or even takes place at the wrong moment, neutralizing some other step in the co-ordination required. The tendency of physiologists and pathologists is to attribute this form of ataxia to the disease of the intrinsic co-ordinating apparatus of the cord itself. The experiments of Tarchanoff on a headless duck, and the determination of the existence of cursorial co-ordinating tracts uniting the brachial and lumbar nuclei in mammals, as well as the observations made on automatic co-ordinate movement in decapitated criminals, demonstrate the existence in the cord of such an apparatus. The combination of the ganglionic centres which underlies this co-ordination {849} is affected by the so-called short tracts of the cord,[48] and it is precisely a portion of these which are involved in the lesion of the column of Burdach. A number of arguments have been advanced against regarding the lesion of this column, or indeed any of the lesions of the posterior column, as explaining the ataxia-producing effect of tabes. Westphal has interposed some potent objections. He holds that lesion of these columns will be found more frequently when examinations shall no longer be limited to those cases where disease is suspected because ataxia was observed during life. He found extensive disease of the posterior columns in sufferers from paretic dementia who did not exhibit the characteristic ataxic gait of tabes. I believe this objection can be met by the very cases cited by Westphal in its support. Where the spinal disorder preceded the cerebral—that is, where paretic dementia occurred as a complication of tabes dorsalis—true locomotor and static ataxia had been present before the insanity exploded. On the other hand, where the spinal disease followed the cerebral, typical ataxia did not ensue. This would seem to indicate that the destruction of cortical control is inimical to the development of typical tabes. Leyden has made a suggestion in the same direction when he attributes the lesser manifestness of locomotor ataxia in tabic females to their inferior cerebral organization.[49] A more convincing proof of the correctness of this conclusion is furnished by the fact that if the pathological process, after destroying the posterior columns and producing ataxia, invades the voluntary motor tract, the ataxic symptom becomes less palpable.[50] This antagonism between lateral-column and posterior-column lesion is frequently exemplified in the combined forms of sclerosis. It would seem, then, that where the brain is healthy and the controlling voluntary tracts are unimpaired, the ataxia is aggravated, supporting the beautiful theory of Adamkiewicz, which assumes that the locomotor ataxia is due to a disturbance of the balance normally existing between the psycho-motor centres and those controlling the muscular tone as well as those mediating reflex excitability.[51]

[Footnote 48: Intersegmental tracts.]

[Footnote 49: In one out of three female eases I found the active disturbance of gait as severe as in males, but Leyden's observation is supported by all who have seen a sufficiently large number of female cases.]

[Footnote 50: Not because of paresis altogether, for it diminishes materially out of proportion to the paresis.]

[Footnote 51: _Archiv für Psychiatrie_, x. p. 545. There is another observation which bears in this direction: James of Boston observed that absolute deaf-mutes in a large percentage of cases are insusceptible to vertigo or to the allied phenomenon of sea-sickness. Certainly, the auditory nerve is a space-sense nerve; its physiological elimination is, however, accompanied by an immunity against a symptom which may be an evidence of disturbed space-sense transmission. In like manner, the destruction of the central perceptive and voluntary centres in the paretic dement inhibits the legitimate results of posterior spinal sclerosis.

The degeneration of the crossed-pyramid tracts in typical tabes seem to be strictly an atrophy from disuse, perhaps facilitated by the general malnutrition of the cord. It is limited to that part supplying the most or solely affected extremities. Thus, where the lower extremities are alone grossly involved it is totally degenerated in the lumbar area, and only in its outer parts in higher levels. As if to fortify this comparison by analogous observations from every great segment of the nervous axis, a similar inhibiting influence of pyramid lesion on co-ordinating disturbance (muscular sense) is noted in secondary degeneration of the interolivary layer; when uncomplicated with pyramid lesion (Meyer and my own case,) ataxia is present; when so complicated (Schrader, Homén) it is not observed, even if determinable.]

{850} Lissauer[52] has recently determined the existence of a degeneration of certain fine nerve-fibres, apparently derived from the outermost of the radicles into which the posterior nerve-roots divide on entry. They are situated on that border of the apex of the posterior horn which is in contact with the lateral column, and were found degenerated in all cases except such as were in the initial period. No symptomatic relation has been claimed for this lesion.

[Footnote 52: _Neurologisches Centralblatt_, 1885, No. 11.]

One of the most important questions which have grown out of the pathological studies of tabes is the relationship between the lesions and the not infrequently observed restoration of functions which had been more or less seriously impaired in an earlier period of the disease. Even those symptoms which ordinarily comprise the continuous and essential clinical background of tabes may exhibit remarkable changes in this direction. I have two well-established observations—one of tabes of eight years' standing, the other of more recent date—in which that symptom which, once established, is the most constant, the reflex iridoplegia, disappeared, to reappear in two months in one case where it had been associated with myosis, and to reappear in eight months in the other, repeating this oscillation the following year. I have now under observation a tabic patient in the sixth year of his illness who two years ago had a return of both knee-phenomena to a nearly normal extent, to lose them in two months, and to regain the reflex on the left side four months ago, retaining it up to the present. These three cases were of syphilitic subjects. In a fourth advanced non-syphilitic tabic patient, whose ataxia had reached a maximal degree, I found a return of both knee-phenomena for three days after its absence had been established by medical examiners for over a year, and had probably been a feature for a much longer period. Hammond the younger and Eulenburg have reported similar cases. Nothing is more surprising to those unfamiliar with the progress of this disease than to find gross ataxia or the electrical pains and anæsthesia to disappear or nearly so; and the alleged success of more than one remedial measure is based on the fallacious attributing to the remedy what was really due to the natural remittence of the disease-process or of its manifestations. The financial success of quacks and the temporary but rapidly evanescent popularity of static electricity, Wilsonia belts, and like contrivances are owing to the hopefulness inspired in the credulous patient by the mere coincidence of spontaneous improvement and the administration of a new remedy, supplemented, it may be, by the influence of mind on body in his sanguine condition. It is to be assumed that the influences which are at work in provoking the trophic and visceral episodes of tabes are of an impalpable character, and that all theorizing regarding the reason of their preponderance in one and their absence in another case are as premature as would be any speculation regarding their rapid development and subsidence in the history of one and the same case. But we have better grounds for explaining the remissions of the ataxia and anæsthesia.

It is only in the most advanced stages of tabes that the destruction of the axis-cylinder becomes absolute or nearly so. Contrary to the opinion of Leyden,[53] who held that the tabic sclerosis differs from disseminated sclerosis in the fact that the axis-cylinder does not survive the myelin {851} disappearance, it is now generally admitted that a certain number of exposed or practically denuded axis-cylinders may be preserved in the sclerotic fields.[54] It is on the theory that these delicate channels may be oppressed at one time, perhaps by inflammatory or congestive pressure, and relieved at another by its subsidence, that we may assume them to be the channels through which the now limited, now liberated, functions are mediated. It is also reasonable to suppose that vicarious action may supplement the impaired function, and to some extent overcome the disturbing factors. This is illustrated by the controlling influence of the visual function—yea, even of the unconscious and ineffectual co-operation of completely amaurotic eyes—in neutralizing both locomotor and static ataxia. One patient who was well advanced in the initial period of tabes, and who had been encouraged to consider the medical opinion to that effect as the result of an exaggerated refinement of diagnosis, made repeated tests of the Romberg symptom in his own case, and deluded himself into the belief that the physician was mistaken because he succeeded in practically overcoming it with an effort that too plainly told its own story; but still he overcame it. Certain peripheral influences have the power of stimulating the dormant activity of potentially vicarious tracts, and perhaps also the blunted activity of those whose function is impaired. The outside temperature, certain barometric conditions, all may exert an influence in this direction for good or evil.

[Footnote 53: _Op. cit._, p. 328, vol. ii.]

[Footnote 54: Babinski (_Neurologisches Centralblatt_, 1885, p. 324) notes this feature, and, consistently with the findings of most modern observers, discovers much more resemblance to disseminated sclerosis than to the systemic sclerosis with which Strümpell and Westphal (in part) incline to classify tabes. Similar objections to the system-disease theory are advanced by Zacher (_Archiv für Psychiatrie_, xv. p. 340). I may not pass over in silence the fact that Babinski considers his observations to militate also against regarding any phase of the tabic sclerosis as a secondary process. But while it may fairly be asked that a sclerosis to be regarded as systemic must be shown to be total, this is not necessary for a secondary process, unless the primary involvement be total also; and that is not the case in tabes.]

ETIOLOGY.—Authorities are now agreed that no single cause can be regarded as the sole responsible factor in all cases of tabes, and that a number of etiological influences are combined in the provocation of this disease in most instances. When the distinctiveness of the affection was first recognized it was customary to attribute it to sexual excesses, and the unfortunate sufferer had frequently to bear the implied reproach of having brought his misery on himself, in addition to the hopeless prospect which those who followed Romberg and other authorities of the day held out to him.[55]

[Footnote 55: This opinion survives in a large portion of the German laity and in French novels. About the time that the poet Heine was dying from an organic spinal affection two other prominent literary characters of Paris were affected with tabes. It so happened that all three were popularly regarded as libidinous, and one of their leading contemporaries, whose name escapes me, took occasion to issue a manifesto addressed to the jeunesse dorée which closed with the apostrophe, “Gardons à nos moelles.”]

Heredity plays a very slight part in the etiology of tabes. Writers of ten and fifteen years ago attributed a greater importance to it than is now done. But this was due to the incorporation with tabes of the so-called family form of locomotor ataxia—a disease which is now regarded as a distinct affection.[56]

[Footnote 56: There is but one record of direct heredity (the father and son being affected nearly at the same time), to my knowledge. It was observed at the Berlin Hospital by Remak (_Berliner klinische Wochenschrift_, 1885, No. 7). Both father and son were syphilitic.]

{852} More importance may be attached to individual predisposition, but thus far no distinct formulation of this factor has been attempted except by Schmeichler,[57] who offers the suggestion that there are persons with a predisposition to the development of connective-tissue proliferation in various organs of the body, and that in them tabes and other sclerotic affections are consequently more frequent than in others. This suggestion appears plausible, but it is unconfirmed by positive observations.

[Footnote 57: _Op. cit._]

Sex appears on a superficial view to be one of the most important elements. It is generally admitted that at most one female becomes tabic for every ten males who do so. Of 81 cases in private practice, I observed but 3 females. Rockwell, Seguin, Birdsall, and Putnam give similar figures. This comparative immunity is probably due to the fact that the female is less exposed to over-exertion, to surface chilling of the feet, to the injurious consequences of sexual excess, and to syphilis[58] than the male. As a rule, the affection in females is more insidiously developed, progresses more slowly, is less marked by crises and trophic disturbances, and not accompanied by as severe pains and profound disturbance of co-ordination as is the corresponding affection in males.

[Footnote 58: Whether the shorter vitality of the syphilitic female as compared with that of the male is a factor in diminishing the accumulation of chronic tertiary sequelæ in that sex, or whether it be the lesser vulnerability of the inferior nervous system, I am unable to decide from the facts at my disposal. In private and clinical experience I have been struck by the fact that women affected with syphilis in the same way and under similar circumstances with tabic syphilitic males develop symptoms of functional disorder of the brain and cord, such as spinal and cerebro-spinal irritation. My cases referred to had in no instance any indication of a syphilitic condition or history, and a distinct and different cause was found in all three.]

The most important element in creating an acquired predisposition to tabes is undoubtedly the existence of constitutional syphilis. Some difference of opinion still exists regarding the proportion of syphilitic tabic patients, chiefly due to the neglect of Erb—when he first announced the prevailing view, and which is generally attributed to him—to differentiate between cases of demonstrated constitutional syphilis and the so-called spurious or soft chancre. But although there occurred a reaction against his view which went to as great an extreme in the opposite direction, the careful and critically registered statistics accumulated in the mean time strengthen the view that there are more syphilitic subjects among the tabic than among any class of sufferers from other nervous affections.[59] Reumont, a physician at Aix-la-Chapelle, to which place syphilitic patients in general resort in large numbers, found that of 3400 cases of syphilis, 290 had nervous affections, 40 being afflicted with tabes. Bernhardt[60] took occasion to examine a group of hospital patients who were free from tabes, and found that not fully 16 per cent. were syphilitic, while of 125 tabic patients, over 46 per cent. were determined to have had positive syphilitic manifestations. Several of those observers who have paid attention to the question of the syphilitic origin of tabes have admitted that the more searching their inquiry the larger the proportion of detected syphilitic antecedent histories. Thus, Rumpf's earlier table shows 66, and his later 80, per cent. of such antecedents. This latter figure exactly corresponds to the percentage of syphilis in my private {853} cases. At a discussion held by members of the American Neurological Association in 1884, Webber gave 54, Putnam 49, Rockwell 40, Birdsall 43,[61] and Seguin 22 per cent.[62] as the proportion in their experiences.

[Footnote 59: Excepting always those having the distinctive and undisputed syphilitic character.]

[Footnote 60: _Archiv für Psychiatrie_, xv. p. 862.]

[Footnote 61: Derived from over five hundred cases which had presented themselves at the clinic of the College of Physicians and Surgeons.]

[Footnote 62: In the _Archives of Medicine_ he tabulates 54 (private) cases as follows:

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, Finger[63] 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 Foster[64] 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 {854} 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.

[Footnote 63: “Ueber eine constante nervöse Störung bei florider Syphilis der Secundärperiode,” _Vierteljahrschrift für Dermatologie und Syphilis_, viii., 1882.]

[Footnote 64: “Auge und Rückenmark,” _Graefe's Archiv für Ophthalmologie_, Bd. xxvii. iii.]

[Footnote 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. Fournier[66] 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.

[Footnote 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 {855} 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]

[Footnote 67: Coitus reservatus, the real crime of the Onan of Scripture.]

[Footnote 68: Leyden states that coitus in the upright position has been accused of producing tabes, without mentioning his authority. I have no observation on this subject touching tabes, but am prepared to credit its bad effect from the account of a masturbator, who during the orgasm produced while standing felt a distinct shock, like that from a battery, shooting from the lumbar region into his lower limbs, and causing him to fall as if knocked down. He consulted me in great alarm—was scarcely able to walk from motor weakness, and had no knee-phenomenon; in a few weeks it returned, and no further morbid sign appeared. Masturbators of the worst type occasionally manifest ataxia, and in three cases I have been able to establish the return of the knee-jerk, together with other improvements in the spinal exhaustion of these subjects. The loss and diminution of the patellar jerk, and the frequently associated urinary incontinence, as well as certain of the peripheral pains found in masturbators, certainly prove that undue repetition of the sexual act (be it natural or artificial) is competent to affect the cord in a way that cannot but be injurious in case of a predisposition to tabes, if not without the latter.]

Of single causes, none exerts so direct and indisputable an influence on the production of tabes as the action of cold and wet upon the lower segment of the body. It is usually the case that such exposure is frequently repeated and combined with over-exertion before the disease is produced, but it is occasionally possible to trace the very first symptom of the disease directly to a single exposure. A soldier who stands up to his knees in a rifle-pit half full of water finds his limbs numb or tingling; develops slight motor weakness, then lightning-like pains, and ultimately a typical tabes. In the case of a peddler who presented an advanced form of the disease, the first symptoms had developed after a single wetting of his feet: while walking along one of our watering-places with his wares the swell of a steamer inundated the beach. He had been subject to perspiring feet before that, and the perspiration remained checked from that time on.[69] The influence of surface chilling was remarkably manifest in all three of my female cases. In one of them it was due to frequent wetting of the feet; in the second, a midwife, the first symptoms began immediately after standing on a cold hearthstone while preparing some article needed in a lying-in case. In the third case, a lady who contracted and safely passed through a scarlatina in her twenty-eighth year was taken out driving while desquamation was going on. She became thoroughly chilled, experienced numbness in the fingers and toes, and from that day on developed a slowly progressing tabes involving all extremities alike.[70]

[Footnote 69: Checking of habitual perspiration by violent measures is mentioned by the German textbook writers as a frequent cause, but occurs quite rarely in the modern tables.]

[Footnote 70: In view of the absence of spinal—or, in fact, any nervous—symptoms prior to the exposure referred to, it does not seem necessary to insist that this was not an instance of a true post-scarlatinal tabes; and possibly the case thus designated by Tuczek (_Archiv für Psychiatrie_, xiii. p. 147) may have been really due to chilling of the delicate body-surface after desquamation or during that process. The typical form of myelitis and sclerosis after exanthematous fevers is rather of the disseminated type.]

Spinal concussion has been mentioned by a number of authorities as a possible cause for tabes, as for other forms of sclerotic spinal disease. In 1 of 81 cases in my own observation the development of the disorder could be distinctly traced to a railway injury; in 2 a sudden aggravation was as distinctly referable to a similar cause.[71] To what extent railroad {856} travelling, with its attendant continual jarring of the body, may predispose to the development of tabes or of other spinal diseases is as yet a matter of mere conjecture. That railroad travelling exerts a bad influence in some cases of the established disease is evident; but in others the patients rather like the motion, and claim to feel benefited by it.

[Footnote 71: A fall from a chair, striking on the back of the latter, while endeavoring to keep a row of books from coming down in one case, and the shock of the Ashtabula disaster in the other. The latter patient, the same one who is referred to as describing the electric-storm sensation in an earlier part of this article, had his foot amputated in consequence of that disaster; but, like one of the characters in _Jacob Faithful_, who felt his toes when the weather changed, though he left both legs at Aboukir, he felt the terrific pains of the disease in the absent foot as distinctly as in the other. Dumenil and Petit (_Archives de Névrologie_, ix. Nos. 25 and 26) relate cases in which a spinal concussion was the only ascertainable cause.]

A number of toxic agents have been charged with producing tabes: thus, Bourdon maintains this of absinthe; Oppenheim attributes one case to poisoning by illuminating gas, the exposure to its influence being immediately followed by a gastric crisis, and this by a regulation tabes.[72] It is supposed that most of the poisons acting on the cord in this or a similar way, such as arsenic, cyanogen,[73] barium, and chloral,[74] do not produce a spinal lesion directly, but through the medium of a secondary cachexia. Of no agent is the effect in producing tabes so well studied as ergot of rye. It had long been known that ergot-poisoning provoked certain co-ordinating, motor, and sensory disturbances, but it was left for Tuczek[75] to show that this vegetable parasite produces a lesion of the spinal cord which in its character and distribution apes typical posterior sclerosis so closely as to justify the designation of a tabes ergotica. Possibly, pellagra, which is sometimes manifested in a similar way,[76] may yet be shown to have a like influence.

[Footnote 72: _Archiv für Psychiatrie_, xv. p. 861.]

[Footnote 73: Bunge, _Archiv für experimentelle Pathologie_, xii.]

[Footnote 74: _Transactions of the Clinical Society of London_, xiii. p. 117, 1880.]

[Footnote 75: _Archiv für Psychiatrie_, xiii. p. 148.]

[Footnote 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]

[Footnote 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 {857} 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]

[Footnote 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.

The discovery of no single symptom of tabes dorsalis marks so important an epoch in its study as Westphal's observation that the knee-phenomenon is usually destroyed in it. Had this symptom not been detected, so Tuczek admits, ergotin tabes would have eluded recognition.[79] It was claimed by a majority of neurologists at first that this jerk is always abolished in tabes, but it is now recognized that there are exceptions, as is shown by cases of Hirt,[80] Westphal, and others, not to mention some well-established cases of its return during the progress of the disease.

[Footnote 79: It is not to be wondered that, like most new discoveries, that of the pathological changes of the patellar reflex should have been made the basis of premature generalizations. The attempt of Shaw (_Archives of Medicine_) to establish a relation between disturbances of the speech-faculty and an increased knee-jerk has not met with any encouragement or confirmation, and has been rebutted by Bettencourt, Rodrigues (_L'Éncephale_, 1885, 2), and others.]

[Footnote 80: _Berliner klinische Wochenschrift_, 1886, 10.]

The knee-phenomenon is supposed to be a constant attribute of physiological man. It is difficult to elicit it in children, and frequently impossible to obtain it in young infants. It also disappears in old age, {858} without having any special signification, except that this occurrence seems to be in direct relation to senile involution. In 2403 boys between the ages of six and thirteen years, Pelizæus[81] found it absent in one only. It is customarily elicited by having the patient while sitting in a chair throw one leg over the other; hereupon the ligamentum patellæ is struck a short, quick blow. Under physiological circumstances the leg is jerked outward involuntarily after an interval of about one-fifth of a second—one that is scarcely appreciated by the eye. But if it be found absent by this mode of examination, the case is not to be regarded as one of absence of the jerk without further ado. The patient is made to sit on a table, his legs dangling down and his body leaning back, while he clenches his fists. By this means the jerk will often be produced where it appears to be impossible to evolve it by the ordinary means. It is also well to try different parts of the ligament, and when comparing both sides to strike on the corresponding spot and in the same direction. Many subjects who appear to be irresponsive will respond very well when a point on the outer edge near the tibial insertion is percussed. The elbow reflex, which has the same signification for the upper extremity that the knee-jerk has for the lower, is elicited in the same manner.

[Footnote 81: _Archiv für Psychiatrie_, xv. p. 206.]

The absence of the knee-jerk is usually regarded as a suspicious circumstance in persons of middle life; and where it can be demonstrated that it has been present years previously and subsequently disappeared, it is looked upon as of grave import. I, however, published three years ago an authentic case of disappearance of the knee-jerk in a physician now in active practice in New York City who to this day enjoys excellent health and has developed no other sign of spinal disease. The knee-jerk is also abolished in a number of conditions not belonging to the domain of strictly spinal diseases, such as diphtheria, diabetes, secondary syphilis, and severe cases of intermittent fever. Of these, diabetes alone can be possibly confounded with tabes dorsalis. The difficulty of differentiating early tabes and diabetes is enhanced by the fact that on the one hand there are often ataxic symptoms with diabetes, while on the other both glycosuria and diabetes insipidus may complicate tabes. Senator, Frerichs, Rosenstein, Leval-Piquechef, Charcot, Raymond, Demange, Féré, Bernard, and T. A. McBride all recognize the occasional presence of the ataxic gait, paræsthesia, belt sensation, and even fulgurating pains, besides the abolition of the jerk, in diabetes mellitus.[82] In pure cases of diabetes, however, I am not aware that spinal myosis or the reflex paralytic pupil has been found.

[Footnote 82: I have now under observation a case of myelitis with predominating sclerosis of the posterior columns of five years' standing in a merchant who has been under antidiabetic treatment for eleven years.]

Abolition of the knee-jerk is found in all organic diseases of the spinal cord which destroy any part of the neural arch at the upper lumbar level, where the translation of the reflex occurs, whether it be in the posterior root-zones or in the gray matter of the origin of the crural nerves. Thus, acute or chronic myelitis, disseminated sclerotic foci of this level, may cause obliteration of the reflex at any time of the disease; so may acute or chronic anterior poliomyelitis, neoplasms, and amyotrophic lateral sclerosis of the anterior cornua type if the destruction of the anterior cornua {859} be complete enough. It is also found abolished with all diseases of the peripheral nerves—traumatic and neuritic—which produce absolute motor paralysis of such nerves.

Among the sources of error possibly incurred in examining for this important symptom the presence of rheumatism is one. There is sometimes a tetanic rigidity of the joints which prevents the reflex from becoming manifest. It is also sometimes found to be absent immediately after severe epileptic attacks, according to Moeli.[83]

[Footnote 83: In three examinations after severe attacks of epilepsy I found it normal.]

The condition of the pupil is perhaps a more constant sign of early tabes than the loss of the knee-jerk; at least it has been found well marked in cases where the jerk had not yet disappeared. It may be regarded as a rule in neuro-pathology that wherever reflex iridoplegia is at any time accompanied by other oculo-motor disturbance, it is either of spinal origin or in exceptional cases due to disease of the pons varolii. The peculiar character of the pupillary disturbance of tabes furnishes us with a criterion for distinguishing it from one affection which in common with it exhibits loss of the knee-jerk—diphtheria. In diphtheria there is also a reflex disturbance of the pupil, but it is the reverse of that of early tabes. In the latter reaction to light is lost, but the accommodative contraction power is retained; in diphtheria accommodative contraction power is lost, but reaction to light is retained.

The bladder disturbance has already been described. It is found as a marked symptom so prominently in no other systemic affection of the cord, and in few of the non-systemic forms, of sclerosis. In none of these is it associated with absence of the patellar jerk, reflex iridoplegia, and fulminating pains, as in tabes, except there be also some motor paresis. It is the combination of any two of the important initial symptoms of tabes without paralysis or atrophy that is regarded as indicative of the disease by most authorities. Thus the swaying in closing the eyes, if associated with the Argyll-Robertson pupil, is considered as sufficient to justify the diagnosis of incipient tabes, even if the knee-jerk be present and fulminating pains and bladder trouble absent. Undoubtedly, the tabic symptoms must begin somewhere. But at what point it is justifiable to give a man the alarming information that he is tabic is a question. I have a number of neurasthenic subjects now under treatment who have had reflex iridoplegia for years; in one the knee-jerk is slowly becoming extinguished; in two it has been becoming more marked after becoming less; in all the three mentioned there is slight swaying in closing the eyes and some difficulty in expelling the last drops of urine while micturating. I do not believe that such a condition justifies a positive opinion, although the surmise that they are on the road to developing tabes may turn out correct for all these and for some of those who have merely reflex iridoplegia.

Incipient tabes cannot be readily confounded with any other chronic disease of the spinal cord. Some of the cases produced by sudden refrigeration resemble a beginning myelitis. But the absence of true paralysis seems to distinguish it from the latter. In all the cases of so-called acute locomotor ataxia of myelitic origin that I can find a record of, paralytic symptoms were marked, if not throughout the disease, at least in the initial period.

{860} Other forms of sclerosis occasionally limited to the posterior columns imitate the symptoms of tabes. It is unusual, however, for such sclerosis to be distributed through so great an extent of the posterior columns as to produce symptoms consistent with tabes in both the upper and lower extremities. And even where this condition is complied with, the typical progress so characteristic of tabes is not adhered to. As previously stated, the progress is weakened by variations in certain symptoms. Such variations are found in other forms of sclerosis, but they are not as great, trophic disturbances not so common, and visceral crises not so violent, as a rule.

The discovery of ataxic phenomena as a symptom of peripheral neuritis has added another to the long list of pseudo-tabic affections. Indeed, Dejerine, who greatly advanced our knowledge of this affection, undertook on the strength of his discovery to place tabes among the peripheral affections complicated by secondary affection of the cord. In a large number of cases of peripheral neuritis, particularly the alcoholic form described by Fischer, the static ataxia, belt sensation, bladder trouble, and reflex iridoplegia are absent. In tabes the severe pains, if influenced by deep pressure at all, are affected favorably, but in peripheral neuritis pressure on the affected nerve-trunk greatly aggravates the trouble.

In addition, those severe forms of neuritis that lead to ataxia, abolition of deep and other reflexes, are accompanied by qualitative electrical changes and atrophic paralysis—features not found in tabes. Sometimes a disseminated neuritis will become so generalized as to cause diplopia and other evidences of ocular paralysis through the affection of the peripheral nerves, but, so far as my observations extend, not with the characteristic pupillary phenomena of tabes.

Cerebellar disease, alcoholic and hysterical neuroses, sometimes produce ataxia, and this may be associated with one or more of the other characteristic symptoms of tabes. Cerebellar ataxia is usually very different from that of tabes, as far as the locomotor element is concerned. In tabes it is the movements the patient makes which cause him to stagger; in cerebellar disease those movements made to prevent staggering are usually co-ordinated. The gait properly called cerebellar is therefore very different from that of tabes. There is, however, static ataxia in both cerebellar and posterior-column disease. In addition, the knee-jerk may be abolished in the former, heightening the resemblance: the history of the case is, however, decisive where these latter symptoms might lead to doubt. Bladder trouble in cerebellar disease is not an early feature, nor are paræsthesias and delayed pain-conduction intrinsic features, of cerebellar disease. Their presence is in favor of tabes.

Alcoholic ataxia is very rapid in its course, while tabic ataxia is exceedingly slow. In addition, the former is accompanied by atrophic paralyses as early features; if such occur in tabes, they occur late in the disease, and are not marked by degenerative electrical reactions as alcoholic ataxia is. This disorder is usually, too, accompanied by fever, which is an exceptional, and certainly never an intrinsic, feature in tabes. Discontinuing the alcoholic poison is usually followed by rapid amelioration of the ataxia. Hysterical ataxia exceptionally apes the ataxia of tabes; the presence of other hysterical phenomena, the rapid and bizarre change of the symptoms, are distinguishing features. There are cases of hysterical {861} ataxia accompanied by concentric limitation of the field of vision.[84] The outline of the limitation is strikingly like that accompanying atrophy, but repeated examination shows a variation of a kind not found in the latter. The blind field advances in one direction to recede in another on one day, and reoccupies the latter and recedes from the former on the next.

[Footnote 84: Landesberg, _Journal of Nervous and Mental Diseases_, vol. xiii. 2.]

Ataxia after most acute diseases, such as scarlatina and typhoid, is not usually accompanied by loss of the knee-jerk, and never by reflex iridoplegia. The ataxia after diphtheria is complicated by the former, but, as already stated, the very opposite state of the pupil serves to distinguish it.

The hereditary form of tabes is frequently confounded to this day with true tabes dorsalis. The family history and age of the patient are collateral evidences of the nature of the case. In the hereditary form the sphincters, optic nerves, and the eye-muscles are not affected; in the acquired form the first and last are always involved; and this involvement occurs so early in the disease as to constitute a valuable discriminating feature. Although the locomotor ataxia is very similar in the two affections, static ataxia, the symptom manifested on closing the eyes, is not found in the hereditary form, while it is found more constantly than even the locomotor ataxia in the acquired form.

The electrical reactions in tabes are either normal or quantitatively slightly increased. This serves to distinguish it from all spinal affections accompanied by marked paralysis. In the later stages, when some atrophy results, there may be a quantitative decrease, but these are without qualitative changes. A change may occur in those exceptional cases where the anterior gray horns become involved, but we then have to deal with a true complication; and complications can be recognized only in their development and by the application of the diagnostic criteria characterizing the complicating disorder when of an independent occurrence.[85]

[Footnote 85: It is not impossible that many of the symptoms described as occurring in advanced tabes are due to independent focal disease. In the case of a female aged seventy years mentioned by Hirt (_Berliner klinische Wochenschrift_, 1885, No. 26), who developed hemiatrophy of the tongue, probably from a hemorrhage in the brain isthmus, there was no tabes, although this symptom when found with tabes is supposed to be part of the tabic symptom-group.]

The TREATMENT of tabes dorsalis will be considered at the end of this article, together with that of the sclerotic processes generally. The duration and prospects of the disorder have been considered with the clinical history. In the vast majority of cases the course of the illness is progressive. A few cases have been reported, but in the only instance where an autopsy was made to test the matter it was found that the sclerosis had not been removed. It may be therefore stated that an arrest of the disease is possible, but that restitution of the nerve-elements, once destroyed, is impossible.

Spastic Spinal Paralysis.